reoder functions in the order they are normally executed

net/http/http_cache_transaction.cc

 // Copyright (c) 2012 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/http/http_cache_transaction.h"
 
 #include "build/build_config.h"  // For OS_POSIX
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 786 matching lines @@
     State state = next_state_;
     next_state_ = STATE_NONE;
     switch (state) {
       case STATE_GET_BACKEND:
         DCHECK_EQ(OK, rv);
         rv = DoGetBackend();
         break;
       case STATE_GET_BACKEND_COMPLETE:
         rv = DoGetBackendComplete(rv);
         break;
-      case STATE_SEND_REQUEST:
-        DCHECK_EQ(OK, rv);
-        rv = DoSendRequest();
-        break;
-      case STATE_SEND_REQUEST_COMPLETE:
-        rv = DoSendRequestComplete(rv);
-        break;
-      case STATE_SUCCESSFUL_SEND_REQUEST:
-        DCHECK_EQ(OK, rv);
-        rv = DoSuccessfulSendRequest();
-        break;
-      case STATE_NETWORK_READ:
-        DCHECK_EQ(OK, rv);
-        rv = DoNetworkRead();
-        break;
-      case STATE_NETWORK_READ_COMPLETE:
-        rv = DoNetworkReadComplete(rv);
-        break;
       case STATE_INIT_ENTRY:
         DCHECK_EQ(OK, rv);
         rv = DoInitEntry();
         break;
       case STATE_OPEN_ENTRY:
         DCHECK_EQ(OK, rv);
         rv = DoOpenEntry();
         break;
       case STATE_OPEN_ENTRY_COMPLETE:
         rv = DoOpenEntryComplete(rv);
         break;
-      case STATE_CREATE_ENTRY:
-        DCHECK_EQ(OK, rv);
-        rv = DoCreateEntry();
-        break;
-      case STATE_CREATE_ENTRY_COMPLETE:
-        rv = DoCreateEntryComplete(rv);
-        break;
       case STATE_DOOM_ENTRY:
         DCHECK_EQ(OK, rv);
         rv = DoDoomEntry();
         break;
       case STATE_DOOM_ENTRY_COMPLETE:
         rv = DoDoomEntryComplete(rv);
         break;
+      case STATE_CREATE_ENTRY:
+        DCHECK_EQ(OK, rv);
+        rv = DoCreateEntry();
+        break;
+      case STATE_CREATE_ENTRY_COMPLETE:
+        rv = DoCreateEntryComplete(rv);
+        break;
       case STATE_ADD_TO_ENTRY:
         DCHECK_EQ(OK, rv);
         rv = DoAddToEntry();
         break;
       case STATE_ADD_TO_ENTRY_COMPLETE:
         rv = DoAddToEntryComplete(rv);
         break;
+      case STATE_CACHE_READ_RESPONSE:
+        DCHECK_EQ(OK, rv);
+        rv = DoCacheReadResponse();
+        break;
+      case STATE_CACHE_READ_RESPONSE_COMPLETE:
+        rv = DoCacheReadResponseComplete(rv);
+        break;
+      case STATE_TOGGLE_UNUSED_SINCE_PREFETCH:
+        DCHECK_EQ(OK, rv);
+        rv = DoCacheToggleUnusedSincePrefetch();
+        break;
+      case STATE_TOGGLE_UNUSED_SINCE_PREFETCH_COMPLETE:
+        rv = DoCacheToggleUnusedSincePrefetchComplete(rv);
+        break;
+      case STATE_CACHE_DISPATCH_VALIDATION:
+        DCHECK_EQ(OK, rv);
+        rv = DoCacheDispatchValidation();
+        break;
+      case STATE_CACHE_QUERY_DATA:
+        DCHECK_EQ(OK, rv);
+        rv = DoCacheQueryData();
+        break;
+      case STATE_CACHE_QUERY_DATA_COMPLETE:
+        rv = DoCacheQueryDataComplete(rv);
+        break;
       case STATE_START_PARTIAL_CACHE_VALIDATION:
         DCHECK_EQ(OK, rv);
         rv = DoStartPartialCacheValidation();
         break;
       case STATE_COMPLETE_PARTIAL_CACHE_VALIDATION:
         rv = DoCompletePartialCacheValidation(rv);
         break;
+      case STATE_SEND_REQUEST:
+        DCHECK_EQ(OK, rv);
+        rv = DoSendRequest();
+        break;
+      case STATE_SEND_REQUEST_COMPLETE:
