feat(crc): add c ffi stuff

crates/crc/Cargo.toml

@@ -5,6 +5,9 @@ edition = "2024"
 
 [dependencies]
 
+[lib]
+path = "src/rs/lib.rs"
+
 [dev-dependencies]
 criterion = "0.3"
 iai = "0.1.1"

crates/crc/Makefile

@@ -0,0 +1,97 @@
+include project.conf
+
+ifndef PROJECT_NAME
+$(error Missing PROJECT_NAME. Put variables at project.conf file)
+endif
+ifndef TEST_BIN
+$(error Missing TEST_BIN. Put variables at project.conf file)
+endif
+
+OS := $(shell uname -s)
+SHELL := bash
+COLOR_PREFIX := e
+
+ifeq ($(OS),Darwin)
+	COLOR_PREFIX := 033
+endif
+
+BROWN=\$(COLOR_PREFIX)[0;33m
+BLUE=\$(COLOR_PREFIX)[1;34m
+END_COLOR=\$(COLOR_PREFIX)[0m
+
+BUILDDIR := target/c/build
+BINDIR := target/c/bin
+SRCDIR := src/c
+LOGDIR := log
+
+SRCEXT := c
+CC := gcc
+
+# Defines the language standards for GCC
+STD := -std=gnu99 # See man gcc for more options
+# Protection for stack-smashing attack
+STACK := -fstack-protector-all -Wstack-protector
+# Specifies to GCC the required warnings
+WARNS := -Wall -Wextra -pedantic # -pedantic warns on language standards
+# Flags for compiling
+CFLAGS := -O3 $(STD) $(STACK) $(WARNS)
+# Debug options
+DEBUG := -g3 -DDEBUG=1
+
+# %.o file names
+NAMES := $(notdir $(basename $(wildcard $(SRCDIR)/*.$(SRCEXT))))
+NAMES_TEST := $(notdir $(basename $(wildcard $(SRCDIR)/test/*.$(SRCEXT))))
+OBJECTS :=$(patsubst %,$(BUILDDIR)/%.o,$(NAMES))
+OBJECTS_TEST :=$(patsubst %,$(BUILDDIR)/test/%.o,$(NAMES_TEST))
+
+.PHONY: help all prepare run build
+
+default: prepare all
+
+help:
+	@echo "C Project Template"
+	@echo "Target rules:"
+	@echo "    all      - Compiles and generates static library and tests"
+	@echo "    build    - Compiles and generates static library"
+	@echo "    test     - Compile and run tests"
+	@echo "    prepare  - Prepare the environment"
+	@echo "    clean    - Clean the project by removing build artifacts"
+	@echo "    help     - Prints a help message with target rules"
+
+prepare:
+	mkdir -p $(BUILDDIR) $(BUILDDIR)/test $(BINDIR) $(LOGDIR)
+
+all: $(BINDIR)/$(TEST_BIN) $(BINDIR)/$(LIBRARY) 
+
+build: prepare $(BINDIR)/$(LIBRARY)
+
+$(BINDIR)/$(LIBRARY): $(OBJECTS)
+	@echo OBJECTS: $(OBJECTS)
+	@echo -en "$(BROWN)LD $(END_COLOR)";
+	gcc-ar rcs $(BINDIR)/$(LIBRARY) $(OBJECTS) 
+	@echo -en "\n--\nLibrary file placed at" \
+			  "$(BROWN)$(BINDIR)/$(LIBRARY)$(END_COLOR)\n";
+
+$(BINDIR)/$(TEST_BIN): $(OBJECTS) $(OBJECTS_TEST)
+	@echo OBJECTS: $(OBJECTS) $(OBJECTS_TEST)
+	@echo -en "$(BROWN)LD $(END_COLOR)";
+	$(CC) -o $(BINDIR)/$(TEST_BIN) $+ $(DEBUG) $(CFLAGS) $(BUILD)
+	@echo -en "\n--\nTest binary file placed at" \
+			  "$(BROWN)$(BINDIR)/$(TEST_BIN)$(END_COLOR)\n";
+
+test: prepare $(BINDIR)/$(TEST_BIN)
+	@echo "Running the tests"
+	@echo "========================================================================="
+	@$(BINDIR)/$(TEST_BIN)
+
+# Rule for object binaries compilation
+$(BUILDDIR)/%.o: $(SRCDIR)/%.$(SRCEXT)
+	@echo -en "$(BROWN)CC $(END_COLOR)";
+	$(CC) -c $^ -o $@ $(DEBUG) $(CFLAGS) $(BUILDDIR)
+
+$(BUILDDIR)/test/%.o: $(SRCDIR)/test/%.$(SRCEXT)
+	@echo -en "$(BROWN)CC $(END_COLOR)";
+	$(CC) -c $^ -o $@ $(DEBUG) $(CFLAGS) $(BUILDDIR)
+
+clean:
+	rm -rvf $(BUILDDIR) $(BINDIR) $(LOGDIR)

