[headless] Embed pak file into binary.

ui/base/resource/data_pack.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/data_pack.h"
 
 #include <errno.h>
 #include <utility>
 
 #include "base/files/file_util.h"
@@ skipping 50 matching lines @@
 };
 
 void LogDataPackError(LoadErrors error) {
   UMA_HISTOGRAM_ENUMERATION("DataPack.Load", error, LOAD_ERRORS_COUNT);
 }
 
 }  // namespace
 
 namespace ui {
 
+class DataPack::DataSource {

[sky, 2017/02/08 22:22:58]

Add description.

[altimin, 2017/02/09 00:13:51]

Done.

+ public:
+  virtual ~DataSource() {}
+
+  virtual size_t Length() const = 0;

[sky, 2017/02/08 22:22:58]

Please use GetLength and GetData.

[altimin, 2017/02/09 00:13:51]

Done.

+  virtual const uint8_t* Data() const = 0;
+};
+
+namespace {
+
+class MemoryMappedDataSource : public DataPack::DataSource {
+ public:
+  explicit MemoryMappedDataSource(std::unique_ptr<base::MemoryMappedFile> mmap)
+      : mmap_(std::move(mmap)) {}
+
+  ~MemoryMappedDataSource() override {}
+
+  size_t Length() const override { return mmap_->length(); }

[sky, 2017/02/08 22:22:58]

Generally we prefix overrides with the class the overrides come from, e.g.:

// DataPack::DataSource:

[altimin, 2017/02/09 00:13:51]

Done.

+
+  const uint8_t* Data() const override { return mmap_->data(); }
+
+ private:
+  std::unique_ptr<base::MemoryMappedFile> mmap_;
+
+  DISALLOW_COPY_AND_ASSIGN(MemoryMappedDataSource);
+};
+
+class BufferDataSource : public DataPack::DataSource {
+ public:
+  explicit BufferDataSource(base::StringPiece buffer) : buffer_(buffer) {}
+
+  ~BufferDataSource() override {}
+
+  size_t Length() const override { return buffer_.length(); }

[sky, 2017/02/08 22:22:58]

Same comment about adding where overrides come from here.

[altimin, 2017/02/09 00:13:52]

Done.

+
+  const uint8_t* Data() const override {
+    return reinterpret_cast<const uint8_t*>(buffer_.data());

[sky, 2017/02/08 22:22:58]

Can't this be a static_cast?

[altimin, 2017/02/09 00:13:52]

It's impossible to cast from const int8_t* to const uint8_t* with static_cast.

+  }
+
+ private:
+  base::StringPiece buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(BufferDataSource);
+};
+
+}  // namespace
+
 DataPack::DataPack(ui::ScaleFactor scale_factor)
     : resource_count_(0),
       text_encoding_type_(BINARY),
       scale_factor_(scale_factor) {
 }
 
 DataPack::~DataPack() {
 }
 
 bool DataPack::LoadFromPath(const base::FilePath& path) {
-  mmap_.reset(new base::MemoryMappedFile);
-  if (!mmap_->Initialize(path)) {
+  std::unique_ptr<base::MemoryMappedFile> mmap(new base::MemoryMappedFile);

[sky, 2017/02/08 22:22:58]

MakeUnique where using unique_ptr.

[altimin, 2017/02/09 00:13:52]

Done.

+  if (!mmap->Initialize(path)) {
     DLOG(ERROR) << "Failed to mmap datapack";
     LogDataPackError(INIT_FAILED);
-    mmap_.reset();
+    mmap.reset();
     return false;
   }
+  data_source_.reset(new MemoryMappedDataSource(std::move(mmap)));
   return LoadImpl();
 }
 
 bool DataPack::LoadFromFile(base::File file) {
   return LoadFromFileRegion(std::move(file),
                             base::MemoryMappedFile::Region::kWholeFile);
 }
 