+        rv = DoSendRequestComplete(rv);
+        break;
+      case STATE_SUCCESSFUL_SEND_REQUEST:
+        DCHECK_EQ(OK, rv);
+        rv = DoSuccessfulSendRequest();
+        break;
       case STATE_UPDATE_CACHED_RESPONSE:
         DCHECK_EQ(OK, rv);
         rv = DoUpdateCachedResponse();
         break;
       case STATE_UPDATE_CACHED_RESPONSE_COMPLETE:
         rv = DoUpdateCachedResponseComplete(rv);
         break;
       case STATE_OVERWRITE_CACHED_RESPONSE:
         DCHECK_EQ(OK, rv);
         rv = DoOverwriteCachedResponse();
         break;
+      case STATE_CACHE_WRITE_RESPONSE:
+        DCHECK_EQ(OK, rv);
+        rv = DoCacheWriteResponse();
+        break;
+      case STATE_CACHE_WRITE_TRUNCATED_RESPONSE:
+        DCHECK_EQ(OK, rv);
+        rv = DoCacheWriteTruncatedResponse();
+        break;
+      case STATE_CACHE_WRITE_RESPONSE_COMPLETE:
+        rv = DoCacheWriteResponseComplete(rv);
+        break;
       case STATE_TRUNCATE_CACHED_DATA:
         DCHECK_EQ(OK, rv);
         rv = DoTruncateCachedData();
         break;
       case STATE_TRUNCATE_CACHED_DATA_COMPLETE:
         rv = DoTruncateCachedDataComplete(rv);
         break;
       case STATE_TRUNCATE_CACHED_METADATA:
         DCHECK_EQ(OK, rv);
         rv = DoTruncateCachedMetadata();
         break;
       case STATE_TRUNCATE_CACHED_METADATA_COMPLETE:
         rv = DoTruncateCachedMetadataComplete(rv);
         break;
       case STATE_PARTIAL_HEADERS_RECEIVED:
         DCHECK_EQ(OK, rv);
         rv = DoPartialHeadersReceived();
         break;
-      case STATE_CACHE_READ_RESPONSE:
-        DCHECK_EQ(OK, rv);
-        rv = DoCacheReadResponse();
-        break;
-      case STATE_CACHE_READ_RESPONSE_COMPLETE:
-        rv = DoCacheReadResponseComplete(rv);
-        break;
-      case STATE_CACHE_DISPATCH_VALIDATION:
-        DCHECK_EQ(OK, rv);
-        rv = DoCacheDispatchValidation();
-        break;
-      case STATE_TOGGLE_UNUSED_SINCE_PREFETCH:
-        DCHECK_EQ(OK, rv);
-        rv = DoCacheToggleUnusedSincePrefetch();
-        break;
-      case STATE_TOGGLE_UNUSED_SINCE_PREFETCH_COMPLETE:
-        rv = DoCacheToggleUnusedSincePrefetchComplete(rv);
-        break;
-      case STATE_CACHE_WRITE_RESPONSE:
-        DCHECK_EQ(OK, rv);
-        rv = DoCacheWriteResponse();
-        break;
-      case STATE_CACHE_WRITE_TRUNCATED_RESPONSE:
-        DCHECK_EQ(OK, rv);
-        rv = DoCacheWriteTruncatedResponse();
-        break;
-      case STATE_CACHE_WRITE_RESPONSE_COMPLETE:
-        rv = DoCacheWriteResponseComplete(rv);
-        break;
       case STATE_CACHE_READ_METADATA:
         DCHECK_EQ(OK, rv);
         rv = DoCacheReadMetadata();
         break;
       case STATE_CACHE_READ_METADATA_COMPLETE:
         rv = DoCacheReadMetadataComplete(rv);
         break;
-      case STATE_CACHE_QUERY_DATA:
+      case STATE_NETWORK_READ:
         DCHECK_EQ(OK, rv);
-        rv = DoCacheQueryData();
+        rv = DoNetworkRead();
         break;
-      case STATE_CACHE_QUERY_DATA_COMPLETE:
-        rv = DoCacheQueryDataComplete(rv);
+      case STATE_NETWORK_READ_COMPLETE:
+        rv = DoNetworkReadComplete(rv);
         break;
       case STATE_CACHE_READ_DATA:
         DCHECK_EQ(OK, rv);
         rv = DoCacheReadData();
         break;
       case STATE_CACHE_READ_DATA_COMPLETE:
         rv = DoCacheReadDataComplete(rv);
         break;
       case STATE_CACHE_WRITE_DATA:
         rv = DoCacheWriteData(rv);
@@ skipping 79 matching lines @@
   } else {
     next_state_ = STATE_INIT_ENTRY;
   }
 
