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Reduced stack usage for greedy matching.

This commit is contained in:
rogerl%netscape.com 2000-03-08 01:08:32 +00:00
Родитель 7e1b3b797a
Коммит 08a7900333
2 изменённых файлов: 186 добавлений и 42 удалений
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114
js/rhino/org/mozilla/javascript/regexp/NativeRegExp.java
Просмотреть файл

@ -1379,7 +1379,63 @@ public class NativeRegExp extends ScriptableObject implements Function {
return false;
}
int matchGreedyKid(MatchState state, RENode ren, RENode stop,
int greedyRecurse(GreedyState grState, int index, int previousKid)
{
int kidMatch;
int match;
int num;
/*
* when the kid match fails, we reset the parencount and run any
* previously succesful kid in order to restablish it's paren
* contents.
*/
num = grState.state.parenCount;
kidMatch = matchRENodes(grState.state, grState.kid, grState.next, index);
if (kidMatch == -1) {
grState.state.parenCount = num;
if (previousKid != -1)
matchRENodes(grState.state, grState.kid, grState.next, previousKid);
return matchRENodes(grState.state, grState.next, grState.stop, index);
}
else {
if (kidMatch == index) return kidMatch; /* no point pursuing an empty match forever */
if ((grState.maxKid == 0) || (++grState.kidCount < grState.maxKid)) {
match = greedyRecurse(grState, kidMatch, index);
if (match != -1) return match;
--grState.kidCount;
grState.state.parenCount = num;
matchRENodes(grState.state, grState.kid, grState.next, index);
}
match = matchRENodes(grState.state, grState.next, grState.stop, kidMatch);
if (match != -1) return match;
/* No subsequent kid could complete; final backtrack attempt with zero kids */
grState.state.parenCount = num;
if (previousKid != -1)
matchRENodes(grState.state, grState.kid, grState.next, previousKid);
return matchRENodes(grState.state, grState.next, grState.stop, index);
}
}
int matchGreedyKid(MatchState state, RENode ren, RENode stop,
int kidCount, int maxKid,
int index, int previousKid)
{
GreedyState grState = new GreedyState();
grState.state = state;
grState.kid = (RENode)ren.kid;
grState.next = ren.next;
grState.stop = stop;
grState.kidCount = kidCount;
grState.maxKid = (ren.op == REOP_QUANT) ? ren.max : 0;
return greedyRecurse(grState, index, previousKid);
}
/*
int matchGreedyKid(MatchState state, RENode ren, RENode stop,
int kidCount, int maxKid,
char[] input, int index, int previousKid)
{
@ -1423,10 +1479,11 @@ public class NativeRegExp extends ScriptableObject implements Function {
return deeper;
}
}
*/
int matchRENodes(MatchState state, RENode ren, RENode stop,
char[] input, int index)
int matchRENodes(MatchState state, RENode ren, RENode stop, int index)
{
char[] input = state.input;
while ((ren != stop) && (ren != null))
{
switch (ren.op) {
@ -1439,7 +1496,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
}
else {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
stop, input, index);
stop, index);
if (kidMatch != -1) return kidMatch;
}
}
@ -1449,7 +1506,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
int lastKid = -1;
for (num = 0; num < ren.min; num++) {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch == -1)
return -1;
else {
@ -1457,37 +1514,41 @@ public class NativeRegExp extends ScriptableObject implements Function {
index = kidMatch;
}
}
return matchGreedyKid(state, ren, stop, num, ren.max,
input, index, lastKid);
if (num < ren.max)
return matchGreedyKid(state, ren, stop, num, ren.max,
index, lastKid);
// Have matched the exact count required,
// need to match the rest of the regexp.
