Revert of Add new HTTP/2 and HPACK decoder in net/http2/.

net/http2/hpack/decoder/hpack_entry_decoder.h

-// 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 NET_HTTP2_HPACK_DECODER_HPACK_ENTRY_DECODER_H_
-#define NET_HTTP2_HPACK_DECODER_HPACK_ENTRY_DECODER_H_
-
-// 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 "base/logging.h"
-#include "net/base/net_export.h"
-#include "net/http2/decoder/decode_buffer.h"
-#include "net/http2/decoder/decode_status.h"
-#include "net/http2/hpack/decoder/hpack_entry_decoder_listener.h"
-#include "net/http2/hpack/decoder/hpack_entry_type_decoder.h"
-#include "net/http2/hpack/decoder/hpack_string_decoder.h"
-#include "net/http2/hpack/http2_hpack_constants.h"
-
-namespace net {
-
-class NET_EXPORT_PRIVATE HpackEntryDecoder {
- public:
-  enum class EntryDecoderState {
-    // Have started decoding the type/varint, but didn't finish on the previous
-    // attempt.  Next state is kResumeDecodingType or kDecodedType.
-    kResumeDecodingType,
-
-    // 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.
-    kDecodedType,
-
-    // 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.
-    kStartDecodingName,
-
-    // Resume decoding the literal name of a header that is split across decode
-    // buffers.
-    kResumeDecodingName,
-
-    // 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.
-    kStartDecodingValue,
-
-    // Resume decoding the literal value of a header that is split across decode
-    // buffers.
-    kResumeDecodingValue,
-  };
-
-  // Only call when the decode buffer has data (i.e. HpackBlockDecoder must
-  // not call until there is data).
-  DecodeStatus Start(DecodeBuffer* db, HpackEntryDecoderListener* listener) {
-    DCHECK(db != nullptr);
-    DCHECK(listener != nullptr);
-    DCHECK(db->HasData());
-    DecodeStatus status = entry_type_decoder_.Start(db);
-    switch (status) {
-      case DecodeStatus::kDecodeDone:
-        // The type of the entry and its varint fit into the current decode
-        // buffer.
-        if (entry_type_decoder_.entry_type() ==
-            HpackEntryType::kIndexedHeader) {
-          // The entry consists solely of the entry type and varint. This
-          // is by far the most common case in practice.
-          listener->OnIndexedHeader(entry_type_decoder_.varint());
-          return DecodeStatus::kDecodeDone;
-        }
-        state_ = EntryDecoderState::kDecodedType;
-        return Resume(db, listener);
-      case DecodeStatus::kDecodeInProgress:
-        // Hit the end of the decode buffer before fully decoding the entry
-        // type and varint.
-        DCHECK_EQ(0u, db->Remaining());
-        state_ = EntryDecoderState::kResumeDecodingType;
-        return status;
-      case DecodeStatus::kDecodeError:
-        // The varint must have been invalid (too long).
-        return status;
-    }
-
-    NOTREACHED();
-    return DecodeStatus::kDecodeError;
-  }
-
-  // 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);
-
-  std::string DebugString() const;
-  void OutputDebugString(std::ostream& out) const;
-
- private:
-  // Implements handling state kDecodedType.
-  bool DispatchOnType(HpackEntryDecoderListener* listener);
-
-  HpackEntryTypeDecoder entry_type_decoder_;
-  HpackStringDecoder string_decoder_;
-  EntryDecoderState state_ = EntryDecoderState();
-};
-
-NET_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& out,
-                                            const HpackEntryDecoder& v);
-NET_EXPORT_PRIVATE std::ostream& operator<<(
-    std::ostream& out,
-    HpackEntryDecoder::EntryDecoderState state);
-
-}  // namespace net
-
-#endif  // NET_HTTP2_HPACK_DECODER_HPACK_ENTRY_DECODER_H_