   // This is only set if we have something to do with the response.
   range_requested_ = (partial_.get() != NULL);
 
   return OK;
 }
 
-int HttpCache::Transaction::DoSendRequest() {
-  DCHECK(mode_ & WRITE || mode_ == NONE);
-  DCHECK(!network_trans_.get());
-
-  send_request_since_ = TimeTicks::Now();
-
-  // Create a network transaction.
-  int rv = cache_->network_layer_->CreateTransaction(priority_,
-                                                     &network_trans_);
-  if (rv != OK)
-    return rv;
-  network_trans_->SetBeforeNetworkStartCallback(before_network_start_callback_);
-  network_trans_->SetBeforeProxyHeadersSentCallback(
-      before_proxy_headers_sent_callback_);
-
-  // Old load timing information, if any, is now obsolete.
-  old_network_trans_load_timing_.reset();
-
-  if (websocket_handshake_stream_base_create_helper_)
-    network_trans_->SetWebSocketHandshakeStreamCreateHelper(
-        websocket_handshake_stream_base_create_helper_);
-
-  next_state_ = STATE_SEND_REQUEST_COMPLETE;
-  rv = network_trans_->Start(request_, io_callback_, net_log_);
-  return rv;
-}
-
-int HttpCache::Transaction::DoSendRequestComplete(int result) {
-  if (!cache_.get())
-    return ERR_UNEXPECTED;
-
-  // If we tried to conditionalize the request and failed, we know
-  // we won't be reading from the cache after this point.
-  if (couldnt_conditionalize_request_)
-    mode_ = WRITE;
-
-  if (result == OK) {
-    next_state_ = STATE_SUCCESSFUL_SEND_REQUEST;
-    return OK;
-  }
-
-  const HttpResponseInfo* response = network_trans_->GetResponseInfo();
-  response_.network_accessed = response->network_accessed;
-
-  // Do not record requests that have network errors or restarts.
-  UpdateTransactionPattern(PATTERN_NOT_COVERED);
-  if (IsCertificateError(result)) {
-    // If we get a certificate error, then there is a certificate in ssl_info,
-    // so GetResponseInfo() should never return NULL here.
-    DCHECK(response);
-    response_.ssl_info = response->ssl_info;
-  } else if (result == ERR_SSL_CLIENT_AUTH_CERT_NEEDED) {
-    DCHECK(response);
-    response_.cert_request_info = response->cert_request_info;
-  } else if (response_.was_cached) {
-    DoneWritingToEntry(true);
-  }
-
-  return result;
-}
-
-// We received the response headers and there is no error.
-int HttpCache::Transaction::DoSuccessfulSendRequest() {
-  DCHECK(!new_response_);
-  const HttpResponseInfo* new_response = network_trans_->GetResponseInfo();
-
-  if (new_response->headers->response_code() == 401 ||
-      new_response->headers->response_code() == 407) {
-    auth_response_ = *new_response;
-    if (!reading_)
-      return OK;
-
-    // We initiated a second request the caller doesn't know about. We should be
-    // able to authenticate this request because we should have authenticated
-    // this URL moments ago.
-    if (IsReadyToRestartForAuth()) {
-      DCHECK(!response_.auth_challenge.get());
-      next_state_ = STATE_SEND_REQUEST_COMPLETE;
-      // In theory we should check to see if there are new cookies, but there
-      // is no way to do that from here.
-      return network_trans_->RestartWithAuth(AuthCredentials(), io_callback_);
-    }
-
-    // We have to perform cleanup at this point so that at least the next
-    // request can succeed.  We do not retry at this point, because data
-    // has been read and we have no way to gather credentials.  We would
-    // fail again, and potentially loop.  This can happen if the credentials
-    // expire while chrome is suspended.
-    if (entry_)
-      DoomPartialEntry(false);
-    mode_ = NONE;
-    partial_.reset();
-    ResetNetworkTransaction();
-    return ERR_CACHE_AUTH_FAILURE_AFTER_READ;
-  }
-
-  new_response_ = new_response;
-  if (!ValidatePartialResponse() && !auth_response_.headers.get()) {
-    // Something went wrong with this request and we have to restart it.
-    // If we have an authentication response, we are exposed to weird things
-    // hapenning if the user cancels the authentication before we receive
-    // the new response.
-    net_log_.AddEvent(NetLog::TYPE_HTTP_CACHE_RE_SEND_PARTIAL_REQUEST);
-    UpdateTransactionPattern(PATTERN_NOT_COVERED);
-    response_ = HttpResponseInfo();
-    ResetNetworkTransaction();
-    new_response_ = NULL;
-    next_state_ = STATE_SEND_REQUEST;
-    return OK;
-  }
-
-  if (handling_206_ && mode_ == READ_WRITE && !truncated_ && !is_sparse_) {
-    // We have stored the full entry, but it changed and the server is
-    // sending a range. We have to delete the old entry.
-    UpdateTransactionPattern(PATTERN_NOT_COVERED);
-    DoneWritingToEntry(false);
-  }
-
-  if (mode_ == WRITE &&
-      transaction_pattern_ != PATTERN_ENTRY_CANT_CONDITIONALIZE) {
-    UpdateTransactionPattern(PATTERN_ENTRY_NOT_CACHED);
-  }
-
-  // Invalidate any cached GET with a successful PUT or DELETE.
-  if (mode_ == WRITE &&
-      (request_->method == "PUT" || request_->method == "DELETE")) {
-    if (NonErrorResponse(new_response->headers->response_code())) {
-      int ret = cache_->DoomEntry(cache_key_, NULL);
-      DCHECK_EQ(OK, ret);
-    }
-    cache_->DoneWritingToEntry(entry_, true);
-    entry_ = NULL;
-    mode_ = NONE;
-  }
-
-  // Invalidate any cached GET with a successful POST.
-  if (!(effective_load_flags_ & LOAD_DISABLE_CACHE) &&
-      request_->method == "POST" &&
-      NonErrorResponse(new_response->headers->response_code())) {
-    cache_->DoomMainEntryForUrl(request_->url);
-  }
-
-  RecordNoStoreHeaderHistogram(request_->load_flags, new_response);
-
-  if (new_response_->headers->response_code() == 416 &&
-      (request_->method == "GET" || request_->method == "POST")) {
-    // If there is an active entry it may be destroyed with this transaction.
-    response_ = *new_response_;
-    return OK;
-  }
-
-  // Are we expecting a response to a conditional query?
-  if (mode_ == READ_WRITE || mode_ == UPDATE) {
-    if (new_response->headers->response_code() == 304 || handling_206_) {
-      UpdateTransactionPattern(PATTERN_ENTRY_VALIDATED);
-      next_state_ = STATE_UPDATE_CACHED_RESPONSE;
-      return OK;
-    }
-    UpdateTransactionPattern(PATTERN_ENTRY_UPDATED);
-    mode_ = WRITE;
-  }
-
-  next_state_ = STATE_OVERWRITE_CACHED_RESPONSE;
-  return OK;
-}
-
-int HttpCache::Transaction::DoNetworkRead() {
-  next_state_ = STATE_NETWORK_READ_COMPLETE;
-  return network_trans_->Read(read_buf_.get(), io_buf_len_, io_callback_);
-}
-
-int HttpCache::Transaction::DoNetworkReadComplete(int result) {
-  DCHECK(mode_ & WRITE || mode_ == NONE);
-
-  if (!cache_.get())
-    return ERR_UNEXPECTED;
-
-  // If there is an error or we aren't saving the data, we are done; just wait
-  // until the destructor runs to see if we can keep the data.
-  if (mode_ == NONE || result < 0)
-    return result;
-
-  next_state_ = STATE_CACHE_WRITE_DATA;
-  return result;
-}
-
 int HttpCache::Transaction::DoInitEntry() {
   DCHECK(!new_entry_);
 
   if (!cache_.get())
     return ERR_UNEXPECTED;
 
   if (mode_ == WRITE) {
     next_state_ = STATE_DOOM_ENTRY;
     return OK;
   }
@@ skipping 45 matching lines @@
     mode_ = NONE;
     next_state_ = STATE_SEND_REQUEST;
     return OK;
   }
 
