Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "adler2"
@@ -98,9 +98,9 @@ dependencies = [
 
 [[package]]
 name = "cbindgen"
-version = "0.27.0"
+version = "0.28.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fce8dd7fcfcbf3a0a87d8f515194b49d6135acab73e18bd380d1d93bb1a15eb"
+checksum = "eadd868a2ce9ca38de7eeafdcec9c7065ef89b42b32f0839278d55f35c54d1ff"
 dependencies = [
  "clap",
  "heck",
@@ -407,9 +407,8 @@ dependencies = [
 
 [[package]]
 name = "servicepoint"
-version = "0.13.1"
+version = "0.13.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+source = "git+https://git.berlin.ccc.de/servicepoint/servicepoint/?branch=next#114385868af03f8cba7c87a630b501bb0106d140"
-checksum = "93b52049be55a15fe37c13249d7f96aa8a5de56e1a41838e74a822ee8316a0c4"
 dependencies = [
  "bitvec",
  "bzip2",

Cargo.toml

@@ -15,14 +15,34 @@ keywords = ["cccb", "cccb-servicepoint", "cbindgen"]
 crate-type = ["staticlib", "cdylib", "rlib"]
 
 [build-dependencies]
-cbindgen = "0.27.0"
+cbindgen = "0.28.0"
 
 [dependencies.servicepoint]
-version = "0.13.1"
+package = "servicepoint"
-features = ["all_compressions"]
+version = "0.13.2"
+default-features = false
+features = ["protocol_udp"]
+git = "https://git.berlin.ccc.de/servicepoint/servicepoint/"
+branch = "next"
+
+[features]
+full = ["servicepoint/all_compressions", "servicepoint/default"]
+default = ["full"]
 
 [lints.rust]
 missing-docs = "warn"
+unsafe_op_in_unsafe_fn = "warn"
+
+[lints.clippy]
+missing_safety_doc = "allow"
 
 [package.metadata.docs.rs]
 all-features = true
+
+[profile.size-optimized]
+inherits = "release"
+opt-level = 'z'     # Optimize for size
+lto = true          # Enable link-time optimization
+codegen-units = 1   # Reduce number of codegen units to increase optimizations
+panic = 'abort'     # Abort on panic
+strip = true        # Strip symbols from binary

README.md

@@ -82,6 +82,21 @@ You have the choice of linking statically (recommended) or dynamically.
 - documentation is included in the header and
   available [online](https://docs.rs/servicepoint_binding_c/latest/servicepoint_binding_c/)
 
+## Safety
+
+Functions expect that C code honors NonNull annotations.
+
+Any created instances have to be freed in some way. 
+Pointers to those instances cannot be used anymore after that.
+
+Instances cannot be shared between threads and need to be locked in the using code.
+
+Enum values have to be used as-is. Do not pass values that are not part of the enum.
+
+UTF-8 or UTF-32 encoding has to be used properly.
+
+Brightness values provided as u8 parameters must be in range.
+
 ## Everything else
 
 Look at the main project [README](https://git.berlin.ccc.de/servicepoint/servicepoint/src/branch/main/README.md) for

build.rs

@@ -6,28 +6,30 @@
 
 use std::{env, fs::copy};
 
-use cbindgen::{generate_with_config, Config};
-
 fn main() {
     let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
     println!("cargo::rerun-if-changed={crate_dir}");
 
     let config =
-        Config::from_file(crate_dir.clone() + "/cbindgen.toml").unwrap();
+        cbindgen::Config::from_file(crate_dir.clone() + "/cbindgen.toml")
+            .unwrap();
 
     let output_dir = env::var("OUT_DIR").unwrap();
     let header_file = output_dir.clone() + "/servicepoint.h";
 
-    generate_with_config(crate_dir, config)
+    if let Ok(bindings) = cbindgen::generate_with_config(crate_dir, config) {
-        .unwrap()
+        bindings.write_to_file(&header_file);
-        .write_to_file(&header_file);
-    println!("cargo:include={output_dir}");
 
-    println!("cargo::rerun-if-env-changed=SERVICEPOINT_HEADER_OUT");
+        println!("cargo:include={output_dir}");
-    if let Ok(header_out) = env::var("SERVICEPOINT_HEADER_OUT") {
+
-        let header_copy = header_out + "/servicepoint.h";
+        println!("cargo::rerun-if-env-changed=SERVICEPOINT_HEADER_OUT");
-        println!("cargo:warning=Copying header to {header_copy}");
+        if let Ok(header_out) = env::var("SERVICEPOINT_HEADER_OUT") {
-        copy(header_file, &header_copy).unwrap();
+            let header_copy = header_out + "/servicepoint.h";
-        println!("cargo::rerun-if-changed={header_copy}");
+            println!("cargo:warning=Copying header to {header_copy}");
+            copy(header_file, &header_copy).unwrap();
+            println!("cargo::rerun-if-changed={header_copy}");
+        }
+    } else {
+        eprintln!("cargo:warning=Servicepoint header could not be generated");
     }
 }

cbindgen.toml

@@ -19,18 +19,27 @@ line_endings = "LF"
 style = "type"
 usize_is_size_t = true
 
-# this is needed because otherwise the order in the C# bindings is different on different machines
+# this is needed because otherwise the order in the C bindings is different on different machines
 sort_by = "Name"
 
 [parse]
-parse_deps = false
+parse_deps = true
+include = ["servicepoint", "std"]
+extra_bindings = ["servicepoint"]
 
 [parse.expand]
-all_features = true
+features = ["full"]
 
 [export]
 include = []
 exclude = []
 
+[export.rename]
+"SpBitVec" = "BitVec"
+"SpByteSlice" = "ByteSlice"
+
 [enum]
 rename_variants = "QualifiedScreamingSnakeCase"
+
+[ptr]
+non_null_attribute = "/*notnull*/"

example/Makefile

@@ -1,30 +1,94 @@
 CC := gcc
+CARGO := rustup run nightly cargo
+
+TARGET := x86_64-unknown-linux-musl
+PROFILE := size-optimized
 
 THIS_DIR := $(dir $(realpath $(lastword $(MAKEFILE_LIST))))
 REPO_ROOT := $(THIS_DIR)/..
+RUST_TARGET_DIR := $(REPO_ROOT)/target/$(TARGET)/$(PROFILE)
+export SERVICEPOINT_HEADER_OUT := $(REPO_ROOT)/include
 
-build: out/example
+RUSTFLAGS := -Zlocation-detail=none \
+	-Zfmt-debug=none \
+	-C linker=musl-gcc \
+	-C link-arg=-s \
+	-C link-arg=--gc-sections \
+	-C link-arg=-z,norelro \
+	-C link-arg=--hash-style=gnu \
+	--crate-type=staticlib \
+	-C panic=abort
+
+CARGOFLAGS := --manifest-path=$(REPO_ROOT)/Cargo.toml \
+	--profile=$(PROFILE) \
+	--no-default-features \
+	--target=$(TARGET) \
+	-Zbuild-std="core,std,alloc,proc_macro,panic_abort" \
+	-Zbuild-std-features="panic_immediate_abort" \
+
+CCFLAGS := -static -Os \
+	-ffunction-sections -fdata-sections \
+	-fwrapv -fomit-frame-pointer -fno-stack-protector\
+	-fwhole-program \
+	-nodefaultlibs -lservicepoint_binding_c -lc \
+	-Wl,--gc-sections \
+	-fno-unroll-loops \
+	-fno-unwind-tables -fno-asynchronous-unwind-tables \
+	-fmerge-all-constants \
+	-Wl,-z,norelro \
+	-Wl,--hash-style=gnu \
+	-fvisibility=hidden \
+	-Bsymbolic \
+	-Wl,--exclude-libs,ALL \
+	-fno-ident \
+	-Wall
+	#-fuse-ld=gold \
+	-fno-exceptions
+	#-Wl,--icf=all \
+
+STRIPFLAGS := -s --strip-unneeded -R .comment -R .gnu.version -R .comment -R .note -R .note.gnu.build-id -R .note.ABI-tag
+
+_c_src := $(wildcard *.c)
+_programs := $(basename $(_c_src))
+_bins := $(addprefix out/, $(_programs))
+_unstripped_bins := $(addsuffix _unstripped, $(_bins))
+_run_programs := $(addprefix run_, $(_programs))
+_rs_src := $(wildcard ../src/**.rs) ../Cargo.lock
+
+all: $(_bins)
 
 clean:
 	rm -r out || true
 	rm include/servicepoint.h || true
 	cargo clean
 
-run: out/example
+PHONY: all clean sizes $(_run_programs)
-	out/example
 
-PHONY: build clean dependencies run
+$(_unstripped_bins): out/%_unstripped: %.c $(SERVICEPOINT_HEADER_OUT)/servicepoint.h $(RUST_TARGET_DIR)/libservicepoint_binding_c.a
-
-out/example: dependencies main.c
 	mkdir -p out || true
-	${CC} main.c \
+	${CC} $^ \
-		-I $(REPO_ROOT)/include \
+		-I $(SERVICEPOINT_HEADER_OUT) \
-		-L $(REPO_ROOT)/target/release \
+		-L $(RUST_TARGET_DIR)\
-		-Wl,-Bstatic -lservicepoint_binding_c \
+		$(CCFLAGS) \
-		-Wl,-Bdynamic -llzma \
+		-o $@
-		-o out/example
 
-dependencies: FORCE
+$(_bins): out/%: out/%_unstripped
-	cargo build --manifest-path=$(REPO_ROOT)/Cargo.toml --release
+	strip $(STRIPFLAGS) $^ -o $@
+
+$(SERVICEPOINT_HEADER_OUT)/servicepoint.h $(RUST_TARGET_DIR)/libservicepoint_binding_c.a: $(_rs_src)
+	mkdir -p include || true
+	# generate servicepoint header and binary to link against
+	${CARGO} rustc $(CARGOFLAGS) -- $(RUSTFLAGS)
+
+$(_run_programs): run_%: out/% FORCE
+	./$<
+
+sizes: $(_bins)
+	ls -lB out
+
+#analyze-size: out/example_unstripped
+#	nm --print-size --size-sort --reverse-sort --radix=d --demangle out/example_unstripped \
+#		| awk '{size=$$2+0; print size "\t" $$4}' \
+#		| less
 
 FORCE: ;

example/announce.c

@@ -0,0 +1,33 @@
+#include "servicepoint.h"
+
+int main(void) {
+    //UdpConnection *connection = sp_udp_open_ipv4(172, 23, 42, 29, 2342);
+    UdpConnection *connection = sp_udp_open_ipv4(127, 0, 0, 1, 2342);
+    if (connection == NULL)
+        return 1;
+
+    sp_udp_send_header(connection, (Header) {.command_code = COMMAND_CODE_CLEAR});
+
+    CharGrid *grid = sp_char_grid_new(5, 2);
+    if (grid == NULL)
+        return 1;
+    
+    sp_char_grid_set(grid, 0, 0, 'H');
+    sp_char_grid_set(grid, 1, 0, 'e');
+    sp_char_grid_set(grid, 2, 0, 'l');
+    sp_char_grid_set(grid, 3, 0, 'l');
+    sp_char_grid_set(grid, 4, 0, 'o');
+    sp_char_grid_set(grid, 0, 1, 'W');
+    sp_char_grid_set(grid, 1, 1, 'o');
+    sp_char_grid_set(grid, 2, 1, 'r');
+    sp_char_grid_set(grid, 3, 1, 'l');
+    sp_char_grid_set(grid, 4, 1, 'd');
+
+    Packet *packet = sp_char_grid_into_packet(grid, 0, 0);
+    if (packet == NULL)
+        return 1;
+    sp_udp_send_packet(connection, packet);
+
+    sp_udp_free(connection);
+    return 0;
+}

example/brightness_tester.c

@@ -0,0 +1,30 @@
+#include "servicepoint.h"
+
+int main(void) {
+    // UdpConnection *connection = sp_udp_open_ipv4(172, 23, 42, 29, 2342);
+    UdpConnection *connection = sp_udp_open_ipv4(127, 0, 0, 1, 2342);
+    if (connection == NULL)
+        return -1;
+
+    Bitmap *all_on = sp_bitmap_new_max_sized();
+    sp_bitmap_fill(all_on, true);
+
+    Packet *packet = sp_bitmap_into_packet(all_on, 0, 0, COMPRESSION_CODE_UNCOMPRESSED);
+    if (packet == NULL)
+        return -1;
+
+    sp_udp_send_packet(connection, packet);
+
+    BrightnessGrid *grid = sp_brightness_grid_new(TILE_WIDTH, TILE_HEIGHT);
+
+    ByteSlice slice = sp_brightness_grid_unsafe_data_ref(grid);
+    for (size_t index = 0; index < slice.length; index++) {
+        slice.start[index] = (uint8_t) (index % ((size_t) Brightness_MAX));
+    }
+
+    packet = sp_brightness_grid_into_packet(grid, 0, 0);
+    sp_udp_send_packet(connection, packet);
+
+    sp_udp_free(connection);
+    return 0;
+}

