Integrating Cuckoo Hash SST Table format into RocksDB

Summary:
Contains the following changes:
- Implementation of cuckoo_table_factory
- Adding cuckoo table into AdaptiveTableFactory
- Adding cuckoo_table_db_test, similar to lines of plain_table_db_test
- Minor fixes to Reader: When a key is found in the table, return the key found instead of the search key.
- Minor fixes to Builder: Add table properties that are required by Version::UpdateTemporaryStats() during Get operation. Don't define curr_node as a reference variable as the memory locations may get reassigned during tree.push_back operation, leading to invalid memory access.

Test Plan:
cuckoo_table_reader_test --enable_perf
cuckoo_table_builder_test
cuckoo_table_db_test
make check all
make valgrind_check
make asan_check

Reviewers: sdong, igor, yhchiang, ljin

Reviewed By: ljin

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21219

Makefile

@@ -117,9 +117,10 @@ TESTS = \
 	thread_local_test \
 	geodb_test \
  	rate_limiter_test \
-	cuckoo_table_builder_test \
 	options_test \
-	cuckoo_table_reader_test
+	cuckoo_table_builder_test \
+	cuckoo_table_reader_test \
+	cuckoo_table_db_test
 
 TOOLS = \
         sst_dump \
@@ -430,6 +431,9 @@ cuckoo_table_builder_test: table/cuckoo_table_builder_test.o $(LIBOBJECTS) $(TES
 cuckoo_table_reader_test: table/cuckoo_table_reader_test.o $(LIBOBJECTS) $(TESTHARNESS) $(BENCHHARNESS)
 	$(CXX) table/cuckoo_table_reader_test.o  $(LIBOBJECTS) $(TESTHARNESS) $(BENCHHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
 
+cuckoo_table_db_test: db/cuckoo_table_db_test.o $(LIBOBJECTS) $(TESTHARNESS)
+	$(CXX) db/cuckoo_table_db_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
+
 options_test: util/options_test.o $(LIBOBJECTS) $(TESTHARNESS)
 	$(CXX) util/options_test.o $(LIBOBJECTS) $(TESTHARNESS) $(EXEC_LDFLAGS) -o $@ $(LDFLAGS) $(COVERAGEFLAGS)
 

