Create libbase.
Move StringPrintf and the string based file I/O from libutils to
libbase.
Change-Id: I0297a6063874b9d92100e0dd5123fddfbda932fe
diff --git a/base/stringprintf.cpp b/base/stringprintf.cpp
new file mode 100644
index 0000000..d55ff52
--- /dev/null
+++ b/base/stringprintf.cpp
@@ -0,0 +1,85 @@
+/*
+ * 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