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Diffstat (limited to 'src/cmd/pprof/internal/profile/filter.go')
-rw-r--r-- | src/cmd/pprof/internal/profile/filter.go | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/cmd/pprof/internal/profile/filter.go b/src/cmd/pprof/internal/profile/filter.go new file mode 100644 index 000000000..903616aac --- /dev/null +++ b/src/cmd/pprof/internal/profile/filter.go @@ -0,0 +1,157 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Implements methods to filter samples from profiles. +package profile + +import "regexp" + +// FilterSamplesByName filters the samples in a profile and only keeps +// samples where at least one frame matches focus but none match ignore. +// Returns true is the corresponding regexp matched at least one sample. +func (p *Profile) FilterSamplesByName(focus, ignore, hide *regexp.Regexp) (fm, im, hm bool) { + focusOrIgnore := make(map[uint64]bool) + hidden := make(map[uint64]bool) + for _, l := range p.Location { + if ignore != nil && l.matchesName(ignore) { + im = true + focusOrIgnore[l.ID] = false + } else if focus == nil || l.matchesName(focus) { + fm = true + focusOrIgnore[l.ID] = true + } + if hide != nil && l.matchesName(hide) { + hm = true + l.Line = l.unmatchedLines(hide) + if len(l.Line) == 0 { + hidden[l.ID] = true + } + } + } + + s := make([]*Sample, 0, len(p.Sample)) + for _, sample := range p.Sample { + if focusedAndNotIgnored(sample.Location, focusOrIgnore) { + if len(hidden) > 0 { + var locs []*Location + for _, loc := range sample.Location { + if !hidden[loc.ID] { + locs = append(locs, loc) + } + } + if len(locs) == 0 { + // Remove sample with no locations (by not adding it to s). + continue + } + sample.Location = locs + } + s = append(s, sample) + } + } + p.Sample = s + + return +} + +// matchesName returns whether the function name or file in the +// location matches the regular expression. +func (loc *Location) matchesName(re *regexp.Regexp) bool { + for _, ln := range loc.Line { + if fn := ln.Function; fn != nil { + if re.MatchString(fn.Name) { + return true + } + if re.MatchString(fn.Filename) { + return true + } + } + } + return false +} + +// unmatchedLines returns the lines in the location that do not match +// the regular expression. +func (loc *Location) unmatchedLines(re *regexp.Regexp) []Line { + var lines []Line + for _, ln := range loc.Line { + if fn := ln.Function; fn != nil { + if re.MatchString(fn.Name) { + continue + } + if re.MatchString(fn.Filename) { + continue + } + } + lines = append(lines, ln) + } + return lines +} + +// focusedAndNotIgnored looks up a slice of ids against a map of +// focused/ignored locations. The map only contains locations that are +// explicitly focused or ignored. Returns whether there is at least +// one focused location but no ignored locations. +func focusedAndNotIgnored(locs []*Location, m map[uint64]bool) bool { + var f bool + for _, loc := range locs { + if focus, focusOrIgnore := m[loc.ID]; focusOrIgnore { + if focus { + // Found focused location. Must keep searching in case there + // is an ignored one as well. + f = true + } else { + // Found ignored location. Can return false right away. + return false + } + } + } + return f +} + +// TagMatch selects tags for filtering +type TagMatch func(key, val string, nval int64) bool + +// FilterSamplesByTag removes all samples from the profile, except +// those that match focus and do not match the ignore regular +// expression. +func (p *Profile) FilterSamplesByTag(focus, ignore TagMatch) (fm, im bool) { + samples := make([]*Sample, 0, len(p.Sample)) + for _, s := range p.Sample { + focused, ignored := focusedSample(s, focus, ignore) + fm = fm || focused + im = im || ignored + if focused && !ignored { + samples = append(samples, s) + } + } + p.Sample = samples + return +} + +// focusedTag checks a sample against focus and ignore regexps. +// Returns whether the focus/ignore regexps match any tags +func focusedSample(s *Sample, focus, ignore TagMatch) (fm, im bool) { + fm = focus == nil + for key, vals := range s.Label { + for _, val := range vals { + if ignore != nil && ignore(key, val, 0) { + im = true + } + if !fm && focus(key, val, 0) { + fm = true + } + } + } + for key, vals := range s.NumLabel { + for _, val := range vals { + if ignore != nil && ignore(key, "", val) { + im = true + } + if !fm && focus(key, "", val) { + fm = true + } + } + } + return fm, im +} |