1 /*
2 * Copyright 2019 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10 #ifndef TEST_LOGGING_LOG_WRITER_H_
11 #define TEST_LOGGING_LOG_WRITER_H_
12
13 #include <stdarg.h>
14
15 #include <memory>
16 #include <string>
17 #include <utility>
18
19 #include "absl/strings/string_view.h"
20 #include "api/rtc_event_log_output.h"
21 #include "rtc_base/strings/string_builder.h"
22
23 namespace webrtc {
24 template <class... Args>
LogWriteFormat(RtcEventLogOutput * out_,const char * fmt,...)25 inline void LogWriteFormat(RtcEventLogOutput* out_, const char* fmt, ...) {
26 va_list args, copy;
27 va_start(args, fmt);
28 va_copy(copy, args);
29 const int predicted_length = std::vsnprintf(nullptr, 0, fmt, copy);
30 va_end(copy);
31
32 RTC_DCHECK_GE(predicted_length, 0);
33 std::string out_str(predicted_length, '\0');
34 if (predicted_length > 0) {
35 // Pass "+ 1" to vsnprintf to include space for the '\0'.
36 const int actual_length =
37 std::vsnprintf(&out_str.front(), predicted_length + 1, fmt, args);
38 RTC_DCHECK_GE(actual_length, 0);
39 }
40 va_end(args);
41 out_->Write(out_str);
42 }
43
44 class LogWriterFactoryInterface {
45 public:
46 virtual std::unique_ptr<RtcEventLogOutput> Create(
47 absl::string_view filename) = 0;
48 virtual ~LogWriterFactoryInterface() = default;
49 };
50
51 class LogWriterFactoryAddPrefix : public LogWriterFactoryInterface {
52 public:
53 LogWriterFactoryAddPrefix(LogWriterFactoryInterface* base,
54 absl::string_view prefix);
55 std::unique_ptr<RtcEventLogOutput> Create(
56 absl::string_view filename) override;
57
58 private:
59 LogWriterFactoryInterface* const base_factory_;
60 const std::string prefix_;
61 };
62
63 } // namespace webrtc
64
65 #endif // TEST_LOGGING_LOG_WRITER_H_
66