Improved CompareStringA performance.

This commit is contained in:
Andrew Lewycky 2000-03-19 21:51:41 +00:00 committed by Alexandre Julliard
parent 728a5894fa
commit c03da6680d

View file

@ -2658,6 +2658,26 @@ UINT16 WINAPI CompareString16(DWORD lcid,DWORD fdwStyle,
return (UINT16)CompareStringA(lcid,fdwStyle,s1,l1,s2,l2);
}
/***********************************************************************
* OLE2NLS_EstimateMappingLength
*
* Estimates the number of characters required to hold the string
* computed by LCMapStringA.
*
* The size is always over-estimated, with a fixed limit on the
* amount of estimation error.
*
* Note that len == -1 is not permitted.
*/
static inline int OLE2NLS_EstimateMappingLength(LCID lcid, DWORD dwMapFlags,
LPCSTR str, DWORD len)
{
/* Estimate only for small strings to keep the estimation error from
* becoming too large. */
if (len < 128) return len * 8 + 5;
else return LCMapStringA(lcid, dwMapFlags, str, len, NULL, 0);
}
/******************************************************************************
* CompareString32A [KERNEL32.143]
* Compares two strings using locale
@ -2705,16 +2725,19 @@ UINT WINAPI CompareStringA(
if(fdwStyle & NORM_IGNORESYMBOLS)
FIXME("IGNORESYMBOLS not supported\n");
if (l1 == -1) l1 = lstrlenA(s1);
if (l2 == -1) l2 = lstrlenA(s2);
mapstring_flags = LCMAP_SORTKEY | fdwStyle ;
len1 = LCMapStringA(lcid,mapstring_flags,s1,l1,NULL,0);
len2 = LCMapStringA(lcid,mapstring_flags,s2,l2,NULL,0);
len1 = OLE2NLS_EstimateMappingLength(lcid, mapstring_flags, s1, l1);
len2 = OLE2NLS_EstimateMappingLength(lcid, mapstring_flags, s2, l2);
if ((len1==0)||(len2==0))
return 0; /* something wrong happened */
sk1 = (LPSTR)HeapAlloc(GetProcessHeap(),0,len1);
sk2 = (LPSTR)HeapAlloc(GetProcessHeap(),0,len2);
sk1 = (LPSTR)HeapAlloc(GetProcessHeap(), 0, len1 + len2);
sk2 = sk1 + len1;
if ( (!LCMapStringA(lcid,mapstring_flags,s1,l1,sk1,len1))
|| (!LCMapStringA(lcid,mapstring_flags,s2,l2,sk2,len2)) )
{
@ -2727,7 +2750,6 @@ UINT WINAPI CompareStringA(
result = strcmp(sk1,sk2);
}
HeapFree(GetProcessHeap(),0,sk1);
HeapFree(GetProcessHeap(),0,sk2);
if (result < 0)
return 1;