ARROW-251: Expose APIs for getting code and message of the status

cpp/src/arrow/util/CMakeLists.txt

@@ -70,3 +70,4 @@ endif()
 ADD_ARROW_TEST(bit-util-test)
 ADD_ARROW_TEST(buffer-test)
 ADD_ARROW_TEST(memory-pool-test)
+ADD_ARROW_TEST(status-test)

cpp/src/arrow/util/status-test.cc

@@ -0,0 +1,38 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements. See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership. The ASF licenses this file
+// to you 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 "gtest/gtest.h"
+
+#include "arrow/util/status.h"
+#include "arrow/test-util.h"
+
+namespace arrow {
+
+TEST(StatusTest, TestCodeAndMessage) {
+ Status ok = Status::OK();
+ ASSERT_EQ(StatusCode::OK, ok.code());
+ Status file_error = Status::IOError("file error");
+ ASSERT_EQ(StatusCode::IOError, file_error.code());
+ ASSERT_EQ("file error", file_error.message());
+}
+
+TEST(StatusTest, TestToString) {
+ Status file_error = Status::IOError("file error");
+ ASSERT_EQ("IOError: file error", file_error.ToString());
+}
+
+} // namespace arrow

cpp/src/arrow/util/status.h

@@ -138,6 +138,18 @@ class ARROW_EXPORT Status {
  // Get the POSIX code associated with this Status, or -1 if there is none.
  int16_t posix_code() const;
 
+ StatusCode code() const {
+ return ((state_ == NULL) ? StatusCode::OK : static_cast<StatusCode>(state_[4]));
+ }
+
+ std::string message() const {
+ uint32_t length;
+ memcpy(&length, state_, sizeof(length));
+ std::string msg;
+ msg.append((state_ + 7), length);
+ return msg;
+ }
+
  private:
  // OK status has a NULL state_. Otherwise, state_ is a new[] array
  // of the following form:
@@ -147,10 +159,6 @@ class ARROW_EXPORT Status {
  // state_[7..] == message
  const char* state_;
 
- StatusCode code() const {
- return ((state_ == NULL) ? StatusCode::OK : static_cast<StatusCode>(state_[4]));
- }
-
  Status(StatusCode code, const std::string& msg, int16_t posix_code);
  static const char* CopyState(const char* s);
 };