fastpastebin/vendor/github.com/dlclark/regexp2/runner.go
Stanislav N. aka pztrn 48d43ca097 Pagination, readable error messages to user, syntax highlighting started.
Pagination now works. Temporary hardcoded 10 pastes per page, will be put
in configuration later. Maybe.

From now user will receive readable error message if error occured.

Started to work on syntax highlighting, tried to make lexers detection
work but apparently to no avail.
2018-05-01 02:37:51 +05:00

1622 lines
34 KiB
Go

package regexp2
import (
"bytes"
"errors"
"fmt"
"math"
"strconv"
"strings"
"time"
"unicode"
"github.com/dlclark/regexp2/syntax"
)
type runner struct {
re *Regexp
code *syntax.Code
runtextstart int // starting point for search
runtext []rune // text to search
runtextpos int // current position in text
runtextend int
// The backtracking stack. Opcodes use this to store data regarding
// what they have matched and where to backtrack to. Each "frame" on
// the stack takes the form of [CodePosition Data1 Data2...], where
// CodePosition is the position of the current opcode and
// the data values are all optional. The CodePosition can be negative, and
// these values (also called "back2") are used by the BranchMark family of opcodes
// to indicate whether they are backtracking after a successful or failed
// match.
// When we backtrack, we pop the CodePosition off the stack, set the current
// instruction pointer to that code position, and mark the opcode
// with a backtracking flag ("Back"). Each opcode then knows how to
// handle its own data.
runtrack []int
runtrackpos int
// This stack is used to track text positions across different opcodes.
// For example, in /(a*b)+/, the parentheses result in a SetMark/CaptureMark
// pair. SetMark records the text position before we match a*b. Then
// CaptureMark uses that position to figure out where the capture starts.
// Opcodes which push onto this stack are always paired with other opcodes
// which will pop the value from it later. A successful match should mean
// that this stack is empty.
runstack []int
runstackpos int
// The crawl stack is used to keep track of captures. Every time a group
// has a capture, we push its group number onto the runcrawl stack. In
// the case of a balanced match, we push BOTH groups onto the stack.
runcrawl []int
runcrawlpos int
runtrackcount int // count of states that may do backtracking
runmatch *Match // result object
ignoreTimeout bool
timeout time.Duration // timeout in milliseconds (needed for actual)
timeoutChecksToSkip int
timeoutAt time.Time
operator syntax.InstOp
codepos int
rightToLeft bool
caseInsensitive bool
}
// run searches for matches and can continue from the previous match
//
// quick is usually false, but can be true to not return matches, just put it in caches
// textstart is -1 to start at the "beginning" (depending on Right-To-Left), otherwise an index in input
// input is the string to search for our regex pattern
func (re *Regexp) run(quick bool, textstart int, input []rune) (*Match, error) {
// get a cached runner
runner := re.getRunner()
defer re.putRunner(runner)
if textstart < 0 {
if re.RightToLeft() {
textstart = len(input)
} else {
textstart = 0
}
}
return runner.scan(input, textstart, quick, re.MatchTimeout)
}
// Scans the string to find the first match. Uses the Match object
// both to feed text in and as a place to store matches that come out.
//
// All the action is in the Go() method. Our
// responsibility is to load up the class members before
// calling Go.
//
// The optimizer can compute a set of candidate starting characters,
// and we could use a separate method Skip() that will quickly scan past
// any characters that we know can't match.
func (r *runner) scan(rt []rune, textstart int, quick bool, timeout time.Duration) (*Match, error) {
r.timeout = timeout
r.ignoreTimeout = (time.Duration(math.MaxInt64) == timeout)
r.runtextstart = textstart
r.runtext = rt
r.runtextend = len(rt)
stoppos := r.runtextend
bump := 1
if r.re.RightToLeft() {
bump = -1
stoppos = 0
}
r.runtextpos = textstart
initted := false
r.startTimeoutWatch()
for {
if r.re.Debug() {
//fmt.Printf("\nSearch content: %v\n", string(r.runtext))
fmt.Printf("\nSearch range: from 0 to %v\n", r.runtextend)
fmt.Printf("Firstchar search starting at %v stopping at %v\n", r.runtextpos, stoppos)
}
if r.findFirstChar() {
if err := r.checkTimeout(); err != nil {
return nil, err
}
if !initted {
r.initMatch()
initted = true
}
if r.re.Debug() {
fmt.Printf("Executing engine starting at %v\n\n", r.runtextpos)
}
if err := r.execute(); err != nil {
return nil, err
}
if r.runmatch.matchcount[0] > 0 {
// We'll return a match even if it touches a previous empty match
return r.tidyMatch(quick), nil
}
// reset state for another go
r.runtrackpos = len(r.runtrack)
r.runstackpos = len(r.runstack)
r.runcrawlpos = len(r.runcrawl)
}
// failure!
