1 files changed, 182 insertions, 0 deletions
diff --git a/src/rocksdb/table/merger_test.cc b/src/rocksdb/table/merger_test.cc
new file mode 100644
index 000000000..71dc798e5
--- /dev/null
+++ b/src/rocksdb/table/merger_test.cc
@@ -0,0 +1,182 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#include <string>
+#include <vector>
+
+#include "table/merging_iterator.h"
+#include "test_util/testharness.h"
+#include "test_util/testutil.h"
+#include "util/random.h"
+#include "util/vector_iterator.h"
+
+namespace ROCKSDB_NAMESPACE {
+
+class MergerTest : public testing::Test {
+ public:
+  MergerTest()
+      : icomp_(BytewiseComparator()),
+        rnd_(3),
+        merging_iterator_(nullptr),
+        single_iterator_(nullptr) {}
+  ~MergerTest() override = default;
+  std::vector<std::string> GenerateStrings(size_t len, int string_len) {
+    std::vector<std::string> ret;
+
+    for (size_t i = 0; i < len; ++i) {
+      InternalKey ik(rnd_.HumanReadableString(string_len), 0,
+                     ValueType::kTypeValue);
+      ret.push_back(ik.Encode().ToString(false));
+    }
+    return ret;
+  }
+
+  void AssertEquivalence() {
+    auto a = merging_iterator_.get();
+    auto b = single_iterator_.get();
+    if (!a->Valid()) {
+      ASSERT_TRUE(!b->Valid());
+    } else {
+      ASSERT_TRUE(b->Valid());
+      ASSERT_EQ(b->key().ToString(), a->key().ToString());
+      ASSERT_EQ(b->value().ToString(), a->value().ToString());
+    }
+  }
+
+  void SeekToRandom() {
+    InternalKey ik(rnd_.HumanReadableString(5), 0, ValueType::kTypeValue);
+    Seek(ik.Encode().ToString(false));
+  }
+
+  void Seek(std::string target) {
+    merging_iterator_->Seek(target);
+    single_iterator_->Seek(target);
+  }
+
+  void SeekToFirst() {
+    merging_iterator_->SeekToFirst();
+    single_iterator_->SeekToFirst();
+  }
+
+  void SeekToLast() {
+    merging_iterator_->SeekToLast();
+    single_iterator_->SeekToLast();
+  }
+
+  void Next(int times) {
+    for (int i = 0; i < times && merging_iterator_->Valid(); ++i) {
+      AssertEquivalence();
+      merging_iterator_->Next();
+      single_iterator_->Next();
+    }
+    AssertEquivalence();
+  }
+
+  void Prev(int times) {
+    for (int i = 0; i < times && merging_iterator_->Valid(); ++i) {
+      AssertEquivalence();
+      merging_iterator_->Prev();
+      single_iterator_->Prev();
+    }
+    AssertEquivalence();
+  }
+
+  void NextAndPrev(int times) {
+    for (int i = 0; i < times && merging_iterator_->Valid(); ++i) {
+      AssertEquivalence();
+      if (rnd_.OneIn(2)) {
+        merging_iterator_->Prev();
+        single_iterator_->Prev();
+      } else {
+        merging_iterator_->Next();
+        single_iterator_->Next();
+      }
+    }
+    AssertEquivalence();
+  }
+
+  void Generate(size_t num_iterators, size_t strings_per_iterator,
+                int letters_per_string) {
+    std::vector<InternalIterator*> small_iterators;
+    for (size_t i = 0; i < num_iterators; ++i) {
+      auto strings = GenerateStrings(strings_per_iterator, letters_per_string);
+      small_iterators.push_back(new VectorIterator(strings, strings, &icomp_));
+      all_keys_.insert(all_keys_.end(), strings.begin(), strings.end());
+    }
+
+    merging_iterator_.reset(
+        NewMergingIterator(&icomp_, &small_iterators[0],
+                           static_cast<int>(small_iterators.size())));
+    single_iterator_.reset(new VectorIterator(all_keys_, all_keys_, &icomp_));
+  }
+
+  InternalKeyComparator icomp_;
+  Random rnd_;
+  std::unique_ptr<InternalIterator> merging_iterator_;
+  std::unique_ptr<InternalIterator> single_iterator_;
+  std::vector<std::string> all_keys_;
+};
+
+TEST_F(MergerTest, SeekToRandomNextTest) {
+  Generate(1000, 50, 50);
+  for (int i = 0; i < 10; ++i) {
+    SeekToRandom();
+    AssertEquivalence();
+    Next(50000);
+  }
+}
+
+TEST_F(MergerTest, SeekToRandomNextSmallStringsTest) {
+  Generate(1000, 50, 2);
+  for (int i = 0; i < 10; ++i) {
+    SeekToRandom();
+    AssertEquivalence();
+    Next(50000);
+  }
+}
+
+TEST_F(MergerTest, SeekToRandomPrevTest) {
+  Generate(1000, 50, 50);
+  for (int i = 0; i < 10; ++i) {
+    SeekToRandom();
+    AssertEquivalence();
+    Prev(50000);
+  }
+}
+
+TEST_F(MergerTest, SeekToRandomRandomTest) {
+  Generate(200, 50, 50);
+  for (int i = 0; i < 3; ++i) {
+    SeekToRandom();
+    AssertEquivalence();
+    NextAndPrev(5000);
+  }
+}
+
+TEST_F(MergerTest, SeekToFirstTest) {
+  Generate(1000, 50, 50);
+  for (int i = 0; i < 10; ++i) {
+    SeekToFirst();
+    AssertEquivalence();
+    Next(50000);
+  }
+}
+
+TEST_F(MergerTest, SeekToLastTest) {
+  Generate(1000, 50, 50);
+  for (int i = 0; i < 10; ++i) {
+    SeekToLast();
+    AssertEquivalence();
+    Prev(50000);
+  }
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+
+int main(int argc, char** argv) {
+  ROCKSDB_NAMESPACE::port::InstallStackTraceHandler();
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}