db/cuckoo_table_db_test.cc

@@ -0,0 +1,291 @@
+//  Copyright (c) 2014, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+
+#include "db/db_impl.h"
+#include "rocksdb/db.h"
+#include "rocksdb/env.h"
+#include "table/meta_blocks.h"
+#include "table/cuckoo_table_factory.h"
+#include "table/cuckoo_table_reader.h"
+#include "util/testharness.h"
+#include "util/testutil.h"
+
+namespace rocksdb {
+
+class CuckooTableDBTest {
+ private:
+  std::string dbname_;
+  Env* env_;
+  DB* db_;
+
+ public:
+  CuckooTableDBTest() : env_(Env::Default()) {
+    dbname_ = test::TmpDir() + "/cuckoo_table_db_test";
+    ASSERT_OK(DestroyDB(dbname_, Options()));
+    db_ = nullptr;
+    Reopen();
+  }
+
+  ~CuckooTableDBTest() {
+    delete db_;
+    ASSERT_OK(DestroyDB(dbname_, Options()));
+  }
+
+  Options CurrentOptions() {
+    Options options;
+    options.table_factory.reset(NewCuckooTableFactory());
+    options.memtable_factory.reset(NewHashLinkListRepFactory(4, 0, 3, true));
+    options.allow_mmap_reads = true;
+    options.create_if_missing = true;
+    options.max_mem_compaction_level = 0;
+    return options;
+  }
+
+  DBImpl* dbfull() {
+    return reinterpret_cast<DBImpl*>(db_);
+  }
+
+  // The following util methods are copied from plain_table_db_test.
+  void Reopen(Options* options = nullptr) {
+    delete db_;
+    db_ = nullptr;
+    Options opts;
+    if (options != nullptr) {
+      opts = *options;
+    } else {
+      opts = CurrentOptions();
+      opts.create_if_missing = true;
+    }
+    ASSERT_OK(DB::Open(opts, dbname_, &db_));
+  }
+
+  Status Put(const Slice& k, const Slice& v) {
+    return db_->Put(WriteOptions(), k, v);
+  }
+
+  Status Delete(const std::string& k) {
+    return db_->Delete(WriteOptions(), k);
+  }
+
+  std::string Get(const std::string& k) {
+    ReadOptions options;
+    std::string result;
+    Status s = db_->Get(options, k, &result);
+    if (s.IsNotFound()) {
+      result = "NOT_FOUND";
+    } else if (!s.ok()) {
+      result = s.ToString();
+    }
+    return result;
+  }
+
+  int NumTableFilesAtLevel(int level) {
+    std::string property;
+    ASSERT_TRUE(
+        db_->GetProperty("rocksdb.num-files-at-level" + NumberToString(level),
+                         &property));
+    return atoi(property.c_str());
+  }
+
+  // Return spread of files per level
+  std::string FilesPerLevel() {
+    std::string result;
+    int last_non_zero_offset = 0;
+    for (int level = 0; level < db_->NumberLevels(); level++) {
+      int f = NumTableFilesAtLevel(level);
+      char buf[100];
+      snprintf(buf, sizeof(buf), "%s%d", (level ? "," : ""), f);
+      result += buf;
+      if (f > 0) {
+        last_non_zero_offset = result.size();
+      }
+    }
+    result.resize(last_non_zero_offset);
+    return result;
+  }
+};
+
+TEST(CuckooTableDBTest, Flush) {
+  // Try with empty DB first.
+  ASSERT_TRUE(dbfull() != nullptr);
+  ASSERT_EQ("NOT_FOUND", Get("key2"));
