shaka-packager/packager/media/file/memory_file.cc

125 lines
2.6 KiB
C++

// Copyright 2015 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#include "packager/media/file/memory_file.h"
#include <string.h> // for memcpy
#include <map>
#include "packager/base/logging.h"
#include "packager/base/memory/scoped_ptr.h"
namespace edash_packager {
namespace media {
namespace {
// A helper filesystem object. This holds the data for the memory files.
class FileSystem {
public:
~FileSystem() {}
static FileSystem* Instance() {
if (!g_file_system_)
g_file_system_.reset(new FileSystem());
return g_file_system_.get();
}
std::vector<uint8_t>* GetFile(const std::string& file_name) {
return &files_[file_name];
}
void Delete(const std::string& file_name) { files_.erase(file_name); }
void DeleteAll() { files_.clear(); }
private:
FileSystem() {}
static scoped_ptr<FileSystem> g_file_system_;
std::map<std::string, std::vector<uint8_t> > files_;
DISALLOW_COPY_AND_ASSIGN(FileSystem);
};
scoped_ptr<FileSystem> FileSystem::g_file_system_;
} // namespace
MemoryFile::MemoryFile(const std::string& file_name)
: File(file_name),
file_(FileSystem::Instance()->GetFile(file_name)),
position_(0) {}
MemoryFile::~MemoryFile() {}
bool MemoryFile::Close() {
delete this;
return true;
}
int64_t MemoryFile::Read(void* buffer, uint64_t length) {
const uint64_t size = Size();
DCHECK_LE(position_, size);
if (position_ >= size)
return 0;
const uint64_t bytes_to_read = std::min(length, size - position_);
memcpy(buffer, &(*file_)[position_], bytes_to_read);
position_ += bytes_to_read;
return bytes_to_read;
}
int64_t MemoryFile::Write(const void* buffer, uint64_t length) {
const uint64_t size = Size();
if (size < position_ + length) {
file_->resize(position_ + length);
}
memcpy(&(*file_)[position_], buffer, length);
position_ += length;
return length;
}
int64_t MemoryFile::Size() {
return file_->size();
}
bool MemoryFile::Flush() {
return true;
}
bool MemoryFile::Seek(uint64_t position) {
if (Size() < static_cast<int64_t>(position))
return false;
position_ = position;
return true;
}
bool MemoryFile::Tell(uint64_t* position) {
*position = position_;
return true;
}
bool MemoryFile::Open() {
position_ = 0;
return true;
}
void MemoryFile::DeleteAll() {
FileSystem::Instance()->DeleteAll();
}
void MemoryFile::Delete(const std::string& file_name) {
FileSystem::Instance()->Delete(file_name);
}
} // namespace media
} // namespace edash_packager