Added regexp-re2 library to external.
Change-Id: I54e60045f0fee91b64e4d7291e5bb6c6cffb4562
diff --git a/util/stringprintf.cc b/util/stringprintf.cc
new file mode 100644
index 0000000..c908181
--- /dev/null
+++ b/util/stringprintf.cc
@@ -0,0 +1,78 @@
+// 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) && (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