webm_parser/src/void_parser.cc

// Copyright (c) 2016 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 "src/void_parser.h"

#include <cassert>
#include <cstdint>

#include "webm/callback.h"
#include "webm/element.h"
#include "webm/id.h"
#include "webm/reader.h"
#include "webm/status.h"

namespace webm {

Status VoidParser::Init(const ElementMetadata& metadata,
                        std::uint64_t max_size) {
  assert(metadata.size == kUnknownElementSize || metadata.size <= max_size);

  if (metadata.size == kUnknownElementSize) {
    return Status(Status::kInvalidElementSize);
  }

  metadata_ = metadata;
  bytes_remaining_ = metadata.size;

  return Status(Status::kOkCompleted);
}

Status VoidParser::Feed(Callback* callback, Reader* reader,
                        std::uint64_t* num_bytes_read) {
  assert(callback != nullptr);
  assert(reader != nullptr);
  assert(num_bytes_read != nullptr);

  const std::uint64_t original_bytes_remaining = bytes_remaining_;
  const Status status = callback->OnVoid(metadata_, reader, &bytes_remaining_);
  assert(bytes_remaining_ <= original_bytes_remaining);

  *num_bytes_read = original_bytes_remaining - bytes_remaining_;
  return status;
}

}  // namespace webm