if r.runtextpos == stoppos {
r.tidyMatch(true)
return nil, nil
}
// Recognize leading []* and various anchors, and bump on failure accordingly
// r.bump by one and start again
r.runtextpos += bump
}
// We never get here
}
func (r *runner) execute() error {
r.goTo(0)
for {
if r.re.Debug() {
r.dumpState()
}
if err := r.checkTimeout(); err != nil {
return err
}
switch r.operator {
case syntax.Stop:
return nil
case syntax.Nothing:
break
case syntax.Goto:
r.goTo(r.operand(0))
continue
case syntax.Testref:
if !r.runmatch.isMatched(r.operand(0)) {
break
}
r.advance(1)
continue
case syntax.Lazybranch:
r.trackPush1(r.textPos())
r.advance(1)
continue
case syntax.Lazybranch | syntax.Back:
r.trackPop()
r.textto(r.trackPeek())
r.goTo(r.operand(0))
continue
case syntax.Setmark:
r.stackPush(r.textPos())
r.trackPush()
r.advance(0)
continue
case syntax.Nullmark:
r.stackPush(-1)
r.trackPush()
r.advance(0)
continue
case syntax.Setmark | syntax.Back, syntax.Nullmark | syntax.Back:
r.stackPop()
break
case syntax.Getmark:
r.stackPop()
r.trackPush1(r.stackPeek())
r.textto(r.stackPeek())
r.advance(0)
continue
case syntax.Getmark | syntax.Back:
r.trackPop()
r.stackPush(r.trackPeek())
break
case syntax.Capturemark:
if r.operand(1) != -1 && !r.runmatch.isMatched(r.operand(1)) {
break
}
r.stackPop()
if r.operand(1) != -1 {
r.transferCapture(r.operand(0), r.operand(1), r.stackPeek(), r.textPos())
} else {
r.capture(r.operand(0), r.stackPeek(), r.textPos())
}
r.trackPush1(r.stackPeek())
r.advance(2)
continue
case syntax.Capturemark | syntax.Back:
r.trackPop()
r.stackPush(r.trackPeek())
r.uncapture()
if r.operand(0) != -1 && r.operand(1) != -1 {
r.uncapture()
}
break
case syntax.Branchmark:
r.stackPop()
matched := r.textPos() - r.stackPeek()
if matched != 0 { // Nonempty match -> loop now
r.trackPush2(r.stackPeek(), r.textPos()) // Save old mark, textpos
r.stackPush(r.textPos()) // Make new mark
r.goTo(r.operand(0)) // Loop
} else { // Empty match -> straight now
r.trackPushNeg1(r.stackPeek()) // Save old mark
r.advance(1) // Straight
}
continue
case syntax.Branchmark | syntax.Back:
r.trackPopN(2)
r.stackPop()
r.textto(r.trackPeekN(1)) // Recall position
r.trackPushNeg1(r.trackPeek()) // Save old mark
r.advance(1) // Straight
continue
case syntax.Branchmark | syntax.Back2:
r.trackPop()
r.stackPush(r.trackPeek()) // Recall old mark
break // Backtrack
case syntax.Lazybranchmark:
{
// We hit this the first time through a lazy loop and after each
// successful match of the inner expression. It simply continues
// on and doesn't loop.
r.stackPop()
oldMarkPos := r.stackPeek()
if r.textPos() != oldMarkPos { // Nonempty match -> try to loop again by going to 'back' state
if oldMarkPos != -1 {
r.trackPush2(oldMarkPos, r.textPos()) // Save old mark, textpos
} else {
r.trackPush2(r.textPos(), r.textPos())
}
} else {
// The inner expression found an empty match, so we'll go directly to 'back2' if we
// backtrack. In this case, we need to push something on the stack, since back2 pops.
// However, in the case of ()+? or similar, this empty match may be legitimate, so push the text
// position associated with that empty match.
r.stackPush(oldMarkPos)
r.trackPushNeg1(r.stackPeek()) // Save old mark
}
r.advance(1)
continue
}
case syntax.Lazybranchmark | syntax.Back:
// After the first time, Lazybranchmark | syntax.Back occurs
// with each iteration of the loop, and therefore with every attempted
// match of the inner expression. We'll try to match the inner expression,
// then go back to Lazybranchmark if successful. If the inner expression
// fails, we go to Lazybranchmark | syntax.Back2
r.trackPopN(2)
pos := r.trackPeekN(1)
r.trackPushNeg1(r.trackPeek()) // Save old mark
r.stackPush(pos) // Make new mark
r.textto(pos) // Recall position
r.goTo(r.operand(0)) // Loop
continue
case syntax.Lazybranchmark | syntax.Back2:
// The lazy loop has failed. We'll do a true backtrack and
// start over before the lazy loop.