example/main.c

@@ -1,17 +0,0 @@
-#include <stdio.h>
-#include "servicepoint.h"
-
-int main(void) {
-    SPConnection *connection = sp_connection_open("localhost:2342");
-    if (connection == NULL)
-        return 1;
-
-    SPBitmap *pixels = sp_bitmap_new(SP_PIXEL_WIDTH, SP_PIXEL_HEIGHT);
-    sp_bitmap_fill(pixels, true);
-
-    SPCommand *command = sp_command_bitmap_linear_win(0, 0, pixels, SP_COMPRESSION_CODE_UNCOMPRESSED);
-    sp_connection_send_command(connection, command);
-
-    sp_connection_free(connection);
-    return 0;
-}

example/random_stuff.c

@@ -0,0 +1,26 @@
+#include <stdio.h>
+#include "servicepoint.h"
+
+int main(void) {
+    UdpConnection *connection = sp_udp_open_ipv4(127, 0, 0, 1, 2342);
+    if (connection == NULL)
+        return 1;
+
+    Bitmap *pixels = sp_bitmap_new(PIXEL_WIDTH, PIXEL_HEIGHT);
+    if (pixels == NULL)
+        return 1;
+
+    sp_bitmap_fill(pixels, true);
+
+    Packet *packet = sp_bitmap_into_packet(pixels, 0, 0, COMPRESSION_CODE_UNCOMPRESSED);
+    if (packet == NULL)
+        return 1;
+
+    Header *header = sp_packet_get_header(packet);
+    printf("[%d, %d, %d, %d, %d]\n", header->command_code, header->a, header->b, header->c, header->d);
+
+    sp_udp_send_packet(connection, packet);
+
+    sp_udp_free(connection);
+    return 0;
+}

flake.nix

@@ -33,25 +33,34 @@
         { pkgs, system }:
         {
           default = pkgs.mkShell rec {
-            packages = with pkgs; [
+            buildInputs = with pkgs;[
+              xe
+              xz
+              libgcc
+              #glibc.static
+              musl
+              libunwind
+              ];
+
+            nativeBuildInputs = with pkgs;[
               (pkgs.symlinkJoin {
                 name = "rust-toolchain";
                 paths = with pkgs; [
-                  rustc
+                  #rustc
-                  cargo
+                  #cargo
-                  rustPlatform.rustcSrc
+                  #rustPlatform.rustcSrc
-                  rustfmt
+                  #rustfmt
-                  clippy
+                  #clippy
                   cargo-expand
                   cargo-tarpaulin
+                  rustup
                 ];
               })
               gcc
               gnumake
-              xe
-              xz
               pkg-config
             ];
+
             RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
           };
         }

src/bitmap.rs

@@ -1,13 +1,22 @@
-//! C functions for interacting with [SPBitmap]s
+use crate::byte_slice::ByteSlice;
-//!
+use crate::{heap_drop, heap_move, heap_move_nonnull, heap_remove, SPBitVec};
-//! prefix `sp_bitmap_`
+use servicepoint::{Bitmap, BitmapCommand, CompressionCode, DataRef, Grid, Origin, Packet};
-
-use servicepoint::{DataRef, Grid};
 use std::ptr::NonNull;
 
-use crate::byte_slice::SPByteSlice;
+/// Creates a new [Bitmap] with the specified dimensions.
-
+///
-/// A grid of pixels.
+/// # Arguments
+///
+/// - `width`: size in pixels in x-direction
+/// - `height`: size in pixels in y-direction
+///
+/// returns: [Bitmap] initialized to all pixels off, or NULL in case of an error.
+///
+/// # Errors
+///
+/// In the following cases, this function will return NULL:
+///
+/// - when the width is not dividable by 8
 ///
 /// # Examples
 ///
@@ -17,135 +26,81 @@ use crate::byte_slice::SPByteSlice;
 /// sp_bitmap_set(grid, 0, 0, false);
 /// sp_bitmap_free(grid);
 /// ```
-pub struct SPBitmap(pub(crate) servicepoint::Bitmap);
-
-/// Creates a new [SPBitmap] with the specified dimensions.
-///
-/// # Arguments
-///
-/// - `width`: size in pixels in x-direction
-/// - `height`: size in pixels in y-direction
-///
-/// returns: [SPBitmap] initialized to all pixels off. Will never return NULL.
-///
-/// # Panics
-///
-/// - when the width is not dividable by 8
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_bitmap_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_new(
     width: usize,
     height: usize,
-) -> NonNull<SPBitmap> {
+) -> *mut Bitmap {
-    let result = Box::new(SPBitmap(servicepoint::Bitmap::new(width, height)));
+    if let Some(bitmap) = Bitmap::new(width, height) {
-    NonNull::from(Box::leak(result))
+        heap_move(bitmap)
+    } else {
+        std::ptr::null_mut()
+    }
 }
 
-/// Creates a new [SPBitmap] with a size matching the screen.
+/// Creates a new [Bitmap] with a size matching the screen.
 ///
-/// returns: [SPBitmap] initialized to all pixels off. Will never return NULL.
+/// returns: [Bitmap] initialized to all pixels off.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling [sp_bitmap_free].
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_new_screen_sized() -> NonNull<SPBitmap> {
+pub unsafe extern "C" fn sp_bitmap_new_max_sized() -> NonNull<Bitmap> {
-    let result = Box::new(SPBitmap(servicepoint::Bitmap::max_sized()));
+    heap_move_nonnull(Bitmap::max_sized())
-    NonNull::from(Box::leak(result))
 }
 
-/// Loads a [SPBitmap] with the specified dimensions from the provided data.
+/// Loads a [Bitmap] with the specified dimensions from the provided data.
 ///
 /// # Arguments
 ///
 /// - `width`: size in pixels in x-direction
 /// - `height`: size in pixels in y-direction
 ///
-/// returns: [SPBitmap] that contains a copy of the provided data. Will never return NULL.
+/// returns: [Bitmap] that contains a copy of the provided data, or NULL in case of an error.
-///
-/// # Panics
-///
-/// - when `data` is NULL
-/// - when the dimensions and data size do not match exactly.
-/// - when the width is not dividable by 8
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `data` points to a valid memory location of at least `data_length` bytes in size.
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_bitmap_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: ByteSlice,
-    data_length: usize,
+) -> *mut Bitmap {
-) -> NonNull<SPBitmap> {
+    let data = unsafe { data.as_slice() };
-    assert!(!data.is_null());
+    if let Ok(bitmap) = Bitmap::load(width, height, data) {
-    let data = std::slice::from_raw_parts(data, data_length);
+        heap_move(bitmap)
-    let result =
+    } else {
-        Box::new(SPBitmap(servicepoint::Bitmap::load(width, height, data)));
+        std::ptr::null_mut()
-    NonNull::from(Box::leak(result))
+    }
 }
 
-/// Clones a [SPBitmap].
+/// Tries to convert the BitVec to a Bitmap.
 ///
-/// Will never return NULL.
+/// The provided BitVec gets consumed.
 ///
-/// # Panics
+/// Returns NULL in case of error.
-///
+#[no_mangle]
-/// - when `bitmap` is NULL
+pub unsafe extern "C" fn sp_bitmap_from_bitvec(
-///
+    width: usize,
-/// # Safety
+    bitvec: NonNull<SPBitVec>,
-///
+) -> *mut Bitmap {
-/// The caller has to make sure that:
+    let bitvec = unsafe { heap_remove(bitvec) };
-///
+    if let Ok(bitmap) = Bitmap::from_bitvec(width, bitvec.0) {
-/// - `bitmap` points to a valid [SPBitmap]
+        heap_move(bitmap)
-/// - `bitmap` is not written to concurrently
+    } else {
-/// - the returned instance is freed in some way, either by using a consuming function or
+        std::ptr::null_mut()
-///   by explicitly calling `sp_bitmap_free`.
+    }
+}
+
+/// Clones a [Bitmap].
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_clone(
-    bitmap: *const SPBitmap,
+    bitmap: NonNull<Bitmap>,
-) -> NonNull<SPBitmap> {
+) -> NonNull<Bitmap> {
-    assert!(!bitmap.is_null());
+    heap_move_nonnull(unsafe { bitmap.as_ref().clone() })
-    let result = Box::new(SPBitmap((*bitmap).0.clone()));
-    NonNull::from(Box::leak(result))
 }
 
-/// Deallocates a [SPBitmap].
+/// Deallocates a [Bitmap].
-///
-/// # Panics
-///
-/// - when `bitmap` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bitmap` points to a valid [SPBitmap]
-/// - `bitmap` is not used concurrently or after bitmap call
-/// - `bitmap` was not passed to another consuming function, e.g. to create a [SPCommand]
-///
-/// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_free(bitmap: *mut SPBitmap) {
+pub unsafe extern "C" fn sp_bitmap_free(bitmap: NonNull<Bitmap>) {
-    assert!(!bitmap.is_null());
+    unsafe { heap_drop(bitmap) }
-    _ = Box::from_raw(bitmap);
 }
 
-/// Gets the current value at the specified position in the [SPBitmap].
+/// Gets the current value at the specified position in the [Bitmap].
 ///
 /// # Arguments
 ///
@@ -154,26 +109,17 @@ pub unsafe extern "C" fn sp_bitmap_free(bitmap: *mut SPBitmap) {
 ///
 /// # Panics
 ///
-/// - when `bitmap` is NULL
 /// - when accessing `x` or `y` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bitmap` points to a valid [SPBitmap]
-/// - `bitmap` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_get(
-    bitmap: *const SPBitmap,
+    bitmap: NonNull<Bitmap>,
     x: usize,
     y: usize,
 ) -> bool {
-    assert!(!bitmap.is_null());
+    unsafe { bitmap.as_ref().get(x, y) }
-    (*bitmap).0.get(x, y)
 }
 
-/// Sets the value of the specified position in the [SPBitmap].
+/// Sets the value of the specified position in the [Bitmap].
 ///
 /// # Arguments
 ///
@@ -181,54 +127,31 @@ pub unsafe extern "C" fn sp_bitmap_get(
 /// - `x` and `y`: position of the cell
 /// - `value`: the value to write to the cell
 ///
-/// returns: old value of the cell
-///
 /// # Panics
 ///
-/// - when `bitmap` is NULL
 /// - when accessing `x` or `y` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bitmap` points to a valid [SPBitmap]
-/// - `bitmap` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_set(
-    bitmap: *mut SPBitmap,
+    bitmap: NonNull<Bitmap>,
     x: usize,
     y: usize,
     value: bool,
 ) {
-    assert!(!bitmap.is_null());
+    unsafe { (*bitmap.as_ptr()).set(x, y, value) };
-    (*bitmap).0.set(x, y, value);
 }
 
-/// Sets the state of all pixels in the [SPBitmap].
+/// Sets the state of all pixels in the [Bitmap].
 ///
 /// # Arguments
 ///
 /// - `bitmap`: instance to write to
 /// - `value`: the value to set all pixels to
-///
-/// # Panics
-///
-/// - when `bitmap` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bitmap` points to a valid [SPBitmap]
-/// - `bitmap` is not written to or read from concurrently
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_fill(bitmap: *mut SPBitmap, value: bool) {
+pub unsafe extern "C" fn sp_bitmap_fill(bitmap: NonNull<Bitmap>, value: bool) {
-    assert!(!bitmap.is_null());
+    unsafe { (*bitmap.as_ptr()).fill(value) };
-    (*bitmap).0.fill(value);
 }
 
-/// Gets the width in pixels of the [SPBitmap] instance.
+/// Gets the width in pixels of the [Bitmap] instance.
 ///
 /// # Arguments
 ///
@@ -242,55 +165,60 @@ pub unsafe extern "C" fn sp_bitmap_fill(bitmap: *mut SPBitmap, value: bool) {
 ///
 /// The caller has to make sure that:
 ///
-/// - `bitmap` points to a valid [SPBitmap]
+/// - `bitmap` points to a valid [Bitmap]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_width(bitmap: *const SPBitmap) -> usize {
+pub unsafe extern "C" fn sp_bitmap_width(bitmap: NonNull<Bitmap>) -> usize {
-    assert!(!bitmap.is_null());
+    unsafe { bitmap.as_ref().width() }
-    (*bitmap).0.width()
 }
 
-/// Gets the height in pixels of the [SPBitmap] instance.
+/// Gets the height in pixels of the [Bitmap] instance.
 ///
 /// # Arguments
 ///
 /// - `bitmap`: instance to read from
-///
-/// # Panics
-///
-/// - when `bitmap` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bitmap` points to a valid [SPBitmap]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_height(bitmap: *const SPBitmap) -> usize {
+pub unsafe extern "C" fn sp_bitmap_height(bitmap: NonNull<Bitmap>) -> usize {
-    assert!(!bitmap.is_null());
+    unsafe { bitmap.as_ref().height() }
-    (*bitmap).0.height()
 }
 
