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      1 // Copyright 2013 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 // This file provides support for parsing coverage profiles
      6 // generated by "go test -coverprofile=cover.out".
      7 // It is a copy of golang.org/x/tools/cover/profile.go.
      8 
      9 package main
     10 
     11 import (
     12 	"bufio"
     13 	"fmt"
     14 	"math"
     15 	"os"
     16 	"regexp"
     17 	"sort"
     18 	"strconv"
     19 	"strings"
     20 )
     21 
     22 // Profile represents the profiling data for a specific file.
     23 type Profile struct {
     24 	FileName string
     25 	Mode     string
     26 	Blocks   []ProfileBlock
     27 }
     28 
     29 // ProfileBlock represents a single block of profiling data.
     30 type ProfileBlock struct {
     31 	StartLine, StartCol int
     32 	EndLine, EndCol     int
     33 	NumStmt, Count      int
     34 }
     35 
     36 type byFileName []*Profile
     37 
     38 func (p byFileName) Len() int           { return len(p) }
     39 func (p byFileName) Less(i, j int) bool { return p[i].FileName < p[j].FileName }
     40 func (p byFileName) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
     41 
     42 // ParseProfiles parses profile data in the specified file and returns a
     43 // Profile for each source file described therein.
     44 func ParseProfiles(fileName string) ([]*Profile, error) {
     45 	pf, err := os.Open(fileName)
     46 	if err != nil {
     47 		return nil, err
     48 	}
     49 	defer pf.Close()
     50 
     51 	files := make(map[string]*Profile)
     52 	buf := bufio.NewReader(pf)
     53 	// First line is "mode: foo", where foo is "set", "count", or "atomic".
     54 	// Rest of file is in the format
     55 	//	encoding/base64/base64.go:34.44,37.40 3 1
     56 	// where the fields are: name.go:line.column,line.column numberOfStatements count
     57 	s := bufio.NewScanner(buf)
     58 	mode := ""
     59 	for s.Scan() {
     60 		line := s.Text()
     61 		if mode == "" {
     62 			const p = "mode: "
     63 			if !strings.HasPrefix(line, p) || line == p {
     64 				return nil, fmt.Errorf("bad mode line: %v", line)
     65 			}
     66 			mode = line[len(p):]
     67 			continue
     68 		}
     69 		m := lineRe.FindStringSubmatch(line)
     70 		if m == nil {
     71 			return nil, fmt.Errorf("line %q doesn't match expected format: %v", m, lineRe)
     72 		}
     73 		fn := m[1]
     74 		p := files[fn]
     75 		if p == nil {
     76 			p = &Profile{
     77 				FileName: fn,
     78 				Mode:     mode,
     79 			}
     80 			files[fn] = p
     81 		}
     82 		p.Blocks = append(p.Blocks, ProfileBlock{
     83 			StartLine: toInt(m[2]),
     84 			StartCol:  toInt(m[3]),
     85 			EndLine:   toInt(m[4]),
     86 			EndCol:    toInt(m[5]),
     87 			NumStmt:   toInt(m[6]),
     88 			Count:     toInt(m[7]),
     89 		})
     90 	}
     91 	if err := s.Err(); err != nil {
     92 		return nil, err
     93 	}
     94 	for _, p := range files {
     95 		sort.Sort(blocksByStart(p.Blocks))
     96 		// Merge samples from the same location.
     97 		j := 1
     98 		for i := 1; i < len(p.Blocks); i++ {
     99 			b := p.Blocks[i]
    100 			last := p.Blocks[j-1]
    101 			if b.StartLine == last.StartLine &&
    102 				b.StartCol == last.StartCol &&
    103 				b.EndLine == last.EndLine &&
    104 				b.EndCol == last.EndCol {
    105 				if b.NumStmt != last.NumStmt {
    106 					return nil, fmt.Errorf("inconsistent NumStmt: changed from %d to %d", last.NumStmt, b.NumStmt)
    107 				}
    108 				if mode == "set" {
    109 					p.Blocks[j-1].Count |= b.Count
    110 				} else {
    111 					p.Blocks[j-1].Count += b.Count
    112 				}
    113 				continue
    114 			}
    115 			p.Blocks[j] = b
    116 			j++
    117 		}
    118 		p.Blocks = p.Blocks[:j]
    119 	}
    120 	// Generate a sorted slice.
