RFC: use some in-memory state in SimpleCache to quickly cache-miss some CantConditionalize cases

net/http/mock_http_cache.h

 // Copyright (c) 2011 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 is a mock of the http cache and related testing classes. To be fair, it
 // is not really a mock http cache given that it uses the real implementation of
 // the http cache, but it has fake implementations of all required components,
 // so it is useful for unit tests at the http layer.
 
 #ifndef NET_HTTP_MOCK_HTTP_CACHE_H_
@@ skipping 46 matching lines @@
                       int buf_len,
                       const CompletionCallback& callback) override;
   int GetAvailableRange(int64_t offset,
                         int len,
                         int64_t* start,
                         const CompletionCallback& callback) override;
   bool CouldBeSparse() const override;
   void CancelSparseIO() override;
   int ReadyForSparseIO(const CompletionCallback& completion_callback) override;
 
+  uint8_t memory_entry_data() const { return memory_entry_data_; }

[gavinp, 2017/06/26 20:18:11]

Is this implemented here to make sure that http_cache_transaction unit tests
test this path?

Should we provide an implementation that mimics the blockfile cache, and always
returns 0?

+  void set_memory_entry_data(uint8_t val) { memory_entry_data_ = val; }
+
   // Fail most subsequent requests.
   void set_fail_requests() { fail_requests_ = true; }
 
   void set_fail_sparse_requests() { fail_sparse_requests_ = true; }
 
   // If |value| is true, don't deliver any completion callbacks until called
   // again with |value| set to false.  Caution: remember to enable callbacks
   // again or all subsequent tests will fail.
   static void IgnoreCallbacks(bool value);
 
@@ skipping 14 matching lines @@
   // delivers any callback previously stored.
   static void StoreAndDeliverCallbacks(bool store,
                                        MockDiskEntry* entry,
                                        const CompletionCallback& callback,
                                        int result);
 
   static const int kNumCacheEntryDataIndices = 3;
 
   std::string key_;
   std::vector<char> data_[kNumCacheEntryDataIndices];
+  unsigned char memory_entry_data_;
   int test_mode_;
   bool doomed_;
   bool sparse_;
   bool fail_requests_;
   bool fail_sparse_requests_;
   bool busy_;
   bool delayed_;
   bool cancel_;
   static bool ignore_callbacks_;
 };
@@ skipping 19 matching lines @@
                          const CompletionCallback& callback) override;
   int DoomEntriesSince(base::Time initial_time,
                        const CompletionCallback& callback) override;
   int CalculateSizeOfAllEntries(const CompletionCallback& callback) override;
   std::unique_ptr<Iterator> CreateIterator() override;
   void GetStats(base::StringPairs* stats) override;
   void OnExternalCacheHit(const std::string& key) override;
   size_t DumpMemoryStats(
       base::trace_event::ProcessMemoryDump* pmd,
       const std::string& parent_absolute_name) const override;
+  uint8_t GetMemoryEntryData(const std::string& key) override;
+  void SetMemoryEntryData(const std::string& key, uint8_t data) override;
 
   // Returns number of times a cache entry was successfully opened.
   int open_count() const { return open_count_; }
 
   // Returns number of times a cache entry was successfully created.
   int create_count() const { return create_count_; }
 
   // Fail any subsequent CreateEntry and OpenEntry.
   void set_fail_requests() { fail_requests_ = true; }
 
@@ skipping 136 matching lines @@
 
   std::unique_ptr<disk_cache::Backend>* backend_;
   CompletionCallback callback_;
   bool block_;
   bool fail_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_MOCK_HTTP_CACHE_H_