-/// Gets an unsafe reference to the data of the [SPBitmap] instance.
+/// Gets an unsafe reference to the data of the [Bitmap] instance.
 ///
-/// # Panics
+/// The returned memory is valid for the lifetime of the bitmap.
-///
-/// - when `bitmap` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bitmap` points to a valid [SPBitmap]
-/// - the returned memory range is never accessed after the passed [SPBitmap] has been freed
-/// - the returned memory range is never accessed concurrently, either via the [SPBitmap] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_unsafe_data_ref(
-    bitmap: *mut SPBitmap,
+    mut bitmap: NonNull<Bitmap>,
-) -> SPByteSlice {
+) -> ByteSlice {
-    assert!(!bitmap.is_null());
+    unsafe { ByteSlice::from_slice(bitmap.as_mut().data_ref_mut()) }
-    let data = (*bitmap).0.data_ref_mut();
+}
-    SPByteSlice {
+
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
+/// Consumes the Bitmap and returns the contained BitVec
-        length: data.len(),
+#[no_mangle]
+pub unsafe extern "C" fn sp_bitmap_into_bitvec(
+    bitmap: NonNull<Bitmap>,
+) -> NonNull<SPBitVec> {
+    let bitmap = unsafe { heap_remove(bitmap) };
+    heap_move_nonnull(SPBitVec(bitmap.into()))
+}
+
+/// Creates a [BitmapCommand] and immediately turns that into a [Packet].
+///
+/// The provided [Bitmap] gets consumed.
+///
+/// Returns NULL in case of an error.
+#[no_mangle]
+pub unsafe extern "C" fn sp_bitmap_into_packet(
+    bitmap: NonNull<Bitmap>,
+    x: usize,
+    y: usize,
+    compression: CompressionCode
+) -> *mut Packet {
+    let bitmap = unsafe { heap_remove(bitmap) };
+    match Packet::try_from(BitmapCommand {
+        bitmap,
+        origin: Origin::new(x, y),
+        compression,
+    }) {
+        Ok(packet) => heap_move(packet),
+        Err(_) => std::ptr::null_mut(),
     }
 }

src/bitvec.rs

@@ -1,8 +1,5 @@
-//! C functions for interacting with [SPBitVec]s
+use crate::{heap_drop, heap_move, heap_move_nonnull, heap_remove, ByteSlice};
-//!
+use servicepoint::{BinaryOperation, BitVecCommand, BitVecU8Msb0, CompressionCode, Packet};
-//! prefix `sp_bitvec_`
-
-use crate::SPByteSlice;
 use std::ptr::NonNull;
 
 /// A vector of bits
@@ -13,19 +10,7 @@ use std::ptr::NonNull;
 /// sp_bitvec_set(vec, 5, true);
 /// sp_bitvec_free(vec);
 /// ```
-pub struct SPBitVec(servicepoint::BitVec);
+pub struct SPBitVec(pub(crate) BitVecU8Msb0);
-
-impl From<servicepoint::BitVec> for SPBitVec {
-    fn from(actual: servicepoint::BitVec) -> Self {
-        Self(actual)
-    }
-}
-
-impl From<SPBitVec> for servicepoint::BitVec {
-    fn from(value: SPBitVec) -> Self {
-        value.0
-    }
-}
 
 impl Clone for SPBitVec {
     fn clone(&self) -> Self {
@@ -39,95 +24,37 @@ impl Clone for SPBitVec {
 ///
 /// - `size`: size in bits.
 ///
-/// returns: [SPBitVec] with all bits set to false. Will never return NULL.
+/// returns: [SPBitVec] with all bits set to false.
 ///
 /// # Panics
 ///
 /// - when `size` is not divisible by 8.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_bitvec_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_new(size: usize) -> NonNull<SPBitVec> {
-    let result = Box::new(SPBitVec(servicepoint::BitVec::repeat(false, size)));
+    heap_move_nonnull(SPBitVec(BitVecU8Msb0::repeat(false, size)))
-    NonNull::from(Box::leak(result))
 }
 
 /// Interpret the data as a series of bits and load then into a new [SPBitVec] instance.
 ///
-/// returns: [SPBitVec] instance containing data. Will never return NULL.
+/// returns: [SPBitVec] instance containing data.
-///
-/// # Panics
-///
-/// - when `data` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `data` points to a valid memory location of at least `data_length`
-///   bytes in size.
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_bitvec_free`.
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_load(
+pub unsafe extern "C" fn sp_bitvec_load(data: ByteSlice) -> NonNull<SPBitVec> {
-    data: *const u8,
+    let data = unsafe { data.as_slice() };
-    data_length: usize,
+    heap_move_nonnull(SPBitVec(BitVecU8Msb0::from_slice(data)))
-) -> NonNull<SPBitVec> {
-    assert!(!data.is_null());
-    let data = std::slice::from_raw_parts(data, data_length);
-    let result = Box::new(SPBitVec(servicepoint::BitVec::from_slice(data)));
-    NonNull::from(Box::leak(result))
 }
 
 /// Clones a [SPBitVec].
-///
-/// returns: new [SPBitVec] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `bit_vec` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
-/// - `bit_vec` is not written to concurrently
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_bitvec_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_clone(
-    bit_vec: *const SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
 ) -> NonNull<SPBitVec> {
-    assert!(!bit_vec.is_null());
+    heap_move_nonnull(unsafe { bit_vec.as_ref().clone() })
-    let result = Box::new((*bit_vec).clone());
-    NonNull::from(Box::leak(result))
 }
 
 /// Deallocates a [SPBitVec].
-///
-/// # Panics
-///
-/// - when `but_vec` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
-/// - `bit_vec` is not used concurrently or after this call
-/// - `bit_vec` was not passed to another consuming function, e.g. to create a [SPCommand]
-///
-/// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_free(bit_vec: *mut SPBitVec) {
+pub unsafe extern "C" fn sp_bitvec_free(bit_vec: NonNull<SPBitVec>) {
-    assert!(!bit_vec.is_null());
+    unsafe { heap_drop(bit_vec) }
-    _ = Box::from_raw(bit_vec);
 }
 
 /// Gets the value of a bit from the [SPBitVec].
@@ -141,22 +68,13 @@ pub unsafe extern "C" fn sp_bitvec_free(bit_vec: *mut SPBitVec) {
 ///
 /// # Panics
 ///
-/// - when `bit_vec` is NULL
 /// - when accessing `index` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
-/// - `bit_vec` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_get(
-    bit_vec: *const SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
     index: usize,
 ) -> bool {
-    assert!(!bit_vec.is_null());
+    unsafe { *bit_vec.as_ref().0.get(index).unwrap() }
-    *(*bit_vec).0.get(index).unwrap()
 }
 
 /// Sets the value of a bit in the [SPBitVec].
@@ -169,23 +87,14 @@ pub unsafe extern "C" fn sp_bitvec_get(
 ///
 /// # Panics
 ///
-/// - when `bit_vec` is NULL
 /// - when accessing `index` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
-/// - `bit_vec` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_set(
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
     index: usize,
     value: bool,
 ) {
-    assert!(!bit_vec.is_null());
+    unsafe { (*bit_vec.as_ptr()).0.set(index, value) }
-    (*bit_vec).0.set(index, value)
 }
 
 /// Sets the value of all bits in the [SPBitVec].
@@ -194,21 +103,12 @@ pub unsafe extern "C" fn sp_bitvec_set(
 ///
 /// - `bit_vec`: instance to write to
 /// - `value`: the value to set all bits to
-///
-/// # Panics
-///
-/// - when `bit_vec` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
-/// - `bit_vec` is not written to or read from concurrently
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_fill(bit_vec: *mut SPBitVec, value: bool) {
+pub unsafe extern "C" fn sp_bitvec_fill(
-    assert!(!bit_vec.is_null());
+    bit_vec: NonNull<SPBitVec>,
-    (*bit_vec).0.fill(value)
+    value: bool,
+) {
+    unsafe { (*bit_vec.as_ptr()).0.fill(value) }
 }
 
 /// Gets the length of the [SPBitVec] in bits.
@@ -216,20 +116,9 @@ pub unsafe extern "C" fn sp_bitvec_fill(bit_vec: *mut SPBitVec, value: bool) {
 /// # Arguments
 ///
 /// - `bit_vec`: instance to write to
-///
-/// # Panics
-///
-/// - when `bit_vec` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_len(bit_vec: *const SPBitVec) -> usize {
+pub unsafe extern "C" fn sp_bitvec_len(bit_vec: NonNull<SPBitVec>) -> usize {
-    assert!(!bit_vec.is_null());
+    unsafe { bit_vec.as_ref().0.len() }
-    (*bit_vec).0.len()
 }
 
 /// Returns true if length is 0.
@@ -237,47 +126,47 @@ pub unsafe extern "C" fn sp_bitvec_len(bit_vec: *const SPBitVec) -> usize {
 /// # Arguments
 ///
 /// - `bit_vec`: instance to write to
-///
-/// # Panics
-///
-/// - when `bit_vec` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_is_empty(bit_vec: *const SPBitVec) -> bool {
+pub unsafe extern "C" fn sp_bitvec_is_empty(
-    assert!(!bit_vec.is_null());
+    bit_vec: NonNull<SPBitVec>,
-    (*bit_vec).0.is_empty()
+) -> bool {
+    unsafe { bit_vec.as_ref().0.is_empty() }
 }
 
 /// Gets an unsafe reference to the data of the [SPBitVec] instance.
 ///
+/// The returned memory is valid for the lifetime of the bitvec.
+///
 /// # Arguments
 ///
 /// - `bit_vec`: instance to write to
-///
-/// # Panics
-///
-/// - when `bit_vec` is NULL
-///
-/// ## Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid [SPBitVec]
-/// - the returned memory range is never accessed after the passed [SPBitVec] has been freed
-/// - the returned memory range is never accessed concurrently, either via the [SPBitVec] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_unsafe_data_ref(
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
-) -> SPByteSlice {
+) -> ByteSlice {
-    assert!(!bit_vec.is_null());
+    unsafe { ByteSlice::from_slice((*bit_vec.as_ptr()).0.as_raw_mut_slice()) }
-    let data = (*bit_vec).0.as_raw_mut_slice();
+}
-    SPByteSlice {
+
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
+/// Creates a [BitVecCommand] and immediately turns that into a [Packet].
-        length: data.len(),
+///
+/// The provided [SPBitVec] gets consumed.
+///
+/// Returns NULL in case of an error.
+#[no_mangle]
+pub unsafe extern "C" fn sp_bitvec_into_packet(
+    bitvec: NonNull<SPBitVec>,
+    offset: usize,
+    operation: BinaryOperation,
+    compression: CompressionCode
+) -> *mut Packet {
+    let bitvec = unsafe { heap_remove(bitvec) }.0;
+    match Packet::try_from(BitVecCommand {
+        bitvec,
+        offset,
+        operation,
+        compression,
+    }) {
+        Ok(packet) => heap_move(packet),
+        Err(_) => std::ptr::null_mut(),
     }
 }

src/brightness_grid.rs

@@ -1,146 +1,71 @@
-//! C functions for interacting with [SPBrightnessGrid]s
+use crate::{heap_drop, heap_move, heap_move_nonnull, heap_remove, ByteSlice};
-//!
+use servicepoint::{
-//! prefix `sp_brightness_grid_`
+    Brightness, BrightnessGrid, BrightnessGridCommand, ByteGrid, DataRef, Grid,
-
+    Origin, Packet,
-use crate::SPByteSlice;
+};
-use servicepoint::{DataRef, Grid};
+use std::mem::transmute;
-use std::convert::Into;
-use std::intrinsics::transmute;
 use std::ptr::NonNull;
 
-/// see [servicepoint::Brightness::MIN]
+/// Creates a new [BrightnessGrid] with the specified dimensions.
-pub const SP_BRIGHTNESS_MIN: u8 = 0;
+///
-/// see [servicepoint::Brightness::MAX]
+/// returns: [BrightnessGrid] initialized to 0.
-pub const SP_BRIGHTNESS_MAX: u8 = 11;
-/// Count of possible brightness values
-pub const SP_BRIGHTNESS_LEVELS: u8 = 12;
-
-/// A grid containing brightness values.
 ///
 /// # Examples
 /// ```C
-/// SPConnection connection = sp_connection_open("127.0.0.1:2342");
+/// UdpConnection connection = sp_udp_open("127.0.0.1:2342");
 /// if (connection == NULL)
 ///     return 1;
 ///
-/// SPBrightnessGrid grid = sp_brightness_grid_new(2, 2);
+/// BrightnessGrid grid = sp_brightness_grid_new(2, 2);
 /// sp_brightness_grid_set(grid, 0, 0, 0);
 /// sp_brightness_grid_set(grid, 1, 1, 10);
 ///
-/// SPCommand command = sp_command_char_brightness(grid);
+/// TypedCommand command = sp_command_char_brightness(grid);
-/// sp_connection_free(connection);
+/// sp_udp_free(connection);
 /// ```
-#[derive(Clone)]
-pub struct SPBrightnessGrid(pub(crate) servicepoint::BrightnessGrid);
-
-/// Creates a new [SPBrightnessGrid] with the specified dimensions.
-///
-/// returns: [SPBrightnessGrid] initialized to 0. Will never return NULL.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_brightness_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_new(
     width: usize,
     height: usize,
-) -> NonNull<SPBrightnessGrid> {
+) -> NonNull<BrightnessGrid> {
-    let result = Box::new(SPBrightnessGrid(servicepoint::BrightnessGrid::new(
+    heap_move_nonnull(BrightnessGrid::new(width, height))
-        width, height,
-    )));
-    NonNull::from(Box::leak(result))
 }
 
