Better caching

codecs/.gitignore

@@ -0,0 +1 @@
+!wasm_build

codecs/mozjpeg/dec/mozjpeg_dec.cpp

@@ -1,57 +0,0 @@
-#include <emscripten/bind.h>
-#include <emscripten/val.h>
-#include "config.h"
-#include "jpeglib.h"
-
-extern "C" {
-#include "cdjpeg.h"
-}
-
-using namespace emscripten;
-
-thread_local const val Uint8ClampedArray = val::global("Uint8ClampedArray");
-thread_local const val ImageData = val::global("ImageData");
-
-val decode(std::string image_in) {
-  uint8_t* image_buffer = (uint8_t*)image_in.c_str();
-
-  jpeg_decompress_struct cinfo;
-  jpeg_error_mgr jerr;
-  // Initialize the JPEG decompression object with default error handling.
-  cinfo.err = jpeg_std_error(&jerr);
-  jpeg_create_decompress(&cinfo);
-
-  jpeg_mem_src(&cinfo, image_buffer, image_in.length());
-  // Read file header, set default decompression parameters
-  jpeg_read_header(&cinfo, TRUE);
-  // Force RGBA decoding, even for grayscale images
-  cinfo.out_color_space = JCS_EXT_RGBA;
-  jpeg_start_decompress(&cinfo);
-
-  // Prepare output buffer
-  size_t output_size = cinfo.output_width * cinfo.output_height * 4;
-  std::vector<uint8_t> output_buffer(output_size);
-  auto stride = cinfo.output_width * 4;
-
-  // Process data
-  while (cinfo.output_scanline < cinfo.output_height) {
-    uint8_t* ptr = &output_buffer[stride * cinfo.output_scanline];
-    jpeg_read_scanlines(&cinfo, &ptr, 1);
-  }
-  jpeg_finish_decompress(&cinfo);
-
-  // Step 7: release JPEG compression object
-
-  auto data = Uint8ClampedArray.new_(typed_memory_view(output_size, &output_buffer[0]));
-  auto js_result = ImageData.new_(data, cinfo.output_width, cinfo.output_height);
-
-  // This is an important step since it will release a good deal of memory.
-  jpeg_destroy_decompress(&cinfo);
-
-  // And we're done!
-  return js_result;
-}
-
-EMSCRIPTEN_BINDINGS(my_module) {
-  function("decode", &decode);
-}

codecs/mozjpeg/flake.nix

@@ -25,7 +25,13 @@
           default = mozjpeg-squoosh;
           mozjpeg-squoosh = stdenv.mkDerivation {
             name = "mozjpeg-squoosh";
-            src = lib.cleanSource ./.;
+            # Only copy files that are actually relevant to avoid unnecessary
+            # cache invalidations.
+            src = runCommand "src" { } ''
+              mkdir $out
+              cp -r ${./.}/enc $out/
+              cp ${./.}/Makefile $out/
+            '';
             nativeBuildInputs = [
               emscripten
               mozjpeg
@@ -52,18 +58,18 @@
               pkg-config
             ];
             configurePhase = ''
-              # $HOME is required for Emscripten to work.
-              # See: https://nixos.org/manual/nixpkgs/stable/#emscripten
-            	export HOME=$TMPDIR
-            	autoreconf -ifv
-              emconfigure ./configure \
-                --disable-shared \
-                --without-turbojpeg \
-                --without-simd \
-                --without-arith-enc \
-                --without-arith-dec \
-                --with-build-date=squoosh \
-                --prefix=$out
+                # $HOME is required for Emscripten to work.
+                # See: https://nixos.org/manual/nixpkgs/stable/#emscripten
+              	export HOME=$TMPDIR
+              	autoreconf -ifv
+                emconfigure ./configure \
+                  --disable-shared \
+                  --without-turbojpeg \
+                  --without-simd \
+                  --without-arith-enc \
+                  --without-arith-dec \
+                  --with-build-date=squoosh \
+                  --prefix=$out
             '';
             buildPhase = ''
               export HOME=$TMPDIR
@@ -77,9 +83,9 @@
             dontFixup = true;
           };
           installScript = writeShellScriptBin "install.sh" ''
-            ${pkgs.coreutils}/bin/rm -rf build
-            ${pkgs.coreutils}/bin/mkdir -p build
-            ${pkgs.rsync}/bin/rsync --chmod=u+w -r ${mozjpeg-squoosh}/* build/
+            ${pkgs.coreutils}/bin/rm -rf wasm_build
+            ${pkgs.coreutils}/bin/mkdir -p wasm_build
+            ${pkgs.rsync}/bin/rsync --chmod=u+w -r ${mozjpeg-squoosh}/* wasm_build/
           '';
         };
         apps = {

