Add brotly as compression algorithm and make it optional, as well as …

…zstd due to binary file size

.gitmodules

@@ -10,3 +10,6 @@
 [submodule "lib/zlib"]
 	path = lib/zlib
 	url = https://github.com/kripton/zlib.git
+[submodule "lib/brotli"]
+	path = lib/brotli
+	url = https://github.com/kripton/brotli.git

src/CMakeLists.txt

@@ -10,11 +10,16 @@ project(rp2040-compressiontest)
 ## Init the pico-sdk. Will instruct the user what to do if deps are missing
 pico_sdk_init()
 
+## Needed so we can fit all compression algos into the Picos flash
+## See below. However, needs to be set here in order to be effective
+add_compile_options(-Os)
+
 ## Include the CMakeLists-files of (non-pico-sdk)-libraries we will be using
 include(../lib/heatshrink/CMakeLists.txt)
 include(../lib/zlib/interfaceLibForPicoSDK.cmake)
 include(../lib/zstd/interfaceLibForPicoSDK.cmake)
 include(../lib/snappy/interfaceLibForPicoSDK.cmake)
+include(../lib/brotli/interfaceLibForPicoSDK.cmake)
 
 ## Add our own C/C++ files here
 ## Sorted alphabetically
@@ -24,9 +29,23 @@ add_executable(${CMAKE_PROJECT_NAME}
     algo-zlib.c
     algo-zstd.c
     algo-snappy.c
+    algo-brotli.c
     main.c
 )
 
+## Unfortunately, including all algortihms would result in a binary file
+## too large for the Pico board (~2.7MB vs. 2MB available)
+## We could try -Os but that contradicts our benchmarking effort ... UPDATE:
+## just trying it revealed that the code is not that much slower.
+## Using -flto broke the build :/
+## This is why you can either exclude ZSTD OR BROTLI, which both add a
+## remarkable amount to the size of the UF2 file.
+## When using -Os (see above), all algos just fit
+target_compile_definitions(${CMAKE_PROJECT_NAME}
+    PUBLIC HAVE_ALGO_ZSTD=1
+    PUBLIC HAVE_ALGO_BROTLI=1
+)
+
 ## Config for the heatshrink library
 target_compile_definitions(${CMAKE_PROJECT_NAME}
     PUBLIC HEATSHRINK_DYNAMIC_ALLOC=0
@@ -54,6 +73,7 @@ target_link_libraries(${CMAKE_PROJECT_NAME}
     zlib
     zstd
     snappy
+    brotli
 )
 
 ## enable usb output, disable uart output

src/algo-brotli.c

@@ -0,0 +1,18 @@
+#include "algo-zlib.h"
+
+#include "../lib/brotli/c/include/brotli/encode.h"
+#include "../lib/brotli/c/include/brotli/decode.h"
+
+void brotli_init()
+{
+}
+
+void brotli_compress(uint8_t *input, size_t insize, uint8_t *output, size_t *outsize)
+{
+    BrotliEncoderCompress(1, 10, BROTLI_DEFAULT_MODE, insize, input, outsize, output);
+}
+
+void brotli_uncompress(uint8_t *input, size_t insize, uint8_t *output, size_t *outsize)
+{
+    BrotliDecoderDecompress(insize, input, outsize, output);
+}

src/algo-brotli.h

@@ -0,0 +1,10 @@
+#ifndef __ALGO_BROTLI_H__
+#define __ALGO_BROTLI_H__
+
+#include "pico/stdlib.h"
+
+void brotli_init();
+void brotli_compress(uint8_t* input, size_t insize, uint8_t* output, size_t* outsize);
+void brotli_uncompress(uint8_t* input, size_t insize, uint8_t* output, size_t* outsize);
+
+#endif // __ALGO_BROTLI_H__

src/main.c

@@ -17,8 +17,13 @@
 
 #include "algo-heatshrink.h"
 #include "algo-zlib.h"
+#if HAVE_ALGO_ZSTD
 #include "algo-zstd.h"
+#endif
 #include "algo-snappy.h"
+#if HAVE_ALGO_BROTLI
+#include "algo-brotli.h"
+#endif
 
 
 // TEST VECTORS
@@ -54,8 +59,13 @@ struct algo {
 enum {
     ALGO_HEATSHRINK,
     ALGO_ZLIB,
+#if HAVE_ALGO_ZSTD
     ALGO_ZSTD,
+#endif
     ALGO_SNAPPY,
+#if HAVE_ALGO_BROTLI
+    ALGO_BROTLI,
+#endif
     // Add more HERE
     ALGO_NUM_TOTAL
 };
@@ -179,34 +189,40 @@ int main() {
     printf("Initializing compression algorithms ... ");
     start_time = time_us_32();
 
-    // Algo 0: heatshrink
     sprintf(algos[ALGO_HEATSHRINK].name, "HEATSHRINK");
     algos[ALGO_HEATSHRINK].init = heatshrink_init;
     algos[ALGO_HEATSHRINK].compress = heatshrink_compress;
     algos[ALGO_HEATSHRINK].uncompress = heatshrink_uncompress;
     algos[ALGO_HEATSHRINK].init();
 
-    // Algo 1: zlib
     sprintf(algos[ALGO_ZLIB].name, "ZLIB");
     algos[ALGO_ZLIB].init = zlib_init;
     algos[ALGO_ZLIB].compress = zlib_compress;
     algos[ALGO_ZLIB].uncompress = zlib_uncompress;
     algos[ALGO_ZLIB].init();
 
-    // Algo 2: zstd
+#if HAVE_ALGO_ZSTD
     sprintf(algos[ALGO_ZSTD].name, "ZSTD");
     algos[ALGO_ZSTD].init = zstd_init;
     algos[ALGO_ZSTD].compress = zstd_compress;
     algos[ALGO_ZSTD].uncompress = zstd_uncompress;
     algos[ALGO_ZSTD].init();
+#endif
 
-    // Algo 2: snappy
     sprintf(algos[ALGO_SNAPPY].name, "SNAPPY");
     algos[ALGO_SNAPPY].init = mysnappy_init;
     algos[ALGO_SNAPPY].compress = mysnappy_compress;
     algos[ALGO_SNAPPY].uncompress = mysnappy_uncompress;
     algos[ALGO_SNAPPY].init();
 
+#if HAVE_ALGO_BROTLI
+    sprintf(algos[ALGO_BROTLI].name, "BROTLI");
+    algos[ALGO_BROTLI].init = brotli_init;
+    algos[ALGO_BROTLI].compress = brotli_compress;
+    algos[ALGO_BROTLI].uncompress = brotli_uncompress;
+    algos[ALGO_BROTLI].init();
+#endif
+
     finish_time = time_us_32();
     elapsed_time = finish_time - start_time;
     printf("%luµs\n", elapsed_time);