net/disk_cache/disk_cache_test_util.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.

#ifndef NET_DISK_CACHE_DISK_CACHE_TEST_UTIL_H_
#define NET_DISK_CACHE_DISK_CACHE_TEST_UTIL_H_

#include <stddef.h>
#include <stdint.h>

#include <string>

#include "base/files/file_path.h"
#include "base/macros.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "base/timer/timer.h"
#include "build/build_config.h"

// Re-creates a given test file inside the cache test folder.
bool CreateCacheTestFile(const base::FilePath& name);

// Deletes all file son the cache.
bool DeleteCache(const base::FilePath& path);

// Fills buffer with random values (may contain nulls unless no_nulls is true).
void CacheTestFillBuffer(char* buffer, size_t len, bool no_nulls);

// Generates a random key of up to 200 bytes.
std::string GenerateKey(bool same_length);

// Returns true if the cache is not corrupt. Assumes blockfile cache.
// |max_size|, if non-zero, will be set as its size.
bool CheckCacheIntegrity(const base::FilePath& path,
                         bool new_eviction,
                         int max_size,
                         uint32_t mask);

// -----------------------------------------------------------------------

// Simple helper to deal with the message loop on a test.
class MessageLoopHelper {
 public:
  MessageLoopHelper();
  ~MessageLoopHelper();

  // Run the message loop and wait for num_callbacks before returning. Returns
  // false if we are waiting to long. Each callback that will be waited on is
  // required to call CallbackWasCalled() to indicate when it was called.
  bool WaitUntilCacheIoFinished(int num_callbacks);

  // True if a given callback was called more times than it expected.
  bool callback_reused_error() const { return callback_reused_error_; }
  void set_callback_reused_error(bool error) {
    callback_reused_error_ = error;
  }

  int callbacks_called() const { return callbacks_called_; }
  // Report that a callback was called. Each callback that will be waited on
  // via WaitUntilCacheIoFinished() is expected to call this method to
  // indicate when it has been executed.
  void CallbackWasCalled() { ++callbacks_called_; }

 private:
  // Sets the number of callbacks that can be received so far.
  void ExpectCallbacks(int num_callbacks) {
    num_callbacks_ = num_callbacks;
    num_iterations_ = last_ = 0;
    completed_ = false;
  }

  // Called periodically to test if WaitUntilCacheIoFinished should return.
  void TimerExpired();

  std::unique_ptr<base::RunLoop> run_loop_;
  int num_callbacks_;
  int num_iterations_;
  int last_;
  bool completed_;

  // True if a callback was called/reused more than expected.
  bool callback_reused_error_;
  int callbacks_called_;

  DISALLOW_COPY_AND_ASSIGN(MessageLoopHelper);
};

// -----------------------------------------------------------------------

// Simple callback to process IO completions from the cache. It allows tests
// with multiple simultaneous IO operations.
class CallbackTest {
 public:
  // Creates a new CallbackTest object. When the callback is called, it will
  // update |helper|. If |reuse| is false and a callback is called more than
  // once, or if |reuse| is true and a callback is called more than twice, an
  // error will be reported to |helper|.
  CallbackTest(MessageLoopHelper* helper, bool reuse);
  ~CallbackTest();

  void Run(int result);

  int last_result() const { return last_result_; }

 private:
  MessageLoopHelper* helper_;
  int reuse_;
  int last_result_;
  DISALLOW_COPY_AND_ASSIGN(CallbackTest);
};

#endif  // NET_DISK_CACHE_DISK_CACHE_TEST_UTIL_H_