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

net/http2/decoder/payload_decoders/settings_payload_decoder.cc

Index: net/http2/decoder/payload_decoders/settings_payload_decoder.cc
diff --git a/net/http2/decoder/payload_decoders/settings_payload_decoder.cc b/net/http2/decoder/payload_decoders/settings_payload_decoder.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f8cc52cb48605086f33b2ed13658f207148cc488
--- /dev/null
+++ b/net/http2/decoder/payload_decoders/settings_payload_decoder.cc
@@ -0,0 +1,97 @@
+// 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.
+
+#include "net/http2/decoder/payload_decoders/settings_payload_decoder.h"
+
+#include "base/logging.h"
+#include "net/http2/decoder/decode_buffer.h"
+#include "net/http2/decoder/http2_frame_decoder_listener.h"
+#include "net/http2/http2_constants.h"
+#include "net/http2/http2_structures.h"
+
+namespace net {
+
+DecodeStatus SettingsPayloadDecoder::StartDecodingPayload(
+    FrameDecoderState* state,
+    DecodeBuffer* db) {
+  const Http2FrameHeader& frame_header = state->frame_header();
+  const uint32_t total_length = frame_header.payload_length;
+
+  DVLOG(2) << "SettingsPayloadDecoder::StartDecodingPayload: " << frame_header;
+  DCHECK_EQ(Http2FrameType::SETTINGS, frame_header.type);
+  DCHECK_LE(db->Remaining(), total_length);
+  DCHECK_EQ(0, frame_header.flags & ~(Http2FrameFlag::FLAG_ACK));
+
+  if (frame_header.IsAck()) {
+    if (total_length == 0) {
+      state->listener()->OnSettingsAck(frame_header);
+      return DecodeStatus::kDecodeDone;
+    } else {
+      state->InitializeRemainders();
+      return state->ReportFrameSizeError();
+    }
+  } else {
+    state->InitializeRemainders();
+    state->listener()->OnSettingsStart(frame_header);
+    return StartDecodingSettings(state, db);
+  }
+}
+
+DecodeStatus SettingsPayloadDecoder::ResumeDecodingPayload(
+    FrameDecoderState* state,
+    DecodeBuffer* db) {
+  DVLOG(2) << "SettingsPayloadDecoder::ResumeDecodingPayload"
+           << "  remaining_payload=" << state->remaining_payload()
+           << "  db->Remaining=" << db->Remaining();
+  DCHECK_EQ(Http2FrameType::SETTINGS, state->frame_header().type);
+  DCHECK_LE(db->Remaining(), state->frame_header().payload_length);
+
+  DecodeStatus status =
+      state->ResumeDecodingStructureInPayload(&setting_fields_, db);
+  if (status == DecodeStatus::kDecodeDone) {
+    state->listener()->OnSetting(setting_fields_);
+    return StartDecodingSettings(state, db);
+  }
+  return HandleNotDone(state, db, status);
+}
+
+DecodeStatus SettingsPayloadDecoder::StartDecodingSettings(
+    FrameDecoderState* state,
+    DecodeBuffer* db) {
+  DVLOG(2) << "SettingsPayloadDecoder::StartDecodingSettings"
+           << "  remaining_payload=" << state->remaining_payload()
+           << "  db->Remaining=" << db->Remaining();
+  while (state->remaining_payload() > 0) {
+    DecodeStatus status =
+        state->StartDecodingStructureInPayload(&setting_fields_, db);
+    if (status == DecodeStatus::kDecodeDone) {
+      state->listener()->OnSetting(setting_fields_);
+      continue;
+    }
+    return HandleNotDone(state, db, status);
+  }
+  DVLOG(2) << "LEAVING SettingsPayloadDecoder::StartDecodingSettings"
+           << "\n\tdb->Remaining=" << db->Remaining()
+           << "\n\t remaining_payload=" << state->remaining_payload();
+  state->listener()->OnSettingsEnd();
+  return DecodeStatus::kDecodeDone;
+}
+
+DecodeStatus SettingsPayloadDecoder::HandleNotDone(FrameDecoderState* state,
+                                                   DecodeBuffer* db,
+                                                   DecodeStatus status) {
+  // Not done decoding the structure. Either we've got more payload to decode,
+  // or we've run out because the payload is too short, in which case
+  // OnFrameSizeError will have already been called.
+  DCHECK(
+      (status == DecodeStatus::kDecodeInProgress &&
+       state->remaining_payload() > 0) ||
+      (status == DecodeStatus::kDecodeError && state->remaining_payload() == 0))
+      << "\n status=" << status
+      << "; remaining_payload=" << state->remaining_payload()
+      << "; db->Remaining=" << db->Remaining();
+  return status;
+}
+
+}  // namespace net