// Copyright 2013 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.
// Package cover provides support for parsing coverage profiles
// generated by "go test -coverprofile=cover.out".
package cover // import "golang.org/x/tools/cover"
import (
"bufio"
"errors"
"fmt"
"io"
"math"
"os"
"sort"
"strconv"
"strings"
)
// Profile represents the profiling data for a specific file.
type Profile struct {
FileName string
Mode string
Blocks []ProfileBlock
}
// ProfileBlock represents a single block of profiling data.
type ProfileBlock struct {
StartLine, StartCol int
EndLine, EndCol int
NumStmt, Count int
}
type byFileName []*Profile
func (p byFileName) Len() int { return len(p) }
func (p byFileName) Less(i, j int) bool { return p[i].FileName < p[j].FileName }
func (p byFileName) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
// ParseProfiles parses profile data in the specified file and returns a
// Profile for each source file described therein.
func ParseProfiles(fileName string) ([]*Profile, error) {
pf, err := os.Open(fileName)
if err != nil {
return nil, err
}
defer pf.Close()
return ParseProfilesFromReader(pf)
}
// ParseProfilesFromReader parses profile data from the Reader and
// returns a Profile for each source file described therein.
func ParseProfilesFromReader(rd io.Reader) ([]*Profile, error) {
// First line is "mode: foo", where foo is "set", "count", or "atomic".
// Rest of file is in the format
// encoding/base64/base64.go:34.44,37.40 3 1
// where the fields are: name.go:line.column,line.column numberOfStatements count
files := make(map[string]*Profile)
s := bufio.NewScanner(rd)
mode := ""
for s.Scan() {
line := s.Text()
if mode == "" {
const p = "mode: "
if !strings.HasPrefix(line, p) || line == p {
return nil, fmt.Errorf("bad mode line: %v", line)
}
mode = line[len(p):]
continue
}
fn, b, err := parseLine(line)
if err != nil {
return nil, fmt.Errorf("line %q doesn't match expected format: %v", line, err)
}
p := files[fn]
if p == nil {
p = &Profile{
FileName: fn,
Mode: mode,
}
files[fn] = p
}
p.Blocks = append(p.Blocks, b)
}
if err := s.Err(); err != nil {
return nil, err
}
for _, p := range files {
sort.Sort(blocksByStart(p.Blocks))
// Merge samples from the same location.
j := 1
for i := 1; i < len(p.Blocks); i++ {
b := p.Blocks[i]
last := p.Blocks[j-1]
if b.StartLine == last.StartLine &&
b.StartCol == last.StartCol &&
b.EndLine == last.EndLine &&
b.EndCol == last.EndCol {
if b.NumStmt != last.NumStmt {
return nil, fmt.Errorf("inconsistent NumStmt: changed from %d to %d", last.NumStmt, b.NumStmt)
}
if mode == "set" {
p.Blocks[j-1].Count |= b.Count
} else {
p.Blocks[j-1].Count += b.Count
}
continue
}
p.Blocks[j] = b
j++
}
p.Blocks = p.Blocks[:j]
}
// Generate a sorted slice.
profiles := make([]*Profile, 0, len(files))
for _, profile := range files {
profiles = append(profiles, profile)
}
sort.Sort(byFileName(profiles))
return profiles, nil
}
// parseLine parses a line from a coverage file.
// It is equivalent to the regex
// ^(.+):([0-9]+)\.([0-9]+),([0-9]+)\.([0-9]+) ([0-9]+) ([0-9]+)$
//
// However, it is much faster: https://golang.org/cl/179377
func parseLine(l string) (fileName string, block ProfileBlock, err error) {
end := len(l)
b := ProfileBlock{}
b.Count, end, err = seekBack(l, ' ', end, "Count")
if err != nil {
return "", b, err
}
b.NumStmt, end, err = seekBack(l, ' ', end, "NumStmt")
if err != nil {
return "", b, err
}
b.EndCol, end, err = seekBack(l, '.', end, "EndCol")
if err != nil {
return "", b, err
}
b.EndLine, end, err = seekBack(l, ',', end, "EndLine")
if err != nil {
return "", b, err
}
b.StartCol, end, err = seekBack(l, '.', end, "StartCol")
if err != nil {
return "", b, err
}
b.StartLine, end, err = seekBack(l, ':', end, "StartLine")
if err != nil {
return "", b, err
}
fn := l[0:end]
if fn == "" {
return "", b, errors.New("a FileName cannot be blank")
}
return fn, b, nil
}
// seekBack searches backwards from end to find sep in l, then returns the
// value between sep and end as an integer.