   // The entry does not exist, and we are not permitted to create a new entry,
   // so we must fail.
   return ERR_CACHE_MISS;
 }
 
+int HttpCache::Transaction::DoDoomEntry() {
+  next_state_ = STATE_DOOM_ENTRY_COMPLETE;
+  cache_pending_ = true;
+  if (first_cache_access_since_.is_null())
+    first_cache_access_since_ = TimeTicks::Now();
+  net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_DOOM_ENTRY);
+  return cache_->DoomEntry(cache_key_, this);
+}
+
+int HttpCache::Transaction::DoDoomEntryComplete(int result) {
+  net_log_.EndEventWithNetErrorCode(NetLog::TYPE_HTTP_CACHE_DOOM_ENTRY, result);
+  next_state_ = STATE_CREATE_ENTRY;
+  cache_pending_ = false;
+  if (result == ERR_CACHE_RACE)
+    next_state_ = STATE_INIT_ENTRY;
+  return OK;
+}
+
 int HttpCache::Transaction::DoCreateEntry() {
   DCHECK(!new_entry_);
   next_state_ = STATE_CREATE_ENTRY_COMPLETE;
   cache_pending_ = true;
   net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_CREATE_ENTRY);
   return cache_->CreateEntry(cache_key_, &new_entry_, this);
 }
 
 int HttpCache::Transaction::DoCreateEntryComplete(int result) {
   // It is important that we go to STATE_ADD_TO_ENTRY whenever the result is
@@ skipping 16 matching lines @@
     // OpenOrCreate() method exposed by the disk cache.
     DLOG(WARNING) << "Unable to create cache entry";
     mode_ = NONE;
     if (partial_.get())
       partial_->RestoreHeaders(&custom_request_->extra_headers);
     next_state_ = STATE_SEND_REQUEST;
   }
   return OK;
 }
 
-int HttpCache::Transaction::DoDoomEntry() {
-  next_state_ = STATE_DOOM_ENTRY_COMPLETE;
-  cache_pending_ = true;
-  if (first_cache_access_since_.is_null())
-    first_cache_access_since_ = TimeTicks::Now();
-  net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_DOOM_ENTRY);
-  return cache_->DoomEntry(cache_key_, this);
-}
-
-int HttpCache::Transaction::DoDoomEntryComplete(int result) {
-  net_log_.EndEventWithNetErrorCode(NetLog::TYPE_HTTP_CACHE_DOOM_ENTRY, result);
-  next_state_ = STATE_CREATE_ENTRY;
-  cache_pending_ = false;
-  if (result == ERR_CACHE_RACE)
-    next_state_ = STATE_INIT_ENTRY;
-  return OK;
-}
-
 int HttpCache::Transaction::DoAddToEntry() {
   DCHECK(new_entry_);
   cache_pending_ = true;
   next_state_ = STATE_ADD_TO_ENTRY_COMPLETE;
   net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_ADD_TO_ENTRY);
   DCHECK(entry_lock_waiting_since_.is_null());
   entry_lock_waiting_since_ = TimeTicks::Now();
   int rv = cache_->AddTransactionToEntry(new_entry_, this);
   if (rv == ERR_IO_PENDING) {
     if (bypass_lock_for_test_) {
@@ skipping 71 matching lines @@
       partial_->RestoreHeaders(&custom_request_->extra_headers);
     next_state_ = STATE_SEND_REQUEST;
   } else {
     // We have to read the headers from the cached entry.
     DCHECK(mode_ & READ_META);
     next_state_ = STATE_CACHE_READ_RESPONSE;
   }
   return OK;
 }
 
