DoomPartialEntry should not attempt to doom an already doomed entry.

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_
 #define NET_HTTP_MOCK_HTTP_CACHE_H_
 
 #include <stdint.h>
 
 #include <unordered_map>
 
 #include "base/strings/string_split.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/http/http_cache.h"
 #include "net/http/http_transaction_test_util.h"
 
 namespace net {
 
 //-----------------------------------------------------------------------------
 // Mock disk cache (a very basic memory cache implementation).
 
 class MockDiskEntry : public disk_cache::Entry,
                       public base::RefCounted<MockDiskEntry> {
  public:
+  enum DeferOp {
+    DEFER_NONE,
+    DEFER_CREATE,
+    DEFER_READ,
+  };
+
   explicit MockDiskEntry(const std::string& key);
 
   bool is_doomed() const { return doomed_; }
 
   void Doom() override;
   void Close() override;
   std::string GetKey() const override;
   base::Time GetLastUsed() const override;
   base::Time GetLastModified() const override;
   int32_t GetDataSize(int index) const override;
@@ skipping 27 matching lines @@
   // 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);
 
+  void SetDefer(DeferOp defer_op) { defer_op_ = defer_op; }
+
+  // Resumes deferred cache operation by posting |resume_callback_| with
+  // |resume_return_code_|. Returns ERR_IO_PENDING.
+  int ResumeDiskEntryOperation();
+
  private:
   friend class base::RefCounted<MockDiskEntry>;
   struct CallbackInfo;
 
   ~MockDiskEntry() override;
 
   // Unlike the callbacks for MockHttpTransaction, we want this one to run even
   // if the consumer called Close on the MockDiskEntry.  We achieve that by
   // leveraging the fact that this class is reference counted.
   void CallbackLater(const CompletionCallback& callback, int result);
@@ skipping 12 matching lines @@
   std::string key_;
   std::vector<char> data_[kNumCacheEntryDataIndices];
   int test_mode_;
   bool doomed_;
   bool sparse_;
   bool fail_requests_;
   bool fail_sparse_requests_;
   bool busy_;
   bool delayed_;
   bool cancel_;
+
+  // Used for pause and restart.
+  DeferOp defer_op_;
+  CompletionCallback resume_callback_;
+  int resume_return_code_;
+
   static bool ignore_callbacks_;
 };
 
 class MockDiskCache : public disk_cache::Backend {
  public:
   MockDiskCache();
   ~MockDiskCache() override;
 
   CacheType GetCacheType() const override;
   int32_t GetEntryCount() const override;
@@ skipping 35 matching lines @@
   void set_soft_failures(bool value) { soft_failures_ = value; }
 
   // Makes sure that CreateEntry is not called twice for a given key.
   void set_double_create_check(bool value) { double_create_check_ = value; }
 
   // Makes all requests for data ranges to fail as not implemented.
   void set_fail_sparse_requests() { fail_sparse_requests_ = true; }
 
   void ReleaseAll();
 
+  // Returns true if a doomed entry exists with this key.
   bool IsDiskEntryDoomed(const std::string& key);
 
+  // Defers invoking the callback for the given operation.

[jkarlin, 2017/07/14 16:45:42]

Please add a comment here on when you should call ResumeCacheOperation vs
ResumeDiskEntryOperation

[shivanisha, 2017/07/14 16:56:49]

Done

+  void SetDefer(MockDiskEntry::DeferOp defer_op) { defer_op_ = defer_op; }
+
+  // Resume deferred cache operation by posting |resume_callback_| with
+  // |resume_return_code_|. Returns ERR_IO_PENDING.
+  int ResumeCacheOperation();
+
+  // Returns a reference to the disk entry with the given |key|.
+  scoped_refptr<MockDiskEntry> GetDiskEntryRef(const std::string& key);
+
  private:
   using EntryMap = std::unordered_map<std::string, MockDiskEntry*>;
   class NotImplementedIterator;
 
   void CallbackLater(const CompletionCallback& callback, int result);
 
   EntryMap entries_;
   int open_count_;
   int create_count_;
   int doomed_count_;
   bool fail_requests_;
   bool soft_failures_;
   bool double_create_check_;
   bool fail_sparse_requests_;
+
+  // Used for pause and restart.
+  MockDiskEntry::DeferOp defer_op_;
+  CompletionCallback resume_callback_;
+  int resume_return_code_;
 };
 
 class MockBackendFactory : public HttpCache::BackendFactory {
  public:
   int CreateBackend(NetLog* net_log,
                     std::unique_ptr<disk_cache::Backend>* backend,
                     const CompletionCallback& callback) override;
 };
 
 class MockHttpCache {
@@ skipping 47 matching lines @@
                           NetLog* net_log);
 
   // Returns the test mode after considering the global override.
   static int GetTestMode(int test_mode);
 
   // Overrides the test mode for a given operation. Remember to reset it after
   // the test! (by setting test_mode to zero).
   static void SetTestMode(int test_mode);
 
   // Functions to test the state of ActiveEntry.
-
   bool IsWriterPresent(const std::string& key);
   bool IsHeadersTransactionPresent(const std::string& key);
   int GetCountReaders(const std::string& key);
   int GetCountAddToEntryQueue(const std::string& key);
   int GetCountDoneHeadersQueue(const std::string& key);
 
  private:
   HttpCache http_cache_;
 };
 
@@ skipping 35 matching lines @@
 
   std::unique_ptr<disk_cache::Backend>* backend_;
   CompletionCallback callback_;
   bool block_;
   bool fail_;
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_MOCK_HTTP_CACHE_H_