85 lines
2.2 KiB
C++
85 lines
2.2 KiB
C++
/*
|
|
* Copyright (C) 2011 The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#include "base/stringprintf.h"
|
|
|
|
#include <stdio.h>
|
|
|
|
#include <string>
|
|
|
|
namespace android {
|
|
namespace base {
|
|
|
|
void StringAppendV(std::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 < static_cast<int>(sizeof(space))) {
|
|
if (result >= 0) {
|
|
// Normal case -- everything fit.
|
|
dst->append(space, result);
|
|
return;
|
|
}
|
|
|
|
if (result < 0) {
|
|
// Just an error.
|
|
return;
|
|
}
|
|
}
|
|
|
|
// Increase the buffer size to the size requested by vsnprintf,
|
|
// plus one for the closing \0.
|
|
int 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;
|
|
}
|
|
|
|
std::string StringPrintf(const char* fmt, ...) {
|
|
va_list ap;
|
|
va_start(ap, fmt);
|
|
std::string result;
|
|
StringAppendV(&result, fmt, ap);
|
|
va_end(ap);
|
|
return result;
|
|
}
|
|
|
|
void StringAppendF(std::string* dst, const char* format, ...) {
|
|
va_list ap;
|
|
va_start(ap, format);
|
|
StringAppendV(dst, format, ap);
|
|
va_end(ap);
|
|
}
|
|
|
|
} // namespace base
|
|
} // namespace android
|