+int HttpCache::Transaction::DoCacheReadResponse() {
+  DCHECK(entry_);
+  next_state_ = STATE_CACHE_READ_RESPONSE_COMPLETE;
+
+  io_buf_len_ = entry_->disk_entry->GetDataSize(kResponseInfoIndex);
+  read_buf_ = new IOBuffer(io_buf_len_);
+
+  net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_READ_INFO);
+  return entry_->disk_entry->ReadData(kResponseInfoIndex, 0, read_buf_.get(),
+                                      io_buf_len_, io_callback_);
+}
+
+int HttpCache::Transaction::DoCacheReadResponseComplete(int result) {
+  net_log_.EndEventWithNetErrorCode(NetLog::TYPE_HTTP_CACHE_READ_INFO, result);
+  if (result != io_buf_len_ ||
+      !HttpCache::ParseResponseInfo(read_buf_->data(), io_buf_len_, &response_,
+                                    &truncated_)) {
+    return OnCacheReadError(result, true);
+  }
+
+  // cert_cache() will be null if the CertCacheTrial field trial is disabled.
+  if (cache_->cert_cache() && response_.ssl_info.is_valid())
+    ReadCertChain();
+
+  // Some resources may have slipped in as truncated when they're not.
+  int current_size = entry_->disk_entry->GetDataSize(kResponseContentIndex);
+  if (response_.headers->GetContentLength() == current_size)
+    truncated_ = false;
+
+  if ((response_.unused_since_prefetch &&
+       !(request_->load_flags & LOAD_PREFETCH)) ||
+      (!response_.unused_since_prefetch &&
+       (request_->load_flags & LOAD_PREFETCH))) {
+    // Either this is the first use of an entry since it was prefetched or
+    // this is a prefetch. The value of response.unused_since_prefetch is valid
+    // for this transaction but the bit needs to be flipped in storage.
+    next_state_ = STATE_TOGGLE_UNUSED_SINCE_PREFETCH;
+    return OK;
+  }
+
+  next_state_ = STATE_CACHE_DISPATCH_VALIDATION;
+  return OK;
+}
+
+int HttpCache::Transaction::DoCacheToggleUnusedSincePrefetch() {
+  // Write back the toggled value for the next use of this entry.
+  response_.unused_since_prefetch = !response_.unused_since_prefetch;
+
+  // TODO(jkarlin): If DoUpdateCachedResponse is also called for this
+  // transaction then metadata will be written to cache twice. If prefetching
+  // becomes more common, consider combining the writes.
+  target_state_ = STATE_TOGGLE_UNUSED_SINCE_PREFETCH_COMPLETE;
+  next_state_ = STATE_CACHE_WRITE_RESPONSE;
+  return OK;
+}
+
+int HttpCache::Transaction::DoCacheToggleUnusedSincePrefetchComplete(
+    int result) {
+  // Restore the original value for this transaction.
+  response_.unused_since_prefetch = !response_.unused_since_prefetch;
+  next_state_ = STATE_CACHE_DISPATCH_VALIDATION;
+  return OK;
+}
+
+int HttpCache::Transaction::DoCacheDispatchValidation() {
+  // We now have access to the cache entry.
+  //
+  //  o if we are a reader for the transaction, then we can start reading the
+  //    cache entry.
+  //
+  //  o if we can read or write, then we should check if the cache entry needs
+  //    to be validated and then issue a network request if needed or just read
+  //    from the cache if the cache entry is already valid.
+  //
+  //  o if we are set to UPDATE, then we are handling an externally
+  //    conditionalized request (if-modified-since / if-none-match). We check
+  //    if the request headers define a validation request.
+  //
+  int result = ERR_FAILED;
+  switch (mode_) {
+    case READ:
+      UpdateTransactionPattern(PATTERN_ENTRY_USED);
+      result = BeginCacheRead();
+      break;
+    case READ_WRITE:
+      result = BeginPartialCacheValidation();
+      break;
+    case UPDATE:
+      result = BeginExternallyConditionalizedRequest();
+      break;
+    case WRITE:
+    default:
+      NOTREACHED();
+  }
+  return result;
+}
+
+int HttpCache::Transaction::DoCacheQueryData() {
+  next_state_ = STATE_CACHE_QUERY_DATA_COMPLETE;
+  return entry_->disk_entry->ReadyForSparseIO(io_callback_);
+}
+
+int HttpCache::Transaction::DoCacheQueryDataComplete(int result) {
+  DCHECK_EQ(OK, result);
+  if (!cache_.get())
+    return ERR_UNEXPECTED;
+
+  return ValidateEntryHeadersAndContinue();
+}
+
 // We may end up here multiple times for a given request.
 int HttpCache::Transaction::DoStartPartialCacheValidation() {
   if (mode_ == NONE)
     return OK;
 
   next_state_ = STATE_COMPLETE_PARTIAL_CACHE_VALIDATION;
   return partial_->ShouldValidateCache(entry_->disk_entry, io_callback_);
 }
 
 int HttpCache::Transaction::DoCompletePartialCacheValidation(int result) {
@@ skipping 15 matching lines @@
                                    &custom_request_->extra_headers);
 
   if (reading_ && partial_->IsCurrentRangeCached()) {
     next_state_ = STATE_CACHE_READ_DATA;
     return OK;
   }
 