-/// Loads a [SPBrightnessGrid] with the specified dimensions from the provided data.
+/// Loads a [BrightnessGrid] with the specified dimensions from the provided data.
 ///
-/// returns: new [SPBrightnessGrid] instance. Will never return NULL.
+/// Any out of range values will be set to [Brightness::MAX] or [Brightness::MIN].
 ///
-/// # Panics
+/// returns: new [BrightnessGrid] instance, or NULL in case of an error.
-///
-/// - when `data` is NULL
-/// - when the provided `data_length` does not match `height` and `width`
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `data` points to a valid memory location of at least `data_length`
-///   bytes in size.
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_brightness_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: ByteSlice,
-    data_length: usize,
+) -> *mut BrightnessGrid {
-) -> NonNull<SPBrightnessGrid> {
+    let data = unsafe { data.as_slice() };
-    assert!(!data.is_null());
+
-    let data = std::slice::from_raw_parts(data, data_length);
+    match ByteGrid::load(width, height, data)
-    let grid = servicepoint::ByteGrid::load(width, height, data);
+        .map(move |grid| grid.map(Brightness::saturating_from))
-    let grid = servicepoint::BrightnessGrid::try_from(grid)
+    {
-        .expect("invalid brightness value");
+        None => std::ptr::null_mut(),
-    let result = Box::new(SPBrightnessGrid(grid));
+        Some(grid) => heap_move(grid),
-    NonNull::from(Box::leak(result))
+    }
 }
 
-/// Clones a [SPBrightnessGrid].
+/// Clones a [BrightnessGrid].
-///
-/// # Arguments
-///
-/// - `brightness_grid`: instance to read from
-///
-/// returns: new [SPBrightnessGrid] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `brightness_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
-/// - `brightness_grid` is not written to concurrently
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_brightness_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_clone(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
-) -> NonNull<SPBrightnessGrid> {
+) -> NonNull<BrightnessGrid> {
-    assert!(!brightness_grid.is_null());
+    heap_move_nonnull(unsafe { brightness_grid.as_ref().clone() })
-    let result = Box::new((*brightness_grid).clone());
-    NonNull::from(Box::leak(result))
 }
 
-/// Deallocates a [SPBrightnessGrid].
+/// Deallocates a [BrightnessGrid].
-///
-/// # Arguments
-///
-/// - `brightness_grid`: instance to read from
-///
-/// # Panics
-///
-/// - when `brightness_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
-/// - `brightness_grid` is not used concurrently or after this call
-/// - `brightness_grid` was not passed to another consuming function, e.g. to create a [SPCommand]
-///
-/// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_free(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
 ) {
-    assert!(!brightness_grid.is_null());
+    unsafe { heap_drop(brightness_grid) }
-    _ = Box::from_raw(brightness_grid);
 }
 
 /// Gets the current value at the specified position.
@@ -153,27 +78,17 @@ pub unsafe extern "C" fn sp_brightness_grid_free(
 /// returns: value at position
 ///
 /// # Panics
-///
-/// - when `brightness_grid` is NULL
 /// - When accessing `x` or `y` out of bounds.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
-/// - `brightness_grid` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_get(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
     x: usize,
     y: usize,
-) -> u8 {
+) -> Brightness {
-    assert!(!brightness_grid.is_null());
+    unsafe { brightness_grid.as_ref().get(x, y) }
-    (*brightness_grid).0.get(x, y).into()
 }
 
-/// Sets the value of the specified position in the [SPBrightnessGrid].
+/// Sets the value of the specified position in the [BrightnessGrid].
 ///
 /// # Arguments
 ///
@@ -185,138 +100,98 @@ pub unsafe extern "C" fn sp_brightness_grid_get(
 ///
 /// # Panics
 ///
-/// - when `brightness_grid` is NULL
 /// - When accessing `x` or `y` out of bounds.
-/// - When providing an invalid brightness value
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
-/// - `brightness_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_set(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
     x: usize,
     y: usize,
-    value: u8,
+    value: Brightness,
 ) {
-    assert!(!brightness_grid.is_null());
+    unsafe { (*brightness_grid.as_ptr()).set(x, y, value) };
-    let brightness = servicepoint::Brightness::try_from(value)
-        .expect("invalid brightness value");
-    (*brightness_grid).0.set(x, y, brightness);
 }
 
-/// Sets the value of all cells in the [SPBrightnessGrid].
+/// Sets the value of all cells in the [BrightnessGrid].
 ///
 /// # Arguments
 ///
 /// - `brightness_grid`: instance to write to
 /// - `value`: the value to set all cells to
-///
-/// # Panics
-///
-/// - when `brightness_grid` is NULL
-/// - When providing an invalid brightness value
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
-/// - `brightness_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_fill(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
-    value: u8,
+    value: Brightness,
 ) {
-    assert!(!brightness_grid.is_null());
+    unsafe { (*brightness_grid.as_ptr()).fill(value) };
-    let brightness = servicepoint::Brightness::try_from(value)
-        .expect("invalid brightness value");
-    (*brightness_grid).0.fill(brightness);
 }
 
-/// Gets the width of the [SPBrightnessGrid] instance.
+/// Gets the width of the [BrightnessGrid] instance.
 ///
 /// # Arguments
 ///
 /// - `brightness_grid`: instance to read from
 ///
 /// returns: width
-///
-/// # Panics
-///
-/// - when `brightness_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_width(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
 ) -> usize {
-    assert!(!brightness_grid.is_null());
+    unsafe { brightness_grid.as_ref().width() }
-    (*brightness_grid).0.width()
 }
 
-/// Gets the height of the [SPBrightnessGrid] instance.
+/// Gets the height of the [BrightnessGrid] instance.
 ///
 /// # Arguments
 ///
 /// - `brightness_grid`: instance to read from
 ///
 /// returns: height
-///
-/// # Panics
-///
-/// - when `brightness_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_height(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
 ) -> usize {
-    assert!(!brightness_grid.is_null());
+    unsafe { brightness_grid.as_ref().height() }
-    (*brightness_grid).0.height()
 }
 
-/// Gets an unsafe reference to the data of the [SPBrightnessGrid] instance.
+/// Gets an unsafe reference to the data of the [BrightnessGrid] instance.
+///
+/// The returned memory is valid for the lifetime of the brightness grid.
 ///
 /// # Arguments
 ///
 /// - `brightness_grid`: instance to read from
 ///
 /// returns: slice of bytes underlying the `brightness_grid`.
-///
-/// # Panics
-///
-/// - when `brightness_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `brightness_grid` points to a valid [SPBrightnessGrid]
-/// - the returned memory range is never accessed after the passed [SPBrightnessGrid] has been freed
-/// - the returned memory range is never accessed concurrently, either via the [SPBrightnessGrid] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_unsafe_data_ref(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
-) -> SPByteSlice {
+) -> ByteSlice {
-    assert!(!brightness_grid.is_null());
+    //noinspection RsAssertEqual
-    assert_eq!(core::mem::size_of::<servicepoint::Brightness>(), 1);
+    const _: () = assert!(size_of::<Brightness>() == 1);
-    let data = (*brightness_grid).0.data_ref_mut();
+
-    // this assumes more about the memory layout than rust guarantees. yikes!
+    let data = unsafe { (*brightness_grid.as_ptr()).data_ref_mut() };
-    let data: &mut [u8] = transmute(data);
+    unsafe {
-    SPByteSlice {
+        ByteSlice::from_slice(transmute::<&mut [Brightness], &mut [u8]>(data))
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
+    }
-        length: data.len(),
+}
+
+/// Creates a [BrightnessGridCommand] and immediately turns that into a [Packet].
+///
+/// The provided [BrightnessGrid] gets consumed.
+///
+/// Returns NULL in case of an error.
+#[no_mangle]
+pub unsafe extern "C" fn sp_brightness_grid_into_packet(
+    grid: NonNull<BrightnessGrid>,
+    x: usize,
+    y: usize,
+) -> *mut Packet {
+    let grid = unsafe { heap_remove(grid) };
+    match Packet::try_from(BrightnessGridCommand {
+        grid,
+        origin: Origin::new(x, y),
+    }) {
+        Ok(packet) => heap_move(packet),
+        Err(_) => std::ptr::null_mut(),
     }
 }

src/byte_slice.rs

@@ -2,10 +2,7 @@
 
 use std::ptr::NonNull;
 
-#[repr(C)]
+/// Represents a span of memory (`&mut [u8]` ) as a struct.
-/// Represents a span of memory (`&mut [u8]` ) as a struct usable by C code.
-///
-/// You should not create an instance of this type in your C code.
 ///
 /// # Safety
 ///
@@ -14,11 +11,29 @@ use std::ptr::NonNull;
 /// - accesses to the memory pointed to with `start` is never accessed outside `length`
 /// - the lifetime of the `CByteSlice` does not outlive the memory it points to, as described in
 ///   the function returning this type.
-/// - an instance of this created from C is never passed to a consuming function, as the rust code
+#[repr(C)]
-///   will try to free the memory of a potentially separate allocator.
+pub struct ByteSlice {
-pub struct SPByteSlice {
+    /// The start address of the memory.
-    /// The start address of the memory
     pub start: NonNull<u8>,
-    /// The amount of memory in bytes
+    /// The amount of memory in bytes.
     pub length: usize,
 }
+
+impl ByteSlice {
+    pub(crate) unsafe fn as_slice(&self) -> &[u8] {
+        unsafe { std::slice::from_raw_parts(self.start.as_ptr(), self.length) }
+    }
+
+    pub(crate) unsafe fn as_slice_mut(&mut self) -> &mut [u8] {
+        unsafe {
+            std::slice::from_raw_parts_mut(self.start.as_ptr(), self.length)
+        }
+    }
+
+    pub(crate) unsafe fn from_slice(slice: &mut [u8]) -> Self {
+        Self {
+            start: NonNull::new(slice.as_mut_ptr()).unwrap(),
+            length: slice.len(),
+        }
+    }
+}

src/char_grid.rs

@@ -1,16 +1,10 @@
-//! C functions for interacting with [SPCharGrid]s
+use crate::{heap_drop, heap_move, heap_move_nonnull, heap_remove, ByteSlice};
-//!
+use servicepoint::{CharGrid, CharGridCommand, Grid, Origin, Packet};
-//! prefix `sp_char_grid_`
-
-use servicepoint::Grid;
 use std::ptr::NonNull;
 
-/// A C-wrapper for grid containing UTF-8 characters.
+/// Creates a new [CharGrid] with the specified dimensions.
 ///
-/// As the rust [char] type is not FFI-safe, characters are passed in their UTF-32 form as 32bit unsigned integers.
+/// returns: [CharGrid] initialized to 0.
-///
-/// The encoding is enforced in most cases by the rust standard library
-/// and will panic when provided with illegal characters.
 ///
 /// # Examples
 ///
@@ -20,115 +14,46 @@ use std::ptr::NonNull;
 /// sp_char_grid_set(grid, 0, 0, '!');
 /// sp_char_grid_free(grid);
 /// ```
-pub struct SPCharGrid(pub(crate) servicepoint::CharGrid);
-
-impl Clone for SPCharGrid {
-    fn clone(&self) -> Self {
-        SPCharGrid(self.0.clone())
-    }
-}
-
-/// Creates a new [SPCharGrid] with the specified dimensions.
-///
-/// returns: [SPCharGrid] initialized to 0. Will never return NULL.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_char_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_new(
     width: usize,
     height: usize,
-) -> NonNull<SPCharGrid> {
+) -> NonNull<CharGrid> {
-    let result =
+    heap_move_nonnull(CharGrid::new(width, height))
-        Box::new(SPCharGrid(servicepoint::CharGrid::new(width, height)));
-    NonNull::from(Box::leak(result))
 }
 