break;
}
case REOP_PLUS: {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch != -1)
return matchGreedyKid(state, ren, stop, 1, 0,
input, kidMatch, index);
kidMatch, index);
else
return -1;
}
case REOP_STAR:
return matchGreedyKid(state, ren, stop,
0, 0, input, index, -1);
0, 0, index, -1);
case REOP_OPT: {
int saveNum = state.parenCount;
if (((ren.flags & RENode.MINIMAL) != 0)) {
int restMatch = matchRENodes(state, ren.next,
stop, input, index);
stop, index);
if (restMatch != -1) return restMatch;
}
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch == -1) {
state.parenCount = saveNum;
break;
}
else {
int restMatch = matchRENodes(state, ren.next,
stop, input, kidMatch);
stop, kidMatch);
if (restMatch == -1) {
// need to undo the result of running the kid
state.parenCount = saveNum;
@ -1526,13 +1587,13 @@ public class NativeRegExp extends ScriptableObject implements Function {
}
case REOP_ASSERT: {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch == -1) return -1;
break;
}
case REOP_ASSERT_NOT: {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch != -1) return -1;
break;
}
@ -1597,7 +1658,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
int cp2;
for (cp2 = index; cp2 < input.length; cp2++) {
int cp3 = matchRENodes(state, ren.next,
stop, input, cp2);
stop, cp2);
if (cp3 != -1) return cp3;
if (input[cp2] == '\n')
return -1;
@ -1611,7 +1672,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
break;
while (cp2 >= index) {
int cp3 = matchRENodes(state, ren.next,
stop, input, cp2);
stop, cp2);
if (cp3 != -1)
return cp3;
cp2--;
@ -1742,14 +1803,14 @@ public class NativeRegExp extends ScriptableObject implements Function {
return index;
}
int matchRegExp(MatchState state, RENode ren, char[] input, int index)
int matchRegExp(MatchState state, RENode ren, int index)
{
// have to include the position beyond the last character
// in order to detect end-of-input/line condition
for (int i = index; i <= input.length; i++) {
for (int i = index; i <= state.input.length; i++) {
state.skipped = i - index;
state.parenCount = 0;
int result = matchRENodes(state, ren, null, input, i);
int result = matchRENodes(state, ren, null, i);
if (result != -1)
return result;
}
@ -1783,6 +1844,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
state.cpend = charArray.length;
state.start = start;
state.skipped = 0;
state.input = charArray;
state.parenCount = 0;
state.maybeParens = new SubString[re.parenCount];
@ -1794,7 +1856,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
* Call the recursive matcher to do the real work. Return null on mismatch
* whether testing or not. On match, return an extended Array object.
*/
index = matchRegExp(state, ren, charArray, index);
index = matchRegExp(state, ren, index);
if (index == -1) {
return null;
}
@ -2249,5 +2311,15 @@ class MatchState {
SubString[] maybeParens; /* possible paren substring pointers */
SubString[] parens; /* certain paren substring matches */
Scriptable scope;
char[] input;
}
class GreedyState {
MatchState state;
RENode kid;
RENode next;
RENode stop;
int kidCount;
int maxKid;
}

114
js/rhino/src/org/mozilla/javascript/regexp/NativeRegExp.java
Просмотреть файл

@ -1379,7 +1379,63 @@ public class NativeRegExp extends ScriptableObject implements Function {
return false;
}
int matchGreedyKid(MatchState state, RENode ren, RENode stop,
int greedyRecurse(GreedyState grState, int index, int previousKid)
{
int kidMatch;
int match;
int num;
/*
* when the kid match fails, we reset the parencount and run any
* previously succesful kid in order to restablish it's paren
* contents.
*/
num = grState.state.parenCount;
kidMatch = matchRENodes(grState.state, grState.kid, grState.next, index);
if (kidMatch == -1) {
grState.state.parenCount = num;
if (previousKid != -1)
matchRENodes(grState.state, grState.kid, grState.next, previousKid);
return matchRENodes(grState.state, grState.next, grState.stop, index);
}
else {
if (kidMatch == index) return kidMatch; /* no point pursuing an empty match forever */
if ((grState.maxKid == 0) || (++grState.kidCount < grState.maxKid)) {
match = greedyRecurse(grState, kidMatch, index);
if (match != -1) return match;
--grState.kidCount;
grState.state.parenCount = num;
matchRENodes(grState.state, grState.kid, grState.next, index);
}
match = matchRENodes(grState.state, grState.next, grState.stop, kidMatch);
if (match != -1) return match;
/* No subsequent kid could complete; final backtrack attempt with zero kids */
grState.state.parenCount = num;
if (previousKid != -1)
matchRENodes(grState.state, grState.kid, grState.next, previousKid);
return matchRENodes(grState.state, grState.next, grState.stop, index);
}
}
int matchGreedyKid(MatchState state, RENode ren, RENode stop,
int kidCount, int maxKid,
int index, int previousKid)
{
GreedyState grState = new GreedyState();
grState.state = state;
grState.kid = (RENode)ren.kid;
grState.next = ren.next;
grState.stop = stop;
grState.kidCount = kidCount;
grState.maxKid = (ren.op == REOP_QUANT) ? ren.max : 0;
return greedyRecurse(grState, index, previousKid);
}
/*
int matchGreedyKid(MatchState state, RENode ren, RENode stop,
int kidCount, int maxKid,
char[] input, int index, int previousKid)
{
@ -1423,10 +1479,11 @@ public class NativeRegExp extends ScriptableObject implements Function {
return deeper;
}
}
*/
int matchRENodes(MatchState state, RENode ren, RENode stop,
char[] input, int index)
int matchRENodes(MatchState state, RENode ren, RENode stop, int index)
{
char[] input = state.input;
while ((ren != stop) && (ren != null))
{
switch (ren.op) {
@ -1439,7 +1496,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
}
else {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
stop, input, index);
stop, index);
if (kidMatch != -1) return kidMatch;
}
}
@ -1449,7 +1506,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
int lastKid = -1;
for (num = 0; num < ren.min; num++) {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch == -1)
return -1;
else {
@ -1457,37 +1514,41 @@ public class NativeRegExp extends ScriptableObject implements Function {
index = kidMatch;
}
}
return matchGreedyKid(state, ren, stop, num, ren.max,
input, index, lastKid);
if (num < ren.max)
return matchGreedyKid(state, ren, stop, num, ren.max,
index, lastKid);
// Have matched the exact count required,
// need to match the rest of the regexp.