crates/crc/benches/crc32bench.rs

@@ -1,10 +1,13 @@
-use crc::{Crc, Crc32};
+use crc::{Crc, Crc32, ffi};
 use criterion::{Criterion, black_box, criterion_group, criterion_main};
 
 pub fn criterion_benchmark(c: &mut Criterion) {
     c.bench_function("crc32", |b| {
         b.iter(|| Crc32::checksum(black_box(&crc::CHECK_DATA)))
     });
+    c.bench_function("ffi::crc32", |b| {
+        b.iter(|| ffi::Crc32::checksum(black_box(&crc::CHECK_DATA)))
+    });
 }
 
 criterion_group!(benches, criterion_benchmark);

crates/crc/benches/crc32bench_iai.rs

@@ -1,8 +1,11 @@
-use crc::{Crc, Crc32};
+use crc::{Crc, Crc32, ffi};
 use iai::black_box;
 
-fn iai_benchmark_short() -> <Crc32 as Crc>::Checksum {
+fn iai_benchmark_native() -> <Crc32 as Crc>::Checksum {
     Crc32::checksum(black_box(&crc::CHECK_DATA))
 }
+fn iai_benchmark_ffi() -> <Crc32 as Crc>::Checksum {
+    ffi::Crc32::checksum(black_box(&crc::CHECK_DATA))
+}
 
-iai::main!(iai_benchmark_short);
+iai::main!(iai_benchmark_native, iai_benchmark_ffi);

crates/crc/build.rs

@@ -0,0 +1,10 @@
+fn main() {
+    let status = std::process::Command::new("make")
+        .status()
+        .expect("could not make c stuff");
+    if !status.success() {
+        panic!("make returned an error")
+    }
+    let cwd = std::env::current_dir().unwrap().display().to_string();
+    println!("cargo::rustc-link-search={cwd}/target/c/bin");
+}

crates/crc/project.conf

@@ -0,0 +1,3 @@
+PROJECT_NAME := crc
+TEST_BIN := crc_test
+LIBRARY := libcrc.a

crates/crc/src/c/crc.h

@@ -0,0 +1 @@
+#include "crc32.h"

crates/crc/src/c/crc32.c

@@ -0,0 +1,70 @@
+#include "crc32.h"
+
+const uint32_t CRC32_INIT = 0xffffffff;
+const uint32_t CRC32_TABLE[256] = {
+    0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f,
+    0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
+    0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
+    0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
+    0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
+    0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
+    0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
+    0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
+    0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
+    0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
+    0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
+    0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
+    0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
+    0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
+    0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
+    0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
+    0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
+    0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
+    0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
+    0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
+    0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
+    0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
+    0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
+    0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
+    0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
+    0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
+    0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
+    0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
+    0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
+    0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
+    0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
+    0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
+    0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
+    0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
+    0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
+    0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
+    0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
+    0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
+    0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
+    0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
+    0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
+    0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
+    0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d,
+};
+
+Crc32 crc32_new() {
+  Crc32 crc32;
+  crc32.buf = 0;
+  return crc32;
+}
+void crc32_process(const char *data, size_t len, Crc32 *crc32) {
+#define chksum crc32->buf
+  chksum = CRC32_INIT;
+  for (uint32_t i = 0; i < len; i++) {
+    chksum ^= data[i];
+    chksum = (chksum >> 8) ^ CRC32_TABLE[(chksum & 0xff)];
+  }
+  chksum ^= CRC32_INIT;
+  return;
+}
+
+ChecksumCrc32 crc32_checksum(const void *data, uint32_t len) {
+  Crc32 crc32 = crc32_new();
+  crc32_process(data, len, &crc32);
+  return crc32.buf;
+}