r.stackPop()
r.trackPop()
r.stackPush(r.trackPeek()) // Recall old mark
break
case syntax.Setcount:
r.stackPush2(r.textPos(), r.operand(0))
r.trackPush()
r.advance(1)
continue
case syntax.Nullcount:
r.stackPush2(-1, r.operand(0))
r.trackPush()
r.advance(1)
continue
case syntax.Setcount | syntax.Back:
r.stackPopN(2)
break
case syntax.Nullcount | syntax.Back:
r.stackPopN(2)
break
case syntax.Branchcount:
// r.stackPush:
// 0: Mark
// 1: Count
r.stackPopN(2)
mark := r.stackPeek()
count := r.stackPeekN(1)
matched := r.textPos() - mark
if count >= r.operand(1) || (matched == 0 && count >= 0) { // Max loops or empty match -> straight now
r.trackPushNeg2(mark, count) // Save old mark, count
r.advance(2) // Straight
} else { // Nonempty match -> count+loop now
r.trackPush1(mark) // remember mark
r.stackPush2(r.textPos(), count+1) // Make new mark, incr count
r.goTo(r.operand(0)) // Loop
}
continue
case syntax.Branchcount | syntax.Back:
// r.trackPush:
// 0: Previous mark
// r.stackPush:
// 0: Mark (= current pos, discarded)
// 1: Count
r.trackPop()
r.stackPopN(2)
if r.stackPeekN(1) > 0 { // Positive -> can go straight
r.textto(r.stackPeek()) // Zap to mark
r.trackPushNeg2(r.trackPeek(), r.stackPeekN(1)-1) // Save old mark, old count
r.advance(2) // Straight
continue
}
r.stackPush2(r.trackPeek(), r.stackPeekN(1)-1) // recall old mark, old count
break
case syntax.Branchcount | syntax.Back2:
// r.trackPush:
// 0: Previous mark
// 1: Previous count
r.trackPopN(2)
r.stackPush2(r.trackPeek(), r.trackPeekN(1)) // Recall old mark, old count
break // Backtrack
case syntax.Lazybranchcount:
// r.stackPush:
// 0: Mark
// 1: Count
r.stackPopN(2)
mark := r.stackPeek()
count := r.stackPeekN(1)
if count < 0 { // Negative count -> loop now
r.trackPushNeg1(mark) // Save old mark
r.stackPush2(r.textPos(), count+1) // Make new mark, incr count
r.goTo(r.operand(0)) // Loop
} else { // Nonneg count -> straight now
r.trackPush3(mark, count, r.textPos()) // Save mark, count, position
r.advance(2) // Straight
}
continue
case syntax.Lazybranchcount | syntax.Back:
// r.trackPush:
// 0: Mark
// 1: Count
// 2: r.textPos
r.trackPopN(3)
mark := r.trackPeek()
textpos := r.trackPeekN(2)
if r.trackPeekN(1) < r.operand(1) && textpos != mark { // Under limit and not empty match -> loop
r.textto(textpos) // Recall position
r.stackPush2(textpos, r.trackPeekN(1)+1) // Make new mark, incr count
r.trackPushNeg1(mark) // Save old mark
r.goTo(r.operand(0)) // Loop
continue
} else { // Max loops or empty match -> backtrack
r.stackPush2(r.trackPeek(), r.trackPeekN(1)) // Recall old mark, count
break // backtrack
}
case syntax.Lazybranchcount | syntax.Back2:
// r.trackPush:
// 0: Previous mark
// r.stackPush:
// 0: Mark (== current pos, discarded)
// 1: Count
r.trackPop()
r.stackPopN(2)
r.stackPush2(r.trackPeek(), r.stackPeekN(1)-1) // Recall old mark, count
break // Backtrack
case syntax.Setjump:
r.stackPush2(r.trackpos(), r.crawlpos())
r.trackPush()
r.advance(0)
continue
case syntax.Setjump | syntax.Back:
r.stackPopN(2)
break
case syntax.Backjump:
// r.stackPush:
// 0: Saved trackpos
// 1: r.crawlpos
r.stackPopN(2)
r.trackto(r.stackPeek())
for r.crawlpos() != r.stackPeekN(1) {
r.uncapture()
}
break
case syntax.Forejump:
// r.stackPush:
// 0: Saved trackpos
// 1: r.crawlpos
r.stackPopN(2)
r.trackto(r.stackPeek())
r.trackPush1(r.stackPeekN(1))
r.advance(0)
continue
case syntax.Forejump | syntax.Back:
// r.trackPush:
// 0: r.crawlpos
r.trackPop()
for r.crawlpos() != r.trackPeek() {
r.uncapture()
}
break
case syntax.Bol:
if r.leftchars() > 0 && r.charAt(r.textPos()-1) != '\n' {
break
}
r.advance(0)
continue
case syntax.Eol:
if r.rightchars() > 0 && r.charAt(r.textPos()) != '\n' {
