1 files changed, 107 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer_unittest.cc b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer_unittest.cc
new file mode 100644
index 0000000000..1509ca5ac1
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer_unittest.cc
@@ -0,0 +1,107 @@
+/*
+ *  Copyright (c) 2018 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.
+ */
+
+#include "modules/audio_processing/agc2/rnn_vad/symmetric_matrix_buffer.h"
+
+#include "modules/audio_processing/agc2/rnn_vad/ring_buffer.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+namespace rnn_vad {
+namespace {
+
+template <typename T, int S>
+void CheckSymmetry(const SymmetricMatrixBuffer<T, S>* sym_matrix_buf) {
+  for (int row = 0; row < S - 1; ++row)
+    for (int col = row + 1; col < S; ++col)
+      EXPECT_EQ(sym_matrix_buf->GetValue(row, col),
+                sym_matrix_buf->GetValue(col, row));
+}
+
+using PairType = std::pair<int, int>;
+
+// Checks that the symmetric matrix buffer contains any pair with a value equal
+// to the given one.
+template <int S>
+bool CheckPairsWithValueExist(
+    const SymmetricMatrixBuffer<PairType, S>* sym_matrix_buf,
+    const int value) {
+  for (int row = 0; row < S - 1; ++row) {
+    for (int col = row + 1; col < S; ++col) {
+      auto p = sym_matrix_buf->GetValue(row, col);
+      if (p.first == value || p.second == value)
+        return true;
+    }
+  }
+  return false;
+}
+
+// Test that shows how to combine RingBuffer and SymmetricMatrixBuffer to
+// efficiently compute pair-wise scores. This test verifies that the evolution
+// of a SymmetricMatrixBuffer instance follows that of RingBuffer.
+TEST(RnnVadTest, SymmetricMatrixBufferUseCase) {
+  // Instance a ring buffer which will be fed with a series of integer values.
+  constexpr int kRingBufSize = 10;
+  RingBuffer<int, 1, kRingBufSize> ring_buf;
+  // Instance a symmetric matrix buffer for the ring buffer above. It stores
+  // pairs of integers with which this test can easily check that the evolution
+  // of RingBuffer and SymmetricMatrixBuffer match.
+  SymmetricMatrixBuffer<PairType, kRingBufSize> sym_matrix_buf;
+  for (int t = 1; t <= 100; ++t) {  // Evolution steps.
+    SCOPED_TRACE(t);
+    const int t_removed = ring_buf.GetArrayView(kRingBufSize - 1)[0];
+    ring_buf.Push({&t, 1});
+    // The head of the ring buffer is `t`.
+    ASSERT_EQ(t, ring_buf.GetArrayView(0)[0]);
+    // Create the comparisons between `t` and the older elements in the ring
+    // buffer.
+    std::array<PairType, kRingBufSize - 1> new_comparions;
+    for (int i = 0; i < kRingBufSize - 1; ++i) {
+      // Start comparing `t` to the second newest element in the ring buffer.
+      const int delay = i + 1;
+      const auto t_prev = ring_buf.GetArrayView(delay)[0];
+      ASSERT_EQ(std::max(0, t - delay), t_prev);
+      // Compare the last element `t` with `t_prev`.
+      new_comparions[i].first = t_prev;
+      new_comparions[i].second = t;
+    }
+    // Push the new comparisons in the symmetric matrix buffer.
+    sym_matrix_buf.Push({new_comparions.data(), new_comparions.size()});
+    // Tests.
+    CheckSymmetry(&sym_matrix_buf);
+    // Check that the pairs resulting from the content in the ring buffer are
+    // in the right position.
+    for (int delay1 = 0; delay1 < kRingBufSize - 1; ++delay1) {
+      for (int delay2 = delay1 + 1; delay2 < kRingBufSize; ++delay2) {
+        const auto t1 = ring_buf.GetArrayView(delay1)[0];
+        const auto t2 = ring_buf.GetArrayView(delay2)[0];
+        ASSERT_LE(t2, t1);
+        const auto p = sym_matrix_buf.GetValue(delay1, delay2);
+        EXPECT_EQ(p.first, t2);
+        EXPECT_EQ(p.second, t1);
+      }
+    }
+    // Check that every older element in the ring buffer still has a
+    // corresponding pair in the symmetric matrix buffer.
+    for (int delay = 1; delay < kRingBufSize; ++delay) {
+      const auto t_prev = ring_buf.GetArrayView(delay)[0];
+      EXPECT_TRUE(CheckPairsWithValueExist(&sym_matrix_buf, t_prev));
+    }
+    // Check that the element removed from the ring buffer has no corresponding
+    // pairs in the symmetric matrix buffer.
+    if (t > kRingBufSize - 1) {
+      EXPECT_FALSE(CheckPairsWithValueExist(&sym_matrix_buf, t_removed));
+    }
+  }
+}
+
+}  // namespace
+}  // namespace rnn_vad
+}  // namespace webrtc