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authordgp <dgp@users.sourceforge.net>2017-06-08 16:44:51 (GMT)
committerdgp <dgp@users.sourceforge.net>2017-06-08 16:44:51 (GMT)
commite760092378d4b34b2f4cbd66a613128dbd703258 (patch)
tree32fc5ac490665c19b6284fbb466c8cf193c1db58 /generic
parent061893f84e1d06c45531c7a4d7a7384e144dc69b (diff)
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When possible delay string rep generation until necessary.
Diffstat (limited to 'generic')
-rw-r--r--generic/tclStringObj.c56
1 files changed, 46 insertions, 10 deletions
diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c
index aae52ba..be71109 100644
--- a/generic/tclStringObj.c
+++ b/generic/tclStringObj.c
@@ -2847,7 +2847,7 @@ TclStringCatObjv(
Tcl_Obj * const objv[],
Tcl_Obj **objPtrPtr)
{
- Tcl_Obj *objPtr, *objResultPtr, * const *ov;
+ Tcl_Obj *objPtr, *objResultPtr, * const *ov, *pendingPtr = NULL;
int oc, length = 0, binary = 1, first = 0, last = 0;
int allowUniChar = 1, requestUniChar = 0;
@@ -2952,14 +2952,37 @@ TclStringCatObjv(
objPtr = *ov++;
- Tcl_GetStringFromObj(objPtr, &numBytes); /* PANIC? */
- if (numBytes) {
+ if ((length == 0) && (objPtr->bytes == NULL) && !pendingPtr) {
+ /* No string rep; Take the chance we can avoid making it */
+
last = objc - oc;
- if (length == 0) {
- first = last;
- }
- if ((length += numBytes) < 0) {
- goto overflow;
+ first = last;
+ pendingPtr = objPtr;
+ } else {
+
+ Tcl_GetStringFromObj(objPtr, &numBytes);/* PANIC? */
+ if (numBytes) {
+ last = objc - oc;
+ if (length == 0) {
+ if (pendingPtr) {
+ int pendingNumBytes;
+
+ Tcl_GetStringFromObj(pendingPtr, &pendingNumBytes); /* PANIC? */
+ if (pendingNumBytes) {
+ if ((length += pendingNumBytes) < 0) {
+ goto overflow;
+ }
+ } else {
+ first = last;
+ }
+ pendingPtr = NULL;
+ } else {
+ first = last;
+ }
+ }
+ if ((length += numBytes) < 0) {
+ goto overflow;
+ }
}
}
} while (--oc);
@@ -3056,13 +3079,18 @@ TclStringCatObjv(
} else {
/* Efficiently concatenate string reps */
char *dst;
+ int start;
if (inPlace && !Tcl_IsShared(*objv)) {
- int start;
-
objResultPtr = *objv++; objc--;
Tcl_GetStringFromObj(objResultPtr, &start);
+ if (pendingPtr) {
+ /* assert ( pendingPtr == objResultPtr ) */
+ if ((length += start) < 0) {
+ goto overflow;
+ }
+ }
if (0 == Tcl_AttemptSetObjLength(objResultPtr, length)) {
if (interp) {
Tcl_SetObjResult(interp, Tcl_ObjPrintf(
@@ -3075,8 +3103,16 @@ TclStringCatObjv(
dst = Tcl_GetString(objResultPtr) + start;
if (length > start) {
TclFreeIntRep(objResultPtr);
+ } else {
+ /* Can't happen ? */
}
} else {
+ if (pendingPtr) {
+ Tcl_GetStringFromObj(pendingPtr, &start);
+ if ((length += start) < 0) {
+ goto overflow;
+ }
+ }
objResultPtr = Tcl_NewObj(); /* PANIC? */
if (0 == Tcl_AttemptSetObjLength(objResultPtr, length)) {
if (interp) {