Compressing .pak resources with new option: "type=GZIPPABLE_BINDATA"

ui/base/resource/resource_bundle.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/base/resource/resource_bundle.h"
 
 #include <stdint.h>
 
 #include <limits>
 #include <utility>
 #include <vector>
 
 #include "base/big_endian.h"
 #include "base/command_line.h"
 #include "base/files/file.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted_memory.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/stl_util.h"
 #include "base/strings/string_piece.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/synchronization/lock.h"
+#include "base/sys_byteorder.h"
 #include "build/build_config.h"
 #include "skia/ext/image_operations.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColor.h"
+#include "third_party/zlib/zlib.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/layout.h"
 #include "ui/base/material_design/material_design_controller.h"
 #include "ui/base/resource/data_pack.h"
 #include "ui/base/ui_base_paths.h"
 #include "ui/base/ui_base_switches.h"
 #include "ui/base/ui_features.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/codec/jpeg_codec.h"
@@ skipping 65 matching lines @@
 #endif  // OS_WIN
 }
 
 SkBitmap CreateEmptyBitmap() {
   SkBitmap bitmap;
   bitmap.allocN32Pixels(32, 32);
   bitmap.eraseARGB(255, 255, 255, 0);
   return bitmap;
 }
 
+// Decodes given gzip input via zlib.
+base::RefCountedBytes* DecodeGzipData(const unsigned char* input_buffer,
+                                      size_t input_size) {
+  z_stream inflateStream;
+  memset(&inflateStream, 0, sizeof(inflateStream));
+  inflateStream.zalloc = Z_NULL;
+  inflateStream.zfree = Z_NULL;
+  inflateStream.opaque = Z_NULL;
+
+  inflateStream.avail_in = input_size;
+  inflateStream.next_in = const_cast<Bytef*>(input_buffer);
+
+  CHECK(input_size >= 4);
+  // Size of output comes from footer of gzip file format, found as the last 4
+  // bytes in the compressed file, which are stored little endian.
+  inflateStream.avail_out = base::ByteSwapToLE32(
+      *reinterpret_cast<const uint32_t*>(&input_buffer[input_size - 4]));
+
+  std::vector<unsigned char> output(inflateStream.avail_out);
+  inflateStream.next_out = reinterpret_cast<Bytef*>(&output[0]);
+
+  CHECK(inflateInit2(&inflateStream, 16) == Z_OK);
+  CHECK(inflate(&inflateStream, Z_FINISH) == Z_STREAM_END);
+  CHECK(inflateEnd(&inflateStream) == Z_OK);
+
+  // Cannot use TakeVector since it puts the RefCounted* into a scoped_refptr,
+  // and callers of this function return a raw pointer (not a scoped_refptr), so
+  // the memory will be deallocated upon exit of the calling function.
+  base::RefCountedBytes* returnVal = new base::RefCountedBytes();
+  returnVal->data().swap(output);
+  return returnVal;
+}
+
 }  // namespace
 
 // An ImageSkiaSource that loads bitmaps for the requested scale factor from
 // ResourceBundle on demand for a given |resource_id|. If the bitmap for the
 // requested scale factor does not exist, it will return the 1x bitmap scaled
 // by the scale factor. This may lead to broken UI if the correct size of the
 // scaled image is not exactly |scale_factor| * the size of the 1x resource.
 // When --highlight-missing-scaled-resources flag is specified, scaled 1x images
 // are higlighted by blending them with red.
 class ResourceBundle::ResourceBundleImageSource : public gfx::ImageSkiaSource {
@@ skipping 322 matching lines @@
 
 base::RefCountedMemory* ResourceBundle::LoadDataResourceBytesForScale(
     int resource_id,
     ScaleFactor scale_factor) const {
   base::RefCountedMemory* bytes = NULL;
   if (delegate_)
     bytes = delegate_->LoadDataResourceBytes(resource_id, scale_factor);
 
   if (!bytes) {
     base::StringPiece data =
-        GetRawDataResourceForScale(resource_id, scale_factor);
+        GetRawDataResourceForScaleImpl(resource_id, scale_factor);
     if (!data.empty()) {
-      bytes = new base::RefCountedStaticMemory(data.data(), data.length());
+      if (data.starts_with(CUSTOM_GZIP_HEADER)) {
+        // Jump past special identification byte prepended to header
+        const unsigned char* gzip_start =
+            reinterpret_cast<const unsigned char*>(data.data()) + 1;
+        bytes = DecodeGzipData(gzip_start, data.length() - 1);
+      } else {
+        bytes = new base::RefCountedStaticMemory(data.data(), data.length());
+      }
     }
   }
 
