Austin Clements | 7f87d66 | 2021-10-08 13:10:28 -0400 | [diff] [blame] | 1 | // Copyright 2021 The Go Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package benchproc |
| 6 | |
| 7 | import ( |
| 8 | "fmt" |
| 9 | "log" |
| 10 | "os" |
| 11 | |
| 12 | "golang.org/x/perf/benchfmt" |
| 13 | "golang.org/x/perf/benchunit" |
| 14 | ) |
| 15 | |
| 16 | // Example shows a complete benchmark processing pipeline that uses |
| 17 | // filtering, projection, accumulation, and sorting. |
| 18 | func Example() { |
| 19 | // Open the example benchmark data. |
| 20 | f, err := os.Open("testdata/suffixarray.bench") |
| 21 | if err != nil { |
| 22 | log.Fatal(err) |
| 23 | } |
| 24 | defer f.Close() |
| 25 | |
| 26 | // Create a filter that extracts just "BenchmarkNew" on the value |
| 27 | // "go" of the name key "text". Typically, the filter expression |
| 28 | // would come from a command-line flag. |
| 29 | filter, err := NewFilter(".name:New /text:go") |
| 30 | if err != nil { |
| 31 | log.Fatal(err) |
| 32 | } |
| 33 | // Create a projection. This projection extracts "/bits=" and |
| 34 | // "/size=" from the benchmark name. It sorts bits in the |
| 35 | // default, first-observation order and size numerically. |
| 36 | // Typically, the projection expression would come from a |
| 37 | // command-line flag. |
| 38 | var pp ProjectionParser |
| 39 | projection, err := pp.Parse("/bits,/size@num", filter) |
| 40 | if err != nil { |
| 41 | log.Fatal(err) |
| 42 | } |
| 43 | // Create a projection that captures all configuration not |
| 44 | // captured by the above projection. We'll use this to check |
| 45 | // if there's unexpected variation in other configuration |
| 46 | // fields and report it. |
| 47 | residue := pp.Residue() |
| 48 | |
| 49 | // We'll accumulate benchmark results by their projection. |
| 50 | // Projections create Keys, which are == if the projected |
| 51 | // values are ==, so they can be used as map keys. |
| 52 | bySize := make(map[Key][]float64) |
| 53 | var keys []Key |
| 54 | var residues []Key |
| 55 | |
| 56 | // Read the benchmark results. |
| 57 | r := benchfmt.NewReader(f, "example") |
| 58 | for r.Scan() { |
| 59 | var res *benchfmt.Result |
| 60 | switch rec := r.Result(); rec := rec.(type) { |
| 61 | case *benchfmt.Result: |
| 62 | res = rec |
| 63 | case *benchfmt.SyntaxError: |
| 64 | // Report a non-fatal parse error. |
| 65 | log.Print(err) |
| 66 | continue |
| 67 | default: |
| 68 | // Unknown record type. Ignore. |
| 69 | continue |
| 70 | } |
| 71 | |
| 72 | // Step 1: If necessary, transform the Result, for example to |
| 73 | // add configuration keys that could be used in filters and |
| 74 | // projections. This example doesn't need any transformation. |
| 75 | |
| 76 | // Step 2: Filter the result. |
| 77 | if match, err := filter.Apply(res); !match { |
| 78 | // Result was fully excluded by the filter. |
| 79 | if err != nil { |
| 80 | // Print the reason we rejected this result. |
| 81 | log.Print(err) |
| 82 | } |
| 83 | continue |
| 84 | } |
| 85 | |
| 86 | // Step 3: Project the result. This produces a Key |
| 87 | // that captures the "size" and "bits" from the result. |
| 88 | key := projection.Project(res) |
| 89 | |
| 90 | // Accumulate the results by configuration. |
| 91 | speed, ok := res.Value("sec/op") |
| 92 | if !ok { |
| 93 | continue |
| 94 | } |
| 95 | if _, ok := bySize[key]; !ok { |
| 96 | keys = append(keys, key) |
| 97 | } |
| 98 | bySize[key] = append(bySize[key], speed) |
| 99 | |
| 100 | // Collect residue configurations. |
| 101 | resConfig := residue.Project(res) |
| 102 | residues = append(residues, resConfig) |
| 103 | } |
| 104 | // Check for I/O errors. |
| 105 | if err := r.Err(); err != nil { |
| 106 | log.Fatal(err) |
| 107 | } |
| 108 | |
| 109 | // Step 4: Sort the collected configurations using the order |
| 110 | // specified by the projection. |
| 111 | SortKeys(keys) |
| 112 | |
| 113 | // Print the results. |
| 114 | fmt.Printf("%-24s %s\n", "config", "sec/op") |
| 115 | for _, config := range keys { |
| 116 | fmt.Printf("%-24s %s\n", config, benchunit.Scale(mean(bySize[config]), benchunit.Decimal)) |
| 117 | } |
| 118 | |
| 119 | // Check if there was variation in any other configuration |
| 120 | // fields that wasn't captured by the projection and warn the |
| 121 | // user that something may be unexpected. |
| 122 | nonsingular := NonSingularFields(residues) |
| 123 | if len(nonsingular) > 0 { |
| 124 | fmt.Printf("warning: results vary in %s\n", nonsingular) |
| 125 | } |
| 126 | |
| 127 | // Output: |
| 128 | // config sec/op |
| 129 | // /bits:32 /size:100K 4.650m |
| 130 | // /bits:32 /size:500K 26.18m |
| 131 | // /bits:32 /size:1M 51.39m |
| 132 | // /bits:32 /size:5M 306.7m |
| 133 | // /bits:32 /size:10M 753.0m |
| 134 | // /bits:32 /size:50M 5.814 |
| 135 | // /bits:64 /size:100K 5.081m |
| 136 | // /bits:64 /size:500K 26.43m |
| 137 | // /bits:64 /size:1M 55.60m |
| 138 | // /bits:64 /size:5M 366.6m |
| 139 | // /bits:64 /size:10M 821.2m |
| 140 | // /bits:64 /size:50M 6.390 |
| 141 | } |