codecs/mozjpeg/wasm_build/enc/mozjpeg_enc.cpp

@@ -0,0 +1,239 @@
+#include <emscripten/bind.h>
+#include <emscripten/val.h>
+#include <inttypes.h>
+#include <setjmp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "jconfig.h"
+#include "jpeglib.h"
+
+extern "C" {
+#include "cdjpeg.h"
+}
+
+using namespace emscripten;
+
+// MozJPEG doesn’t expose a numeric version, so I have to do some fun C macro
+// hackery to turn it into a string. More details here:
+// https://gcc.gnu.org/onlinedocs/cpp/Stringizing.html
+#define xstr(s) str(s)
+#define str(s) #s
+
+struct MozJpegOptions {
+  int quality;
+  bool baseline;
+  bool arithmetic;
+  bool progressive;
+  bool optimize_coding;
+  int smoothing;
+  int color_space;
+  int quant_table;
+  bool trellis_multipass;
+  bool trellis_opt_zero;
+  bool trellis_opt_table;
+  int trellis_loops;
+  bool auto_subsample;
+  int chroma_subsample;
+  bool separate_chroma_quality;
+  int chroma_quality;
+};
+
+int version() {
+  char buffer[] = xstr(MOZJPEG_VERSION);
+  int version = 0;
+  int last_index = 0;
+  for (int i = 0; i < strlen(buffer); i++) {
+    if (buffer[i] == '.') {
+      buffer[i] = '\0';
+      version = version << 8 | atoi(&buffer[last_index]);
+      buffer[i] = '.';
+      last_index = i + 1;
+    }
+  }
+  version = version << 8 | atoi(&buffer[last_index]);
+  return version;
+}
+
+thread_local const val Uint8Array = val::global("Uint8Array");
+
+val encode(std::string image_in, int image_width, int image_height, MozJpegOptions opts) {
+  uint8_t* image_buffer = (uint8_t*)image_in.c_str();
+
+  // The code below is basically the `write_JPEG_file` function from
+  // https://github.com/mozilla/mozjpeg/blob/master/example.c
+  // I just write to memory instead of a file.
+
+  /* Step 1: allocate and initialize JPEG compression object */
+
+  /* This struct contains the JPEG compression parameters and pointers to
+   * working space (which is allocated as needed by the JPEG library).
+   * It is possible to have several such structures, representing multiple
+   * compression/decompression processes, in existence at once.  We refer
+   * to any one struct (and its associated working data) as a "JPEG object".
+   */
+  jpeg_compress_struct cinfo;
+  /* This struct represents a JPEG error handler.  It is declared separately
+   * because applications often want to supply a specialized error handler
+   * (see the second half of this file for an example).  But here we just
+   * take the easy way out and use the standard error handler, which will
+   * print a message on stderr and call exit() if compression fails.
+   * Note that this struct must live as long as the main JPEG parameter
+   * struct, to avoid dangling-pointer problems.
+   */
+  jpeg_error_mgr jerr;
+  /* We have to set up the error handler first, in case the initialization
+   * step fails.  (Unlikely, but it could happen if you are out of memory.)
+   * This routine fills in the contents of struct jerr, and returns jerr's
+   * address which we place into the link field in cinfo.
+   */
+  cinfo.err = jpeg_std_error(&jerr);
+  /* Now we can initialize the JPEG compression object. */
+  jpeg_create_compress(&cinfo);
+
+  /* Step 2: specify data destination (eg, a file) */
+  /* Note: steps 2 and 3 can be done in either order. */
+
+  /* Here we use the library-supplied code to send compressed data to a
+   * stdio stream.  You can also write your own code to do something else.
+   * VERY IMPORTANT: use "b" option to fopen() if you are on a machine that
+   * requires it in order to write binary files.
+   */
+  // if ((outfile = fopen(filename, "wb")) == NULL) {
+  //   fprintf(stderr, "can't open %s\n", filename);
+  //   exit(1);
+  // }
+  uint8_t* output = nullptr;
+  unsigned long size = 0;
+  jpeg_mem_dest(&cinfo, &output, &size);
+
+  /* Step 3: set parameters for compression */
+
+  /* First we supply a description of the input image.
+   * Four fields of the cinfo struct must be filled in:
+   */
+  cinfo.image_width = image_width; /* image width and height, in pixels */
+  cinfo.image_height = image_height;
+  cinfo.input_components = 4;          /* # of color components per pixel */
+  cinfo.in_color_space = JCS_EXT_RGBA; /* colorspace of input image */
+  /* Now use the library's routine to set default compression parameters.
+   * (You must set at least cinfo.in_color_space before calling this,
+   * since the defaults depend on the source color space.)
