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BString: Use memchr and memrchr to optimize two Find routines.

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All BString tests are still passing.
This commit is contained in:
Augustin Cavalier
2026-03-30 18:30:32 -04:00
parent 53b69c0037
commit 75b91674e9
1 changed files with 18 additions and 29 deletions
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src/kits/support/String.cpp
+18 -29
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@@ -14,6 +14,10 @@
/*! String class supporting common string operations. */
#ifndef _DEFAULT_SOURCE
#define _DEFAULT_SOURCE
#endif
#include <String.h>
#include <ctype.h>
@@ -1167,41 +1171,21 @@ BString::FindFirst(const char* string, int32 fromOffset) const
int32
BString::FindFirst(char c) const
{
const char* start = String();
const char* end = String() + Length();
// Scans the string until we found the
// character, or we reach the string's start
while (start != end && *start != c) {
start++;
}
if (start == end)
return B_ERROR;
return start - String();
return FindFirst(c, 0);
}
int32
BString::FindFirst(char c, int32 fromOffset) const
{
if (fromOffset < 0)
if (fromOffset < 0 || fromOffset >= Length())
return B_ERROR;
const char* start = String() + min_clamp0(fromOffset, Length());
const char* end = String() + Length();
// Scans the string until we found the
// character, or we reach the string's start
while (start < end && *start != c) {
start++;
}
if (start >= end)
const void* start = memchr(String() + fromOffset, c, Length());
if (start == NULL)
return B_ERROR;
return start - String();
return (const char*)start - String();
}
@@ -2545,12 +2529,17 @@ int32
BString::_FindBefore(const char* string, int32 offset, int32 length) const
{
if (fPrivateData != NULL) {
const char* ptr = fPrivateData + offset - length;
const char* end = fPrivateData + offset - (length - 1);
while (end >= fPrivateData) {
const char* ptr = (const char*)memrchr(fPrivateData,
string[0], end - fPrivateData);
if (ptr == NULL)
break;
while (ptr >= fPrivateData) {
if (!memcmp(ptr, string, length))
if (memcmp(ptr, string, length) == 0)
return ptr - fPrivateData;
ptr--;
end = ptr;
}
}
return B_ERROR;