| // 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 "webm/buffer_reader.h" |
| |
| #include <algorithm> |
| #include <cassert> |
| #include <cstddef> |
| #include <cstdint> |
| #include <initializer_list> |
| #include <utility> |
| #include <vector> |
| |
| #include "webm/status.h" |
| |
| namespace webm { |
| |
| BufferReader::BufferReader(std::initializer_list<std::uint8_t> bytes) |
| : data_(bytes) {} |
| |
| BufferReader::BufferReader(const std::vector<std::uint8_t>& vector) |
| : data_(vector) {} |
| |
| BufferReader::BufferReader(std::vector<std::uint8_t>&& vector) |
| : data_(std::move(vector)) {} |
| |
| BufferReader::BufferReader(BufferReader&& other) |
| : data_(std::move(other.data_)), pos_(other.pos_) { |
| other.pos_ = 0; |
| } |
| |
| BufferReader& BufferReader::operator=(BufferReader&& other) { |
| if (this != &other) { |
| data_ = std::move(other.data_); |
| pos_ = other.pos_; |
| other.pos_ = 0; |
| } |
| return *this; |
| } |
| |
| BufferReader& BufferReader::operator=( |
| std::initializer_list<std::uint8_t> bytes) { |
| data_ = std::vector<std::uint8_t>(bytes); |
| pos_ = 0; |
| return *this; |
| } |
| |
| Status BufferReader::Read(std::size_t num_to_read, std::uint8_t* buffer, |
| std::uint64_t* num_actually_read) { |
| assert(num_to_read > 0); |
| assert(buffer != nullptr); |
| assert(num_actually_read != nullptr); |
| |
| *num_actually_read = 0; |
| std::size_t expected = num_to_read; |
| |
| std::size_t num_remaining = data_.size() - pos_; |
| if (num_remaining == 0) { |
| return Status(Status::kEndOfFile); |
| } |
| |
| if (num_to_read > num_remaining) { |
| num_to_read = static_cast<std::size_t>(num_remaining); |
| } |
| |
| std::copy_n(data_.data() + pos_, num_to_read, buffer); |
| *num_actually_read = num_to_read; |
| pos_ += num_to_read; |
| |
| if (*num_actually_read != expected) { |
| return Status(Status::kOkPartial); |
| } |
| |
| return Status(Status::kOkCompleted); |
| } |
| |
| Status BufferReader::Skip(std::uint64_t num_to_skip, |
| std::uint64_t* num_actually_skipped) { |
| assert(num_to_skip > 0); |
| assert(num_actually_skipped != nullptr); |
| |
| *num_actually_skipped = 0; |
| std::uint64_t expected = num_to_skip; |
| |
| std::size_t num_remaining = data_.size() - pos_; |
| if (num_remaining == 0) { |
| return Status(Status::kEndOfFile); |
| } |
| |
| if (num_to_skip > num_remaining) { |
| num_to_skip = static_cast<std::uint64_t>(num_remaining); |
| } |
| |
| *num_actually_skipped = num_to_skip; |
| pos_ += num_to_skip; |
| |
| if (*num_actually_skipped != expected) { |
| return Status(Status::kOkPartial); |
| } |
| |
| return Status(Status::kOkCompleted); |
| } |
| |
| std::uint64_t BufferReader::Position() const { return pos_; } |
| |
| } // namespace webm |