+   */
+  jpeg_set_defaults(&cinfo);
+
+  jpeg_set_colorspace(&cinfo, (J_COLOR_SPACE)opts.color_space);
+
+  if (opts.quant_table != -1) {
+    jpeg_c_set_int_param(&cinfo, JINT_BASE_QUANT_TBL_IDX, opts.quant_table);
+  }
+
+  cinfo.optimize_coding = opts.optimize_coding;
+
+  if (opts.arithmetic) {
+    cinfo.arith_code = TRUE;
+    cinfo.optimize_coding = FALSE;
+  }
+
+  cinfo.smoothing_factor = opts.smoothing;
+
+  jpeg_c_set_bool_param(&cinfo, JBOOLEAN_USE_SCANS_IN_TRELLIS, opts.trellis_multipass);
+  jpeg_c_set_bool_param(&cinfo, JBOOLEAN_TRELLIS_EOB_OPT, opts.trellis_opt_zero);
+  jpeg_c_set_bool_param(&cinfo, JBOOLEAN_TRELLIS_Q_OPT, opts.trellis_opt_table);
+  jpeg_c_set_int_param(&cinfo, JINT_TRELLIS_NUM_LOOPS, opts.trellis_loops);
+  jpeg_c_set_int_param(&cinfo, JINT_DC_SCAN_OPT_MODE, 0);
+
+  // A little hacky to build a string for this, but it means we can use
+  // set_quality_ratings which does some useful heuristic stuff.
+  std::string quality_str = std::to_string(opts.quality);
+
+  if (opts.separate_chroma_quality && opts.color_space == JCS_YCbCr) {
+    quality_str += "," + std::to_string(opts.chroma_quality);
+  }
+
+  char const* pqual = quality_str.c_str();
+
+  set_quality_ratings(&cinfo, (char*)pqual, opts.baseline);
+
+  if (!opts.auto_subsample && opts.color_space == JCS_YCbCr) {
+    cinfo.comp_info[0].h_samp_factor = opts.chroma_subsample;
+    cinfo.comp_info[0].v_samp_factor = opts.chroma_subsample;
+
+    if (opts.chroma_subsample > 2) {
+      // Otherwise encoding fails.
+      jpeg_c_set_int_param(&cinfo, JINT_DC_SCAN_OPT_MODE, 1);
+    }
+  }
+
+  if (!opts.baseline && opts.progressive) {
+    jpeg_simple_progression(&cinfo);
+  } else {
+    cinfo.num_scans = 0;
+    cinfo.scan_info = NULL;
+  }
+  /* Step 4: Start compressor */
+
+  /* TRUE ensures that we will write a complete interchange-JPEG file.
+   * Pass TRUE unless you are very sure of what you're doing.
+   */
+  jpeg_start_compress(&cinfo, TRUE);
+
+  /* Step 5: while (scan lines remain to be written) */
+  /*           jpeg_write_scanlines(...); */
+
+  /* Here we use the library's state variable cinfo.next_scanline as the
+   * loop counter, so that we don't have to keep track ourselves.
+   * To keep things simple, we pass one scanline per call; you can pass
+   * more if you wish, though.
+   */
+  int row_stride = image_width * 4; /* JSAMPLEs per row in image_buffer */
+
+  while (cinfo.next_scanline < cinfo.image_height) {
+    /* jpeg_write_scanlines expects an array of pointers to scanlines.
+     * Here the array is only one element long, but you could pass
+     * more than one scanline at a time if that's more convenient.
+     */
+
+    JSAMPROW row_pointer =
+        &image_buffer[cinfo.next_scanline * row_stride]; /* pointer to JSAMPLE row[s] */
+    (void)jpeg_write_scanlines(&cinfo, &row_pointer, 1);
+  }
+
+  /* Step 6: Finish compression */
+
+  jpeg_finish_compress(&cinfo);
+
+  /* Step 7: release JPEG compression object */
+
+  auto js_result = Uint8Array.new_(typed_memory_view(size, output));
+
+  /* This is an important step since it will release a good deal of memory. */
+  jpeg_destroy_compress(&cinfo);
+  free(output);
+
+  /* And we're done! */
+  return js_result;
+}
+
+EMSCRIPTEN_BINDINGS(my_module) {
+  value_object<MozJpegOptions>("MozJpegOptions")
+      .field("quality", &MozJpegOptions::quality)
+      .field("baseline", &MozJpegOptions::baseline)
+      .field("arithmetic", &MozJpegOptions::arithmetic)
+      .field("progressive", &MozJpegOptions::progressive)
+      .field("optimize_coding", &MozJpegOptions::optimize_coding)
+      .field("smoothing", &MozJpegOptions::smoothing)
+      .field("color_space", &MozJpegOptions::color_space)
+      .field("quant_table", &MozJpegOptions::quant_table)
+      .field("trellis_multipass", &MozJpegOptions::trellis_multipass)
+      .field("trellis_opt_zero", &MozJpegOptions::trellis_opt_zero)
+      .field("trellis_opt_table", &MozJpegOptions::trellis_opt_table)
+      .field("trellis_loops", &MozJpegOptions::trellis_loops)
+      .field("chroma_subsample", &MozJpegOptions::chroma_subsample)
+      .field("auto_subsample", &MozJpegOptions::auto_subsample)
+      .field("separate_chroma_quality", &MozJpegOptions::separate_chroma_quality)
+      .field("chroma_quality", &MozJpegOptions::chroma_quality);
+
+  function("version", &version);
+  function("encode", &encode);
+}

