ref: c3bf8375726cc844434440cbdbe36c3576329166
dir: /third_party/libwebm/mkvreader.cpp/
// Copyright (c) 2010 The WebM project authors. All Rights Reserved. // // Use of this source code is governed by a BSD-style license // that can be found in the LICENSE file in the root of the source // tree. An additional intellectual property rights grant can be found // in the file PATENTS. All contributing project authors may // be found in the AUTHORS file in the root of the source tree. #include "mkvreader.hpp" #include <cassert> namespace mkvparser { MkvReader::MkvReader() : m_file(NULL), reader_owns_file_(true) {} MkvReader::MkvReader(FILE* fp) : m_file(fp), reader_owns_file_(false) { GetFileSize(); } MkvReader::~MkvReader() { if (reader_owns_file_) Close(); m_file = NULL; } int MkvReader::Open(const char* fileName) { if (fileName == NULL) return -1; if (m_file) return -1; #ifdef _MSC_VER const errno_t e = fopen_s(&m_file, fileName, "rb"); if (e) return -1; // error #else m_file = fopen(fileName, "rb"); if (m_file == NULL) return -1; #endif return !GetFileSize(); } bool MkvReader::GetFileSize() { if (m_file == NULL) return false; #ifdef _MSC_VER int status = _fseeki64(m_file, 0L, SEEK_END); if (status) return false; // error m_length = _ftelli64(m_file); #else fseek(m_file, 0L, SEEK_END); m_length = ftell(m_file); #endif assert(m_length >= 0); if (m_length < 0) return false; #ifdef _MSC_VER status = _fseeki64(m_file, 0L, SEEK_SET); if (status) return false; // error #else fseek(m_file, 0L, SEEK_SET); #endif return true; } void MkvReader::Close() { if (m_file != NULL) { fclose(m_file); m_file = NULL; } } int MkvReader::Length(long long* total, long long* available) { if (m_file == NULL) return -1; if (total) *total = m_length; if (available) *available = m_length; return 0; } int MkvReader::Read(long long offset, long len, unsigned char* buffer) { if (m_file == NULL) return -1; if (offset < 0) return -1; if (len < 0) return -1; if (len == 0) return 0; if (offset >= m_length) return -1; #ifdef _MSC_VER const int status = _fseeki64(m_file, offset, SEEK_SET); if (status) return -1; // error #else fseek(m_file, offset, SEEK_SET); #endif const size_t size = fread(buffer, 1, len, m_file); if (size < size_t(len)) return -1; // error return 0; // success } } // end namespace mkvparser