diff --git a/cmd/cover/html.go b/cmd/cover/html.go
index 76bed291..e7336e44 100644
--- a/cmd/cover/html.go
+++ b/cmd/cover/html.go
@@ -11,6 +11,7 @@ import (
"html"
"io"
"io/ioutil"
+ "math"
"os"
"os/exec"
"path/filepath"
@@ -162,18 +163,43 @@ type Token struct {
Pos int
Start bool
Count int
+ Norm float64 // count normalized to 0-1
}
// Tokens returns a Profile as a set of Tokens within the provided src.
func (p *Profile) Tokens(src []byte) (tokens []Token) {
- line, col := 1, 1
+ // Find maximum counts.
+ max := 0
+ for _, b := range p.Blocks {
+ if b.Count > max {
+ max = b.Count
+ }
+ }
+ // Divisor for normalization.
+ divisor := math.Log(float64(max + 1))
+
+ // tok returns a Token, populating the Norm field with a normalized Count.
+ tok := func(pos int, start bool, count int) Token {
+ t := Token{Pos: pos, Start: start, Count: count}
+ if !start || count == 0 {
+ return t
+ }
+ if max == 1 {
+ t.Norm = 0.4 // "set" mode; use pale color
+ } else {
+ t.Norm = math.Log(float64(count+1)) / divisor
+ }
+ return t
+ }
+
+ line, col := 1, 2
for si, bi := 0, 0; si < len(src) && bi < len(p.Blocks); {
b := p.Blocks[bi]
if b.StartLine == line && b.StartCol == col {
- tokens = append(tokens, Token{Pos: si, Start: true, Count: b.Count})
+ tokens = append(tokens, tok(si, true, b.Count))
}
if b.EndLine == line && b.EndCol == col {
- tokens = append(tokens, Token{Pos: si, Start: false})
+ tokens = append(tokens, tok(si, false, 0))
bi++
continue // Don't advance through src; maybe the next block starts here.
}
@@ -203,16 +229,21 @@ func (t tokensByPos) Less(i, j int) bool {
// source code, and tokens, and writes it to the given Writer.
func htmlGen(w io.Writer, filename string, src []byte, tokens []Token) error {
dst := bufio.NewWriter(w)
+ fmt.Fprintln(dst, ``)
fmt.Fprintf(dst, "%s
\n", html.EscapeString(filename))
for i := range src {
for len(tokens) > 0 && tokens[0].Pos == i {
t := tokens[0]
if t.Start {
- color := "#CFC" // Green
- if t.Count == 0 {
- color = "#FCC" // Red
+ c := "rgb(255, 0, 0)" // Red
+ if t.Count > 0 {
+ // Gradient from pale green (low count)
+ // to bright green (high count)
+ r := 240 - int(220*t.Norm)
+ b := 170 + r/3
+ c = fmt.Sprintf("rgb(%v, 255, %v)", r, b)
}
- fmt.Fprintf(dst, ``, color, t.Count)
+ fmt.Fprintf(dst, ``, c, t.Count)
} else {
dst.WriteString("")
}