Polish absurlreplacer

diff --git a/transform/absurlreplacer.go b/transform/absurlreplacer.go
index 40c9be75e34961de16a240aaca729500f42d5075..e1ba9e54c109eb59a79d4b03fe62ff0aa6a6a78d 100644 (file)
--- a/transform/absurlreplacer.go
+++ b/transform/absurlreplacer.go
@@ -17,8 +17,11 @@ const (
        matchStateFull
 )
 
-type contentlexer struct {
+type absurllexer struct {
+       // the source to absurlify
        content []byte
+       // the target for the new absurlified content
+       w io.Writer
 
        pos   int // input position
        start int // item start position
@@ -31,16 +34,19 @@ type contentlexer struct {
        matches [3]bool // track matches of the 3 prefixes
        idx     int     // last index in matches checked
 
-       w io.Writer
 }
 
-type stateFunc func(*contentlexer) stateFunc
+type stateFunc func(*absurllexer) stateFunc
 
+// prefix is how to identify and which func to handle the replacement.
 type prefix struct {
        r []rune
-       f func(l *contentlexer)
+       f func(l *absurllexer)
 }
 
+// new prefixes can be added below, but note:
+// - the matches array above must be expanded.
+// - the prefix must with the current logic end with '='
 var prefixes = []*prefix{
        &prefix{r: []rune{'s', 'r', 'c', '='}, f: checkCandidateBase},
        &prefix{r: []rune{'h', 'r', 'e', 'f', '='}, f: checkCandidateBase},
@@ -53,7 +59,8 @@ type absURLMatcher struct {
        replacementURL []byte
 }
 
-func (l *contentlexer) match(r rune) {
+// match check rune inside word. Will be != ' '.
+func (l *absurllexer) match(r rune) {
 
        var found bool
 
@@ -68,8 +75,6 @@ func (l *contentlexer) match(r rune) {
                                if l.checkMatchState(r, j) {
                                        return
                                }
-                       } else {
-                               l.matches[j] = false
                        }
                }
 
@@ -95,14 +100,12 @@ func (l *contentlexer) match(r rune) {
                }
        }
 
-       if found {
-               return
+       if !found {
+               l.ms = matchStateNone
        }
-
-       l.ms = matchStateNone
 }
 
-func (l *contentlexer) checkMatchState(r rune, idx int) bool {
+func (l *absurllexer) checkMatchState(r rune, idx int) bool {
        if r == '=' {
                l.ms = matchStateFull
                for k := range l.matches {
@@ -118,12 +121,13 @@ func (l *contentlexer) checkMatchState(r rune, idx int) bool {
        return false
 }
 
-func (l *contentlexer) emit() {
+func (l *absurllexer) emit() {
        l.w.Write(l.content[l.start:l.pos])
        l.start = l.pos
 }
 
-func checkCandidateBase(l *contentlexer) {
+// handle URLs in src and href.
+func checkCandidateBase(l *absurllexer) {
        for _, m := range l.matchers {
                if !bytes.HasPrefix(l.content[l.pos:], m.match) {
                        continue
@@ -148,7 +152,8 @@ func checkCandidateBase(l *contentlexer) {
        }
 }
 
-func checkCandidateSrcset(l *contentlexer) {
+// handle URLs in srcset.
+func checkCandidateSrcset(l *absurllexer) {
        // special case, not frequent (me think)
        for _, m := range l.matchers {
                if !bytes.HasPrefix(l.content[l.pos:], m.match) {
@@ -201,7 +206,8 @@ func checkCandidateSrcset(l *contentlexer) {
        }
 }
 
-func (l *contentlexer) replace() {
+// main loop
+func (l *absurllexer) replace() {
        contentLength := len(l.content)
        var r rune
 
@@ -227,8 +233,8 @@ func (l *contentlexer) replace() {
                                for i, m := range l.matches {
                                        if m {
                                                p = prefixes[i]
+                                               l.matches[i] = false
                                        }
-                                       l.matches[i] = false
                                }
                                if p == nil {
                                        panic("illegal state: curr is nil when state is full")
@@ -246,7 +252,7 @@ func (l *contentlexer) replace() {
 }
 
 func doReplace(ct contentTransformer, matchers []absURLMatcher) {
-       lexer := &contentlexer{
+       lexer := &absurllexer{
                content:  ct.Content(),
                w:        ct,
                matchers: matchers}