1 files changed, 65 insertions, 0 deletions
diff --git a/third_party/libwebrtc/test/logging/log_writer.h b/third_party/libwebrtc/test/logging/log_writer.h
new file mode 100644
index 0000000000..335dab353f
--- /dev/null
+++ b/third_party/libwebrtc/test/logging/log_writer.h
@@ -0,0 +1,65 @@
+/*
+ *  Copyright 2019 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef TEST_LOGGING_LOG_WRITER_H_
+#define TEST_LOGGING_LOG_WRITER_H_
+
+#include <stdarg.h>
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "absl/strings/string_view.h"
+#include "api/rtc_event_log_output.h"
+#include "rtc_base/strings/string_builder.h"
+
+namespace webrtc {
+template <class... Args>
+inline void LogWriteFormat(RtcEventLogOutput* out_, const char* fmt, ...) {
+  va_list args, copy;
+  va_start(args, fmt);
+  va_copy(copy, args);
+  const int predicted_length = std::vsnprintf(nullptr, 0, fmt, copy);
+  va_end(copy);
+
+  RTC_DCHECK_GE(predicted_length, 0);
+  std::string out_str(predicted_length, '\0');
+  if (predicted_length > 0) {
+    // Pass "+ 1" to vsnprintf to include space for the '\0'.
+    const int actual_length =
+        std::vsnprintf(&out_str.front(), predicted_length + 1, fmt, args);
+    RTC_DCHECK_GE(actual_length, 0);
+  }
+  va_end(args);
+  out_->Write(out_str);
+}
+
+class LogWriterFactoryInterface {
+ public:
+  virtual std::unique_ptr<RtcEventLogOutput> Create(
+      absl::string_view filename) = 0;
+  virtual ~LogWriterFactoryInterface() = default;
+};
+
+class LogWriterFactoryAddPrefix : public LogWriterFactoryInterface {
+ public:
+  LogWriterFactoryAddPrefix(LogWriterFactoryInterface* base,
+                            absl::string_view prefix);
+  std::unique_ptr<RtcEventLogOutput> Create(
+      absl::string_view filename) override;
+
+ private:
+  LogWriterFactoryInterface* const base_factory_;
+  const std::string prefix_;
+};
+
+}  // namespace webrtc
+
+#endif  // TEST_LOGGING_LOG_WRITER_H_