+
+  // Add some values to db.
+  Options options = CurrentOptions();
+  Reopen(&options);
+
+  ASSERT_OK(Put("key1", "v1"));
+  ASSERT_OK(Put("key2", "v2"));
+  ASSERT_OK(Put("key3", "v3"));
+  dbfull()->TEST_FlushMemTable();
+
+  TablePropertiesCollection ptc;
+  reinterpret_cast<DB*>(dbfull())->GetPropertiesOfAllTables(&ptc);
+  ASSERT_EQ(1U, ptc.size());
+  ASSERT_EQ(3, ptc.begin()->second->num_entries);
+  ASSERT_EQ("1", FilesPerLevel());
+
+  ASSERT_EQ("v1", Get("key1"));
+  ASSERT_EQ("v2", Get("key2"));
+  ASSERT_EQ("v3", Get("key3"));
+  ASSERT_EQ("NOT_FOUND", Get("key4"));
+  ASSERT_EQ("Invalid argument: Length of key is invalid.", Get("somelongkey"));
+  ASSERT_EQ("Invalid argument: Length of key is invalid.", Get("s"));
+
+  // Now add more keys and flush.
+  ASSERT_OK(Put("key4", "v4"));
+  ASSERT_OK(Put("key5", "v5"));
+  ASSERT_OK(Put("key6", "v6"));
+  dbfull()->TEST_FlushMemTable();
+
+  reinterpret_cast<DB*>(dbfull())->GetPropertiesOfAllTables(&ptc);
+  ASSERT_EQ(2U, ptc.size());
+  auto row = ptc.begin();
+  ASSERT_EQ(3, row->second->num_entries);
+  ASSERT_EQ(3, (++row)->second->num_entries);
+  ASSERT_EQ("2", FilesPerLevel());
+  ASSERT_EQ("v1", Get("key1"));
+  ASSERT_EQ("v2", Get("key2"));
+  ASSERT_EQ("v3", Get("key3"));
+  ASSERT_EQ("v4", Get("key4"));
+  ASSERT_EQ("v5", Get("key5"));
+  ASSERT_EQ("v6", Get("key6"));
+
+  ASSERT_OK(Delete("key6"));
+  ASSERT_OK(Delete("key5"));
+  ASSERT_OK(Delete("key4"));
+  dbfull()->TEST_FlushMemTable();
+  reinterpret_cast<DB*>(dbfull())->GetPropertiesOfAllTables(&ptc);
+  ASSERT_EQ(3U, ptc.size());
+  row = ptc.begin();
+  ASSERT_EQ(3, row->second->num_entries);
+  ASSERT_EQ(3, (++row)->second->num_entries);
+  ASSERT_EQ(3, (++row)->second->num_entries);
+  ASSERT_EQ("3", FilesPerLevel());
+  ASSERT_EQ("v1", Get("key1"));
+  ASSERT_EQ("v2", Get("key2"));
+  ASSERT_EQ("v3", Get("key3"));
+  ASSERT_EQ("NOT_FOUND", Get("key4"));
+  ASSERT_EQ("NOT_FOUND", Get("key5"));
+  ASSERT_EQ("NOT_FOUND", Get("key6"));
+}
+
+TEST(CuckooTableDBTest, FlushWithDuplicateKeys) {
+  Options options = CurrentOptions();
+  Reopen(&options);
+  ASSERT_OK(Put("key1", "v1"));
+  ASSERT_OK(Put("key2", "v2"));
+  ASSERT_OK(Put("key1", "v3"));  // Duplicate
+  dbfull()->TEST_FlushMemTable();
+
+  TablePropertiesCollection ptc;
+  reinterpret_cast<DB*>(dbfull())->GetPropertiesOfAllTables(&ptc);
+  ASSERT_EQ(1U, ptc.size());
+  ASSERT_EQ(2, ptc.begin()->second->num_entries);
+  ASSERT_EQ("1", FilesPerLevel());
+  ASSERT_EQ("v3", Get("key1"));
+  ASSERT_EQ("v2", Get("key2"));
+}
+
+namespace {
+static std::string Key(int i) {
+  char buf[100];
+  snprintf(buf, sizeof(buf), "key_______%06d", i);
+  return std::string(buf);
+}
+}
+
+TEST(CuckooTableDBTest, CompactionTrigger) {
+  Options options = CurrentOptions();
+  options.write_buffer_size = 100 << 10;  // 100KB
+  options.level0_file_num_compaction_trigger = 2;
+  Reopen(&options);
