libgo: Update to weekly.2011-12-14.

[pf3gnuchains/gcc-fork.git] / libgo / go / regexp / exec.go

diff --git a/libgo/go/regexp/exec.go b/libgo/go/regexp/exec.go
index d7057a1..e16a1b5 100644 (file)
--- a/libgo/go/regexp/exec.go
+++ b/libgo/go/regexp/exec.go
@@ -1,6 +1,9 @@
 package regexp
 
-import "regexp/syntax"
+import (
+       "io"
+       "regexp/syntax"
+)
 
 // A queue is a 'sparse array' holding pending threads of execution.
 // See http://research.swtch.com/2008/03/using-uninitialized-memory-for-fun-and.html
@@ -34,6 +37,28 @@ type machine struct {
        pool     []*thread    // pool of available threads
        matched  bool         // whether a match was found
        matchcap []int        // capture information for the match
+
+       // cached inputs, to avoid allocation
+       inputBytes  inputBytes
+       inputString inputString
+       inputReader inputReader
+}
+
+func (m *machine) newInputBytes(b []byte) input {
+       m.inputBytes.str = b
+       return &m.inputBytes
+}
+
+func (m *machine) newInputString(s string) input {
+       m.inputString.str = s
+       return &m.inputString
+}
+
+func (m *machine) newInputReader(r io.RuneReader) input {
+       m.inputReader.r = r
+       m.inputReader.atEOT = false
+       m.inputReader.pos = 0
+       return &m.inputReader
 }
 
 // progMachine returns a new machine running the prog p.
@@ -74,6 +99,9 @@ func (m *machine) alloc(i *syntax.Inst) *thread {
 
 // free returns t to the free pool.
 func (m *machine) free(t *thread) {
+       m.inputBytes.str = nil
+       m.inputString.str = ""
+       m.inputReader.r = nil
        m.pool = append(m.pool, t)
 }
 
@@ -287,8 +315,16 @@ var empty = make([]int, 0)
 
 // doExecute finds the leftmost match in the input and returns
 // the position of its subexpressions.
-func (re *Regexp) doExecute(i input, pos int, ncap int) []int {
+func (re *Regexp) doExecute(r io.RuneReader, b []byte, s string, pos int, ncap int) []int {
        m := re.get()
+       var i input
+       if r != nil {
+               i = m.newInputReader(r)
+       } else if b != nil {
+               i = m.newInputBytes(b)
+       } else {
+               i = m.newInputString(s)
+       }
        m.init(ncap)
        if !m.match(i, pos) {
                re.put(m)