mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-11-12 02:23:14 +00:00
79 lines
1.9 KiB
C++
79 lines
1.9 KiB
C++
// Copyright 2002 The RE2 Authors. All Rights Reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
#include "util/util.h"
|
|
|
|
namespace re2 {
|
|
|
|
static void StringAppendV(string* dst, const char* format, va_list ap) {
|
|
// First try with a small fixed size buffer
|
|
char space[1024];
|
|
|
|
// It's possible for methods that use a va_list to invalidate
|
|
// the data in it upon use. The fix is to make a copy
|
|
// of the structure before using it and use that copy instead.
|
|
va_list backup_ap;
|
|
va_copy(backup_ap, ap);
|
|
int result = vsnprintf(space, sizeof(space), format, backup_ap);
|
|
va_end(backup_ap);
|
|
|
|
if ((result >= 0) && (static_cast<size_t>(result) < sizeof(space))) {
|
|
// It fit
|
|
dst->append(space, result);
|
|
return;
|
|
}
|
|
|
|
// Repeatedly increase buffer size until it fits
|
|
int length = sizeof(space);
|
|
while (true) {
|
|
if (result < 0) {
|
|
// Older behavior: just try doubling the buffer size
|
|
length *= 2;
|
|
} else {
|
|
// We need exactly "result+1" characters
|
|
length = result+1;
|
|
}
|
|
char* buf = new char[length];
|
|
|
|
// Restore the va_list before we use it again
|
|
va_copy(backup_ap, ap);
|
|
result = vsnprintf(buf, length, format, backup_ap);
|
|
va_end(backup_ap);
|
|
|
|
if ((result >= 0) && (result < length)) {
|
|
// It fit
|
|
dst->append(buf, result);
|
|
delete[] buf;
|
|
return;
|
|
}
|
|
delete[] buf;
|
|
}
|
|
}
|
|
|
|
string StringPrintf(const char* format, ...) {
|
|
va_list ap;
|
|
va_start(ap, format);
|
|
string result;
|
|
StringAppendV(&result, format, ap);
|
|
va_end(ap);
|
|
return result;
|
|
}
|
|
|
|
void SStringPrintf(string* dst, const char* format, ...) {
|
|
va_list ap;
|
|
va_start(ap, format);
|
|
dst->clear();
|
|
StringAppendV(dst, format, ap);
|
|
va_end(ap);
|
|
}
|
|
|
|
void StringAppendF(string* dst, const char* format, ...) {
|
|
va_list ap;
|
|
va_start(ap, format);
|
|
StringAppendV(dst, format, ap);
|
|
va_end(ap);
|
|
}
|
|
|
|
} // namespace re2
|