codecs/mozjpeg/wasm_build/enc/mozjpeg_enc.d.ts

@@ -0,0 +1,37 @@
+export const enum MozJpegColorSpace {
+  GRAYSCALE = 1,
+  RGB,
+  YCbCr,
+}
+
+export interface EncodeOptions {
+  quality: number;
+  baseline: boolean;
+  arithmetic: boolean;
+  progressive: boolean;
+  optimize_coding: boolean;
+  smoothing: number;
+  color_space: MozJpegColorSpace;
+  quant_table: number;
+  trellis_multipass: boolean;
+  trellis_opt_zero: boolean;
+  trellis_opt_table: boolean;
+  trellis_loops: number;
+  auto_subsample: boolean;
+  chroma_subsample: number;
+  separate_chroma_quality: boolean;
+  chroma_quality: number;
+}
+
+export interface MozJPEGModule extends EmscriptenWasm.Module {
+  encode(
+    data: BufferSource,
+    width: number,
+    height: number,
+    options: EncodeOptions,
+  ): Uint8Array;
+}
+
+declare var moduleFactory: EmscriptenWasm.ModuleFactory<MozJPEGModule>;
+
+export default moduleFactory;

src/features/encoders/mozJPEG/shared/meta.ts

@@ -13,7 +13,7 @@
 import {
   EncodeOptions,
   MozJpegColorSpace,
-} from 'codecs/mozjpeg/build/enc/mozjpeg_enc';
+} from 'codecs/mozjpeg/wasm_build/enc/mozjpeg_enc';
 export { EncodeOptions, MozJpegColorSpace };
 
 export const label = 'MozJPEG';

src/features/encoders/mozJPEG/worker/mozjpegEncode.ts

@@ -12,7 +12,7 @@
  */
 import mozjpeg_enc, {
   MozJPEGModule,
-} from 'codecs/mozjpeg/build/enc/mozjpeg_enc';
+} from 'codecs/mozjpeg/wasm_build/enc/mozjpeg_enc';
 import { EncodeOptions } from '../shared/meta';
 import { initEmscriptenModule } from 'features/worker-utils';