1 files changed, 99 insertions, 0 deletions
diff --git a/test/pc/e2e/analyzer/video/multi_head_queue.h b/test/pc/e2e/analyzer/video/multi_head_queue.h
new file mode 100644
index 0000000000..52314a60d5
--- /dev/null
+++ b/test/pc/e2e/analyzer/video/multi_head_queue.h
@@ -0,0 +1,99 @@
+/*
+ *  Copyright (c) 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_PC_E2E_ANALYZER_VIDEO_MULTI_HEAD_QUEUE_H_
+#define TEST_PC_E2E_ANALYZER_VIDEO_MULTI_HEAD_QUEUE_H_
+
+#include <deque>
+#include <memory>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "rtc_base/checks.h"
+
+namespace webrtc {
+namespace webrtc_pc_e2e {
+
+// A queue that allows more than one reader. Readers are independent, and all
+// readers will see all elements; an inserted element stays in the queue until
+// all readers have extracted it. Elements are copied and copying is assumed to
+// be cheap.
+template <typename T>
+class MultiHeadQueue {
+ public:
+  // Creates queue with exactly |readers_count| readers.
+  explicit MultiHeadQueue(size_t readers_count) {
+    for (size_t i = 0; i < readers_count; ++i) {
+      queues_.push_back(std::deque<T>());
+    }
+  }
+
+  // Add value to the end of the queue. Complexity O(readers_count).
+  void PushBack(T value) {
+    for (auto& queue : queues_) {
+      queue.push_back(value);
+    }
+  }
+
+  // Extract element from specified head. Complexity O(1).
+  absl::optional<T> PopFront(size_t index) {
+    RTC_CHECK_LT(index, queues_.size());
+    if (queues_[index].empty()) {
+      return absl::nullopt;
+    }
+    T out = queues_[index].front();
+    queues_[index].pop_front();
+    return out;
+  }
+
+  // Returns element at specified head. Complexity O(1).
+  absl::optional<T> Front(size_t index) const {
+    RTC_CHECK_LT(index, queues_.size());
+    if (queues_[index].empty()) {
+      return absl::nullopt;
+    }
+    return queues_[index].front();
+  }
+
+  // Returns true if for specified head there are no more elements in the queue
+  // or false otherwise. Complexity O(1).
+  bool IsEmpty(size_t index) const {
+    RTC_CHECK_LT(index, queues_.size());
+    return queues_[index].empty();
+  }
+
+  // Returns size of the longest queue between all readers.
+  // Complexity O(readers_count).
+  size_t size() const {
+    size_t size = 0;
+    for (auto& queue : queues_) {
+      if (queue.size() > size) {
+        size = queue.size();
+      }
+    }
+    return size;
+  }
+
+  // Returns size of the specified queue. Complexity O(1).
+  size_t size(size_t index) const {
+    RTC_CHECK_LT(index, queues_.size());
+    return queues_[index].size();
+  }
+
+  size_t readers_count() const { return queues_.size(); }
+
+ private:
+  std::vector<std::deque<T>> queues_;
+};
+
+}  // namespace webrtc_pc_e2e
+}  // namespace webrtc
+
+#endif  // TEST_PC_E2E_ANALYZER_VIDEO_MULTI_HEAD_QUEUE_H_