| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef QUICHE_SPDY_CORE_HPACK_HPACK_OUTPUT_STREAM_H_ |
| #define QUICHE_SPDY_CORE_HPACK_HPACK_OUTPUT_STREAM_H_ |
| |
| #include <cstdint> |
| #include <map> |
| #include <string> |
| |
| #include "absl/strings/string_view.h" |
| #include "common/platform/api/quiche_export.h" |
| #include "spdy/core/hpack/hpack_constants.h" |
| |
| // All section references below are to |
| // http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-08 |
| |
| namespace spdy { |
| |
| // An HpackOutputStream handles all the low-level details of encoding |
| // header fields. |
| class QUICHE_EXPORT_PRIVATE HpackOutputStream { |
| public: |
| HpackOutputStream(); |
| HpackOutputStream(const HpackOutputStream&) = delete; |
| HpackOutputStream& operator=(const HpackOutputStream&) = delete; |
| ~HpackOutputStream(); |
| |
| // Appends the lower |bit_size| bits of |bits| to the internal buffer. |
| // |
| // |bit_size| must be > 0 and <= 8. |bits| must not have any bits |
| // set other than the lower |bit_size| bits. |
| void AppendBits(uint8_t bits, size_t bit_size); |
| |
| // Simply forwards to AppendBits(prefix.bits, prefix.bit-size). |
| void AppendPrefix(HpackPrefix prefix); |
| |
| // Directly appends |buffer|. |
| void AppendBytes(absl::string_view buffer); |
| |
| // Appends the given integer using the representation described in |
| // 6.1. If the internal buffer ends on a byte boundary, the prefix |
| // length N is taken to be 8; otherwise, it is taken to be the |
| // number of bits to the next byte boundary. |
| // |
| // It is guaranteed that the internal buffer will end on a byte |
| // boundary after this function is called. |
| void AppendUint32(uint32_t I); |
| |
| // Return pointer to internal buffer. |bit_offset_| needs to be zero. |
| std::string* MutableString(); |
| |
| // Swaps the internal buffer with |output|, then resets state. |
| void TakeString(std::string* output); |
| |
| // Gives up to |max_size| bytes of the internal buffer to |output|. Resets |
| // internal state with the overflow. |
| void BoundedTakeString(size_t max_size, std::string* output); |
| |
| // Size in bytes of stream's internal buffer. |
| size_t size() const { return buffer_.size(); } |
| |
| // Returns the estimate of dynamically allocated memory in bytes. |
| size_t EstimateMemoryUsage() const; |
| |
| private: |
| // The internal bit buffer. |
| std::string buffer_; |
| |
| // If 0, the buffer ends on a byte boundary. If non-zero, the buffer |
| // ends on the nth most significant bit. Guaranteed to be < 8. |
| size_t bit_offset_; |
| }; |
| |
| } // namespace spdy |
| |
| #endif // QUICHE_SPDY_CORE_HPACK_HPACK_OUTPUT_STREAM_H_ |