    121 	profiles := make([]*Profile, 0, len(files))
    122 	for _, profile := range files {
    123 		profiles = append(profiles, profile)
    124 	}
    125 	sort.Sort(byFileName(profiles))
    126 	return profiles, nil
    127 }
    128 
    129 type blocksByStart []ProfileBlock
    130 
    131 func (b blocksByStart) Len() int      { return len(b) }
    132 func (b blocksByStart) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
    133 func (b blocksByStart) Less(i, j int) bool {
    134 	bi, bj := b[i], b[j]
    135 	return bi.StartLine < bj.StartLine || bi.StartLine == bj.StartLine && bi.StartCol < bj.StartCol
    136 }
    137 
    138 var lineRe = regexp.MustCompile(`^(.+):([0-9]+).([0-9]+),([0-9]+).([0-9]+) ([0-9]+) ([0-9]+)$`)
    139 
    140 func toInt(s string) int {
    141 	i, err := strconv.Atoi(s)
    142 	if err != nil {
    143 		panic(err)
    144 	}
    145 	return i
    146 }
    147 
    148 // Boundary represents the position in a source file of the beginning or end of a
    149 // block as reported by the coverage profile. In HTML mode, it will correspond to
    150 // the opening or closing of a <span> tag and will be used to colorize the source
    151 type Boundary struct {
    152 	Offset int     // Location as a byte offset in the source file.
    153 	Start  bool    // Is this the start of a block?
    154 	Count  int     // Event count from the cover profile.
    155 	Norm   float64 // Count normalized to [0..1].
    156 }
    157 
    158 // Boundaries returns a Profile as a set of Boundary objects within the provided src.
    159 func (p *Profile) Boundaries(src []byte) (boundaries []Boundary) {
    160 	// Find maximum count.
    161 	max := 0
    162 	for _, b := range p.Blocks {
    163 		if b.Count > max {
    164 			max = b.Count
    165 		}
    166 	}
    167 	// Divisor for normalization.
    168 	divisor := math.Log(float64(max))
    169 
    170 	// boundary returns a Boundary, populating the Norm field with a normalized Count.
    171 	boundary := func(offset int, start bool, count int) Boundary {
    172 		b := Boundary{Offset: offset, Start: start, Count: count}
    173 		if !start || count == 0 {
    174 			return b
    175 		}
    176 		if max <= 1 {
    177 			b.Norm = 0.8 // Profile is in"set" mode; we want a heat map. Use cov8 in the CSS.
    178 		} else if count > 0 {
    179 			b.Norm = math.Log(float64(count)) / divisor
    180 		}
    181 		return b
    182 	}
    183 
    184 	line, col := 1, 2 // TODO: Why is this 2?
    185 	for si, bi := 0, 0; si < len(src) && bi < len(p.Blocks); {
    186 		b := p.Blocks[bi]
    187 		if b.StartLine == line && b.StartCol == col {
    188 			boundaries = append(boundaries, boundary(si, true, b.Count))
    189 		}
    190 		if b.EndLine == line && b.EndCol == col || line > b.EndLine {
    191 			boundaries = append(boundaries, boundary(si, false, 0))
    192 			bi++
    193 			continue // Don't advance through src; maybe the next block starts here.
    194 		}
    195 		if src[si] == '\n' {
    196 			line++
    197 			col = 0
    198 		}
    199 		col++
    200 		si++
    201 	}
    202 	sort.Sort(boundariesByPos(boundaries))
    203 	return
    204 }
    205 
    206 type boundariesByPos []Boundary
    207 
    208 func (b boundariesByPos) Len() int      { return len(b) }
    209 func (b boundariesByPos) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
    210 func (b boundariesByPos) Less(i, j int) bool {
    211 	if b[i].Offset == b[j].Offset {
    212 		return !b[i].Start && b[j].Start
    213 	}
    214 	return b[i].Offset < b[j].Offset
    215 }
    216