libvpx: Pull from upstream

source/libvpx/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