libbase: add parsedouble.h.
Bug: http://b/24905115
Test: run libbase_test --gtest_filter=parsedouble.smoke.
Change-Id: I604424772f2082b420935e6647da03981c0b8929
diff --git a/Android.bp b/Android.bp
index 88d8ad1..e6ad15b 100644
--- a/Android.bp
+++ b/Android.bp
@@ -73,6 +73,7 @@
"errors_test.cpp",
"file_test.cpp",
"logging_test.cpp",
+ "parsedouble_test.cpp",
"parseint_test.cpp",
"parsenetaddress_test.cpp",
"quick_exit_test.cpp",
diff --git a/include/android-base/parsedouble.h b/include/android-base/parsedouble.h
new file mode 100644
index 0000000..daa6902
--- /dev/null
+++ b/include/android-base/parsedouble.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+
+#ifndef ANDROID_BASE_PARSEDOUBLE_H
+#define ANDROID_BASE_PARSEDOUBLE_H
+
+#include <errno.h>
+#include <stdlib.h>
+
+#include <limits>
+
+namespace android {
+namespace base {
+
+// Parse double value in the string 's' and sets 'out' to that value.
+// Optionally allows the caller to define a 'min' and 'max' beyond which
+// otherwise valid values will be rejected. Returns boolean success.
+static inline bool ParseDouble(const char* s, double* out,
+ double min = std::numeric_limits<double>::lowest(),
+ double max = std::numeric_limits<double>::max()) {
+ errno = 0;
+ char* end;
+ double result = strtod(s, &end);
+ if (errno != 0 || s == end || *end != '\0') {
+ return false;
+ }
+ if (result < min || max < result) {
+ return false;
+ }
+ *out = result;
+ return true;
+}
+
+} // namespace base
+} // namespace android
+
+#endif // ANDROID_BASE_PARSEDOUBLE_H
diff --git a/parsedouble_test.cpp b/parsedouble_test.cpp
new file mode 100644
index 0000000..8734c42
--- /dev/null
+++ b/parsedouble_test.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2016 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 "android-base/parsedouble.h"
+
+#include <gtest/gtest.h>
+
+TEST(parsedouble, smoke) {
+ double d;
+ ASSERT_FALSE(android::base::ParseDouble("", &d));
+ ASSERT_FALSE(android::base::ParseDouble("x", &d));
+ ASSERT_FALSE(android::base::ParseDouble("123.4x", &d));
+
+ ASSERT_TRUE(android::base::ParseDouble("123.4", &d));
+ ASSERT_DOUBLE_EQ(123.4, d);
+ ASSERT_TRUE(android::base::ParseDouble("-123.4", &d));
+ ASSERT_DOUBLE_EQ(-123.4, d);
+
+ ASSERT_TRUE(android::base::ParseDouble("0", &d, 0.0));
+ ASSERT_DOUBLE_EQ(0.0, d);
+ ASSERT_FALSE(android::base::ParseDouble("0", &d, 1e-9));
+ ASSERT_FALSE(android::base::ParseDouble("3.0", &d, -1.0, 2.0));
+ ASSERT_TRUE(android::base::ParseDouble("1.0", &d, 0.0, 2.0));
+ ASSERT_DOUBLE_EQ(1.0, d);
+}