-/// Loads a [SPCharGrid] with the specified dimensions from the provided data.
+/// Loads a [CharGrid] with the specified dimensions from the provided data.
 ///
-/// Will never return NULL.
+/// returns: new CharGrid or NULL in case of an error
-///
-/// # Panics
-///
-/// - when `data` is NULL
-/// - when the provided `data_length` does not match `height` and `width`
-/// - when `data` is not valid UTF-8
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `data` points to a valid memory location of at least `data_length`
-///   bytes in size.
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_char_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: ByteSlice,
-    data_length: usize,
+) -> *mut CharGrid {
-) -> NonNull<SPCharGrid> {
+    let data = unsafe { data.as_slice() };
-    assert!(data.is_null());
+    if let Ok(grid) = CharGrid::load_utf8(width, height, data.to_vec()) {
-    let data = std::slice::from_raw_parts(data, data_length);
+        heap_move(grid)
-    let result = Box::new(SPCharGrid(
+    } else {
-        servicepoint::CharGrid::load_utf8(width, height, data.to_vec())
+        std::ptr::null_mut()
-            .unwrap(),
+    }
-    ));
-    NonNull::from(Box::leak(result))
 }
 
-/// Clones a [SPCharGrid].
+/// Clones a [CharGrid].
-///
-/// Will never return NULL.
-///
-/// # Panics
-///
-/// - when `char_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `char_grid` points to a valid [SPCharGrid]
-/// - `char_grid` is not written to concurrently
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_char_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_clone(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
-) -> NonNull<SPCharGrid> {
+) -> NonNull<CharGrid> {
-    assert!(!char_grid.is_null());
+    heap_move_nonnull(unsafe { char_grid.as_ref().clone() })
-    let result = Box::new((*char_grid).clone());
-    NonNull::from(Box::leak(result))
 }
 
-/// Deallocates a [SPCharGrid].
+/// Deallocates a [CharGrid].
-///
-/// # Panics
-///
-/// - when `char_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `char_grid` points to a valid [SPCharGrid]
-/// - `char_grid` is not used concurrently or after char_grid call
-/// - `char_grid` was not passed to another consuming function, e.g. to create a [SPCommand]
-///
-/// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_char_grid_free(char_grid: *mut SPCharGrid) {
+pub unsafe extern "C" fn sp_char_grid_free(char_grid: NonNull<CharGrid>) {
-    assert!(!char_grid.is_null());
+    unsafe { heap_drop(char_grid) }
-    _ = Box::from_raw(char_grid);
 }
 
-/// Gets the current value at the specified position.
+/// Returns the current value at the specified position.
 ///
 /// # Arguments
 ///
@@ -137,26 +62,17 @@ pub unsafe extern "C" fn sp_char_grid_free(char_grid: *mut SPCharGrid) {
 ///
 /// # Panics
 ///
-/// - when `char_grid` is NULL
 /// - when accessing `x` or `y` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `char_grid` points to a valid [SPCharGrid]
-/// - `char_grid` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_get(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
     x: usize,
     y: usize,
 ) -> u32 {
-    assert!(!char_grid.is_null());
+    unsafe { char_grid.as_ref().get(x, y) as u32 }
-    (*char_grid).0.get(x, y) as u32
 }
 
-/// Sets the value of the specified position in the [SPCharGrid].
+/// Sets the value of the specified position in the [CharGrid].
 ///
 /// # Arguments
 ///
@@ -168,96 +84,72 @@ pub unsafe extern "C" fn sp_char_grid_get(
 ///
 /// # Panics
 ///
-/// - when `char_grid` is NULL
 /// - when accessing `x` or `y` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `char_grid` points to a valid [SPBitVec]
-/// - `char_grid` is not written to or read from concurrently
-///
-/// [SPBitVec]: [crate::SPBitVec]
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_set(
-    char_grid: *mut SPCharGrid,
+    char_grid: NonNull<CharGrid>,
     x: usize,
     y: usize,
     value: u32,
 ) {
-    assert!(!char_grid.is_null());
+    unsafe { (*char_grid.as_ptr()).set(x, y, char::from_u32(value).unwrap()) };
-    (*char_grid).0.set(x, y, char::from_u32(value).unwrap());
 }
 
-/// Sets the value of all cells in the [SPCharGrid].
+/// Sets the value of all cells in the [CharGrid].
 ///
 /// # Arguments
 ///
 /// - `char_grid`: instance to write to
 /// - `value`: the value to set all cells to
-///
-/// # Panics
-///
-/// - when `char_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `char_grid` points to a valid [SPCharGrid]
-/// - `char_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_fill(
-    char_grid: *mut SPCharGrid,
+    char_grid: NonNull<CharGrid>,
     value: u32,
 ) {
-    assert!(!char_grid.is_null());
+    unsafe { (*char_grid.as_ptr()).fill(char::from_u32(value).unwrap()) };
-    (*char_grid).0.fill(char::from_u32(value).unwrap());
 }
 
-/// Gets the width of the [SPCharGrid] instance.
+/// Gets the width of the [CharGrid] instance.
 ///
 /// # Arguments
 ///
 /// - `char_grid`: instance to read from
-///
-/// # Panics
-///
-/// - when `char_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `char_grid` points to a valid [SPCharGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_width(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
 ) -> usize {
-    assert!(!char_grid.is_null());
+    unsafe { char_grid.as_ref().width() }
-    (*char_grid).0.width()
 }
 
-/// Gets the height of the [SPCharGrid] instance.
+/// Gets the height of the [CharGrid] instance.
 ///
 /// # Arguments
 ///
 /// - `char_grid`: instance to read from
-///
-/// # Panics
-///
-/// - when `char_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `char_grid` points to a valid [SPCharGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_height(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
 ) -> usize {
-    assert!(!char_grid.is_null());
+    unsafe { char_grid.as_ref().height() }
-    (*char_grid).0.height()
+}
+
+/// Creates a [CharGridCommand] and immediately turns that into a [Packet].
+///
+/// The provided [CharGrid] gets consumed.
+///
+/// Returns NULL in case of an error.
+#[no_mangle]
+pub unsafe extern "C" fn sp_char_grid_into_packet(
+    grid: NonNull<CharGrid>,
+    x: usize,
+    y: usize,
+) -> *mut Packet {
+    let grid = unsafe { heap_remove(grid) };
+    match Packet::try_from(CharGridCommand {
+        grid,
+        origin: Origin::new(x, y),
+    }) {
+        Ok(packet) => heap_move(packet),
+        Err(_) => std::ptr::null_mut(),
+    }
 }

src/command.rs

@@ -1,498 +0,0 @@
-//! C functions for interacting with [SPCommand]s
-//!
-//! prefix `sp_command_`
-
-use std::ptr::{null_mut, NonNull};
-
-use crate::{
-    SPBitVec, SPBitmap, SPBrightnessGrid, SPCharGrid, SPCompressionCode,
-    SPCp437Grid, SPPacket,
-};
-
-/// A low-level display command.
-///
-/// This struct and associated functions implement the UDP protocol for the display.
-///
-/// To send a [SPCommand], use a [SPConnection].
-///
-/// # Examples
-///
-/// ```C
-/// sp_connection_send_command(connection, sp_command_clear());
-/// sp_connection_send_command(connection, sp_command_brightness(5));
-/// ```
-///
-/// [SPConnection]: [crate::SPConnection]
-pub struct SPCommand(pub(crate) servicepoint::Command);
-
-impl Clone for SPCommand {
-    fn clone(&self) -> Self {
-        SPCommand(self.0.clone())
-    }
-}
-
-/// Tries to turn a [SPPacket] into a [SPCommand].
-///
-/// The packet is deallocated in the process.
-///
-/// Returns: pointer to new [SPCommand] instance or NULL if parsing failed.
-///
-/// # Panics
-///
-/// - when `packet` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - [SPPacket] points to a valid instance of [SPPacket]
-/// - [SPPacket] is not used concurrently or after this call
-/// - the result is checked for NULL
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_try_from_packet(
-    packet: *mut SPPacket,
-) -> *mut SPCommand {
-    let packet = *Box::from_raw(packet);
-    match servicepoint::Command::try_from(packet.0) {
-        Err(_) => null_mut(),
-        Ok(command) => Box::into_raw(Box::new(SPCommand(command))),
-    }
-}
-
-/// Clones a [SPCommand] instance.
-///
-/// returns: new [SPCommand] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `command` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `command` points to a valid instance of [SPCommand]
-/// - `command` is not written to concurrently
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_clone(
-    command: *const SPCommand,
-) -> NonNull<SPCommand> {
-    assert!(!command.is_null());
-    let result = Box::new((*command).clone());
-    NonNull::from(Box::leak(result))
-}
-
-/// Set all pixels to the off state.
-///
-/// Does not affect brightness.
-///
-/// Returns: a new [servicepoint::Command::Clear] instance. Will never return NULL.
-///
-/// # Examples
-///
-/// ```C
-/// sp_connection_send_command(connection, sp_command_clear());
-/// ```
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_clear() -> NonNull<SPCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::Clear));
-    NonNull::from(Box::leak(result))
-}
-
-/// Kills the udp daemon on the display, which usually results in a restart.
-///
-/// Please do not send this in your normal program flow.
-///
-/// Returns: a new [servicepoint::Command::HardReset] instance. Will never return NULL.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<SPCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::HardReset));
-    NonNull::from(Box::leak(result))
-}
-
-/// A yet-to-be-tested command.
-///
-/// Returns: a new [servicepoint::Command::FadeOut] instance. Will never return NULL.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_fade_out() -> NonNull<SPCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::FadeOut));
-    NonNull::from(Box::leak(result))
-}
-
-/// Set the brightness of all tiles to the same value.
-///
-/// Returns: a new [servicepoint::Command::Brightness] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - When the provided brightness value is out of range (0-11).
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_brightness(
-    brightness: u8,
-) -> NonNull<SPCommand> {
-    let brightness = servicepoint::Brightness::try_from(brightness)
-        .expect("invalid brightness");
-    let result =
-        Box::new(SPCommand(servicepoint::Command::Brightness(brightness)));
-    NonNull::from(Box::leak(result))
-}
-
-/// Set the brightness of individual tiles in a rectangular area of the display.
-///
-/// The passed [SPBrightnessGrid] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::CharBrightness] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `grid` points to a valid instance of [SPBrightnessGrid]
-/// - `grid` is not used concurrently or after this call
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_char_brightness(
-    x: usize,
-    y: usize,
-    grid: *mut SPBrightnessGrid,
-) -> NonNull<SPCommand> {
-    assert!(!grid.is_null());
-    let byte_grid = *Box::from_raw(grid);
-    let result = Box::new(SPCommand(servicepoint::Command::CharBrightness(
-        servicepoint::Origin::new(x, y),
-        byte_grid.0,
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Set pixel data starting at the pixel offset on screen.
-///
-/// The screen will continuously overwrite more pixel data without regarding the offset, meaning
-/// once the starting row is full, overwriting will continue on column 0.
-///
-/// The contained [SPBitVec] is always uncompressed.
-///
-/// The passed [SPBitVec] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::BitmapLinear] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `bit_vec` is null
-/// - when `compression_code` is not a valid value
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid instance of [SPBitVec]
-/// - `bit_vec` is not used concurrently or after this call
-/// - `compression` matches one of the allowed enum values
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_bitmap_linear(
-    offset: usize,
-    bit_vec: *mut SPBitVec,
-    compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinear(
-        offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Set pixel data according to an and-mask starting at the offset.
-///
-/// The screen will continuously overwrite more pixel data without regarding the offset, meaning
-/// once the starting row is full, overwriting will continue on column 0.
-///
-/// The contained [SPBitVec] is always uncompressed.
-///
-/// The passed [SPBitVec] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::BitmapLinearAnd] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `bit_vec` is null
-/// - when `compression_code` is not a valid value
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid instance of [SPBitVec]
-/// - `bit_vec` is not used concurrently or after this call
-/// - `compression` matches one of the allowed enum values
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_bitmap_linear_and(
-    offset: usize,
-    bit_vec: *mut SPBitVec,
-    compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearAnd(
-        offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Set pixel data according to an or-mask starting at the offset.
-///
-/// The screen will continuously overwrite more pixel data without regarding the offset, meaning
-/// once the starting row is full, overwriting will continue on column 0.
-///
-/// The contained [SPBitVec] is always uncompressed.
-///
-/// The passed [SPBitVec] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::BitmapLinearOr] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `bit_vec` is null
-/// - when `compression_code` is not a valid value
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid instance of [SPBitVec]
-/// - `bit_vec` is not used concurrently or after this call
-/// - `compression` matches one of the allowed enum values
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_bitmap_linear_or(
-    offset: usize,
-    bit_vec: *mut SPBitVec,
-    compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearOr(
-        offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Set pixel data according to a xor-mask starting at the offset.
-///
-/// The screen will continuously overwrite more pixel data without regarding the offset, meaning
-/// once the starting row is full, overwriting will continue on column 0.
-///
-/// The contained [SPBitVec] is always uncompressed.
-///
-/// The passed [SPBitVec] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::BitmapLinearXor] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `bit_vec` is null
-/// - when `compression_code` is not a valid value
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bit_vec` points to a valid instance of [SPBitVec]
-/// - `bit_vec` is not used concurrently or after this call
-/// - `compression` matches one of the allowed enum values
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_bitmap_linear_xor(
-    offset: usize,
-    bit_vec: *mut SPBitVec,
-    compression: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bit_vec.is_null());
-    let bit_vec = *Box::from_raw(bit_vec);
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearXor(
-        offset,
-        bit_vec.into(),
-        compression.try_into().expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Show codepage 437 encoded text on the screen.
-///
-/// The passed [SPCp437Grid] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::Cp437Data] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `grid` is null
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `grid` points to a valid instance of [SPCp437Grid]
-/// - `grid` is not used concurrently or after this call
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_cp437_data(
-    x: usize,
-    y: usize,
-    grid: *mut SPCp437Grid,
-) -> NonNull<SPCommand> {
-    assert!(!grid.is_null());
-    let grid = *Box::from_raw(grid);
-    let result = Box::new(SPCommand(servicepoint::Command::Cp437Data(
-        servicepoint::Origin::new(x, y),
-        grid.0,
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Show UTF-8 encoded text on the screen.
-///
-/// The passed [SPCharGrid] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::Utf8Data] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `grid` is null
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `grid` points to a valid instance of [SPCharGrid]
-/// - `grid` is not used concurrently or after this call
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_utf8_data(
-    x: usize,
-    y: usize,
-    grid: *mut SPCharGrid,
-) -> NonNull<SPCommand> {
-    assert!(!grid.is_null());
-    let grid = *Box::from_raw(grid);
-    let result = Box::new(SPCommand(servicepoint::Command::Utf8Data(
-        servicepoint::Origin::new(x, y),
-        grid.0,
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Sets a window of pixels to the specified values.
-///
-/// The passed [SPBitmap] gets consumed.
-///
-/// Returns: a new [servicepoint::Command::BitmapLinearWin] instance. Will never return NULL.
-///
-/// # Panics
-///
-/// - when `bitmap` is null
-/// - when `compression_code` is not a valid value
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `bitmap` points to a valid instance of [SPBitmap]
-/// - `bitmap` is not used concurrently or after this call
-/// - `compression` matches one of the allowed enum values
-/// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_command_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_bitmap_linear_win(
-    x: usize,
-    y: usize,
-    bitmap: *mut SPBitmap,
-    compression_code: SPCompressionCode,
-) -> NonNull<SPCommand> {
-    assert!(!bitmap.is_null());
-    let byte_grid = (*Box::from_raw(bitmap)).0;
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearWin(
-        servicepoint::Origin::new(x, y),
-        byte_grid,
-        compression_code
-            .try_into()
-            .expect("invalid compression code"),
-    )));
-    NonNull::from(Box::leak(result))
-}
-
-/// Deallocates a [SPCommand].
-///
-/// # Examples
-///
-/// ```C
-/// SPCommand c = sp_command_clear();
-/// sp_command_free(c);
-/// ```
-///
-/// # Panics
-///
-/// - when `command` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `command` points to a valid [SPCommand]
-/// - `command` is not used concurrently or after this call
-/// - `command` was not passed to another consuming function, e.g. to create a [SPPacket]
-#[no_mangle]
-pub unsafe extern "C" fn sp_command_free(command: *mut SPCommand) {
-    assert!(!command.is_null());
-    _ = Box::from_raw(command);
-}