 bool DataPack::LoadFromFileRegion(
     base::File file,
     const base::MemoryMappedFile::Region& region) {
-  mmap_.reset(new base::MemoryMappedFile);
-  if (!mmap_->Initialize(std::move(file), region)) {
+  std::unique_ptr<base::MemoryMappedFile> mmap(new base::MemoryMappedFile);
+  if (!mmap->Initialize(std::move(file), region)) {
     DLOG(ERROR) << "Failed to mmap datapack";
     LogDataPackError(INIT_FAILED_FROM_FILE);
-    mmap_.reset();
+    mmap.reset();
     return false;
   }
+  data_source_.reset(new MemoryMappedDataSource(std::move(mmap)));
+  return LoadImpl();
+}
+
+bool DataPack::LoadFromBuffer(base::StringPiece buffer) {
+  data_source_.reset(new BufferDataSource(buffer));
   return LoadImpl();
 }
 
 bool DataPack::LoadImpl() {
   // Sanity check the header of the file.
-  if (kHeaderLength > mmap_->length()) {
+  if (kHeaderLength > data_source_->Length()) {
     DLOG(ERROR) << "Data pack file corruption: incomplete file header.";
     LogDataPackError(HEADER_TRUNCATED);
-    mmap_.reset();
+    data_source_.reset();

[sky, 2017/02/08 22:22:58]

I think this code would be less fragile if you passed the
std::unique_ptr<DataSource> to this function and it's only set as a member if
you to the last branch.

[altimin, 2017/02/09 00:13:52]

Great suggestion, thanks!
Done.

     return false;
   }
 
   // Parse the header of the file.
   // First uint32_t: version; second: resource count;
-  const uint32_t* ptr = reinterpret_cast<const uint32_t*>(mmap_->data());
+  const uint32_t* ptr = reinterpret_cast<const uint32_t*>(data_source_->Data());
   uint32_t version = ptr[0];
   if (version != kFileFormatVersion) {
     LOG(ERROR) << "Bad data pack version: got " << version << ", expected "
                << kFileFormatVersion;
     LogDataPackError(BAD_VERSION);
-    mmap_.reset();
+    data_source_.reset();
     return false;
   }
   resource_count_ = ptr[1];
 
   // third: text encoding.
   const uint8_t* ptr_encoding = reinterpret_cast<const uint8_t*>(ptr + 2);
   text_encoding_type_ = static_cast<TextEncodingType>(*ptr_encoding);
   if (text_encoding_type_ != UTF8 && text_encoding_type_ != UTF16 &&
       text_encoding_type_ != BINARY) {
     LOG(ERROR) << "Bad data pack text encoding: got " << text_encoding_type_
                << ", expected between " << BINARY << " and " << UTF16;
     LogDataPackError(WRONG_ENCODING);
-    mmap_.reset();
+    data_source_.reset();
     return false;
   }
 
   // Sanity check the file.
   // 1) Check we have enough entries. There's an extra entry after the last item
   // which gives the length of the last item.
   if (kHeaderLength + (resource_count_ + 1) * sizeof(DataPackEntry) >
-      mmap_->length()) {
+      data_source_->Length()) {
     LOG(ERROR) << "Data pack file corruption: too short for number of "
                   "entries specified.";
     LogDataPackError(INDEX_TRUNCATED);
-    mmap_.reset();
+    data_source_.reset();
     return false;
   }
   // 2) Verify the entries are within the appropriate bounds. There's an extra
   // entry after the last item which gives us the length of the last item.
   for (size_t i = 0; i < resource_count_ + 1; ++i) {
     const DataPackEntry* entry = reinterpret_cast<const DataPackEntry*>(
-        mmap_->data() + kHeaderLength + (i * sizeof(DataPackEntry)));
-    if (entry->file_offset > mmap_->length()) {
+        data_source_->Data() + kHeaderLength + (i * sizeof(DataPackEntry)));
+    if (entry->file_offset > data_source_->Length()) {
       LOG(ERROR) << "Entry #" << i << " in data pack points off end of file. "
                  << "Was the file corrupted?";
       LogDataPackError(ENTRY_NOT_FOUND);
-      mmap_.reset();
+      data_source_.reset();
       return false;
     }
   }
 