break
}
r.advance(0)
continue
case syntax.Boundary:
if !r.isBoundary(r.textPos(), 0, r.runtextend) {
break
}
r.advance(0)
continue
case syntax.Nonboundary:
if r.isBoundary(r.textPos(), 0, r.runtextend) {
break
}
r.advance(0)
continue
case syntax.ECMABoundary:
if !r.isECMABoundary(r.textPos(), 0, r.runtextend) {
break
}
r.advance(0)
continue
case syntax.NonECMABoundary:
if r.isECMABoundary(r.textPos(), 0, r.runtextend) {
break
}
r.advance(0)
continue
case syntax.Beginning:
if r.leftchars() > 0 {
break
}
r.advance(0)
continue
case syntax.Start:
if r.textPos() != r.textstart() {
break
}
r.advance(0)
continue
case syntax.EndZ:
if r.rightchars() > 1 || r.rightchars() == 1 && r.charAt(r.textPos()) != '\n' {
break
}
r.advance(0)
continue
case syntax.End:
if r.rightchars() > 0 {
break
}
r.advance(0)
continue
case syntax.One:
if r.forwardchars() < 1 || r.forwardcharnext() != rune(r.operand(0)) {
break
}
r.advance(1)
continue
case syntax.Notone:
if r.forwardchars() < 1 || r.forwardcharnext() == rune(r.operand(0)) {
break
}
r.advance(1)
continue
case syntax.Set:
if r.forwardchars() < 1 || !r.code.Sets[r.operand(0)].CharIn(r.forwardcharnext()) {
break
}
r.advance(1)
continue
case syntax.Multi:
if !r.runematch(r.code.Strings[r.operand(0)]) {
break
}
r.advance(1)
continue
case syntax.Ref:
capnum := r.operand(0)
if r.runmatch.isMatched(capnum) {
if !r.refmatch(r.runmatch.matchIndex(capnum), r.runmatch.matchLength(capnum)) {
break
}
} else {
if (r.re.options & ECMAScript) == 0 {
break
}
}
r.advance(1)
continue
case syntax.Onerep:
c := r.operand(1)
if r.forwardchars() < c {
break
}
ch := rune(r.operand(0))
for c > 0 {
if r.forwardcharnext() != ch {
goto BreakBackward
}
c--
}
r.advance(2)
continue
case syntax.Notonerep:
c := r.operand(1)
if r.forwardchars() < c {
break
}
ch := rune(r.operand(0))
for c > 0 {
if r.forwardcharnext() == ch {
goto BreakBackward
}
c--
}
r.advance(2)
continue
case syntax.Setrep:
c := r.operand(1)
if r.forwardchars() < c {
break
}
set := r.code.Sets[r.operand(0)]
for c > 0 {
if !set.CharIn(r.forwardcharnext()) {
goto BreakBackward
}
c--
}
r.advance(2)
continue
case syntax.Oneloop:
c := r.operand(1)
if c > r.forwardchars() {
c = r.forwardchars()
}
ch := rune(r.operand(0))
i := c
for ; i > 0; i-- {
if r.forwardcharnext() != ch {
r.backwardnext()
break
}
}
if c > i {
r.trackPush2(c-i-1, r.textPos()-r.bump())
}
r.advance(2)
continue
case syntax.Notoneloop:
c := r.operand(1)
if c > r.forwardchars() {
c = r.forwardchars()
}
ch := rune(r.operand(0))
i := c
for ; i > 0; i-- {
if r.forwardcharnext() == ch {
r.backwardnext()
break
}
}
if c > i {
r.trackPush2(c-i-1, r.textPos()-r.bump())
}
r.advance(2)
continue
case syntax.Setloop:
c := r.operand(1)
if c > r.forwardchars() {
c = r.forwardchars()
}
set := r.code.Sets[r.operand(0)]
i := c
for ; i > 0; i-- {
if !set.CharIn(r.forwardcharnext()) {
r.backwardnext()
break
}
}
if c > i {
r.trackPush2(c-i-1, r.textPos()-r.bump())
}
r.advance(2)
continue
case syntax.Oneloop | syntax.Back, syntax.Notoneloop | syntax.Back:
r.trackPopN(2)
i := r.trackPeek()
pos := r.trackPeekN(1)
r.textto(pos)
if i > 0 {
r.trackPush2(i-1, pos-r.bump())
}
r.advance(2)
continue
case syntax.Setloop | syntax.Back:
r.trackPopN(2)
i := r.trackPeek()
pos := r.trackPeekN(1)
r.textto(pos)
if i > 0 {
r.trackPush2(i-1, pos-r.bump())
}
r.advance(2)
continue
case syntax.Onelazy, syntax.Notonelazy:
c := r.operand(1)
if c > r.forwardchars() {
c = r.forwardchars()
}
if c > 0 {
r.trackPush2(c-1, r.textPos())
}
r.advance(2)
continue
case syntax.Setlazy:
c := r.operand(1)
if c > r.forwardchars() {
c = r.forwardchars()
}
if c > 0 {
r.trackPush2(c-1, r.textPos())
}
r.advance(2)
continue
case syntax.Onelazy | syntax.Back:
