diff --git a/base/Android.bp b/base/Android.bp index 88d8ad111..e6ad15bf4 100644 --- a/base/Android.bp +++ b/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", diff --git a/base/include/android-base/parsedouble.h b/base/include/android-base/parsedouble.h new file mode 100644 index 000000000..daa69024c --- /dev/null +++ b/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 +#include + +#include + +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::lowest(), + double max = std::numeric_limits::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/base/parsedouble_test.cpp b/base/parsedouble_test.cpp new file mode 100644 index 000000000..8734c4257 --- /dev/null +++ b/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 + +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); +}