break;
}
case REOP_PLUS: {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch != -1)
return matchGreedyKid(state, ren, stop, 1, 0,
input, kidMatch, index);
kidMatch, index);
else
return -1;
}
case REOP_STAR:
return matchGreedyKid(state, ren, stop,
0, 0, input, index, -1);
0, 0, index, -1);
case REOP_OPT: {
int saveNum = state.parenCount;
if (((ren.flags & RENode.MINIMAL) != 0)) {
int restMatch = matchRENodes(state, ren.next,
stop, input, index);
stop, index);
if (restMatch != -1) return restMatch;
}
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch == -1) {
state.parenCount = saveNum;
break;
}
else {
int restMatch = matchRENodes(state, ren.next,
stop, input, kidMatch);
stop, kidMatch);
if (restMatch == -1) {
// need to undo the result of running the kid
state.parenCount = saveNum;
@ -1526,13 +1587,13 @@ public class NativeRegExp extends ScriptableObject implements Function {
}
case REOP_ASSERT: {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch == -1) return -1;
break;
}
case REOP_ASSERT_NOT: {
int kidMatch = matchRENodes(state, (RENode)ren.kid,
ren.next, input, index);
ren.next, index);
if (kidMatch != -1) return -1;
break;
}
@ -1597,7 +1658,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
int cp2;
for (cp2 = index; cp2 < input.length; cp2++) {
int cp3 = matchRENodes(state, ren.next,
stop, input, cp2);
stop, cp2);
if (cp3 != -1) return cp3;
if (input[cp2] == '\n')
return -1;
@ -1611,7 +1672,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
break;
while (cp2 >= index) {
int cp3 = matchRENodes(state, ren.next,
stop, input, cp2);
stop, cp2);
if (cp3 != -1)
return cp3;
cp2--;
@ -1742,14 +1803,14 @@ public class NativeRegExp extends ScriptableObject implements Function {
return index;
}
int matchRegExp(MatchState state, RENode ren, char[] input, int index)
int matchRegExp(MatchState state, RENode ren, int index)
{
// have to include the position beyond the last character
// in order to detect end-of-input/line condition
for (int i = index; i <= input.length; i++) {
for (int i = index; i <= state.input.length; i++) {
state.skipped = i - index;
state.parenCount = 0;
int result = matchRENodes(state, ren, null, input, i);
int result = matchRENodes(state, ren, null, i);
if (result != -1)
return result;
}
@ -1783,6 +1844,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
state.cpend = charArray.length;
state.start = start;
state.skipped = 0;
state.input = charArray;
state.parenCount = 0;
state.maybeParens = new SubString[re.parenCount];
@ -1794,7 +1856,7 @@ public class NativeRegExp extends ScriptableObject implements Function {
* Call the recursive matcher to do the real work. Return null on mismatch
* whether testing or not. On match, return an extended Array object.
*/
index = matchRegExp(state, ren, charArray, index);
index = matchRegExp(state, ren, index);
if (index == -1) {
return null;
}
@ -2249,5 +2311,15 @@ class MatchState {
SubString[] maybeParens; /* possible paren substring pointers */
SubString[] parens; /* certain paren substring matches */
Scriptable scope;
char[] input;
}
class GreedyState {
MatchState state;
RENode kid;
RENode next;
RENode stop;
int kidCount;
int maxKid;
}