Multi reader/writer cache/buffer

media/blink/rangemap_unittests.cc

Index: media/blink/rangemap_unittests.cc
diff --git a/media/blink/rangemap_unittests.cc b/media/blink/rangemap_unittests.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bef21be1360316479394a31d62c8d9101408d1a6
--- /dev/null
+++ b/media/blink/rangemap_unittests.cc
@@ -0,0 +1,103 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stdint.h>
+
+#include <string>
+
+#include "base/strings/stringprintf.h"
+#include "media/blink/rangemap.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+const int kTestSize = 16;
+
+class SimpleRangeMap {
+ public:
+  SimpleRangeMap() : data_(kTestSize) {
+  }
+
+  void IncrementRange(int32_t from, int32_t to, int32_t howmuch) {
+    for (int32_t i = from; i < to; i++) {
+      data_[i] += howmuch;
+    }
+  }
+
+  int32_t operator[](int32_t index) const {
+    return data_[index];
+  }
+
+ private:
+  std::vector<int32_t> data_;
+};
+
+class RangeMapTest : public testing::Test {
+ public:
+  void IncrementRange(int32_t from, int32_t to, int32_t howmuch) {
+    truth_.IncrementRange(from, to, howmuch);
+    testee_.IncrementRange(from, to, howmuch);
+    std::string message = base::StringPrintf(
+        "After [%d - %d) += %d",
+        from, to, howmuch);
+    Compare(message);
+    if (HasFailure()) {
+      for (int i = 0; i < kTestSize; i++) {
+        LOG(ERROR) << "Truth[" << i << "] =" << truth_[i];
+      }
+      media::RangeMap<int32_t, int32_t>::MapType::const_iterator i;
+      for (i = testee_.map().begin();
+           i != testee_.map().end();
+           ++i) {
+        LOG(ERROR) << "Testee[" << i->first << "..] = " << i->second;
+      }
+    }
+  }
+
+  void Compare(const std::string& message) {
+    for (int i = 0; i < kTestSize; i++) {
+      EXPECT_EQ(truth_[i], testee_[i])
+          << " i = " << i << " " << message;
+    }
+    EXPECT_EQ(testee_[-1], 0) << message;
+    EXPECT_EQ(testee_[kTestSize], 0) << message;
+    int32_t prev_ = 0;
+    media::RangeMap<int32_t, int32_t>::MapType::const_iterator i;
+    for (i = testee_.map().begin();
+         i != testee_.map().end();
+         ++i) {
+      EXPECT_GE(i->first, 0) << message;
+      EXPECT_LE(i->first, kTestSize) << message;
+      EXPECT_NE(i->second, prev_) << message;
+      prev_ = i->second;
+    }
+    EXPECT_EQ(prev_, 0) << message;
+  }
+
+  void Clear() {
+    for (int j = 0; j < kTestSize; j++) {
+      IncrementRange(j, j + 1, -truth_[j]);
+    }
+  }
+
+ private:
+  SimpleRangeMap truth_;
+  media::RangeMap<int32_t, int32_t> testee_;
+};
+
+}
+
+TEST_F(RangeMapTest, RandomTest) {
+  for (int j = 0; j < 100; j++) {
+    Clear();
+    for (int i = 0; i < 100; i++) {
+      int32_t begin = rand() % (kTestSize - 1);
+      int32_t end = begin + 1 + rand() % (kTestSize - begin - 1);
+      IncrementRange(begin, end, (rand() & 32) ? 1 : -1);
+      if (HasFailure()) {
+        return;
+      }
+    }
+  }
+}