src/commands/mod.rs

@@ -0,0 +1,3 @@
+mod typed;
+
+pub use typed::*;

src/commands/typed.rs

@@ -0,0 +1,201 @@
+use crate::{heap_drop, heap_move, heap_move_nonnull, SPBitVec};
+use servicepoint::{
+    BinaryOperation, Bitmap, Brightness, BrightnessGrid, CharGrid,
+    CompressionCode, Cp437Grid, GlobalBrightnessCommand, Packet, TypedCommand,
+};
+use std::ptr::NonNull;
+
+/// Tries to turn a [Packet] into a [TypedCommand].
+///
+/// The packet is deallocated in the process.
+///
+/// Returns: pointer to new [TypedCommand] instance or NULL if parsing failed.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_try_from_packet(
+    packet: NonNull<Packet>,
+) -> *mut TypedCommand {
+    let packet = *unsafe { Box::from_raw(packet.as_ptr()) };
+    match servicepoint::TypedCommand::try_from(packet) {
+        Err(_) => std::ptr::null_mut(),
+        Ok(command) => heap_move(command),
+    }
+}
+
+/// Clones a [TypedCommand] instance.
+///
+/// returns: new [TypedCommand] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_clone(
+    command: NonNull<TypedCommand>,
+) -> NonNull<TypedCommand> {
+    heap_move_nonnull(unsafe { command.as_ref().clone() })
+}
+
+/// Set all pixels to the off state.
+///
+/// Does not affect brightness.
+///
+/// Returns: a new [servicepoint::Command::Clear] instance.
+///
+/// # Examples
+///
+/// ```C
+/// sp_udp_send_command(connection, sp_command_clear());
+/// ```
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_clear() -> NonNull<TypedCommand> {
+    heap_move_nonnull(servicepoint::ClearCommand.into())
+}
+
+/// Kills the udp daemon on the display, which usually results in a restart.
+///
+/// Please do not send this in your normal program flow.
+///
+/// Returns: a new [servicepoint::Command::HardReset] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<TypedCommand> {
+    heap_move_nonnull(servicepoint::HardResetCommand.into())
+}
+
+/// A yet-to-be-tested command.
+///
+/// Returns: a new [servicepoint::Command::FadeOut] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_fade_out() -> NonNull<TypedCommand> {
+    heap_move_nonnull(servicepoint::FadeOutCommand.into())
+}
+
+/// Set the brightness of all tiles to the same value.
+///
+/// Returns: a new [servicepoint::Command::Brightness] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_global_brightness(
+    brightness: Brightness,
+) -> NonNull<TypedCommand> {
+    heap_move_nonnull(GlobalBrightnessCommand::from(brightness).into())
+}
+
+/// Set the brightness of individual tiles in a rectangular area of the display.
+///
+/// The passed [BrightnessGrid] gets consumed.
+///
+/// Returns: a new [servicepoint::Command::CharBrightness] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_brightness_grid(
+    x: usize,
+    y: usize,
+    grid: NonNull<BrightnessGrid>,
+) -> NonNull<TypedCommand> {
+    let grid = unsafe { *Box::from_raw(grid.as_ptr()) };
+    let result = servicepoint::BrightnessGridCommand {
+        origin: servicepoint::Origin::new(x, y),
+        grid,
+    }
+    .into();
+    heap_move_nonnull(result)
+}
+
+/// Set pixel data starting at the pixel offset on screen.
+///
+/// The screen will continuously overwrite more pixel data without regarding the offset, meaning
+/// once the starting row is full, overwriting will continue on column 0.
+///
+/// The [`BinaryOperation`] will be applied on the display comparing old and sent bit.
+///
+/// `new_bit = old_bit op sent_bit`
+///
+/// For example, [`BinaryOperation::Or`] can be used to turn on some pixels without affecting other pixels.
+///
+/// The contained [`BitVecU8Msb0`] is always uncompressed.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_bitvec(
+    offset: usize,
+    bit_vec: NonNull<SPBitVec>,
+    compression: CompressionCode,
+    operation: BinaryOperation,
+) -> *mut TypedCommand {
+    let bit_vec = unsafe { *Box::from_raw(bit_vec.as_ptr()) };
+    let command = servicepoint::BitVecCommand {
+        offset,
+        operation,
+        bitvec: bit_vec.0,
+        compression,
+    }
+    .into();
+    heap_move(command)
+}
+
+/// Show codepage 437 encoded text on the screen.
+///
+/// The passed [Cp437Grid] gets consumed.
+///
+/// Returns: a new [servicepoint::Cp437GridCommand] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_cp437_grid(
+    x: usize,
+    y: usize,
+    grid: NonNull<Cp437Grid>,
+) -> NonNull<TypedCommand> {
+    let grid = *unsafe { Box::from_raw(grid.as_ptr()) };
+    let result = servicepoint::Cp437GridCommand {
+        origin: servicepoint::Origin::new(x, y),
+        grid,
+    }
+    .into();
+    heap_move_nonnull(result)
+}
+
+/// Show UTF-8 encoded text on the screen.
+///
+/// The passed [CharGrid] gets consumed.
+///
+/// Returns: a new [servicepoint::CharGridCommand] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_char_grid(
+    x: usize,
+    y: usize,
+    grid: NonNull<CharGrid>,
+) -> NonNull<TypedCommand> {
+    let grid = unsafe { *Box::from_raw(grid.as_ptr()) };
+    let result = servicepoint::CharGridCommand {
+        origin: servicepoint::Origin::new(x, y),
+        grid,
+    }
+    .into();
+    heap_move_nonnull(result)
+}
+
+/// Sets a window of pixels to the specified values.
+///
+/// The passed [Bitmap] gets consumed.
+///
+/// Returns: a new [servicepoint::BitmapCommand] instance.
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_bitmap(
+    x: usize,
+    y: usize,
+    bitmap: NonNull<Bitmap>,
+    compression: CompressionCode,
+) -> *mut TypedCommand {
+    let bitmap = unsafe { *Box::from_raw(bitmap.as_ptr()) };
+    let command = servicepoint::BitmapCommand {
+        origin: servicepoint::Origin::new(x, y),
+        bitmap,
+        compression,
+    }
+    .into();
+    heap_move(command)
+}
+
+/// Deallocates a [TypedCommand].
+///
+/// # Examples
+///
+/// ```C
+/// TypedCommand c = sp_command_clear();
+/// sp_command_free(c);
+/// ```
+#[no_mangle]
+pub unsafe extern "C" fn sp_command_free(command: NonNull<TypedCommand>) {
+    unsafe { heap_drop(command) }
+}

src/connection.rs

@@ -1,139 +1,119 @@
-//! C functions for interacting with [SPConnection]s
+use crate::{heap_drop, heap_move, heap_remove};
-//!
+use servicepoint::{Connection, Header, Packet, TypedCommand, UdpConnection};
-//! prefix `sp_connection_`
-
 use std::ffi::{c_char, CStr};
-use std::ptr::{null_mut, NonNull};
+use std::net::{Ipv4Addr, SocketAddrV4};
+use std::ptr::NonNull;
 
-use crate::{SPCommand, SPPacket};
+/// Creates a new instance of [UdpConnection].
-
+///
-/// A connection to the display.
+/// returns: NULL if connection fails, or connected instance
 ///
 /// # Examples
 ///
 /// ```C
-/// CConnection connection = sp_connection_open("172.23.42.29:2342");
+/// UdpConnection connection = sp_udp_open("172.23.42.29:2342");
 /// if (connection != NULL)
-///     sp_connection_send_command(connection, sp_command_clear());
+///     sp_udp_send_command(connection, sp_command_clear());
 /// ```
-pub struct SPConnection(pub(crate) servicepoint::Connection);
-
-/// Creates a new instance of [SPConnection].
-///
-/// returns: NULL if connection fails, or connected instance
-///
-/// # Panics
-///
-/// - when `host` is null or an invalid host
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_connection_free`.
 #[no_mangle]
-pub unsafe extern "C" fn sp_connection_open(
+pub unsafe extern "C" fn sp_udp_open(
-    host: *const c_char,
+    host: NonNull<c_char>,
-) -> *mut SPConnection {
+) -> *mut UdpConnection {
-    assert!(!host.is_null());
+    let host = unsafe { CStr::from_ptr(host.as_ptr()) }
-    let host = CStr::from_ptr(host).to_str().expect("Bad encoding");
+        .to_str()
-    let connection = match servicepoint::Connection::open(host) {
+        .expect("Bad encoding");
-        Err(_) => return null_mut(),
+    let connection = match UdpConnection::open(host) {
+        Err(_) => return std::ptr::null_mut(),
         Ok(value) => value,
     };
 
-    Box::into_raw(Box::new(SPConnection(connection)))
+    heap_move(connection)
 }
 
-/// Creates a new instance of [SPConnection] for testing that does not actually send anything.
+/// Creates a new instance of [UdpConnection].
 ///
-/// returns: a new instance. Will never return NULL.
+/// returns: NULL if connection fails, or connected instance
 ///
-/// # Safety
+/// # Examples
 ///
-/// The caller has to make sure that:
+/// ```C
-///
+/// UdpConnection connection = sp_udp_open_ipv4(172, 23, 42, 29, 2342);
-/// - the returned instance is freed in some way, either by using a consuming function or
+/// if (connection != NULL)
-///   by explicitly calling `sp_connection_free`.
+///     sp_udp_send_command(connection, sp_command_clear());
+/// ```
 #[no_mangle]
-pub unsafe extern "C" fn sp_connection_fake() -> NonNull<SPConnection> {
+pub unsafe extern "C" fn sp_udp_open_ipv4(
-    let result = Box::new(SPConnection(servicepoint::Connection::Fake));
+    ip1: u8,
-    NonNull::from(Box::leak(result))
+    ip2: u8,
+    ip3: u8,
+    ip4: u8,
+    port: u16,
+) -> *mut UdpConnection {
+    let addr = SocketAddrV4::new(Ipv4Addr::from([ip1, ip2, ip3, ip4]), port);
+    let connection = match UdpConnection::open(addr) {
+        Err(_) => return std::ptr::null_mut(),
+        Ok(value) => value,
+    };
+    heap_move(connection)
 }
 
