Project import generated by Copybara.
PiperOrigin-RevId: 224614037
Change-Id: I14e53449d4aeccb328f86828c76b5f09dea0d4b8
diff --git a/http2/hpack/decoder/hpack_decoder_string_buffer.h b/http2/hpack/decoder/hpack_decoder_string_buffer.h
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+++ b/http2/hpack/decoder/hpack_decoder_string_buffer.h
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+// Copyright 2016 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_HTTP2_HPACK_DECODER_HPACK_DECODER_STRING_BUFFER_H_
+#define QUICHE_HTTP2_HPACK_DECODER_HPACK_DECODER_STRING_BUFFER_H_
+
+// HpackDecoderStringBuffer helps an HPACK decoder to avoid copies of a string
+// literal (name or value) except when necessary (e.g. when split across two
+// or more HPACK block fragments).
+
+#include <stddef.h>
+
+#include <ostream>
+
+#include "net/third_party/quiche/src/http2/hpack/huffman/hpack_huffman_decoder.h"
+#include "net/third_party/quiche/src/http2/platform/api/http2_export.h"
+#include "net/third_party/quiche/src/http2/platform/api/http2_string.h"
+#include "net/third_party/quiche/src/http2/platform/api/http2_string_piece.h"
+
+namespace http2 {
+
+class HTTP2_EXPORT_PRIVATE HpackDecoderStringBuffer {
+ public:
+ enum class State : uint8_t { RESET, COLLECTING, COMPLETE };
+ enum class Backing : uint8_t { RESET, UNBUFFERED, BUFFERED, STATIC };
+
+ HpackDecoderStringBuffer();
+ ~HpackDecoderStringBuffer();
+
+ HpackDecoderStringBuffer(const HpackDecoderStringBuffer&) = delete;
+ HpackDecoderStringBuffer& operator=(const HpackDecoderStringBuffer&) = delete;
+
+ void Reset();
+ void Set(Http2StringPiece value, bool is_static);
+
+ // Note that for Huffman encoded strings the length of the string after
+ // decoding may be larger (expected), the same or even smaller; the latter
+ // are unlikely, but possible if the encoder makes odd choices.
+ void OnStart(bool huffman_encoded, size_t len);
+ bool OnData(const char* data, size_t len);
+ bool OnEnd();
+ void BufferStringIfUnbuffered();
+ bool IsBuffered() const;
+ size_t BufferedLength() const;
+
+ // Accessors for the completely collected string (i.e. Set or OnEnd has just
+ // been called, and no reset of the state has occurred).
+
+ // Returns a Http2StringPiece pointing to the backing store for the string,
+ // either the internal buffer or the original transport buffer (e.g. for a
+ // literal value that wasn't Huffman encoded, and that wasn't split across
+ // transport buffers).
+ Http2StringPiece str() const;
+
+ // Returns the completely collected string by value, using std::move in an
+ // effort to avoid unnecessary copies. ReleaseString() must not be called
+ // unless the string has been buffered (to avoid forcing a potentially
+ // unnecessary copy). ReleaseString() also resets the instance so that it can
+ // be used to collect another string.
+ Http2String ReleaseString();
+
+ State state_for_testing() const { return state_; }
+ Backing backing_for_testing() const { return backing_; }
+ void OutputDebugStringTo(std::ostream& out) const;
+
+ // Returns the estimate of dynamically allocated memory in bytes.
+ size_t EstimateMemoryUsage() const;
+
+ private:
+ // Storage for the string being buffered, if buffering is necessary
+ // (e.g. if Huffman encoded, buffer_ is storage for the decoded string).
+ Http2String buffer_;
+
+ // The Http2StringPiece to be returned by HpackDecoderStringBuffer::str(). If
+ // a string has been collected, but not buffered, value_ points to that
+ // string.
+ Http2StringPiece value_;
+
+ // The decoder to use if the string is Huffman encoded.
+ HpackHuffmanDecoder decoder_;
+
+ // Count of bytes not yet passed to OnData.
+ size_t remaining_len_;
+
+ // Is the HPACK string Huffman encoded?
+ bool is_huffman_encoded_;
+
+ // State of the string decoding process.
+ State state_;
+
+ // Where is the string stored?
+ Backing backing_;
+};
+
+HTTP2_EXPORT_PRIVATE std::ostream& operator<<(
+ std::ostream& out,
+ const HpackDecoderStringBuffer& v);
+
+} // namespace http2
+
+#endif // QUICHE_HTTP2_HPACK_DECODER_HPACK_DECODER_STRING_BUFFER_H_