   return BeginCacheValidation();
 }
 
+int HttpCache::Transaction::DoSendRequest() {
+  DCHECK(mode_ & WRITE || mode_ == NONE);
+  DCHECK(!network_trans_.get());
+
+  send_request_since_ = TimeTicks::Now();
+
+  // Create a network transaction.
+  int rv =
+      cache_->network_layer_->CreateTransaction(priority_, &network_trans_);
+  if (rv != OK)
+    return rv;
+  network_trans_->SetBeforeNetworkStartCallback(before_network_start_callback_);
+  network_trans_->SetBeforeProxyHeadersSentCallback(
+      before_proxy_headers_sent_callback_);
+
+  // Old load timing information, if any, is now obsolete.
+  old_network_trans_load_timing_.reset();
+
+  if (websocket_handshake_stream_base_create_helper_)
+    network_trans_->SetWebSocketHandshakeStreamCreateHelper(
+        websocket_handshake_stream_base_create_helper_);
+
+  next_state_ = STATE_SEND_REQUEST_COMPLETE;
+  rv = network_trans_->Start(request_, io_callback_, net_log_);
+  return rv;
+}
+
+int HttpCache::Transaction::DoSendRequestComplete(int result) {
+  if (!cache_.get())
+    return ERR_UNEXPECTED;
+
+  // If we tried to conditionalize the request and failed, we know
+  // we won't be reading from the cache after this point.
+  if (couldnt_conditionalize_request_)
+    mode_ = WRITE;
+
+  if (result == OK) {
+    next_state_ = STATE_SUCCESSFUL_SEND_REQUEST;
+    return OK;
+  }
+
+  const HttpResponseInfo* response = network_trans_->GetResponseInfo();
+  response_.network_accessed = response->network_accessed;
+
+  // Do not record requests that have network errors or restarts.
+  UpdateTransactionPattern(PATTERN_NOT_COVERED);
+  if (IsCertificateError(result)) {
+    // If we get a certificate error, then there is a certificate in ssl_info,
+    // so GetResponseInfo() should never return NULL here.
+    DCHECK(response);
+    response_.ssl_info = response->ssl_info;
+  } else if (result == ERR_SSL_CLIENT_AUTH_CERT_NEEDED) {
+    DCHECK(response);
+    response_.cert_request_info = response->cert_request_info;
+  } else if (response_.was_cached) {
+    DoneWritingToEntry(true);
+  }
+
+  return result;
+}
+
+// We received the response headers and there is no error.
+int HttpCache::Transaction::DoSuccessfulSendRequest() {
+  DCHECK(!new_response_);
+  const HttpResponseInfo* new_response = network_trans_->GetResponseInfo();
+
+  if (new_response->headers->response_code() == 401 ||
+      new_response->headers->response_code() == 407) {
+    auth_response_ = *new_response;
+    if (!reading_)
+      return OK;
+
+    // We initiated a second request the caller doesn't know about. We should be
+    // able to authenticate this request because we should have authenticated
+    // this URL moments ago.
+    if (IsReadyToRestartForAuth()) {
+      DCHECK(!response_.auth_challenge.get());
+      next_state_ = STATE_SEND_REQUEST_COMPLETE;
+      // In theory we should check to see if there are new cookies, but there
+      // is no way to do that from here.
+      return network_trans_->RestartWithAuth(AuthCredentials(), io_callback_);
+    }
+
+    // We have to perform cleanup at this point so that at least the next
+    // request can succeed.  We do not retry at this point, because data
+    // has been read and we have no way to gather credentials.  We would
+    // fail again, and potentially loop.  This can happen if the credentials
+    // expire while chrome is suspended.
+    if (entry_)
+      DoomPartialEntry(false);
+    mode_ = NONE;
+    partial_.reset();
+    ResetNetworkTransaction();
+    return ERR_CACHE_AUTH_FAILURE_AFTER_READ;
+  }
+
+  new_response_ = new_response;
+  if (!ValidatePartialResponse() && !auth_response_.headers.get()) {
+    // Something went wrong with this request and we have to restart it.
+    // If we have an authentication response, we are exposed to weird things
+    // hapenning if the user cancels the authentication before we receive
+    // the new response.
+    net_log_.AddEvent(NetLog::TYPE_HTTP_CACHE_RE_SEND_PARTIAL_REQUEST);
+    UpdateTransactionPattern(PATTERN_NOT_COVERED);
+    response_ = HttpResponseInfo();
+    ResetNetworkTransaction();
+    new_response_ = NULL;
+    next_state_ = STATE_SEND_REQUEST;
+    return OK;
+  }
+
+  if (handling_206_ && mode_ == READ_WRITE && !truncated_ && !is_sparse_) {
+    // We have stored the full entry, but it changed and the server is
+    // sending a range. We have to delete the old entry.
+    UpdateTransactionPattern(PATTERN_NOT_COVERED);
+    DoneWritingToEntry(false);
+  }
+
+  if (mode_ == WRITE &&
+      transaction_pattern_ != PATTERN_ENTRY_CANT_CONDITIONALIZE) {
+    UpdateTransactionPattern(PATTERN_ENTRY_NOT_CACHED);
+  }
+
+  // Invalidate any cached GET with a successful PUT or DELETE.
+  if (mode_ == WRITE &&
+      (request_->method == "PUT" || request_->method == "DELETE")) {
+    if (NonErrorResponse(new_response->headers->response_code())) {
+      int ret = cache_->DoomEntry(cache_key_, NULL);
+      DCHECK_EQ(OK, ret);
+    }
+    cache_->DoneWritingToEntry(entry_, true);
+    entry_ = NULL;
+    mode_ = NONE;
+  }
+
+  // Invalidate any cached GET with a successful POST.
+  if (!(effective_load_flags_ & LOAD_DISABLE_CACHE) &&
+      request_->method == "POST" &&
+      NonErrorResponse(new_response->headers->response_code())) {
+    cache_->DoomMainEntryForUrl(request_->url);
+  }
+
+  RecordNoStoreHeaderHistogram(request_->load_flags, new_response);
+
+  if (new_response_->headers->response_code() == 416 &&
+      (request_->method == "GET" || request_->method == "POST")) {
+    // If there is an active entry it may be destroyed with this transaction.
+    response_ = *new_response_;
+    return OK;
+  }
+
+  // Are we expecting a response to a conditional query?
+  if (mode_ == READ_WRITE || mode_ == UPDATE) {
+    if (new_response->headers->response_code() == 304 || handling_206_) {
+      UpdateTransactionPattern(PATTERN_ENTRY_VALIDATED);
+      next_state_ = STATE_UPDATE_CACHED_RESPONSE;
+      return OK;
+    }
+    UpdateTransactionPattern(PATTERN_ENTRY_UPDATED);
+    mode_ = WRITE;
+  }
+
+  next_state_ = STATE_OVERWRITE_CACHED_RESPONSE;
+  return OK;
+}
+
 // We received 304 or 206 and we want to update the cached response headers.
 int HttpCache::Transaction::DoUpdateCachedResponse() {
   next_state_ = STATE_UPDATE_CACHED_RESPONSE_COMPLETE;
   int rv = OK;
   // Update the cached response based on the headers and properties of
   // new_response_.
   response_.headers->Update(*new_response_->headers.get());
   response_.response_time = new_response_->response_time;
   response_.request_time = new_response_->request_time;
   response_.network_accessed = new_response_->network_accessed;
@@ skipping 88 matching lines @@
     next_state_ = STATE_PARTIAL_HEADERS_RECEIVED;
     return OK;
   }
 
   target_state_ = STATE_TRUNCATE_CACHED_DATA;
   next_state_ = truncated_ ? STATE_CACHE_WRITE_TRUNCATED_RESPONSE :
                              STATE_CACHE_WRITE_RESPONSE;
   return OK;
 }
 