-/// Sends a [SPPacket] to the display using the [SPConnection].
+/// Sends a [Packet] to the display using the [UdpConnection].
 ///
 /// The passed `packet` gets consumed.
 ///
 /// returns: true in case of success
-///
-/// # Panics
-///
-/// - when `connection` is NULL
-/// - when `packet` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `connection` points to a valid instance of [SPConnection]
-/// - `packet` points to a valid instance of [SPPacket]
-/// - `packet` is not used concurrently or after this call
 #[no_mangle]
-pub unsafe extern "C" fn sp_connection_send_packet(
+pub unsafe extern "C" fn sp_udp_send_packet(
-    connection: *const SPConnection,
+    connection: NonNull<UdpConnection>,
-    packet: *mut SPPacket,
+    packet: NonNull<Packet>,
 ) -> bool {
-    assert!(!connection.is_null());
+    let packet = unsafe { heap_remove(packet) };
-    assert!(!packet.is_null());
+    unsafe { connection.as_ref().send(packet) }.is_ok()
-    let packet = Box::from_raw(packet);
-    (*connection).0.send((*packet).0).is_ok()
 }
 
-/// Sends a [SPCommand] to the display using the [SPConnection].
+/// Sends a [TypedCommand] to the display using the [UdpConnection].
 ///
 /// The passed `command` gets consumed.
 ///
 /// returns: true in case of success
 ///
-/// # Panics
+/// # Examples
 ///
-/// - when `connection` is NULL
+/// ```C
-/// - when `command` is NULL
+/// sp_udp_send_command(connection, sp_command_brightness(5));
-///
+/// ```
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `connection` points to a valid instance of [SPConnection]
-/// - `command` points to a valid instance of [SPPacket]
-/// - `command` is not used concurrently or after this call
 #[no_mangle]
-pub unsafe extern "C" fn sp_connection_send_command(
+pub unsafe extern "C" fn sp_udp_send_command(
-    connection: *const SPConnection,
+    connection: NonNull<UdpConnection>,
-    command: *mut SPCommand,
+    command: NonNull<TypedCommand>,
 ) -> bool {
-    assert!(!connection.is_null());
+    let command = unsafe { heap_remove(command) };
-    assert!(!command.is_null());
+    unsafe { connection.as_ref().send(command) }.is_ok()
-    let command = (*Box::from_raw(command)).0;
-    (*connection).0.send(command).is_ok()
 }
 
-/// Closes and deallocates a [SPConnection].
+/// Sends a [Header] to the display using the [UdpConnection].
 ///
-/// # Panics
+/// returns: true in case of success
 ///
-/// - when `connection` is NULL
+/// # Examples
 ///
-/// # Safety
+/// ```C
-///
+/// sp_udp_send_header(connection, sp_command_brightness(5));
-/// The caller has to make sure that:
+/// ```
-///
-/// - `connection` points to a valid [SPConnection]
-/// - `connection` is not used concurrently or after this call
 #[no_mangle]
-pub unsafe extern "C" fn sp_connection_free(connection: *mut SPConnection) {
+pub unsafe extern "C" fn sp_udp_send_header(
-    assert!(!connection.is_null());
+    udp_connection: NonNull<UdpConnection>,
-    _ = Box::from_raw(connection);
+    header: Header,
+) -> bool {
+    let packet = Packet {
+        header,
+        payload: vec![],
+    };
+    unsafe { udp_connection.as_ref() }.send(packet).is_ok()
+}
+
+/// Closes and deallocates a [UdpConnection].
+#[no_mangle]
+pub unsafe extern "C" fn sp_udp_free(connection: NonNull<UdpConnection>) {
+    unsafe { heap_drop(connection) }
 }

src/constants.rs

@@ -1,48 +0,0 @@
-//! re-exported constants for use in C
-
-use servicepoint::CompressionCode;
-use std::time::Duration;
-
-/// size of a single tile in one dimension
-pub const SP_TILE_SIZE: usize = 8;
-
-/// Display tile count in the x-direction
-pub const SP_TILE_WIDTH: usize = 56;
-
-/// Display tile count in the y-direction
-pub const SP_TILE_HEIGHT: usize = 20;
-
-/// Display width in pixels
-pub const SP_PIXEL_WIDTH: usize = SP_TILE_WIDTH * SP_TILE_SIZE;
-
-/// Display height in pixels
-pub const SP_PIXEL_HEIGHT: usize = SP_TILE_HEIGHT * SP_TILE_SIZE;
-
-/// pixel count on whole screen
-pub const SP_PIXEL_COUNT: usize = SP_PIXEL_WIDTH * SP_PIXEL_HEIGHT;
-
-/// Actual hardware limit is around 28-29ms/frame. Rounded up for less dropped packets.
-pub const SP_FRAME_PACING_MS: u128 = Duration::from_millis(30).as_millis();
-
-/// Specifies the kind of compression to use.
-#[repr(u16)]
-pub enum SPCompressionCode {
-    /// no compression
-    Uncompressed = 0x0,
-    /// compress using flate2 with zlib header
-    Zlib = 0x677a,
-    /// compress using bzip2
-    Bzip2 = 0x627a,
-    /// compress using lzma
-    Lzma = 0x6c7a,
-    /// compress using Zstandard
-    Zstd = 0x7a73,
-}
-
-impl TryFrom<SPCompressionCode> for CompressionCode {
-    type Error = ();
-
-    fn try_from(value: SPCompressionCode) -> Result<Self, Self::Error> {
-        CompressionCode::try_from(value as u16)
-    }
-}

src/cp437_grid.rs

@@ -1,127 +1,46 @@
-//! C functions for interacting with [SPCp437Grid]s
+use crate::{heap_drop, heap_move, heap_move_nonnull, heap_remove, ByteSlice};
-//!
+use servicepoint::{Cp437Grid, Cp437GridCommand, DataRef, Grid, Origin, Packet};
-//! prefix `sp_cp437_grid_`
-
-use crate::SPByteSlice;
-use servicepoint::{DataRef, Grid};
 use std::ptr::NonNull;
 
-/// A C-wrapper for grid containing codepage 437 characters.
+/// Creates a new [Cp437Grid] with the specified dimensions.
 ///
-/// The encoding is currently not enforced.
+/// returns: [Cp437Grid] initialized to 0.
-///
-/// # Examples
-///
-/// ```C
-/// Cp437Grid grid = sp_cp437_grid_new(4, 3);
-/// sp_cp437_grid_fill(grid, '?');
-/// sp_cp437_grid_set(grid, 0, 0, '!');
-/// sp_cp437_grid_free(grid);
-/// ```
-pub struct SPCp437Grid(pub(crate) servicepoint::Cp437Grid);
-
-impl Clone for SPCp437Grid {
-    fn clone(&self) -> Self {
-        SPCp437Grid(self.0.clone())
-    }
-}
-
-/// Creates a new [SPCp437Grid] with the specified dimensions.
-///
-/// returns: [SPCp437Grid] initialized to 0. Will never return NULL.
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_cp437_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_new(
     width: usize,
     height: usize,
-) -> NonNull<SPCp437Grid> {
+) -> NonNull<Cp437Grid> {
-    let result =
+    heap_move_nonnull(Cp437Grid::new(width, height))
-        Box::new(SPCp437Grid(servicepoint::Cp437Grid::new(width, height)));
-    NonNull::from(Box::leak(result))
 }
 
-/// Loads a [SPCp437Grid] with the specified dimensions from the provided data.
+/// Loads a [Cp437Grid] with the specified dimensions from the provided data.
-///
-/// Will never return NULL.
-///
-/// # Panics
-///
-/// - when `data` is NULL
-/// - when the provided `data_length` does not match `height` and `width`
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `data` points to a valid memory location of at least `data_length`
-///   bytes in size.
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_cp437_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: ByteSlice,
-    data_length: usize,
+) -> *mut Cp437Grid {
-) -> NonNull<SPCp437Grid> {
+    let data = unsafe { data.as_slice() };
-    assert!(data.is_null());
+    let grid = Cp437Grid::load(width, height, data);
-    let data = std::slice::from_raw_parts(data, data_length);
+    if let Some(grid) = grid {
-    let result = Box::new(SPCp437Grid(servicepoint::Cp437Grid::load(
+        heap_move(grid)
-        width, height, data,
+    } else {
-    )));
+        std::ptr::null_mut()
-    NonNull::from(Box::leak(result))
+    }
 }
 
-/// Clones a [SPCp437Grid].
+/// Clones a [Cp437Grid].
-///
-/// Will never return NULL.
-///
-/// # Panics
-///
-/// - when `cp437_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPCp437Grid]
-/// - `cp437_grid` is not written to concurrently
-/// - the returned instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_cp437_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_clone(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
-) -> NonNull<SPCp437Grid> {
+) -> NonNull<Cp437Grid> {
-    assert!(!cp437_grid.is_null());
+    heap_move_nonnull(unsafe { cp437_grid.as_ref().clone() })
-    let result = Box::new((*cp437_grid).clone());
-    NonNull::from(Box::leak(result))
 }
 
-/// Deallocates a [SPCp437Grid].
+/// Deallocates a [Cp437Grid].
-///
-/// # Panics
-///
-/// - when `cp437_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPCp437Grid]
-/// - `cp437_grid` is not used concurrently or after cp437_grid call
-/// - `cp437_grid` was not passed to another consuming function, e.g. to create a [SPCommand]
-///
-/// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_cp437_grid_free(cp437_grid: *mut SPCp437Grid) {
+pub unsafe extern "C" fn sp_cp437_grid_free(cp437_grid: NonNull<Cp437Grid>) {
-    assert!(!cp437_grid.is_null());
+    unsafe { heap_drop(cp437_grid) }
-    _ = Box::from_raw(cp437_grid);
 }
 
 /// Gets the current value at the specified position.
@@ -133,26 +52,17 @@ pub unsafe extern "C" fn sp_cp437_grid_free(cp437_grid: *mut SPCp437Grid) {
 ///
 /// # Panics
 ///
-/// - when `cp437_grid` is NULL
 /// - when accessing `x` or `y` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPCp437Grid]
-/// - `cp437_grid` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_get(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
     x: usize,
     y: usize,
 ) -> u8 {
-    assert!(!cp437_grid.is_null());
+    unsafe { cp437_grid.as_ref().get(x, y) }
-    (*cp437_grid).0.get(x, y)
 }
 
-/// Sets the value of the specified position in the [SPCp437Grid].
+/// Sets the value of the specified position in the [Cp437Grid].
 ///
 /// # Arguments
 ///
@@ -164,122 +74,82 @@ pub unsafe extern "C" fn sp_cp437_grid_get(
 ///
 /// # Panics
 ///
-/// - when `cp437_grid` is NULL
 /// - when accessing `x` or `y` out of bounds
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPBitVec]
-/// - `cp437_grid` is not written to or read from concurrently
-///
-/// [SPBitVec]: [crate::SPBitVec]
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_set(
-    cp437_grid: *mut SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
     x: usize,
     y: usize,
     value: u8,
 ) {
-    assert!(!cp437_grid.is_null());
+    unsafe { (*cp437_grid.as_ptr()).set(x, y, value) };
-    (*cp437_grid).0.set(x, y, value);
 }
 
-/// Sets the value of all cells in the [SPCp437Grid].
+/// Sets the value of all cells in the [Cp437Grid].
 ///
 /// # Arguments
 ///
 /// - `cp437_grid`: instance to write to
 /// - `value`: the value to set all cells to
-///
-/// # Panics
-///
-/// - when `cp437_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPCp437Grid]
-/// - `cp437_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_fill(
-    cp437_grid: *mut SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
     value: u8,
 ) {
-    assert!(!cp437_grid.is_null());
+    unsafe { (*cp437_grid.as_ptr()).fill(value) };
-    (*cp437_grid).0.fill(value);
 }
 
-/// Gets the width of the [SPCp437Grid] instance.
+/// Gets the width of the [Cp437Grid] instance.
 ///
 /// # Arguments
 ///
 /// - `cp437_grid`: instance to read from
-///
-/// # Panics
-///
-/// - when `cp437_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPCp437Grid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_width(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
 ) -> usize {
-    assert!(!cp437_grid.is_null());
+    unsafe { cp437_grid.as_ref().width() }
-    (*cp437_grid).0.width()
 }
 