   return bytes;
 }
 
 base::StringPiece ResourceBundle::GetRawDataResource(int resource_id) const {
   return GetRawDataResourceForScale(resource_id, ui::SCALE_FACTOR_NONE);
 }
 
 base::StringPiece ResourceBundle::GetRawDataResourceForScale(
     int resource_id,
     ScaleFactor scale_factor) const {
-  base::StringPiece data;
-  if (delegate_ &&
-      delegate_->GetRawDataResource(resource_id, scale_factor, &data))
-    return data;
+  base::StringPiece data =
+      GetRawDataResourceForScaleImpl(resource_id, scale_factor);
 
-  if (scale_factor != ui::SCALE_FACTOR_100P) {
-    for (size_t i = 0; i < data_packs_.size(); i++) {
-      if (data_packs_[i]->GetScaleFactor() == scale_factor &&
-          data_packs_[i]->GetStringPiece(static_cast<uint16_t>(resource_id),
-                                         &data))
-        return data;
-    }
-  }
+  // Do not allow this function to retrieve gzip compressed resources.
+  CHECK(!data.starts_with(CUSTOM_GZIP_HEADER));
 
-  for (size_t i = 0; i < data_packs_.size(); i++) {
-    if ((data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_100P ||
-         data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_200P ||
-         data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_300P ||
-         data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_NONE) &&
-        data_packs_[i]->GetStringPiece(static_cast<uint16_t>(resource_id),
-                                       &data))
-      return data;
-  }
-
-  return base::StringPiece();
+  return data;
 }
 
 base::string16 ResourceBundle::GetLocalizedString(int message_id) {
   base::string16 string;
   if (delegate_ && delegate_->GetLocalizedString(message_id, &string))
     return string;
 
   // Ensure that ReloadLocaleResources() doesn't drop the resources while
   // we're using them.
   base::AutoLock lock_scope(*locale_resources_data_lock_);
@@ skipping 332 matching lines @@
       data_handle_100_percent &&
       LoadBitmap(*data_handle_100_percent, resource_id, bitmap,
                  fell_back_to_1x)) {
     *fell_back_to_1x = true;
     return true;
   }
 
   return false;
 }
 
+base::StringPiece ResourceBundle::GetRawDataResourceForScaleImpl(
+    int resource_id,
+    ScaleFactor scale_factor) const {
+  base::StringPiece data;
+  if (delegate_ &&
+      delegate_->GetRawDataResource(resource_id, scale_factor, &data))
+    return data;
+
+  if (scale_factor != ui::SCALE_FACTOR_100P) {
+    for (size_t i = 0; i < data_packs_.size(); i++) {
+      if (data_packs_[i]->GetScaleFactor() == scale_factor &&
+          data_packs_[i]->GetStringPiece(static_cast<uint16_t>(resource_id),
+                                         &data))
+        return data;
+    }
+  }
+
+  for (size_t i = 0; i < data_packs_.size(); i++) {
+    if ((data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_100P ||
+         data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_200P ||
+         data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_300P ||
+         data_packs_[i]->GetScaleFactor() == ui::SCALE_FACTOR_NONE) &&
+        data_packs_[i]->GetStringPiece(static_cast<uint16_t>(resource_id),
+                                       &data))
+      return data;
+  }
+
+  return base::StringPiece();
+}
+
 gfx::Image& ResourceBundle::GetEmptyImage() {
   base::AutoLock lock(*images_and_fonts_lock_);
 
   if (empty_image_.IsEmpty()) {
     // The placeholder bitmap is bright red so people notice the problem.
     SkBitmap bitmap = CreateEmptyBitmap();
     empty_image_ = gfx::Image::CreateFrom1xBitmap(bitmap);
   }
   return empty_image_;
 }
@@ skipping 36 matching lines @@
 // static
 bool ResourceBundle::DecodePNG(const unsigned char* buf,
                                size_t size,
                                SkBitmap* bitmap,
                                bool* fell_back_to_1x) {
   *fell_back_to_1x = PNGContainsFallbackMarker(buf, size);
   return gfx::PNGCodec::Decode(buf, size, bitmap);
 }
 
 }  // namespace ui