1 /*
2 * Copyright (C) 2019 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef INCLUDE_PERFETTO_TRACE_PROCESSOR_STATUS_H_
18 #define INCLUDE_PERFETTO_TRACE_PROCESSOR_STATUS_H_
19
20 #include <stdarg.h>
21 #include <string>
22
23 #include "perfetto/base/export.h"
24
25 namespace perfetto {
26 namespace trace_processor {
27
28 // Status and related methods are inside util for consistency with embedders of
29 // trace processor.
30 namespace util {
31
32 // Represents either the success or the failure message of a function.
33 // This can used as the return type of functions which would usually return an
34 // bool for success or int for errno but also wants to add some string context
35 // (ususally for logging).
36 class PERFETTO_EXPORT Status {
37 public:
Status()38 Status() : ok_(true) {}
Status(std::string error)39 explicit Status(std::string error) : ok_(false), message_(std::move(error)) {}
40
41 // Copy operations.
42 Status(const Status&) = default;
43 Status& operator=(const Status&) = default;
44
45 // Move operations. The moved-from state is valid but unspecified.
46 Status(Status&&) noexcept = default;
47 Status& operator=(Status&&) = default;
48
ok()49 bool ok() const { return ok_; }
50
51 // Only valid to call when this message has an Err status (i.e. ok() returned
52 // false or operator bool() returned true).
message()53 const std::string& message() const { return message_; }
54
55 // Only valid to call when this message has an Err status (i.e. ok() returned
56 // false or operator bool() returned true).
c_message()57 const char* c_message() const { return message_.c_str(); }
58
59 private:
60 bool ok_ = false;
61 std::string message_;
62 };
63
64 // Returns a status object which represents the Ok status.
OkStatus()65 inline Status OkStatus() {
66 return Status();
67 }
68
69 // Returns a status object which represents an error with the given message
70 // formatted using printf.
ErrStatus(const char * format,...)71 __attribute__((__format__(__printf__, 1, 2))) inline Status ErrStatus(
72 const char* format,
73 ...) {
74 va_list ap;
75 va_start(ap, format);
76
77 char buffer[1024];
78 vsnprintf(buffer, sizeof(buffer), format, ap);
79 return Status(std::string(buffer));
80 }
81
82 } // namespace util
83 } // namespace trace_processor
84 } // namespace perfetto
85
86 #endif // INCLUDE_PERFETTO_TRACE_PROCESSOR_STATUS_H_
87