60 lines
1.8 KiB
C++
60 lines
1.8 KiB
C++
// Copyright (c) 2016 The WebM project authors. All Rights Reserved.
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//
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// Use of this source code is governed by a BSD-style license
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// that can be found in the LICENSE file in the root of the source
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// tree. An additional intellectual property rights grant can be found
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// in the file PATENTS. All contributing project authors may
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// be found in the AUTHORS file in the root of the source tree.
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#include "src/skip_parser.h"
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#include <cassert>
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#include <cstdint>
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#include "webm/element.h"
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#include "webm/reader.h"
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#include "webm/status.h"
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namespace webm {
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Status SkipParser::Init(const ElementMetadata& metadata,
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std::uint64_t max_size) {
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assert(metadata.size == kUnknownElementSize || metadata.size <= max_size);
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if (metadata.size == kUnknownElementSize) {
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return Status(Status::kInvalidElementSize);
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}
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num_bytes_remaining_ = metadata.size;
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return Status(Status::kOkCompleted);
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}
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Status SkipParser::Feed(Callback* callback, Reader* reader,
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std::uint64_t* num_bytes_read) {
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assert(callback != nullptr);
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assert(reader != nullptr);
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assert(num_bytes_read != nullptr);
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*num_bytes_read = 0;
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if (num_bytes_remaining_ == 0) {
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return Status(Status::kOkCompleted);
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}
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Status status;
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do {
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std::uint64_t local_num_bytes_read = 0;
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status = reader->Skip(num_bytes_remaining_, &local_num_bytes_read);
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assert((status.completed_ok() &&
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local_num_bytes_read == num_bytes_remaining_) ||
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(status.ok() && local_num_bytes_read < num_bytes_remaining_) ||
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(!status.ok() && local_num_bytes_read == 0));
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*num_bytes_read += local_num_bytes_read;
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num_bytes_remaining_ -= local_num_bytes_read;
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} while (status.code == Status::kOkPartial);
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return status;
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}
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} // namespace webm
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