+
+  // Write 11 values, each 10016 B
+  for (int idx = 0; idx < 11; ++idx) {
+    ASSERT_OK(Put(Key(idx), std::string(10000, 'a' + idx)));
+  }
+  dbfull()->TEST_WaitForFlushMemTable();
+  ASSERT_EQ("1", FilesPerLevel());
+
+  // Generate one more file in level-0, and should trigger level-0 compaction
+  for (int idx = 11; idx < 22; ++idx) {
+    ASSERT_OK(Put(Key(idx), std::string(10000, 'a' + idx)));
+  }
+  dbfull()->TEST_WaitForFlushMemTable();
+  dbfull()->TEST_CompactRange(0, nullptr, nullptr);
+
+  ASSERT_EQ("0,2", FilesPerLevel());
+  for (int idx = 0; idx < 22; ++idx) {
+    ASSERT_EQ(std::string(10000, 'a' + idx), Get(Key(idx)));
+  }
+}
+
+TEST(CuckooTableDBTest, SameKeyInsertedInTwoDifferentFilesAndCompacted) {
+  // Insert same key twice so that they go to different SST files. Then wait for
+  // compaction and check if the latest value is stored and old value removed.
+  Options options = CurrentOptions();
+  options.write_buffer_size = 100 << 10;  // 100KB
+  options.level0_file_num_compaction_trigger = 2;
+  Reopen(&options);
+
+  // Write 11 values, each 10016 B
+  for (int idx = 0; idx < 11; ++idx) {
+    ASSERT_OK(Put(Key(idx), std::string(10000, 'a')));
+  }
+  dbfull()->TEST_WaitForFlushMemTable();
+  ASSERT_EQ("1", FilesPerLevel());
+
+  // Generate one more file in level-0, and should trigger level-0 compaction
+  for (int idx = 0; idx < 11; ++idx) {
+    ASSERT_OK(Put(Key(idx), std::string(10000, 'a' + idx)));
+  }
+  dbfull()->TEST_WaitForFlushMemTable();
+  dbfull()->TEST_CompactRange(0, nullptr, nullptr);
+
+  ASSERT_EQ("0,1", FilesPerLevel());
+  for (int idx = 0; idx < 11; ++idx) {
+    ASSERT_EQ(std::string(10000, 'a' + idx), Get(Key(idx)));
+  }
+}
+
+TEST(CuckooTableDBTest, AdaptiveTable) {
+  Options options = CurrentOptions();
+
+  // Write some keys using cuckoo table.
+  options.table_factory.reset(NewCuckooTableFactory());
+  Reopen(&options);
+
+  ASSERT_OK(Put("key1", "v1"));
+  ASSERT_OK(Put("key2", "v2"));
+  ASSERT_OK(Put("key3", "v3"));
+  dbfull()->TEST_FlushMemTable();
+
+  // Write some keys using plain table.
+  options.create_if_missing = false;
+  options.table_factory.reset(NewPlainTableFactory());
+  Reopen(&options);
+  ASSERT_OK(Put("key4", "v4"));
+  ASSERT_OK(Put("key1", "v5"));
+  dbfull()->TEST_FlushMemTable();
+
+  // Write some keys using block based table.
+  std::shared_ptr<TableFactory> block_based_factory(
+      NewBlockBasedTableFactory());
+  options.table_factory.reset(NewAdaptiveTableFactory(block_based_factory));
+  Reopen(&options);
+  ASSERT_OK(Put("key5", "v6"));
+  ASSERT_OK(Put("key2", "v7"));
+  dbfull()->TEST_FlushMemTable();
+
+  ASSERT_EQ("v5", Get("key1"));
+  ASSERT_EQ("v7", Get("key2"));
+  ASSERT_EQ("v3", Get("key3"));
+  ASSERT_EQ("v4", Get("key4"));
+  ASSERT_EQ("v6", Get("key5"));
+}
+}  // namespace rocksdb
+
+int main(int argc, char** argv) { return rocksdb::test::RunAllTests(); }