// If seekBack fails, the returned error will reference what.
func seekBack(l string, sep byte, end int, what string) (value int, nextSep int, err error) {
// Since we're seeking backwards and we know only ASCII is legal for these values,
// we can ignore the possibility of non-ASCII characters.
for start := end - 1; start >= 0; start-- {
if l[start] == sep {
i, err := strconv.Atoi(l[start+1 : end])
if err != nil {
return 0, 0, fmt.Errorf("couldn't parse %q: %v", what, err)
}
if i < 0 {
return 0, 0, fmt.Errorf("negative values are not allowed for %s, found %d", what, i)
}
return i, start, nil
}
}
return 0, 0, fmt.Errorf("couldn't find a %s before %s", string(sep), what)
}
type blocksByStart []ProfileBlock
func (b blocksByStart) Len() int { return len(b) }
func (b blocksByStart) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
func (b blocksByStart) Less(i, j int) bool {
bi, bj := b[i], b[j]
return bi.StartLine < bj.StartLine || bi.StartLine == bj.StartLine && bi.StartCol < bj.StartCol
}
// Boundary represents the position in a source file of the beginning or end of a
// block as reported by the coverage profile. In HTML mode, it will correspond to
// the opening or closing of a <span> tag and will be used to colorize the source
type Boundary struct {
Offset int // Location as a byte offset in the source file.
Start bool // Is this the start of a block?
Count int // Event count from the cover profile.
Norm float64 // Count normalized to [0..1].
Index int // Order in input file.
}
// Boundaries returns a Profile as a set of Boundary objects within the provided src.
func (p *Profile) Boundaries(src []byte) (boundaries []Boundary) {
// Find maximum count.
max := 0
for _, b := range p.Blocks {
if b.Count > max {
max = b.Count
}
}
// Divisor for normalization.
divisor := math.Log(float64(max))
// boundary returns a Boundary, populating the Norm field with a normalized Count.
index := 0
boundary := func(offset int, start bool, count int) Boundary {
b := Boundary{Offset: offset, Start: start, Count: count, Index: index}
index++
if !start || count == 0 {
return b
}
if max <= 1 {
b.Norm = 0.8 // Profile is in"set" mode; we want a heat map. Use cov8 in the CSS.
} else if count > 0 {
b.Norm = math.Log(float64(count)) / divisor
}
return b
}
line, col := 1, 2 // TODO: Why is this 2?
for si, bi := 0, 0; si < len(src) && bi < len(p.Blocks); {
b := p.Blocks[bi]
if b.StartLine == line && b.StartCol == col {
boundaries = append(boundaries, boundary(si, true, b.Count))
}
if b.EndLine == line && b.EndCol == col || line > b.EndLine {
boundaries = append(boundaries, boundary(si, false, 0))
bi++
continue // Don't advance through src; maybe the next block starts here.
}
if src[si] == '\n' {
line++
col = 0
}
col++
si++
}
sort.Sort(boundariesByPos(boundaries))
return
}
type boundariesByPos []Boundary
func (b boundariesByPos) Len() int { return len(b) }
func (b boundariesByPos) Swap(i, j int) { b[i], b[j] = b[j], b[i] }
func (b boundariesByPos) Less(i, j int) bool {
if b[i].Offset == b[j].Offset {
// Boundaries at the same offset should be ordered according to
// their original position.
return b[i].Index < b[j].Index
}
return b[i].Offset < b[j].Offset
}
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