1 // Copyright (c) 2018 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef CHROME_BROWSER_MEDIA_WEBRTC_WEBRTC_EVENT_LOG_MANAGER_UNITTEST_HELPERS_H_
6 #define CHROME_BROWSER_MEDIA_WEBRTC_WEBRTC_EVENT_LOG_MANAGER_UNITTEST_HELPERS_H_
7 
8 #include <memory>
9 #include <string>
10 
11 #include "base/files/file_path.h"
12 #include "build/build_config.h"
13 #include "chrome/browser/media/webrtc/webrtc_event_log_manager_common.h"
14 
15 namespace webrtc_event_logging {
16 
17 // Which type of compression, if any, LogFileWriterTest should use.
18 enum class WebRtcEventLogCompression {
19   NONE,
20   GZIP_NULL_ESTIMATION,
21   GZIP_PERFECT_ESTIMATION
22 };
23 
24 // Produce a LogFileWriter::Factory object.
25 std::unique_ptr<LogFileWriter::Factory> CreateLogFileWriterFactory(
26     WebRtcEventLogCompression compression);
27 
28 #if defined(OS_POSIX)
29 void RemoveWritePermissions(const base::FilePath& path);
30 #endif  // defined(OS_POSIX)
31 
32 // Always estimates strings to be compressed to zero bytes.
33 class NullEstimator : public CompressedSizeEstimator {
34  public:
35   class Factory : public CompressedSizeEstimator::Factory {
36    public:
37     ~Factory() override = default;
38 
39     std::unique_ptr<CompressedSizeEstimator> Create() const override;
40   };
41 
42   ~NullEstimator() override = default;
43 
44   size_t EstimateCompressedSize(const std::string& input) const override;
45 };
46 
47 // Provides a perfect estimation of the compressed size by cheating - performing
48 // actual compression, then reporting the resulting size.
49 // This class is stateful; the number, nature and order of calls to
50 // EstimateCompressedSize() is important.
51 class PerfectGzipEstimator : public CompressedSizeEstimator {
52  public:
53   class Factory : public CompressedSizeEstimator::Factory {
54    public:
55     ~Factory() override = default;
56 
57     std::unique_ptr<CompressedSizeEstimator> Create() const override;
58   };
59 
60   PerfectGzipEstimator();
61 
62   ~PerfectGzipEstimator() override;
63 
64   size_t EstimateCompressedSize(const std::string& input) const override;
65 
66  private:
67   // This compressor allows EstimateCompressedSize to return an exact estimate.
68   // EstimateCompressedSize is normally const, but here we fake it, so we set
69   // it as mutable.
70   mutable std::unique_ptr<LogCompressor> compressor_;
71 };
72 
73 // Check the gzipped size of |uncompressed|, including header and footer,
74 // assuming it were gzipped on its own.
75 size_t GzippedSize(const std::string& uncompressed);
76 
77 // Same as other version, but with elements compressed in sequence.
78 size_t GzippedSize(const std::vector<std::string>& uncompressed);
79 
80 }  // namespace webrtc_event_logging
81 
82 #endif  // CHROME_BROWSER_MEDIA_WEBRTC_WEBRTC_EVENT_LOG_MANAGER_UNITTEST_HELPERS_H_
83