include/rocksdb/table.h

@@ -192,6 +192,9 @@ struct CuckooTablePropertyNames {
   static const std::string kIsLastLevel;
 };
 
+extern TableFactory* NewCuckooTableFactory(double hash_table_ratio = 0.9,
+    uint32_t max_search_depth = 100);
+
 #endif  // ROCKSDB_LITE
 
 // A base class for table factories.
@@ -263,7 +266,8 @@ class TableFactory {
 extern TableFactory* NewAdaptiveTableFactory(
     std::shared_ptr<TableFactory> table_factory_to_write = nullptr,
     std::shared_ptr<TableFactory> block_based_table_factory = nullptr,
-    std::shared_ptr<TableFactory> plain_table_factory = nullptr);
+    std::shared_ptr<TableFactory> plain_table_factory = nullptr,
+    std::shared_ptr<TableFactory> cuckoo_table_factory = nullptr);
 
 #endif  // ROCKSDB_LITE
 

table/adaptive_table_factory.cc

@@ -12,10 +12,12 @@ namespace rocksdb {
 AdaptiveTableFactory::AdaptiveTableFactory(
     std::shared_ptr<TableFactory> table_factory_to_write,
     std::shared_ptr<TableFactory> block_based_table_factory,
-    std::shared_ptr<TableFactory> plain_table_factory)
+    std::shared_ptr<TableFactory> plain_table_factory,
+    std::shared_ptr<TableFactory> cuckoo_table_factory)
     : table_factory_to_write_(table_factory_to_write),
       block_based_table_factory_(block_based_table_factory),
-      plain_table_factory_(plain_table_factory) {
+      plain_table_factory_(plain_table_factory),
+      cuckoo_table_factory_(cuckoo_table_factory) {
   if (!table_factory_to_write_) {
     table_factory_to_write_ = block_based_table_factory_;
   }
@@ -25,12 +27,16 @@ AdaptiveTableFactory::AdaptiveTableFactory(
   if (!block_based_table_factory_) {
     block_based_table_factory_.reset(NewBlockBasedTableFactory());
   }
+  if (!cuckoo_table_factory_) {
+    cuckoo_table_factory_.reset(NewCuckooTableFactory());
+  }
 }
 
 extern const uint64_t kPlainTableMagicNumber;
 extern const uint64_t kLegacyPlainTableMagicNumber;
 extern const uint64_t kBlockBasedTableMagicNumber;
 extern const uint64_t kLegacyBlockBasedTableMagicNumber;
+extern const uint64_t kCuckooTableMagicNumber;
 
 Status AdaptiveTableFactory::NewTableReader(
     const Options& options, const EnvOptions& soptions,
@@ -49,6 +55,9 @@ Status AdaptiveTableFactory::NewTableReader(
       footer.table_magic_number() == kLegacyBlockBasedTableMagicNumber) {
     return block_based_table_factory_->NewTableReader(
         options, soptions, icomp, std::move(file), file_size, table);
+  } else if (footer.table_magic_number() == kCuckooTableMagicNumber) {
+    return cuckoo_table_factory_->NewTableReader(
+        options, soptions, icomp, std::move(file), file_size, table);
   } else {
     return Status::NotSupported("Unidentified table format");
   }
@@ -64,9 +73,10 @@ TableBuilder* AdaptiveTableFactory::NewTableBuilder(
 extern TableFactory* NewAdaptiveTableFactory(
     std::shared_ptr<TableFactory> table_factory_to_write,
     std::shared_ptr<TableFactory> block_based_table_factory,
-    std::shared_ptr<TableFactory> plain_table_factory) {
+    std::shared_ptr<TableFactory> plain_table_factory,
-  return new AdaptiveTableFactory(
+    std::shared_ptr<TableFactory> cuckoo_table_factory) {
-      table_factory_to_write, block_based_table_factory, plain_table_factory);
+  return new AdaptiveTableFactory(table_factory_to_write,
+      block_based_table_factory, plain_table_factory, cuckoo_table_factory);
 }
 
 }  // namespace rocksdb

table/adaptive_table_factory.h

@@ -28,7 +28,8 @@ class AdaptiveTableFactory : public TableFactory {
   explicit AdaptiveTableFactory(
       std::shared_ptr<TableFactory> table_factory_to_write,
       std::shared_ptr<TableFactory> block_based_table_factory,
-      std::shared_ptr<TableFactory> plain_table_factory);
+      std::shared_ptr<TableFactory> plain_table_factory,
+      std::shared_ptr<TableFactory> cuckoo_table_factory);
   const char* Name() const override { return "AdaptiveTableFactory"; }
   Status NewTableReader(const Options& options, const EnvOptions& soptions,
                         const InternalKeyComparator& internal_comparator,
@@ -44,6 +45,7 @@ class AdaptiveTableFactory : public TableFactory {
   std::shared_ptr<TableFactory> table_factory_to_write_;
   std::shared_ptr<TableFactory> block_based_table_factory_;
   std::shared_ptr<TableFactory> plain_table_factory_;
+  std::shared_ptr<TableFactory> cuckoo_table_factory_;
 };
 
