1# Copyright 2013 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 5from telemetry.value import failure 6from telemetry.value import skip 7 8 9def MergeLikeValuesFromSamePage(all_values): 10 """Merges values that measure the same thing on the same page. 11 12 A page may end up being measured multiple times, meaning that we may end up 13 with something like this: 14 ScalarValue(page1, 'x', 1) 15 ScalarValue(page2, 'x', 4) 16 ScalarValue(page1, 'x', 2) 17 ScalarValue(page2, 'x', 5) 18 19 This function will produce: 20 ListOfScalarValues(page1, 'x', [1, 2]) 21 ListOfScalarValues(page2, 'x', [4, 5]) 22 23 The workhorse of this code is Value.MergeLikeValuesFromSamePage. 24 25 This requires (but assumes) that the values passed in with the same grouping 26 key pass the Value.IsMergableWith test. If this is not obeyed, the 27 results will be undefined. 28 """ 29 return _MergeLikeValuesCommon( 30 all_values, 31 lambda x: (x.page, x.name), 32 lambda v0, merge_group: v0.MergeLikeValuesFromSamePage(merge_group)) 33 34 35def MergeLikeValuesFromDifferentPages(all_values, group_by_name_suffix=False): 36 """Merges values that measure the same thing on different pages. 37 38 After using MergeLikeValuesFromSamePage, one still ends up with values from 39 different pages: 40 ScalarValue(page1, 'x', 1) 41 ScalarValue(page1, 'y', 30) 42 ScalarValue(page2, 'x', 2) 43 ScalarValue(page2, 'y', 40) 44 45 This function will group the values of the same value_name together: 46 ListOfScalarValues(None, 'x', [1, 2]) 47 ListOfScalarValues(None, 'y', [30, 40]) 48 49 If group_by_name_suffix is True, then x.z and y.z are considered to be the 50 same value and are grouped together. If false, then x.z and y.z are 51 considered different. 52 53 The workhorse of this code is Value.MergeLikeValuesFromDifferentPages. 54 55 Not all values that go into this function will come out: not every value can 56 be merged across pages. Values whose MergeLikeValuesFromDifferentPages returns 57 None will be omitted from the results. 58 59 This requires (but assumes) that the values passed in with the same name pass 60 the Value.IsMergableWith test. If this is not obeyed, the results 61 will be undefined. 62 """ 63 if group_by_name_suffix: 64 def key(value): 65 return value.name_suffix 66 else: 67 key = lambda x: x.name 68 return _MergeLikeValuesCommon( 69 all_values, 70 key, 71 lambda v0, merge_group: v0.MergeLikeValuesFromDifferentPages( 72 merge_group, group_by_name_suffix=group_by_name_suffix)) 73 74 75def _MergeLikeValuesCommon(all_values, key_func, merge_func): 76 """Groups all_values by key_func then applies merge_func to the groups. 77 78 This takes the all_values list and groups each item in that using the key 79 provided by key_func. This produces groups of values with like keys. Thes are 80 then handed to the merge_func to produce a new key. If merge_func produces a 81 non-None return, it is added to the list of returned values. 82 """ 83 # When merging, we want to merge values in a consistent order, e.g. so that 84 # Scalar(1), Scalar(2) predictably produces ListOfScalarValues([1,2]) rather 85 # than 2,1. 86 # 87 # To do this, the values are sorted by key up front. Then, grouping is 88 # performed using a dictionary, but as new groups are found, the order in 89 # which they were found is also noted. 90 # 91 # Merging is then performed on groups in group-creation-order. This ensures 92 # that the returned array is in a stable order, group by group. 93 # 94 # Within a group, the order is stable because of the original sort. 95 all_values = list(all_values) 96 merge_groups = GroupStably(all_values, key_func) 97 98 res = [] 99 for merge_group in merge_groups: 100 v0 = merge_group[0] 101 vM = merge_func(v0, merge_group) 102 if vM: 103 res.append(vM) 104 return res 105 106def GroupStably(all_values, key_func): 107 """Groups an array by key_func, with the groups returned in a stable order. 108 109 Returns a list of groups. 110 """ 111 all_values = list(all_values) 112 113 merge_groups = {} 114 merge_groups_in_creation_order = [] 115 for value in all_values: 116 # TODO(chrishenry): This is temporary. When we figure out the 117 # right summarization strategy for page runs with failures/skips, we 118 # should use that instead. 119 should_skip_value = (isinstance(value, failure.FailureValue) or 120 isinstance(value, skip.SkipValue)) 121 122 if should_skip_value: 123 continue 124 125 key = key_func(value) 126 if key not in merge_groups: 127 merge_groups[key] = [] 128 merge_groups_in_creation_order.append(merge_groups[key]) 129 merge_groups[key].append(value) 130 return merge_groups_in_creation_order 131