Merge "libbase: add parsedouble.h."

base/Android.bp

@@ -73,6 +73,7 @@ cc_test {
         "errors_test.cpp",
         "file_test.cpp",
         "logging_test.cpp",
+        "parsedouble_test.cpp",
         "parseint_test.cpp",
         "parsenetaddress_test.cpp",
         "quick_exit_test.cpp",

base/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

base/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);
+}