r.trackPopN(2)
pos := r.trackPeekN(1)
r.textto(pos)
if r.forwardcharnext() != rune(r.operand(0)) {
break
}
i := r.trackPeek()
if i > 0 {
r.trackPush2(i-1, pos+r.bump())
}
r.advance(2)
continue
case syntax.Notonelazy | syntax.Back:
r.trackPopN(2)
pos := r.trackPeekN(1)
r.textto(pos)
if r.forwardcharnext() == rune(r.operand(0)) {
break
}
i := r.trackPeek()
if i > 0 {
r.trackPush2(i-1, pos+r.bump())
}
r.advance(2)
continue
case syntax.Setlazy | syntax.Back:
r.trackPopN(2)
pos := r.trackPeekN(1)
r.textto(pos)
if !r.code.Sets[r.operand(0)].CharIn(r.forwardcharnext()) {
break
}
i := r.trackPeek()
if i > 0 {
r.trackPush2(i-1, pos+r.bump())
}
r.advance(2)
continue
default:
return errors.New("unknown state in regex runner")
}
BreakBackward:
;
// "break Backward" comes here:
r.backtrack()
}
}
// increase the size of stack and track storage
func (r *runner) ensureStorage() {
if r.runstackpos < r.runtrackcount*4 {
doubleIntSlice(&r.runstack, &r.runstackpos)
}
if r.runtrackpos < r.runtrackcount*4 {
doubleIntSlice(&r.runtrack, &r.runtrackpos)
}
}
func doubleIntSlice(s *[]int, pos *int) {
oldLen := len(*s)
newS := make([]int, oldLen*2)
copy(newS[oldLen:], *s)
*pos += oldLen
*s = newS
}
// Save a number on the longjump unrolling stack
func (r *runner) crawl(i int) {
if r.runcrawlpos == 0 {
doubleIntSlice(&r.runcrawl, &r.runcrawlpos)
}
r.runcrawlpos--
r.runcrawl[r.runcrawlpos] = i
}
// Remove a number from the longjump unrolling stack
func (r *runner) popcrawl() int {
val := r.runcrawl[r.runcrawlpos]
r.runcrawlpos++
return val
}
// Get the height of the stack
func (r *runner) crawlpos() int {
return len(r.runcrawl) - r.runcrawlpos
}
func (r *runner) advance(i int) {
r.codepos += (i + 1)
r.setOperator(r.code.Codes[r.codepos])
}
func (r *runner) goTo(newpos int) {
// when branching backward, ensure storage
if newpos < r.codepos {
r.ensureStorage()
}
r.setOperator(r.code.Codes[newpos])
r.codepos = newpos
}
func (r *runner) textto(newpos int) {
r.runtextpos = newpos
}
func (r *runner) trackto(newpos int) {
r.runtrackpos = len(r.runtrack) - newpos
}
func (r *runner) textstart() int {
return r.runtextstart
}
func (r *runner) textPos() int {
return r.runtextpos
}
// push onto the backtracking stack
func (r *runner) trackpos() int {
return len(r.runtrack) - r.runtrackpos
}
func (r *runner) trackPush() {
r.runtrackpos--
r.runtrack[r.runtrackpos] = r.codepos
}
func (r *runner) trackPush1(I1 int) {
r.runtrackpos--
r.runtrack[r.runtrackpos] = I1
r.runtrackpos--
r.runtrack[r.runtrackpos] = r.codepos
}
func (r *runner) trackPush2(I1, I2 int) {
r.runtrackpos--
r.runtrack[r.runtrackpos] = I1
r.runtrackpos--
r.runtrack[r.runtrackpos] = I2
r.runtrackpos--
r.runtrack[r.runtrackpos] = r.codepos
}
func (r *runner) trackPush3(I1, I2, I3 int) {
r.runtrackpos--
r.runtrack[r.runtrackpos] = I1
r.runtrackpos--
r.runtrack[r.runtrackpos] = I2
r.runtrackpos--
r.runtrack[r.runtrackpos] = I3
r.runtrackpos--
r.runtrack[r.runtrackpos] = r.codepos
}
func (r *runner) trackPushNeg1(I1 int) {
r.runtrackpos--
r.runtrack[r.runtrackpos] = I1
r.runtrackpos--
r.runtrack[r.runtrackpos] = -r.codepos
}
func (r *runner) trackPushNeg2(I1, I2 int) {
r.runtrackpos--
r.runtrack[r.runtrackpos] = I1
r.runtrackpos--
r.runtrack[r.runtrackpos] = I2
r.runtrackpos--
r.runtrack[r.runtrackpos] = -r.codepos
}
func (r *runner) backtrack() {
newpos := r.runtrack[r.runtrackpos]
r.runtrackpos++
if r.re.Debug() {
if newpos < 0 {
fmt.Printf(" Backtracking (back2) to code position %v\n", -newpos)
} else {
fmt.Printf(" Backtracking to code position %v\n", newpos)
}
}
if newpos < 0 {
newpos = -newpos
r.setOperator(r.code.Codes[newpos] | syntax.Back2)
} else {
r.setOperator(r.code.Codes[newpos] | syntax.Back)
}