 }  // namespace rocksdb

table/cuckoo_table_builder.cc

@@ -213,8 +213,11 @@ Status CuckooTableBuilder::Finish() {
     }
   }
   assert(num_added == NumEntries());
+  properties_.raw_key_size = num_added * properties_.fixed_key_len;
+  properties_.raw_value_size = num_added * value_length;
 
   uint64_t offset = buckets.size() * bucket_size;
+  properties_.data_size = offset;
   unused_bucket.resize(properties_.fixed_key_len);
   properties_.user_collected_properties[
     CuckooTablePropertyNames::kEmptyKey] = unused_bucket;
@@ -330,7 +333,8 @@ bool CuckooTableBuilder::MakeSpaceForKey(
   uint32_t curr_pos = 0;
   while (!null_found && curr_pos < tree.size()) {
     CuckooNode& curr_node = tree[curr_pos];
-    if (curr_node.depth >= max_search_depth_) {
+    uint32_t curr_depth = curr_node.depth;
+    if (curr_depth >= max_search_depth_) {
       break;
     }
     CuckooBucket& curr_bucket = (*buckets)[curr_node.bucket_id];
@@ -345,7 +349,7 @@ bool CuckooTableBuilder::MakeSpaceForKey(
       }
       (*buckets)[child_bucket_id].make_space_for_key_call_id =
         make_space_for_key_call_id;
-      tree.push_back(CuckooNode(child_bucket_id, curr_node.depth + 1,
+      tree.push_back(CuckooNode(child_bucket_id, curr_depth + 1,
             curr_pos));
       if ((*buckets)[child_bucket_id].vector_idx == kMaxVectorIdx) {
         null_found = true;

table/cuckoo_table_builder_test.cc

@@ -51,6 +51,8 @@ class CuckooBuilderTest {
           kCuckooTableMagicNumber, env_, nullptr, &props));
     ASSERT_EQ(props->num_entries, keys.size());
     ASSERT_EQ(props->fixed_key_len, keys.empty() ? 0 : keys[0].size());
+    ASSERT_EQ(props->data_size, keys.size()*expected_unused_bucket.size());
+    ASSERT_EQ(props->raw_key_size, keys.size()*props->fixed_key_len);
 
     // Check unused bucket.
     std::string unused_key = props->user_collected_properties[
@@ -62,6 +64,7 @@ class CuckooBuilderTest {
       *reinterpret_cast<const uint32_t*>(props->user_collected_properties[
                 CuckooTablePropertyNames::kValueLength].data());
     ASSERT_EQ(values.empty() ? 0 : values[0].size(), value_len_found);
+    ASSERT_EQ(props->raw_value_size, values.size()*value_len_found);
     const uint64_t max_buckets =
       *reinterpret_cast<const uint64_t*>(props->user_collected_properties[
                 CuckooTablePropertyNames::kMaxNumBuckets].data());