-/// Gets the height of the [SPCp437Grid] instance.
+/// Gets the height of the [Cp437Grid] instance.
 ///
 /// # Arguments
 ///
 /// - `cp437_grid`: instance to read from
-///
-/// # Panics
-///
-/// - when `cp437_grid` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPCp437Grid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_height(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
 ) -> usize {
-    assert!(!cp437_grid.is_null());
+    unsafe { cp437_grid.as_ref().height() }
-    (*cp437_grid).0.height()
 }
 
-/// Gets an unsafe reference to the data of the [SPCp437Grid] instance.
+/// Gets an unsafe reference to the data of the [Cp437Grid] instance.
 ///
-/// Will never return NULL.
+/// The returned memory is valid for the lifetime of the grid.
-///
-/// # Panics
-///
-/// - when `cp437_grid` is NULL
-///
-/// ## Safety
-///
-/// The caller has to make sure that:
-///
-/// - `cp437_grid` points to a valid [SPCp437Grid]
-/// - the returned memory range is never accessed after the passed [SPCp437Grid] has been freed
-/// - the returned memory range is never accessed concurrently, either via the [SPCp437Grid] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_unsafe_data_ref(
-    cp437_grid: *mut SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
-) -> SPByteSlice {
+) -> ByteSlice {
-    let data = (*cp437_grid).0.data_ref_mut();
+    unsafe { ByteSlice::from_slice((*cp437_grid.as_ptr()).data_ref_mut()) }
-    SPByteSlice {
+}
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
+
-        length: data.len(),
+/// Creates a [Cp437GridCommand] and immediately turns that into a [Packet].
+///
+/// The provided [Cp437Grid] gets consumed.
+///
+/// Returns NULL in case of an error.
+#[no_mangle]
+pub unsafe extern "C" fn sp_cp437_grid_into_packet(
+    grid: NonNull<Cp437Grid>,
+    x: usize,
+    y: usize,
+) -> *mut Packet {
+    let grid = unsafe { heap_remove(grid) };
+    match Packet::try_from(Cp437GridCommand {
+        grid,
+        origin: Origin::new(x, y),
+    }) {
+        Ok(packet) => heap_move(packet),
+        Err(_) => std::ptr::null_mut(),
     }
 }

src/lib.rs

@@ -9,18 +9,18 @@
 //! #include "servicepoint.h"
 //!
 //! int main(void) {
-//!     SPConnection *connection = sp_connection_open("172.23.42.29:2342");
+//!     UdpConnection *connection = sp_udp_open("172.23.42.29:2342");
 //!     if (connection == NULL)
 //!         return 1;
 //!
-//!     SPBitmap *pixels = sp_bitmap_new(SP_PIXEL_WIDTH, SP_PIXEL_HEIGHT);
+//!     Bitmap *pixels = sp_bitmap_new(SP_PIXEL_WIDTH, SP_PIXEL_HEIGHT);
 //!     sp_bitmap_fill(pixels, true);
 //!
-//!     SPCommand *command = sp_command_bitmap_linear_win(0, 0, pixels, Uncompressed);
+//!     TypedCommand *command = sp_command_bitmap_linear_win(0, 0, pixels, Uncompressed);
-//!     while (sp_connection_send_command(connection, sp_command_clone(command)));
+//!     while (sp_udp_send_command(connection, sp_command_clone(command)));
 //!
 //!     sp_command_free(command);
-//!     sp_connection_free(connection);
+//!     sp_udp_free(connection);
 //!     return 0;
 //! }
 //! ```
@@ -30,19 +30,40 @@ pub use crate::bitvec::*;
 pub use crate::brightness_grid::*;
 pub use crate::byte_slice::*;
 pub use crate::char_grid::*;
-pub use crate::command::*;
+pub use crate::commands::*;
 pub use crate::connection::*;
-pub use crate::constants::*;
 pub use crate::cp437_grid::*;
 pub use crate::packet::*;
+pub use servicepoint::CommandCode;
+use std::ptr::NonNull;
 
 mod bitmap;
 mod bitvec;
 mod brightness_grid;
 mod byte_slice;
 mod char_grid;
-mod command;
+mod commands;
 mod connection;
-mod constants;
 mod cp437_grid;
 mod packet;
+
+use std::time::Duration;
+
+/// Actual hardware limit is around 28-29ms/frame. Rounded up for less dropped packets.
+pub const SP_FRAME_PACING_MS: u128 = Duration::from_millis(30).as_millis();
+
+pub(crate) fn heap_move<T>(x: T) -> *mut T {
+    Box::into_raw(Box::new(x))
+}
+
+pub(crate) fn heap_move_nonnull<T>(x: T) -> NonNull<T> {
+    NonNull::from(Box::leak(Box::new(x)))
+}
+
+pub(crate) unsafe fn heap_drop<T>(x: NonNull<T>) {
+    drop(unsafe { heap_remove(x) });
+}
+
+pub(crate) unsafe fn heap_remove<T>(x: NonNull<T>) -> T {
+    unsafe { *Box::from_raw(x.as_ptr()) }
+}

src/packet.rs

@@ -1,166 +1,128 @@
-//! C functions for interacting with [SPPacket]s
+use crate::{heap_drop, heap_move, heap_move_nonnull, heap_remove, ByteSlice};
-//!
+use servicepoint::{CommandCode, Header, Packet, TypedCommand};
-//! prefix `sp_packet_`
+use std::ptr::NonNull;
 
-use std::ptr::{null_mut, NonNull};
+/// Turns a [TypedCommand] into a [Packet].
-
+/// The [TypedCommand] gets consumed.
-use crate::SPCommand;
-
-/// The raw packet
-pub struct SPPacket(pub(crate) servicepoint::Packet);
-
-/// Turns a [SPCommand] into a [SPPacket].
-/// The [SPCommand] gets consumed.
 ///
-/// Will never return NULL.
+/// Returns NULL in case of an error.
-///
-/// # Panics
-///
-/// - when `command` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - [SPCommand] points to a valid instance of [SPCommand]
-/// - [SPCommand] is not used concurrently or after this call
-/// - the returned [SPPacket] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_packet_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_from_command(
-    command: *mut SPCommand,
+    command: NonNull<TypedCommand>,
-) -> NonNull<SPPacket> {
+) -> *mut Packet {
-    assert!(!command.is_null());
+    let command = unsafe { heap_remove(command) };
-    let command = *Box::from_raw(command);
+    if let Ok(packet) = command.try_into() {
-    let result = Box::new(SPPacket(command.0.into()));
+        heap_move(packet)
-    NonNull::from(Box::leak(result))
+    } else {
-}
+        std::ptr::null_mut()
-
-/// Tries to load a [SPPacket] from the passed array with the specified length.
-///
-/// returns: NULL in case of an error, pointer to the allocated packet otherwise
-///
-/// # Panics
-///
-/// - when `data` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `data` points to a valid memory region of at least `length` bytes
-/// - `data` is not written to concurrently
-/// - the returned [SPPacket] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling `sp_packet_free`.
-#[no_mangle]
-pub unsafe extern "C" fn sp_packet_try_load(
-    data: *const u8,
-    length: usize,
-) -> *mut SPPacket {
-    assert!(!data.is_null());
-    let data = std::slice::from_raw_parts(data, length);
-    match servicepoint::Packet::try_from(data) {
-        Err(_) => null_mut(),
-        Ok(packet) => Box::into_raw(Box::new(SPPacket(packet))),
     }
 }
 
-/// Creates a raw [SPPacket] from parts.
+/// Tries to load a [Packet] from the passed array with the specified length.
 ///
-/// # Arguments
+/// returns: NULL in case of an error, pointer to the allocated packet otherwise
-///
+#[no_mangle]
-/// - `command_code` specifies which command this packet contains
+pub unsafe extern "C" fn sp_packet_try_load(data: ByteSlice) -> *mut Packet {
-/// - `a`, `b`, `c` and `d` are command-specific header values
+    let data = unsafe { data.as_slice() };
-/// - `payload` is the optional data that is part of the command
+    match servicepoint::Packet::try_from(data) {
-/// - `payload_len` is the size of the payload
+        Err(_) => std::ptr::null_mut(),
+        Ok(packet) => heap_move(packet),
+    }
+}
+
+/// Creates a raw [Packet] from parts.
 ///
 /// returns: new instance. Will never return null.
-///
-/// # Panics
-///
-/// - when `payload` is null, but `payload_len` is not zero
-/// - when `payload_len` is zero, but `payload` is nonnull
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `payload` points to a valid memory region of at least `payload_len` bytes
-/// - `payload` is not written to concurrently
-/// - the returned [SPPacket] instance is freed in some way, either by using a consuming function or
-///   by explicitly calling [sp_packet_free].
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_from_parts(
-    command_code: u16,
+    header: Header,
-    a: u16,
+    payload: *const ByteSlice,
-    b: u16,
+) -> NonNull<Packet> {
-    c: u16,
-    d: u16,
-    payload: *const u8,
-    payload_len: usize,
-) -> NonNull<SPPacket> {
-    assert_eq!(payload.is_null(), payload_len == 0);
-
     let payload = if payload.is_null() {
         vec![]
     } else {
-        let payload = std::slice::from_raw_parts(payload, payload_len);
+        let payload = unsafe { (*payload).as_slice() };
         Vec::from(payload)
     };
 
-    let packet = servicepoint::Packet {
+    heap_move_nonnull(Packet { header, payload })
-        header: servicepoint::Header {
-            command_code,
-            a,
-            b,
-            c,
-            d,
-        },
-        payload,
-    };
-    let result = Box::new(SPPacket(packet));
-    NonNull::from(Box::leak(result))
 }
 
-/// Clones a [SPPacket].
+/// Returns a pointer to the header field of the provided packet.
 ///
-/// Will never return NULL.
+/// The returned header can be changed and will be valid for the lifetime of the packet.
+#[no_mangle]
+pub unsafe extern "C" fn sp_packet_get_header(
+    packet: NonNull<Packet>,
+) -> NonNull<Header> {
+    NonNull::from(&mut unsafe { (*packet.as_ptr()).header })
+}
+
+/// Returns a pointer to the current payload of the provided packet.
+///
+/// The returned memory can be changed and will be valid until a new payload is set.
+#[no_mangle]
+pub unsafe extern "C" fn sp_packet_get_payload(
+    packet: NonNull<Packet>,
+) -> ByteSlice {
+    unsafe { ByteSlice::from_slice(&mut (*packet.as_ptr()).payload) }
+}
+
+/// Sets the payload of the provided packet to the provided data.
+///
+/// This makes previous payload pointers invalid.
+#[no_mangle]
+pub unsafe extern "C" fn sp_packet_set_payload(
+    packet: NonNull<Packet>,
+    data: ByteSlice,
+) {
+    unsafe { (*packet.as_ptr()).payload = data.as_slice().to_vec() }
+}
+
+/// Serialize the packet into the provided buffer.
 ///
 /// # Panics
 ///
-/// - when `packet` is NULL
+/// - if the buffer is not big enough to hold header+payload.
-///
+#[no_mangle]
-/// # Safety
+pub unsafe extern "C" fn sp_packet_serialize_to(
-///
+    packet: NonNull<Packet>,
-/// The caller has to make sure that:
+    mut buffer: ByteSlice,
-///
+) {
-/// - `packet` points to a valid [SPPacket]
+    unsafe {
-/// - `packet` is not written to concurrently
+        packet.as_ref().serialize_to(buffer.as_slice_mut());
-/// - the returned instance is freed in some way, either by using a consuming function or
+    }
-///   by explicitly calling `sp_packet_free`.
+}
+
+/// Clones a [Packet].
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_clone(
-    packet: *const SPPacket,
+    packet: NonNull<Packet>,
-) -> NonNull<SPPacket> {
+) -> NonNull<Packet> {
-    assert!(!packet.is_null());
+    heap_move_nonnull(unsafe { packet.as_ref().clone() })
-    let result = Box::new(SPPacket((*packet).0.clone()));
-    NonNull::from(Box::leak(result))
 }
 
-/// Deallocates a [SPPacket].
+/// Deallocates a [Packet].
-///
-/// # Panics
-///
-/// - when `packet` is NULL
-///
-/// # Safety
-///
-/// The caller has to make sure that:
-///
-/// - `packet` points to a valid [SPPacket]
-/// - `packet` is not used concurrently or after this call
 #[no_mangle]
-pub unsafe extern "C" fn sp_packet_free(packet: *mut SPPacket) {
+pub unsafe extern "C" fn sp_packet_free(packet: NonNull<Packet>) {
-    assert!(!packet.is_null());
+    unsafe { heap_drop(packet) }
-    _ = Box::from_raw(packet)
+}
+
+/// Converts u16 into [CommandCode].
+///
+/// If the provided value is not valid, false is returned and result is not changed.
+#[no_mangle]
+pub unsafe extern "C" fn sp_u16_to_command_code(
+    code: u16,
+    result: *mut CommandCode,
+) -> bool {
+    match CommandCode::try_from(code) {
+        Ok(code) => {
+            unsafe {
+                *result = code;
+            }
+            true
+        }
+        Err(_) => false,
+    }
 }