Changing IMkvReadableWriter to IMkvWriteEOFReader

Changing the IMkvReadableWriter interface to IMkvWriteEOFReader.
Also changing the default implementation.

Change-Id: Id37ffd7ef0af2ff7a392fb4fb0b1b134664ab20f

mkvwriteeofreader.cpp

@@ -0,0 +1,146 @@
+// Copyright (c) 2013 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 "mkvwriteeofreader.hpp"
+
+#ifdef _MSC_VER
+#include <share.h>  // for _SH_DENYWR
+#endif
+
+#include <cstdio>
+#include <new>
+
+namespace mkvmuxer {
+
+MkvWriteEOFReader::MkvWriteEOFReader() : file_(NULL),
+                                             writes_allowed_(true) {
+}
+
+MkvWriteEOFReader::~MkvWriteEOFReader() {
+  Close();
+}
+
+int32 MkvWriteEOFReader::Write(const void* buffer, uint32 length) {
+  if (file_ == NULL || !writes_allowed_)
+    return -1;
+
+  if (length == 0)
+    return 0;
+
+  if (buffer == NULL)
+    return -1;
+
+  const size_t bytes_written = fwrite(buffer, 1, length, file_);
+
+  return (bytes_written == length) ? 0 : -1;
+}
+
+bool MkvWriteEOFReader::Open(const char* filename, bool create_temp_file) {
+  if (filename == NULL && !create_temp_file)
+    return false;
+
+  if (file_ != NULL)
+    return false;
+
+#ifdef _MSC_VER
+  file_ = create_temp_file ? tmpfile() : _fsopen(filename, "wb+", _SH_DENYWR);
+#else
+  file_ = create_temp_file ? tmpfile() : fopen(filename, "wb+");
+#endif
+  if (file_ == NULL)
+    return false;
+  return true;
+}
+
+void MkvWriteEOFReader::Close() {
+  if (file_ != NULL) {
+    fclose(file_);
+    file_ = NULL;
+  }
+}
+
+int64 MkvWriteEOFReader::Position() const {
+  if (file_ == NULL)
+    return 0;
+
+#ifdef _MSC_VER
+    return _ftelli64(file_);
+#else
+    return ftell(file_);
+#endif
+}
+
+int32 MkvWriteEOFReader::Position(int64 position) {
+  if (file_ == NULL)
+    return -1;
+
+#ifdef _MSC_VER
+    return _fseeki64(file_, position, SEEK_SET);
+#else
+    return fseek(file_, position, SEEK_SET);
+#endif
+}
+
+bool MkvWriteEOFReader::Seekable() const {
+  return true;
+}
+
+void MkvWriteEOFReader::ElementStartNotify(uint64, int64) {
+}
+
+int MkvWriteEOFReader::Read(int64 offset, int32 len, uint8* buffer) {
+  if (file_ == NULL)
+    return -1;
+
+  if (offset < 0)
+    return -1;
+
+  if (len < 0)
+    return -1;
+
+  if (writes_allowed_)
+    writes_allowed_ = false;
+
+  if (len == 0)
+    return 0;
+
+  fflush(file_);
+
+#ifdef _MSC_VER
+  int64 pos = _ftelli64(file_);
+#else
+  int64 pos = ftell(file_);
+#endif
+
+#ifdef WIN32
+  int status = _fseeki64(file_, offset, SEEK_SET);
+
+  if (status)
+    return -1;  //error
+#else
+  fseek(file_, offset, SEEK_SET);
+#endif
+
+  const size_t size = fread(buffer, 1, len, file_);
+
+#ifdef WIN32
+  status = _fseeki64(file_, pos, SEEK_SET);
+
+  if (status)
+    return -1;  //error
+#else
+  fseek(file_, pos, SEEK_SET);
+#endif
+
+  if (size < static_cast<size_t>(len))
+    return -1;  //error
+
+  return 0;  //success
+}
+
+}  // namespace mkvmuxer