// When branching backward, ensure storage
if newpos < r.codepos {
r.ensureStorage()
}
r.codepos = newpos
}
func (r *runner) setOperator(op int) {
r.caseInsensitive = (0 != (op & syntax.Ci))
r.rightToLeft = (0 != (op & syntax.Rtl))
r.operator = syntax.InstOp(op & ^(syntax.Rtl | syntax.Ci))
}
func (r *runner) trackPop() {
r.runtrackpos++
}
// pop framesize items from the backtracking stack
func (r *runner) trackPopN(framesize int) {
r.runtrackpos += framesize
}
// Technically we are actually peeking at items already popped. So if you want to
// get and pop the top item from the stack, you do
// r.trackPop();
// r.trackPeek();
func (r *runner) trackPeek() int {
return r.runtrack[r.runtrackpos-1]
}
// get the ith element down on the backtracking stack
func (r *runner) trackPeekN(i int) int {
return r.runtrack[r.runtrackpos-i-1]
}
// Push onto the grouping stack
func (r *runner) stackPush(I1 int) {
r.runstackpos--
r.runstack[r.runstackpos] = I1
}
func (r *runner) stackPush2(I1, I2 int) {
r.runstackpos--
r.runstack[r.runstackpos] = I1
r.runstackpos--
r.runstack[r.runstackpos] = I2
}
func (r *runner) stackPop() {
r.runstackpos++
}
// pop framesize items from the grouping stack
func (r *runner) stackPopN(framesize int) {
r.runstackpos += framesize
}
// Technically we are actually peeking at items already popped. So if you want to
// get and pop the top item from the stack, you do
// r.stackPop();
// r.stackPeek();
func (r *runner) stackPeek() int {
return r.runstack[r.runstackpos-1]
}
// get the ith element down on the grouping stack
func (r *runner) stackPeekN(i int) int {
return r.runstack[r.runstackpos-i-1]
}
func (r *runner) operand(i int) int {
return r.code.Codes[r.codepos+i+1]
}
func (r *runner) leftchars() int {
return r.runtextpos
}
func (r *runner) rightchars() int {
return r.runtextend - r.runtextpos
}
func (r *runner) bump() int {
if r.rightToLeft {
return -1
}
return 1
}
func (r *runner) forwardchars() int {
if r.rightToLeft {
return r.runtextpos
}
return r.runtextend - r.runtextpos
}
func (r *runner) forwardcharnext() rune {
var ch rune
if r.rightToLeft {
r.runtextpos--
ch = r.runtext[r.runtextpos]
} else {
ch = r.runtext[r.runtextpos]
r.runtextpos++
}
if r.caseInsensitive {
return unicode.ToLower(ch)
}
return ch
}
func (r *runner) runematch(str []rune) bool {
var pos int
c := len(str)
if !r.rightToLeft {
if r.runtextend-r.runtextpos < c {
return false
}
pos = r.runtextpos + c
} else {
if r.runtextpos-0 < c {
return false
}
pos = r.runtextpos
}
if !r.caseInsensitive {
for c != 0 {
c--
pos--
if str[c] != r.runtext[pos] {
return false
}
}
} else {
for c != 0 {
c--
pos--
if str[c] != unicode.ToLower(r.runtext[pos]) {
return false
}
}
}
if !r.rightToLeft {
pos += len(str)
}
r.runtextpos = pos
return true
}
func (r *runner) refmatch(index, len int) bool {
var c, pos, cmpos int
if !r.rightToLeft {
if r.runtextend-r.runtextpos < len {
return false
}
pos = r.runtextpos + len
} else {
if r.runtextpos-0 < len {
return false
}
pos = r.runtextpos
}
cmpos = index + len
c = len
if !r.caseInsensitive {
for c != 0 {
c--
cmpos--
pos--
if r.runtext[cmpos] != r.runtext[pos] {
return false
}
}
} else {
for c != 0 {
c--
cmpos--
pos--
if unicode.ToLower(r.runtext[cmpos]) != unicode.ToLower(r.runtext[pos]) {
return false
}
}
}
if !r.rightToLeft {
pos += len
}
r.runtextpos = pos
return true
}
func (r *runner) backwardnext() {
if r.rightToLeft {
r.runtextpos++
} else {
r.runtextpos--
}
}
func (r *runner) charAt(j int) rune {
return r.runtext[j]
}
func (r *runner) findFirstChar() bool {
if 0 != (r.code.Anchors & (syntax.AnchorBeginning | syntax.AnchorStart | syntax.AnchorEndZ | syntax.AnchorEnd)) {
if !r.code.RightToLeft {
