diff options
Diffstat (limited to 'generic/tclStringObj.c')
| -rw-r--r-- | generic/tclStringObj.c | 82 |
1 files changed, 65 insertions, 17 deletions
diff --git a/generic/tclStringObj.c b/generic/tclStringObj.c index 23f98e0..716c272 100644 --- a/generic/tclStringObj.c +++ b/generic/tclStringObj.c @@ -33,12 +33,20 @@ * See the file "license.terms" for information on usage and redistribution of * this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * RCS: @(#) $Id: tclStringObj.c,v 1.120 2009/02/19 14:55:55 dgp Exp $ */ + * RCS: @(#) $Id: tclStringObj.c,v 1.121 2009/02/22 04:38:58 dgp Exp $ */ #include "tclInt.h" #include "tommath.h" /* + * Set COMPAT to 1 to restore the shimmering patterns to those of Tcl 8.5. + * This is an escape hatch in case the changes have some unexpected unwelcome + * impact on performance. If things go well, this mechanism can go away when + * post-8.6 development begins. + */ +#define COMPAT 0 + +/* * Prototypes for functions defined later in this file: */ @@ -484,18 +492,12 @@ Tcl_GetCharLength( TclNumUtfChars(numChars, objPtr->bytes, objPtr->length); stringPtr->numChars = numChars; - /* - * Disabled the auto-fill of the unicode rep when multi-byte - * characters have been detected, on the YAGNI principle. - */ -#if 1 +#if COMPAT if (numChars < objPtr->length) { /* * Since we've just computed the number of chars, and not all * UTF chars are 1-byte long, go ahead and populate the unicode * string. - * - * TODO: Examine does this really help? How? */ FillUnicodeRep(objPtr); @@ -1215,8 +1217,11 @@ Tcl_AppendUnicodeToObj( * objPtr's string rep. */ - /* TODO: shift appends to empty to work on Unicode? */ - if (stringPtr->hasUnicode && stringPtr->numChars > 0) { + if (stringPtr->hasUnicode +#if COMPAT + && stringPtr->numChars > 0 +#endif + ) { AppendUnicodeToUnicodeRep(objPtr, unicode, length); } else { AppendUnicodeToUtfRep(objPtr, unicode, length); @@ -1291,8 +1296,11 @@ Tcl_AppendObjToObj( * appendObjPtr and append it. */ - /* TODO: optimize unicode appends */ - if (stringPtr->hasUnicode && stringPtr->numChars > 0) { + if (stringPtr->hasUnicode +#if COMPAT + && stringPtr->numChars > 0 +#endif + ) { /* * If appendObjPtr is not of the "String" type, don't convert it. */ @@ -1325,7 +1333,11 @@ Tcl_AppendObjToObj( AppendUtfToUtfRep(objPtr, bytes, length); - if (numChars >= 0 && appendNumChars >= 0) { + if (numChars >= 0 && appendNumChars >= 0 +#if COMPAT + && appendNumChars == length +#endif + ) { stringPtr->numChars = numChars + appendNumChars; } } @@ -1443,9 +1455,10 @@ AppendUnicodeToUtfRep( stringPtr->numChars += numChars; } - /* TODO: Condition on (numChars > 0) ? or change caller & eliminate ? */ +#if COMPAT /* Invalidate the unicode rep */ stringPtr->hasUnicode = 0; +#endif } /* @@ -2674,6 +2687,43 @@ DupStringInternalRep( String *srcStringPtr = GET_STRING(srcPtr); String *copyStringPtr = NULL; +#if COMPAT==0 + if (srcStringPtr->numChars == -1) { + /* + * The String struct in the source value holds zero useful data. + * Don't bother copying it. Don't even bother allocating space in + * which to copy it. Just let the copy be untyped. + */ + return; + } + + if (srcStringPtr->hasUnicode) { + int copyMaxChars; + if (srcStringPtr->maxChars / 2 >= srcStringPtr->numChars) { + copyMaxChars = 2 * srcStringPtr->numChars; + } else { + copyMaxChars = srcStringPtr->maxChars; + } + copyStringPtr = stringAlloc(copyMaxChars); + copyStringPtr->maxChars = copyMaxChars; + memcpy(copyStringPtr->unicode, srcStringPtr->unicode, + srcStringPtr->numChars * sizeof(Tcl_UniChar)); + copyStringPtr->unicode[srcStringPtr->numChars] = 0; + } else { + copyStringPtr = stringAlloc(0); + copyStringPtr->maxChars = 0; + copyStringPtr->unicode[0] = 0; + } + copyStringPtr->hasUnicode = srcStringPtr->hasUnicode; + copyStringPtr->numChars = srcStringPtr->numChars; + + /* + * Tricky point: the string value was copied by generic object + * management code, so it doesn't contain any extra bytes that + * might exist in the source object. + */ + copyStringPtr->allocated = copyPtr->bytes ? copyPtr->length : 0; +#else /* * If the src obj is a string of 1-byte Utf chars, then copy the string * rep of the source object and create an "empty" Unicode internal rep for @@ -2683,8 +2733,6 @@ DupStringInternalRep( if (srcStringPtr->hasUnicode && srcStringPtr->numChars > 0) { /* Copy the full allocation for the Unicode buffer. */ - /* TODO: consider a more limited copy to the min of - * the current maxChars value and twice the current numChars */ copyStringPtr = stringAlloc(srcStringPtr->maxChars); copyStringPtr->maxChars = srcStringPtr->maxChars; memcpy(copyStringPtr->unicode, srcStringPtr->unicode, @@ -2692,7 +2740,6 @@ DupStringInternalRep( copyStringPtr->unicode[srcStringPtr->numChars] = 0; copyStringPtr->allocated = 0; } else { - /* TODO: consider not bothering to make a String intrep. */ copyStringPtr = stringAlloc(0); copyStringPtr->unicode[0] = 0; copyStringPtr->maxChars = 0; @@ -2705,6 +2752,7 @@ DupStringInternalRep( } copyStringPtr->numChars = srcStringPtr->numChars; copyStringPtr->hasUnicode = srcStringPtr->hasUnicode; +#endif SET_STRING(copyPtr, copyStringPtr); copyPtr->typePtr = &tclStringType; |