table/cuckoo_table_factory.cc

@@ -0,0 +1,60 @@
+// Copyright (c) 2014, Facebook, Inc. All rights reserved.
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree. An additional grant
+// of patent rights can be found in the PATENTS file in the same directory.
+
+#ifndef ROCKSDB_LITE
+#include "table/cuckoo_table_factory.h"
+
+#include "db/dbformat.h"
+#include "table/cuckoo_table_builder.h"
+#include "table/cuckoo_table_reader.h"
+#include "util/murmurhash.h"
+
+namespace rocksdb {
+extern const uint32_t kMaxNumHashTable = 64;
+
+extern uint64_t GetSliceMurmurHash(const Slice& s, uint32_t index,
+    uint64_t max_num_buckets) {
+  static constexpr uint32_t seeds[kMaxNumHashTable] = {
+    816922183, 506425713, 949485004, 22513986, 421427259, 500437285,
+    888981693, 847587269, 511007211, 722295391, 934013645, 566947683,
+    193618736, 428277388, 770956674, 819994962, 755946528, 40807421,
+    263144466, 241420041, 444294464, 731606396, 304158902, 563235655,
+    968740453, 336996831, 462831574, 407970157, 985877240, 637708754,
+    736932700, 205026023, 755371467, 729648411, 807744117, 46482135,
+    847092855, 620960699, 102476362, 314094354, 625838942, 550889395,
+    639071379, 834567510, 397667304, 151945969, 443634243, 196618243,
+    421986347, 407218337, 964502417, 327741231, 493359459, 452453139,
+    692216398, 108161624, 816246924, 234779764, 618949448, 496133787,
+    156374056, 316589799, 982915425, 553105889 };
+  return MurmurHash(s.data(), s.size(), seeds[index]) % max_num_buckets;
+}
+
+Status CuckooTableFactory::NewTableReader(const Options& options,
+    const EnvOptions& soptions, const InternalKeyComparator& icomp,
+    std::unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
+    std::unique_ptr<TableReader>* table) const {
+  std::unique_ptr<CuckooTableReader> new_reader(new CuckooTableReader(options,
+      std::move(file), file_size, GetSliceMurmurHash));
+  Status s = new_reader->status();
+  if (s.ok()) {
+    *table = std::move(new_reader);
+  }
+  return s;
+}
+
+TableBuilder* CuckooTableFactory::NewTableBuilder(
+    const Options& options, const InternalKeyComparator& internal_comparator,
+    WritableFile* file, CompressionType compression_type) const {
+  return new CuckooTableBuilder(file, hash_table_ratio_, kMaxNumHashTable,
+      max_search_depth_, GetSliceMurmurHash);
+}
+
+TableFactory* NewCuckooTableFactory(double hash_table_ratio,
+    uint32_t max_search_depth) {
+  return new CuckooTableFactory(hash_table_ratio, max_search_depth);
+}
+
+}  // namespace rocksdb
+#endif  // ROCKSDB_LITE

table/cuckoo_table_factory.h

@@ -6,27 +6,44 @@
 #pragma once
 #ifndef ROCKSDB_LITE
 
-#include "util/murmurhash.h"
+#include "rocksdb/table.h"
 
 namespace rocksdb {
 
-static const uint32_t kMaxNumHashTable  = 64;
+extern uint64_t GetSliceMurmurHash(const Slice& s, uint32_t index,
-
+    uint64_t max_num_buckets);
-uint64_t GetSliceMurmurHash(const Slice& s, uint32_t index,
+
-    uint64_t max_num_buckets) {
+// Cuckoo Table is designed for applications that require fast point lookups
-  static constexpr uint32_t seeds[kMaxNumHashTable] = {
+// but not fast range scans.
-    816922183, 506425713, 949485004, 22513986, 421427259, 500437285,
+//
-    888981693, 847587269, 511007211, 722295391, 934013645, 566947683,
+// Some assumptions:
-    193618736, 428277388, 770956674, 819994962, 755946528, 40807421,
+// - Key length and Value length are fixed.
-    263144466, 241420041, 444294464, 731606396, 304158902, 563235655,
+// - Does not support Snapshot.
-    968740453, 336996831, 462831574, 407970157, 985877240, 637708754,
+// - Does not support Merge operations.
-    736932700, 205026023, 755371467, 729648411, 807744117, 46482135,
+// - Only supports Bytewise comparators.
-    847092855, 620960699, 102476362, 314094354, 625838942, 550889395,
+class CuckooTableFactory : public TableFactory {
-    639071379, 834567510, 397667304, 151945969, 443634243, 196618243,
+ public:
-    421986347, 407218337, 964502417, 327741231, 493359459, 452453139,
+  CuckooTableFactory(double hash_table_ratio, uint32_t max_search_depth)
-    692216398, 108161624, 816246924, 234779764, 618949448, 496133787,
+    : hash_table_ratio_(hash_table_ratio),
-    156374056, 316589799, 982915425, 553105889 };
+      max_search_depth_(max_search_depth) {}
-  return MurmurHash(s.data(), s.size(), seeds[index]) % max_num_buckets;
+  ~CuckooTableFactory() {}
-}
+
+  const char* Name() const override { return "CuckooTable"; }
+
+  Status NewTableReader(
+      const Options& options, const EnvOptions& soptions,
+      const InternalKeyComparator& internal_comparator,
+      unique_ptr<RandomAccessFile>&& file, uint64_t file_size,
+      unique_ptr<TableReader>* table) const override;
+
+  TableBuilder* NewTableBuilder(const Options& options,
+      const InternalKeyComparator& icomparator, WritableFile* file,
+      CompressionType compression_type) const override;
+
+ private:
+  const double hash_table_ratio_;
+  const uint32_t max_search_depth_;
+};
+
 }  // namespace rocksdb
 #endif  // ROCKSDB_LITE

