blob: 256e7c28f40993c2ed9a5cb1589271d904aacc68 [file] [log] [blame]
// 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.
// HpackEntryDecoder decodes a single HPACK entry (i.e. one header or one
// dynamic table size update), in a resumable fashion. The first call, Start(),
// must provide a non-empty decode buffer. Continue with calls to Resume() if
// Start, and any subsequent calls to Resume, returns kDecodeInProgress.
#include <string>
#include "http2/decoder/decode_buffer.h"
#include "http2/decoder/decode_status.h"
#include "http2/hpack/decoder/hpack_decoding_error.h"
#include "http2/hpack/decoder/hpack_entry_decoder_listener.h"
#include "http2/hpack/decoder/hpack_entry_type_decoder.h"
#include "http2/hpack/decoder/hpack_string_decoder.h"
#include "http2/hpack/http2_hpack_constants.h"
#include "http2/platform/api/http2_logging.h"
#include "common/platform/api/quiche_export.h"
namespace http2 {
class QUICHE_EXPORT_PRIVATE HpackEntryDecoder {
enum class EntryDecoderState {
// Have started decoding the type/varint, but didn't finish on the previous
// attempt. Next state is kResumeDecodingType or kDecodedType.
// Have just finished decoding the type/varint. Final state if the type is
// kIndexedHeader or kDynamicTableSizeUpdate. Otherwise, the next state is
// kStartDecodingName (if the varint is 0), else kStartDecodingValue.
// Ready to start decoding the literal name of a header entry. Next state
// is kResumeDecodingName (if the name is split across decode buffers),
// else kStartDecodingValue.
// Resume decoding the literal name of a header that is split across decode
// buffers.
// Ready to start decoding the literal value of a header entry. Final state
// if the value string is entirely in the decode buffer, else the next state
// is kResumeDecodingValue.
// Resume decoding the literal value of a header that is split across decode
// buffers.
// Only call when the decode buffer has data (i.e. HpackBlockDecoder must
// not call until there is data).
DecodeStatus Start(DecodeBuffer* db, HpackEntryDecoderListener* listener);
// Only call Resume if the previous call (Start or Resume) returned
// kDecodeInProgress; Resume is also called from Start when it has succeeded
// in decoding the entry type and its varint.
DecodeStatus Resume(DecodeBuffer* db, HpackEntryDecoderListener* listener);
// Return error code after decoding error occurred.
HpackDecodingError error() const { return error_; }
std::string DebugString() const;
void OutputDebugString(std::ostream& out) const;
// Implements handling state kDecodedType.
bool DispatchOnType(HpackEntryDecoderListener* listener);
HpackEntryTypeDecoder entry_type_decoder_;
HpackStringDecoder string_decoder_;
EntryDecoderState state_ = EntryDecoderState();
HpackDecodingError error_ = HpackDecodingError::kOk;
QUICHE_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
const HpackEntryDecoder& v);
QUICHE_EXPORT_PRIVATE std::ostream& operator<<(
std::ostream& out,
HpackEntryDecoder::EntryDecoderState state);
} // namespace http2