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https://github.com/ilyakooo0/urbit.git
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27dd121d14
git-subtree-dir: outside/re2 git-subtree-mainline: f94738bfd171ae447133e0964843addbb497894f git-subtree-split: 539b44fc4c5a49c3453b80e3af85d297f4cab4bf
79 lines
1.9 KiB
C++
79 lines
1.9 KiB
C++
// Copyright 2002 The RE2 Authors. All Rights Reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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#include "util/util.h"
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namespace re2 {
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static void StringAppendV(string* dst, const char* format, va_list ap) {
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// First try with a small fixed size buffer
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char space[1024];
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// It's possible for methods that use a va_list to invalidate
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// the data in it upon use. The fix is to make a copy
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// of the structure before using it and use that copy instead.
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va_list backup_ap;
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va_copy(backup_ap, ap);
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int result = vsnprintf(space, sizeof(space), format, backup_ap);
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va_end(backup_ap);
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if ((result >= 0) && (result < sizeof(space))) {
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// It fit
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dst->append(space, result);
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return;
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}
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// Repeatedly increase buffer size until it fits
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int length = sizeof(space);
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while (true) {
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if (result < 0) {
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// Older behavior: just try doubling the buffer size
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length *= 2;
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} else {
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// We need exactly "result+1" characters
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length = result+1;
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}
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char* buf = new char[length];
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// Restore the va_list before we use it again
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va_copy(backup_ap, ap);
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result = vsnprintf(buf, length, format, backup_ap);
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va_end(backup_ap);
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if ((result >= 0) && (result < length)) {
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// It fit
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dst->append(buf, result);
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delete[] buf;
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return;
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}
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delete[] buf;
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}
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}
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string StringPrintf(const char* format, ...) {
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va_list ap;
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va_start(ap, format);
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string result;
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StringAppendV(&result, format, ap);
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va_end(ap);
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return result;
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}
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void SStringPrintf(string* dst, const char* format, ...) {
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va_list ap;
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va_start(ap, format);
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dst->clear();
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StringAppendV(dst, format, ap);
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va_end(ap);
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}
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void StringAppendF(string* dst, const char* format, ...) {
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va_list ap;
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va_start(ap, format);
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StringAppendV(dst, format, ap);
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va_end(ap);
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}
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} // namespace re2
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