table/cuckoo_table_reader.cc

@@ -89,6 +89,10 @@ Status CuckooTableReader::Get(
   if (!ParseInternalKey(key, &ikey)) {
     return Status::Corruption("Unable to parse key into inernal key.");
   }
+  if ((is_last_level_ && key.size() != key_length_ + 8) ||
+      (!is_last_level_ && key.size() != key_length_)) {
+    return Status::InvalidArgument("Length of key is invalid.");
+  }
   for (uint32_t hash_cnt = 0; hash_cnt < num_hash_fun_; ++hash_cnt) {
     uint64_t hash_val = get_slice_hash_(ikey.user_key, hash_cnt, num_buckets_);
     assert(hash_val < num_buckets_);
@@ -101,7 +105,15 @@ Status CuckooTableReader::Get(
     // per user key and we don't support sanpshot.
     if (ikey.user_key.compare(Slice(bucket, ikey.user_key.size())) == 0) {
       Slice value = Slice(&bucket[key_length_], value_length_);
-      result_handler(handle_context, ikey, value);
+      if (is_last_level_) {
+        ParsedInternalKey found_ikey(Slice(bucket, key_length_), 0, kTypeValue);
+        result_handler(handle_context, found_ikey, value);
+      } else {
+        Slice full_key(bucket, key_length_);
+        ParsedInternalKey found_ikey;
+        ParseInternalKey(full_key, &found_ikey);
+        result_handler(handle_context, found_ikey, value);
+      }
       // We don't support merge operations. So, we return here.
       return Status::OK();
     }

table/cuckoo_table_reader_test.cc

@@ -37,6 +37,7 @@ DEFINE_bool(enable_perf, false, "Run Benchmark Tests too.");
 namespace rocksdb {
 
 extern const uint64_t kCuckooTableMagicNumber;
+extern const uint64_t kMaxNumHashTable;
 
 namespace {
 const uint32_t kNumHashFunc = 10;
@@ -311,6 +312,22 @@ TEST(CuckooReaderTest, WhenKeyNotFound) {
   ASSERT_EQ(0, v.call_count);
   ASSERT_OK(reader.status());
 
+  // Test read with key of invalid length.
+  IterKey k;
+  k.SetInternalKey("very_long_key", 0, kTypeValue);
+  ASSERT_TRUE(reader.Get(
+        ReadOptions(), k.GetKey(), &v,
+        AssertValues, nullptr).IsInvalidArgument());
+  ASSERT_EQ(0, v.call_count);
+  ASSERT_OK(reader.status());
+  k.Clear();
+  k.SetInternalKey("s", 0, kTypeValue);
+  ASSERT_TRUE(reader.Get(
+        ReadOptions(), k.GetKey(), &v,
+        AssertValues, nullptr).IsInvalidArgument());
+  ASSERT_EQ(0, v.call_count);
+  ASSERT_OK(reader.status());
+
   // Test read when key is unused key.
   std::string unused_key =
     reader.GetTableProperties()->user_collected_properties.at(