if (0 != (r.code.Anchors&syntax.AnchorBeginning) && r.runtextpos > 0) ||
(0 != (r.code.Anchors&syntax.AnchorStart) && r.runtextpos > r.runtextstart) {
r.runtextpos = r.runtextend
return false
}
if 0 != (r.code.Anchors&syntax.AnchorEndZ) && r.runtextpos < r.runtextend-1 {
r.runtextpos = r.runtextend - 1
} else if 0 != (r.code.Anchors&syntax.AnchorEnd) && r.runtextpos < r.runtextend {
r.runtextpos = r.runtextend
}
} else {
if (0 != (r.code.Anchors&syntax.AnchorEnd) && r.runtextpos < r.runtextend) ||
(0 != (r.code.Anchors&syntax.AnchorEndZ) && (r.runtextpos < r.runtextend-1 ||
(r.runtextpos == r.runtextend-1 && r.charAt(r.runtextpos) != '\n'))) ||
(0 != (r.code.Anchors&syntax.AnchorStart) && r.runtextpos < r.runtextstart) {
r.runtextpos = 0
return false
}
if 0 != (r.code.Anchors&syntax.AnchorBeginning) && r.runtextpos > 0 {
r.runtextpos = 0
}
}
if r.code.BmPrefix != nil {
return r.code.BmPrefix.IsMatch(r.runtext, r.runtextpos, 0, r.runtextend)
}
return true // found a valid start or end anchor
} else if r.code.BmPrefix != nil {
r.runtextpos = r.code.BmPrefix.Scan(r.runtext, r.runtextpos, 0, r.runtextend)
if r.runtextpos == -1 {
if r.code.RightToLeft {
r.runtextpos = 0
} else {
r.runtextpos = r.runtextend
}
return false
}
return true
} else if r.code.FcPrefix == nil {
return true
}
r.rightToLeft = r.code.RightToLeft
r.caseInsensitive = r.code.FcPrefix.CaseInsensitive
set := r.code.FcPrefix.PrefixSet
if set.IsSingleton() {
ch := set.SingletonChar()
for i := r.forwardchars(); i > 0; i-- {
if ch == r.forwardcharnext() {
r.backwardnext()
return true
}
}
} else {
for i := r.forwardchars(); i > 0; i-- {
n := r.forwardcharnext()
//fmt.Printf("%v in %v: %v\n", string(n), set.String(), set.CharIn(n))
if set.CharIn(n) {
r.backwardnext()
return true
}
}
}
return false
}
func (r *runner) initMatch() {
// Use a hashtable'ed Match object if the capture numbers are sparse
if r.runmatch == nil {
if r.re.caps != nil {
r.runmatch = newMatchSparse(r.re, r.re.caps, r.re.capsize, r.runtext, r.runtextstart)
} else {
r.runmatch = newMatch(r.re, r.re.capsize, r.runtext, r.runtextstart)
}
} else {
r.runmatch.reset(r.runtext, r.runtextstart)
}
// note we test runcrawl, because it is the last one to be allocated
// If there is an alloc failure in the middle of the three allocations,
// we may still return to reuse this instance, and we want to behave
// as if the allocations didn't occur. (we used to test _trackcount != 0)
if r.runcrawl != nil {
r.runtrackpos = len(r.runtrack)
r.runstackpos = len(r.runstack)
r.runcrawlpos = len(r.runcrawl)
return
}
r.initTrackCount()
tracksize := r.runtrackcount * 8
stacksize := r.runtrackcount * 8
if tracksize < 32 {
tracksize = 32
}
if stacksize < 16 {
stacksize = 16
}
r.runtrack = make([]int, tracksize)
r.runtrackpos = tracksize
r.runstack = make([]int, stacksize)
r.runstackpos = stacksize
r.runcrawl = make([]int, 32)
r.runcrawlpos = 32
}
func (r *runner) tidyMatch(quick bool) *Match {
if !quick {
match := r.runmatch
r.runmatch = nil
match.tidy(r.runtextpos)
return match
} else {
// send back our match -- it's not leaving the package, so it's safe to not clean it up
// this reduces allocs for frequent calls to the "IsMatch" bool-only functions
return r.runmatch
}
}
// capture captures a subexpression. Note that the
// capnum used here has already been mapped to a non-sparse
// index (by the code generator RegexWriter).
func (r *runner) capture(capnum, start, end int) {
if end < start {
T := end
end = start
start = T
}
r.crawl(capnum)
r.runmatch.addMatch(capnum, start, end-start)
}
// transferCapture captures a subexpression. Note that the
// capnum used here has already been mapped to a non-sparse
// index (by the code generator RegexWriter).
