1 // Copyright (c) 2016 The WebM project authors. All Rights Reserved. 2 // 3 // Use of this source code is governed by a BSD-style license 4 // that can be found in the LICENSE file in the root of the source 5 // tree. An additional intellectual property rights grant can be found 6 // in the file PATENTS. All contributing project authors may 7 // be found in the AUTHORS file in the root of the source tree. 8 #include "src/skip_parser.h" 9 10 #include <cassert> 11 #include <cstdint> 12 13 #include "webm/element.h" 14 #include "webm/reader.h" 15 #include "webm/status.h" 16 17 namespace webm { 18 Init(const ElementMetadata & metadata,std::uint64_t max_size)19Status SkipParser::Init(const ElementMetadata& metadata, 20 std::uint64_t max_size) { 21 assert(metadata.size == kUnknownElementSize || metadata.size <= max_size); 22 23 if (metadata.size == kUnknownElementSize) { 24 return Status(Status::kInvalidElementSize); 25 } 26 27 num_bytes_remaining_ = metadata.size; 28 29 return Status(Status::kOkCompleted); 30 } 31 Feed(Callback * callback,Reader * reader,std::uint64_t * num_bytes_read)32Status SkipParser::Feed(Callback* callback, Reader* reader, 33 std::uint64_t* num_bytes_read) { 34 assert(callback != nullptr); 35 assert(reader != nullptr); 36 assert(num_bytes_read != nullptr); 37 38 *num_bytes_read = 0; 39 40 if (num_bytes_remaining_ == 0) { 41 return Status(Status::kOkCompleted); 42 } 43 44 Status status; 45 do { 46 std::uint64_t local_num_bytes_read = 0; 47 status = reader->Skip(num_bytes_remaining_, &local_num_bytes_read); 48 assert((status.completed_ok() && 49 local_num_bytes_read == num_bytes_remaining_) || 50 (status.ok() && local_num_bytes_read < num_bytes_remaining_) || 51 (!status.ok() && local_num_bytes_read == 0)); 52 *num_bytes_read += local_num_bytes_read; 53 num_bytes_remaining_ -= local_num_bytes_read; 54 } while (status.code == Status::kOkPartial); 55 56 return status; 57 } 58 59 } // namespace webm 60