Adds a new class HttpCache::Writers for multiple cache transactions reading from the network.

net/http/http_cache_transaction.h

 // 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.
 
 // This file declares HttpCache::Transaction, a private class of HttpCache so
 // it should only be included by http_cache.cc
 
 #ifndef NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 #define NET_HTTP_HTTP_CACHE_TRANSACTION_H_
 
@@ skipping 158 matching lines @@
       const BeforeNetworkStartCallback& callback) override;
   void SetBeforeHeadersSentCallback(
       const BeforeHeadersSentCallback& callback) override;
   int ResumeNetworkStart() override;
   void GetConnectionAttempts(ConnectionAttempts* out) const override;
 
   // Invoked when parallel validation cannot proceed due to response failure
   // and this transaction needs to be restarted.
   void SetValidatingCannotProceed();
 
+  // Invoked to remove the association between a transaction waiting to be
+  // added to an entry and the entry.
+  void ResetCachePendingState() { cache_pending_ = false; }
+
   // Returns the estimate of dynamically allocated memory in bytes.
   size_t EstimateMemoryUsage() const;
 
+  // Sets fail state such that a future Read fails with |error_code|.
+  void SetSharedWritingFailState(int error_code);
+
+  RequestPriority priority() const { return priority_; }
+  PartialData* partial() { return partial_.get(); }
+
  private:
   static const size_t kNumValidationHeaders = 2;
   // Helper struct to pair a header name with its value, for
   // headers used to validate cache entries.
   struct ValidationHeaders {
     ValidationHeaders() : initialized(false) {}
 
     std::string values[kNumValidationHeaders];
     void Reset() {
       initialized = false;
@@ skipping 12 matching lines @@
     STATE_GET_BACKEND_COMPLETE,
     STATE_INIT_ENTRY,
     STATE_OPEN_ENTRY,
     STATE_OPEN_ENTRY_COMPLETE,
     STATE_DOOM_ENTRY,
     STATE_DOOM_ENTRY_COMPLETE,
     STATE_CREATE_ENTRY,
     STATE_CREATE_ENTRY_COMPLETE,
     STATE_ADD_TO_ENTRY,
     STATE_ADD_TO_ENTRY_COMPLETE,
+    STATE_DONE_HEADERS_ADD_TO_ENTRY_COMPLETE,
     STATE_CACHE_READ_RESPONSE,
     STATE_CACHE_READ_RESPONSE_COMPLETE,
     STATE_TOGGLE_UNUSED_SINCE_PREFETCH,
     STATE_TOGGLE_UNUSED_SINCE_PREFETCH_COMPLETE,
     STATE_CACHE_DISPATCH_VALIDATION,
     STATE_CACHE_QUERY_DATA,
     STATE_CACHE_QUERY_DATA_COMPLETE,
     STATE_START_PARTIAL_CACHE_VALIDATION,
     STATE_COMPLETE_PARTIAL_CACHE_VALIDATION,
     STATE_SEND_REQUEST,
@@ skipping 51 matching lines @@
   int DoGetBackendComplete(int result);
   int DoInitEntry();
   int DoOpenEntry();
   int DoOpenEntryComplete(int result);
   int DoDoomEntry();
   int DoDoomEntryComplete(int result);
   int DoCreateEntry();
   int DoCreateEntryComplete(int result);
   int DoAddToEntry();
   int DoAddToEntryComplete(int result);
+  int DoDoneHeadersAddToEntryComplete(int result);
   int DoCacheReadResponse();
   int DoCacheReadResponseComplete(int result);
   int DoCacheToggleUnusedSincePrefetch();
   int DoCacheToggleUnusedSincePrefetchComplete(int result);
   int DoCacheDispatchValidation();
   int DoCacheQueryData();
   int DoCacheQueryDataComplete(int result);
   int DoStartPartialCacheValidation();
   int DoCompletePartialCacheValidation(int result);
   int DoSendRequest();
@@ skipping 200 matching lines @@
   std::string cache_key_;
   Mode mode_;
   bool reading_;  // We are already reading. Never reverts to false once set.
   bool invalid_range_;  // We may bypass the cache for this request.
   bool truncated_;  // We don't have all the response data.
   bool is_sparse_;  // The data is stored in sparse byte ranges.
   bool range_requested_;  // The user requested a byte range.
   bool handling_206_;  // We must deal with this 206 response.
   bool cache_pending_;  // We are waiting for the HttpCache.
   bool done_reading_;  // All available data was read.
+
+  // Headers have been received from the network and it's not a match with the
+  // existing entry.
+  bool done_headers_create_new_entry_;
+
   bool vary_mismatch_;  // The request doesn't match the stored vary data.
   bool couldnt_conditionalize_request_;
   bool bypass_lock_for_test_;  // A test is exercising the cache lock.
   bool bypass_lock_after_headers_for_test_;  // A test is exercising the cache
                                              // lock.
   bool fail_conditionalization_for_test_;  // Fail ConditionalizeRequest.
   scoped_refptr<IOBuffer> read_buf_;
   int io_buf_len_;
   int read_offset_;
   int effective_load_flags_;
@@ skipping 40 matching lines @@
   bool in_do_loop_;
 
   base::WeakPtrFactory<Transaction> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Transaction);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_TRANSACTION_H_