   return true;
 }
 
 bool DataPack::HasResource(uint16_t resource_id) const {
-  return !!bsearch(&resource_id, mmap_->data() + kHeaderLength, resource_count_,
-                   sizeof(DataPackEntry), DataPackEntry::CompareById);
+  return !!bsearch(&resource_id, data_source_->Data() + kHeaderLength,
+                   resource_count_, sizeof(DataPackEntry),
+                   DataPackEntry::CompareById);
 }
 
 bool DataPack::GetStringPiece(uint16_t resource_id,
                               base::StringPiece* data) const {
   // It won't be hard to make this endian-agnostic, but it's not worth
   // bothering to do right now.
 #if defined(__BYTE_ORDER)
   // Linux check
   static_assert(__BYTE_ORDER == __LITTLE_ENDIAN,
                 "datapack assumes little endian");
 #elif defined(__BIG_ENDIAN__)
   // Mac check
   #error DataPack assumes little endian
 #endif
 
-  const DataPackEntry* target = reinterpret_cast<const DataPackEntry*>(
-      bsearch(&resource_id, mmap_->data() + kHeaderLength, resource_count_,
-              sizeof(DataPackEntry), DataPackEntry::CompareById));
+  const DataPackEntry* target = reinterpret_cast<const DataPackEntry*>(bsearch(
+      &resource_id, data_source_->Data() + kHeaderLength, resource_count_,
+      sizeof(DataPackEntry), DataPackEntry::CompareById));
   if (!target) {
     return false;
   }
 
   const DataPackEntry* next_entry = target + 1;
   // If the next entry points beyond the end of the file this data pack's entry
   // table is corrupt. Log an error and return false. See
   // http://crbug.com/371301.
-  if (next_entry->file_offset > mmap_->length()) {
-    size_t entry_index = target -
-        reinterpret_cast<const DataPackEntry*>(mmap_->data() + kHeaderLength);
+  if (next_entry->file_offset > data_source_->Length()) {
+    size_t entry_index = target - reinterpret_cast<const DataPackEntry*>(
+                                      data_source_->Data() + kHeaderLength);
     LOG(ERROR) << "Entry #" << entry_index << " in data pack points off end "
                << "of file. This should have been caught when loading. Was the "
                << "file modified?";
     return false;
   }
 
   size_t length = next_entry->file_offset - target->file_offset;
-  data->set(reinterpret_cast<const char*>(mmap_->data() + target->file_offset),
-            length);
+  data->set(
+      reinterpret_cast<const char*>(data_source_->Data() + target->file_offset),

[sky, 2017/02/08 22:22:58]

Can this be a static_cast?

[altimin, 2017/02/09 00:13:51]

See above.

+      length);
   return true;
 }
 
 base::RefCountedStaticMemory* DataPack::GetStaticMemory(
     uint16_t resource_id) const {
   base::StringPiece piece;
   if (!GetStringPiece(resource_id, &piece))
     return NULL;
 
   return new base::RefCountedStaticMemory(piece.data(), piece.length());
 }
 
 ResourceHandle::TextEncodingType DataPack::GetTextEncodingType() const {
   return text_encoding_type_;
 }
 
 ui::ScaleFactor DataPack::GetScaleFactor() const {
   return scale_factor_;
 }
 
 #if DCHECK_IS_ON()
 void DataPack::CheckForDuplicateResources(
     const ScopedVector<ResourceHandle>& packs) {
   for (size_t i = 0; i < resource_count_ + 1; ++i) {
     const DataPackEntry* entry = reinterpret_cast<const DataPackEntry*>(
-        mmap_->data() + kHeaderLength + (i * sizeof(DataPackEntry)));
+        data_source_->Data() + kHeaderLength + (i * sizeof(DataPackEntry)));
     const uint16_t resource_id = entry->resource_id;
     const float resource_scale = GetScaleForScaleFactor(scale_factor_);
     for (const ResourceHandle* handle : packs) {
       if (GetScaleForScaleFactor(handle->GetScaleFactor()) != resource_scale)
         continue;
       DCHECK(!handle->HasResource(resource_id)) << "Duplicate resource "
                                                 << resource_id << " with scale "
                                                 << resource_scale;
     }
   }
@@ skipping 85 matching lines @@
       return false;
     }
   }
 
   base::CloseFile(file);
 
   return true;
 }
 
 }  // namespace ui