Initial release

thirdparty/libwebm/webm_parser/include/webm/buffer_reader.h

@@ -0,0 +1,138 @@
+// 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.
+#ifndef INCLUDE_WEBM_BUFFER_READER_H_
+#define INCLUDE_WEBM_BUFFER_READER_H_
+
+#include <cstddef>
+#include <cstdint>
+#include <initializer_list>
+#include <vector>
+
+#include "./reader.h"
+#include "./status.h"
+
+/**
+ \file
+ A `Reader` implementation that reads from a `std::vector<std::uint8_t>`.
+ */
+
+namespace webm {
+
+/**
+ \addtogroup PUBLIC_API
+ @{
+ */
+
+/**
+ A simple reader that reads data from a buffer of bytes.
+ */
+class BufferReader : public Reader {
+ public:
+  /**
+   Constructs a new, empty reader.
+   */
+  BufferReader() = default;
+
+  /**
+   Constructs a new reader by copying the provided reader into the new reader.
+
+   \param other The source reader to copy.
+   */
+  BufferReader(const BufferReader& other) = default;
+
+  /**
+   Copies the provided reader into this reader.
+
+   \param other The source reader to copy. May be equal to `*this`, in which
+   case this is a no-op.
+   \return `*this`.
+   */
+  BufferReader& operator=(const BufferReader& other) = default;
+
+  /**
+   Constructs a new reader by moving the provided reader into the new reader.
+
+   \param other The source reader to move. After moving, it will be reset to an
+   empty stream.
+   */
+  BufferReader(BufferReader&&);
+
+  /**
+   Moves the provided reader into this reader.
+
+   \param other The source reader to move. After moving, it will be reset to an
+   empty stream. May be equal to `*this`, in which case this is a no-op.
+   \return `*this`.
+   */
+  BufferReader& operator=(BufferReader&&);
+
+  /**
+   Creates a new `BufferReader` populated with the provided bytes.
+
+   \param bytes Bytes that are assigned to the internal buffer and used as the
+   source which is read from.
+   */
+  BufferReader(std::initializer_list<std::uint8_t> bytes);
+
+  /**
+   Creates a new `BufferReader` populated with the provided data.
+
+   \param vector A vector of bytes that is copied to the internal buffer and
+   used as the source which is read from.
+   */
+  explicit BufferReader(const std::vector<std::uint8_t>& vector);
+
+  /**
+   Creates a new `BufferReader` populated with the provided data.
+
+   \param vector A vector of bytes that is moved to the internal buffer and used
+   as the source which is read from.
+   */
+  explicit BufferReader(std::vector<std::uint8_t>&& vector);
+
+  /**
+   Resets the reader to read from the given list of bytes, starting at the
+   beginning.
+
+   This makes `reader = {1, 2, 3};` effectively equivalent to `reader =
+   BufferReader({1, 2, 3});`.
+
+   \param bytes Bytes that are assigned to the internal buffer and used as the
+   source which is read from.
+   \return `*this`.
+   */
+  BufferReader& operator=(std::initializer_list<std::uint8_t> bytes);
+
+  Status Read(std::size_t num_to_read, std::uint8_t* buffer,
+              std::uint64_t* num_actually_read) override;
+
+  Status Skip(std::uint64_t num_to_skip,
+              std::uint64_t* num_actually_skipped) override;
+
+  std::uint64_t Position() const override;
+
+  /**
+   Gets the total size of the buffer.
+   */
+  std::size_t size() const { return data_.size(); }
+
+ private:
+  // Stores the byte buffer from which data is read.
+  std::vector<std::uint8_t> data_;
+
+  // The position of the reader in the byte buffer.
+  std::size_t pos_ = 0;
+};
+
+/**
+ @}
+ */
+
+}  // namespace webm
+
+#endif  // INCLUDE_WEBM_BUFFER_READER_H_