func (r *runner) transferCapture(capnum, uncapnum, start, end int) {
var start2, end2 int
// these are the two intervals that are cancelling each other
if end < start {
T := end
end = start
start = T
}
start2 = r.runmatch.matchIndex(uncapnum)
end2 = start2 + r.runmatch.matchLength(uncapnum)
// The new capture gets the innermost defined interval
if start >= end2 {
end = start
start = end2
} else if end <= start2 {
start = start2
} else {
if end > end2 {
end = end2
}
if start2 > start {
start = start2
}
}
r.crawl(uncapnum)
r.runmatch.balanceMatch(uncapnum)
if capnum != -1 {
r.crawl(capnum)
r.runmatch.addMatch(capnum, start, end-start)
}
}
// revert the last capture
func (r *runner) uncapture() {
capnum := r.popcrawl()
r.runmatch.removeMatch(capnum)
}
//debug
func (r *runner) dumpState() {
back := ""
if r.operator&syntax.Back != 0 {
back = " Back"
}
if r.operator&syntax.Back2 != 0 {
back += " Back2"
}
fmt.Printf("Text: %v\nTrack: %v\nStack: %v\n %s%s\n\n",
r.textposDescription(),
r.stackDescription(r.runtrack, r.runtrackpos),
r.stackDescription(r.runstack, r.runstackpos),
r.code.OpcodeDescription(r.codepos),
back)
}
func (r *runner) stackDescription(a []int, index int) string {
buf := &bytes.Buffer{}
fmt.Fprintf(buf, "%v/%v", len(a)-index, len(a))
if buf.Len() < 8 {
buf.WriteString(strings.Repeat(" ", 8-buf.Len()))
}
buf.WriteRune('(')
for i := index; i < len(a); i++ {
if i > index {
buf.WriteRune(' ')
}
buf.WriteString(strconv.Itoa(a[i]))
}
buf.WriteRune(')')
return buf.String()
}
func (r *runner) textposDescription() string {
buf := &bytes.Buffer{}
buf.WriteString(strconv.Itoa(r.runtextpos))
if buf.Len() < 8 {
buf.WriteString(strings.Repeat(" ", 8-buf.Len()))
}
if r.runtextpos > 0 {
buf.WriteString(syntax.CharDescription(r.runtext[r.runtextpos-1]))
} else {
buf.WriteRune('^')
}
buf.WriteRune('>')
for i := r.runtextpos; i < r.runtextend; i++ {
buf.WriteString(syntax.CharDescription(r.runtext[i]))
}
if buf.Len() >= 64 {
buf.Truncate(61)
buf.WriteString("...")
} else {
buf.WriteRune('$')
}
return buf.String()
}
// decide whether the pos
// at the specified index is a boundary or not. It's just not worth
// emitting inline code for this logic.
func (r *runner) isBoundary(index, startpos, endpos int) bool {
return (index > startpos && syntax.IsWordChar(r.runtext[index-1])) !=
(index < endpos && syntax.IsWordChar(r.runtext[index]))
}
func (r *runner) isECMABoundary(index, startpos, endpos int) bool {
return (index > startpos && syntax.IsECMAWordChar(r.runtext[index-1])) !=
(index < endpos && syntax.IsECMAWordChar(r.runtext[index]))
}
// this seems like a comment to justify randomly picking 1000 :-P
// We have determined this value in a series of experiments where x86 retail
// builds (ono-lab-optimized) were run on different pattern/input pairs. Larger values
// of TimeoutCheckFrequency did not tend to increase performance; smaller values
// of TimeoutCheckFrequency tended to slow down the execution.
const timeoutCheckFrequency int = 1000
func (r *runner) startTimeoutWatch() {
if r.ignoreTimeout {
return
}
r.timeoutChecksToSkip = timeoutCheckFrequency
r.timeoutAt = time.Now().Add(r.timeout)
}
func (r *runner) checkTimeout() error {
if r.ignoreTimeout {
return nil
}
r.timeoutChecksToSkip--
if r.timeoutChecksToSkip != 0 {
return nil
}
r.timeoutChecksToSkip = timeoutCheckFrequency
return r.doCheckTimeout()
}
func (r *runner) doCheckTimeout() error {
current := time.Now()
if current.Before(r.timeoutAt) {
return nil
}
if r.re.Debug() {
//Debug.WriteLine("")
//Debug.WriteLine("RegEx match timeout occurred!")
//Debug.WriteLine("Specified timeout: " + TimeSpan.FromMilliseconds(_timeout).ToString())
//Debug.WriteLine("Timeout check frequency: " + TimeoutCheckFrequency)
//Debug.WriteLine("Search pattern: " + _runregex._pattern)
//Debug.WriteLine("Input: " + r.runtext)
//Debug.WriteLine("About to throw RegexMatchTimeoutException.")
}
return fmt.Errorf("match timeout after %v on input `%v`", r.timeout, string(r.runtext))
}
func (r *runner) initTrackCount() {
r.runtrackcount = r.code.TrackCount
}
// getRunner returns a run to use for matching re.
// It uses the re's runner cache if possible, to avoid
// unnecessary allocation.
func (re *Regexp) getRunner() *runner {
re.muRun.Lock()
if n := len(re.runner); n > 0 {
z := re.runner[n-1]
re.runner = re.runner[:n-1]
re.muRun.Unlock()
return z
}
re.muRun.Unlock()
z := &runner{
re: re,
code: re.code,
}
return z
}
// putRunner returns a runner to the re's cache.
// There is no attempt to limit the size of the cache, so it will
// grow to the maximum number of simultaneous matches
// run using re. (The cache empties when re gets garbage collected.)
func (re *Regexp) putRunner(r *runner) {
re.muRun.Lock()
re.runner = append(re.runner, r)
re.muRun.Unlock()
}