crates/crc/src/c/crc32.h

@@ -0,0 +1,21 @@
+#ifndef CRC32_h
+#define CRC32_h
+#include <stddef.h>
+#include <stdint.h>
+
+// it needs to be declared but not implemented, otherwise, multiple definitions
+// will occur
+extern const uint32_t CRC32_INIT;
+extern const uint32_t CRC32_TABLE[256];
+
+typedef uint32_t ChecksumCrc32;
+
+typedef struct Crc32 {
+  ChecksumCrc32 buf;
+} Crc32;
+
+Crc32 crc32_new();
+void crc32_process(const char *data, size_t len, Crc32 *crc32);
+
+ChecksumCrc32 crc32_checksum(const void *data, uint32_t len);
+#endif

crates/crc/src/c/test/test.c

@@ -0,0 +1,15 @@
+#include "../crc32.h"
+#include <assert.h>
+#include <stdio.h>
+
+const char CHECK_DATA[9] = "123456789";
+
+int main() {
+
+  ChecksumCrc32 c = crc32_checksum(CHECK_DATA, 9);
+  printf("checksum: of \"%s\": 0x%x\n", CHECK_DATA + '\0', c);
+  assert(crc32_checksum(CHECK_DATA, 9) == 0xCBF43926);
+  printf("Success");
+
+  return 0;
+}

crates/crc/src/rs/ffi/crc32.rs

@@ -0,0 +1,58 @@
+use core::ffi::c_void;
+
+use crate::{Crc, ffi::ref_to_voidptr};
+
+pub type ChecksumCrc32 = u32; // uint32_t in C
+
+#[link(name = "crc", kind = "static")]
+unsafe extern "C" {
+    fn crc32_new() -> Crc32;
+    fn crc32_process(data: *const c_void, len: u32, crc32: *mut Crc32);
+
+    fn crc32_checksum(data: *const c_void, len: u32) -> ChecksumCrc32;
+}
+
+#[repr(C)]
+pub struct Crc32 {
+    buf: ChecksumCrc32,
+}
+
+impl Crc for Crc32 {
+    type Input = [u8];
+
+    type Checksum = ChecksumCrc32;
+
+    #[inline]
+    fn new() -> Self {
+        unsafe { crc32_new() }
+    }
+
+    #[inline]
+    fn process(&mut self, data: &Self::Input) {
+        unsafe { crc32_process(ref_to_voidptr(data), data.len() as u32, self as *mut Self) }
+    }
+
+    #[inline]
+    fn shift_reg(&mut self) -> &mut Self::Checksum {
+        &mut self.buf
+    }
+
+    #[inline]
+    fn checksum(data: &Self::Input) -> Self::Checksum {
+        unsafe { crc32_checksum(ref_to_voidptr(data), data.len() as u32) }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::CHECK_DATA;
+
+    use super::*;
+
+    #[test]
+    fn test_check() {
+        // see https://reveng.sourceforge.io/crc-catalogue/17plus.htm#crc.cat-bits.32 for the check
+        // value
+        assert_eq!(Crc32::checksum(&CHECK_DATA), 0xCBF43926);
+    }
+}

crates/crc/src/rs/ffi/mod.rs

@@ -0,0 +1,9 @@
+mod crc32;
+use core::ffi::c_void;
+
+pub use crc32::*;
+
+#[inline]
+pub(crate) fn ref_to_voidptr<T: ?Sized>(r: &T) -> *const c_void {
+    r as *const T as *const c_void
+}

crates/crc/src/rs/lib.rs

@@ -9,12 +9,14 @@
 
 #![cfg_attr(not(test), no_std)]
 
+/// CRCs from this module are implemented in C instead of Rust
+pub mod ffi;
+
 mod crc_32;
+pub use crc_32::*;
 
 pub const CHECK_DATA: [u8; 9] = *b"123456789";
 
-pub use crc_32::*;
-
 pub trait Crc: Sized {
     type Input: ?Sized;
     type Checksum: Eq + Default + Copy;