+int HttpCache::Transaction::DoCacheWriteResponse() {
+  // TODO(rtenneti): Remove ScopedTracker below once crbug.com/422516 is fixed.
+  tracked_objects::ScopedTracker tracking_profile(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "422516 HttpCache::Transaction::DoCacheWriteResponse"));
+
+  if (entry_) {
+    if (net_log_.IsCapturing())
+      net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_WRITE_INFO);
+  }
+  return WriteResponseInfoToEntry(false);
+}
+
+int HttpCache::Transaction::DoCacheWriteTruncatedResponse() {
+  if (entry_) {
+    if (net_log_.IsCapturing())
+      net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_WRITE_INFO);
+  }
+  return WriteResponseInfoToEntry(true);
+}
+
+int HttpCache::Transaction::DoCacheWriteResponseComplete(int result) {
+  next_state_ = target_state_;
+  target_state_ = STATE_NONE;
+  if (!entry_)
+    return OK;
+  if (net_log_.IsCapturing()) {
+    net_log_.EndEventWithNetErrorCode(NetLog::TYPE_HTTP_CACHE_WRITE_INFO,
+                                      result);
+  }
+
+  // Balance the AddRef from WriteResponseInfoToEntry.
+  if (result != io_buf_len_) {
+    DLOG(ERROR) << "failed to write response info to cache";
+    DoneWritingToEntry(false);
+  }
+  return OK;
+}
 int HttpCache::Transaction::DoTruncateCachedData() {
   next_state_ = STATE_TRUNCATE_CACHED_DATA_COMPLETE;
   if (!entry_)
     return OK;
   if (net_log_.IsCapturing())
     net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_WRITE_DATA);
   // Truncate the stream.
   return WriteToEntry(kResponseContentIndex, 0, NULL, 0, io_callback_);
 }
 
@@ skipping 47 matching lines @@
       next_state_ = STATE_CACHE_READ_DATA;
     }
   } else if (mode_ != NONE) {
     // We are about to return the headers for a byte-range request to the user,
     // so let's fix them.
     partial_->FixResponseHeaders(response_.headers.get(), true);
   }
   return OK;
 }
 
-int HttpCache::Transaction::DoCacheReadResponse() {
-  DCHECK(entry_);
-  next_state_ = STATE_CACHE_READ_RESPONSE_COMPLETE;
-
-  io_buf_len_ = entry_->disk_entry->GetDataSize(kResponseInfoIndex);
-  read_buf_ = new IOBuffer(io_buf_len_);
-
-  net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_READ_INFO);
-  return entry_->disk_entry->ReadData(kResponseInfoIndex, 0, read_buf_.get(),
-                                      io_buf_len_, io_callback_);
-}
-
-int HttpCache::Transaction::DoCacheReadResponseComplete(int result) {
-  net_log_.EndEventWithNetErrorCode(NetLog::TYPE_HTTP_CACHE_READ_INFO, result);
-  if (result != io_buf_len_ ||
-      !HttpCache::ParseResponseInfo(read_buf_->data(), io_buf_len_,
-                                    &response_, &truncated_)) {
-    return OnCacheReadError(result, true);
-  }
-
-  // cert_cache() will be null if the CertCacheTrial field trial is disabled.
-  if (cache_->cert_cache() && response_.ssl_info.is_valid())
-    ReadCertChain();
-
-  // Some resources may have slipped in as truncated when they're not.
-  int current_size = entry_->disk_entry->GetDataSize(kResponseContentIndex);
-  if (response_.headers->GetContentLength() == current_size)
-    truncated_ = false;
-
-  if ((response_.unused_since_prefetch &&
-       !(request_->load_flags & LOAD_PREFETCH)) ||
-      (!response_.unused_since_prefetch &&
-       (request_->load_flags & LOAD_PREFETCH))) {
-    // Either this is the first use of an entry since it was prefetched or
-    // this is a prefetch. The value of response.unused_since_prefetch is valid
-    // for this transaction but the bit needs to be flipped in storage.
-    next_state_ = STATE_TOGGLE_UNUSED_SINCE_PREFETCH;
-    return OK;
-  }
-
-  next_state_ = STATE_CACHE_DISPATCH_VALIDATION;
-  return OK;
-}
-
-int HttpCache::Transaction::DoCacheDispatchValidation() {
-  // We now have access to the cache entry.
-  //
-  //  o if we are a reader for the transaction, then we can start reading the
-  //    cache entry.
-  //
-  //  o if we can read or write, then we should check if the cache entry needs
-  //    to be validated and then issue a network request if needed or just read
-  //    from the cache if the cache entry is already valid.
-  //
-  //  o if we are set to UPDATE, then we are handling an externally
-  //    conditionalized request (if-modified-since / if-none-match). We check
-  //    if the request headers define a validation request.
-  //
-  int result = ERR_FAILED;
-  switch (mode_) {
-    case READ:
-      UpdateTransactionPattern(PATTERN_ENTRY_USED);
-      result = BeginCacheRead();
-      break;
-    case READ_WRITE:
-      result = BeginPartialCacheValidation();
-      break;
-    case UPDATE:
-      result = BeginExternallyConditionalizedRequest();
-      break;
-    case WRITE:
-    default:
-      NOTREACHED();
-  }
-  return result;
-}
-
-int HttpCache::Transaction::DoCacheToggleUnusedSincePrefetch() {
-  // Write back the toggled value for the next use of this entry.
-  response_.unused_since_prefetch = !response_.unused_since_prefetch;
-
-  // TODO(jkarlin): If DoUpdateCachedResponse is also called for this
-  // transaction then metadata will be written to cache twice. If prefetching
-  // becomes more common, consider combining the writes.
-  target_state_ = STATE_TOGGLE_UNUSED_SINCE_PREFETCH_COMPLETE;
-  next_state_ = STATE_CACHE_WRITE_RESPONSE;
-  return OK;
-}
-
-int HttpCache::Transaction::DoCacheToggleUnusedSincePrefetchComplete(
-    int result) {
-  // Restore the original value for this transaction.
-  response_.unused_since_prefetch = !response_.unused_since_prefetch;
-  next_state_ = STATE_CACHE_DISPATCH_VALIDATION;
-  return OK;
-}
-
-int HttpCache::Transaction::DoCacheWriteResponse() {
-  // TODO(rtenneti): Remove ScopedTracker below once crbug.com/422516 is fixed.
-  tracked_objects::ScopedTracker tracking_profile(
-      FROM_HERE_WITH_EXPLICIT_FUNCTION(
-          "422516 HttpCache::Transaction::DoCacheWriteResponse"));
-
-  if (entry_) {
-    if (net_log_.IsCapturing())
-      net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_WRITE_INFO);
-  }
-  return WriteResponseInfoToEntry(false);
-}
-
-int HttpCache::Transaction::DoCacheWriteTruncatedResponse() {
-  if (entry_) {
-    if (net_log_.IsCapturing())
-      net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_WRITE_INFO);
-  }
-  return WriteResponseInfoToEntry(true);
-}
-
-int HttpCache::Transaction::DoCacheWriteResponseComplete(int result) {
-  next_state_ = target_state_;
-  target_state_ = STATE_NONE;
-  if (!entry_)
-    return OK;
-  if (net_log_.IsCapturing()) {
-    net_log_.EndEventWithNetErrorCode(NetLog::TYPE_HTTP_CACHE_WRITE_INFO,
-                                      result);
-  }
-
-  // Balance the AddRef from WriteResponseInfoToEntry.
-  if (result != io_buf_len_) {
-    DLOG(ERROR) << "failed to write response info to cache";
-    DoneWritingToEntry(false);
-  }
-  return OK;
-}
-
 int HttpCache::Transaction::DoCacheReadMetadata() {
   DCHECK(entry_);
   DCHECK(!response_.metadata.get());
   next_state_ = STATE_CACHE_READ_METADATA_COMPLETE;
 
