1# Copyright 2017 The Chromium OS 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"""This throttler reduces result size by deleting files permanently."""
6
7import os
8
9try:
10    from autotest_lib.client.bin.result_tools import throttler_lib
11    from autotest_lib.client.bin.result_tools import utils_lib
12except ImportError:
13    import throttler_lib
14    import utils_lib
15
16
17# Default threshold of file size in KB for a file to be qualified for deletion.
18DEFAULT_FILE_SIZE_THRESHOLD_BYTE = 1024 * 1024
19
20# Regex for file path that should not be deleted.
21NON_DELETABLE_FILE_PATH_PATTERNS = [
22        '.*perf.data$',       # Performance test data.
23        ]
24
25def _delete_file(file_info):
26    """Delete the given file and update the summary.
27
28    @param file_info: A ResultInfo object containing summary for the file to be
29            shrunk.
30    """
31    utils_lib.LOG('Deleting file %s.' % file_info.path)
32    try:
33        os.remove(file_info.path)
34    except OSError as e:
35        utils_lib.LOG('Failed to delete file %s Error: %s' %
36                      (file_info.path, e))
37
38    # Update the trimmed_size in ResultInfo.
39    file_info.trimmed_size = 0
40
41
42def throttle(summary, max_result_size_KB,
43             file_size_threshold_byte=DEFAULT_FILE_SIZE_THRESHOLD_BYTE,
44             exclude_file_patterns=[]):
45    """Throttle the files in summary by trimming file content.
46
47    Stop throttling until all files are processed or the result size is already
48    reduced to be under the given max_result_size_KB.
49
50    @param summary: A ResultInfo object containing result summary.
51    @param max_result_size_KB: Maximum test result size in KB.
52    @param file_size_threshold_byte: Threshold of file size in byte for a file
53            to be qualified for deletion. All qualified files will be deleted,
54            until all files are processed or the result size is under the given
55            max_result_size_KB.
56    @param exclude_file_patterns: A list of regex pattern for files not to be
57            throttled. Default is an empty list.
58    """
59    file_infos, _ = throttler_lib.sort_result_files(summary)
60    file_infos = throttler_lib.get_throttleable_files(
61            file_infos,
62            exclude_file_patterns + NON_DELETABLE_FILE_PATH_PATTERNS)
63
64    for info in file_infos:
65        if info.trimmed_size > file_size_threshold_byte:
66            _delete_file(info)
67            if throttler_lib.check_throttle_limit(summary, max_result_size_KB):
68                return
69