   response_.metadata =
       new IOBufferWithSize(entry_->disk_entry->GetDataSize(kMetadataIndex));
 
   net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_READ_INFO);
   return entry_->disk_entry->ReadData(kMetadataIndex, 0,
                                       response_.metadata.get(),
                                       response_.metadata->size(),
                                       io_callback_);
 }
 
 int HttpCache::Transaction::DoCacheReadMetadataComplete(int result) {
   net_log_.EndEventWithNetErrorCode(NetLog::TYPE_HTTP_CACHE_READ_INFO, result);
   if (result != response_.metadata->size())
     return OnCacheReadError(result, false);
   return OK;
 }
 
-int HttpCache::Transaction::DoCacheQueryData() {
-  next_state_ = STATE_CACHE_QUERY_DATA_COMPLETE;
-  return entry_->disk_entry->ReadyForSparseIO(io_callback_);
+int HttpCache::Transaction::DoNetworkRead() {
+  next_state_ = STATE_NETWORK_READ_COMPLETE;
+  return network_trans_->Read(read_buf_.get(), io_buf_len_, io_callback_);
 }
 
-int HttpCache::Transaction::DoCacheQueryDataComplete(int result) {
-  DCHECK_EQ(OK, result);
+int HttpCache::Transaction::DoNetworkReadComplete(int result) {
+  DCHECK(mode_ & WRITE || mode_ == NONE);
+
   if (!cache_.get())
     return ERR_UNEXPECTED;
 
-  return ValidateEntryHeadersAndContinue();
+  // If there is an error or we aren't saving the data, we are done; just wait
+  // until the destructor runs to see if we can keep the data.
+  if (mode_ == NONE || result < 0)
+    return result;
+
+  next_state_ = STATE_CACHE_WRITE_DATA;
+  return result;
 }
 
 int HttpCache::Transaction::DoCacheReadData() {
   DCHECK(entry_);
   next_state_ = STATE_CACHE_READ_DATA_COMPLETE;
 
   if (net_log_.IsCapturing())
     net_log_.BeginEvent(NetLog::TYPE_HTTP_CACHE_READ_DATA);
   if (partial_.get()) {
     return partial_->CacheRead(entry_->disk_entry, read_buf_.get(), io_buf_len_,
@@ skipping 786 matching lines @@
   mode_ = READ;
 
   if (request_->method == "HEAD")
     FixHeadersForHead();
 
   if (entry_->disk_entry->GetDataSize(kMetadataIndex))
     next_state_ = STATE_CACHE_READ_METADATA;
   return OK;
 }
 
-
 int HttpCache::Transaction::ReadFromNetwork(IOBuffer* data, int data_len) {
   read_buf_ = data;
   io_buf_len_ = data_len;
   next_state_ = STATE_NETWORK_READ;
   return DoLoop(OK);
 }
 
 int HttpCache::Transaction::ReadFromEntry(IOBuffer* data, int data_len) {
   if (request_->method == "HEAD")
     return 0;
@@ skipping 305 matching lines @@
     default:
       NOTREACHED();
   }
 }
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   DoLoop(result);
 }
 
 }  // namespace net