548: Support Spdb memtable in Java

CMakeLists.txt

@@ -818,6 +818,7 @@ set(SOURCES
         memory/memory_allocator.cc
         memtable/alloc_tracker.cc
         memtable/hash_linklist_rep.cc
+        memtable/hash_spdb_rep.cc
         memtable/hash_skiplist_rep.cc
         memtable/skiplistrep.cc
         memtable/vectorrep.cc

HISTORY.md

@@ -64,7 +64,7 @@ Also switch to waiting a sec on the CV each time. This is required since a bg er
 * db_bench: Create a WBM once for all db-s regardless of their use in different groups (#550)
 * Tompstone unit test faiure (#560)
 * build: Remove unused variables in unit tests (#581)
-
+* support hash_spdb in java (#548)
 ### Miscellaneous
 * disable failing unit tests and paired bloom filter stress testing
 * version: update Speedb patch version to 2.4.1 (#503)

include/rocksdb/memtablerep.h

@@ -519,4 +519,7 @@ extern MemTableRepFactory* NewHashLinkListRepFactory(
     bool if_log_bucket_dist_when_flash = true,
     uint32_t threshold_use_skiplist = 256);
 
+// The factory is to create memtables based on a sorted hash table - spdb hash:
+extern MemTableRepFactory* NewHashSpdbRepFactory(size_t bucket_count = 1000000);
+
 }  // namespace ROCKSDB_NAMESPACE

java/CMakeLists.txt

@@ -157,6 +157,7 @@ set(JAVA_MAIN_CLASSES
   src/main/java/org/rocksdb/FlushOptions.java
   src/main/java/org/rocksdb/HashLinkedListMemTableConfig.java
   src/main/java/org/rocksdb/HashSkipListMemTableConfig.java
+  src/main/java/org/rocksdb/HashSpdbMemTableConfig.java
   src/main/java/org/rocksdb/HistogramData.java
   src/main/java/org/rocksdb/HistogramType.java
   src/main/java/org/rocksdb/Holder.java
@@ -455,6 +456,7 @@ if(${CMAKE_VERSION} VERSION_LESS "3.11.4")
           org.rocksdb.FlushOptions
           org.rocksdb.HashLinkedListMemTableConfig
           org.rocksdb.HashSkipListMemTableConfig
+          org.rocksdb.HashSpdbMemTableConfig
           org.rocksdb.IngestExternalFileOptions
           org.rocksdb.Logger
           org.rocksdb.LRUCache

java/Makefile

@@ -39,6 +39,7 @@ NATIVE_JAVA_CLASSES = \
 	org.rocksdb.IngestExternalFileOptions\
 	org.rocksdb.HashLinkedListMemTableConfig\
 	org.rocksdb.HashSkipListMemTableConfig\
+	org.rocksdb.HashSpdbMemTableConfig\
 	org.rocksdb.ConcurrentTaskLimiter\
 	org.rocksdb.ConcurrentTaskLimiterImpl\
 	org.rocksdb.KeyMayExist\

java/benchmark/src/main/java/org/rocksdb/benchmark/DbBenchmark.java

@@ -515,6 +515,9 @@ private void prepareOptions(Options options) throws RocksDBException {
                 .setBucketCount(hashBucketCount_));
         options.useFixedLengthPrefixExtractor(prefixSize_);
         break;
+      case "hash_spdb":
+        options.setMemTableConfig(new HashSpdbMemTableConfig().setBucketCount(hashBucketCount_));
+        break;
       default:
         System.err.format(
             "unable to detect the specified memtable, " +

java/rocksjni/memtablejni.cc

@@ -7,6 +7,7 @@
 
 #include "include/org_rocksdb_HashLinkedListMemTableConfig.h"
 #include "include/org_rocksdb_HashSkipListMemTableConfig.h"
+#include "include/org_rocksdb_HashSpdbMemTableConfig.h"
 #include "include/org_rocksdb_SkipListMemTableConfig.h"
 #include "include/org_rocksdb_VectorMemTableConfig.h"
 #include "rocksdb/memtablerep.h"
@@ -32,6 +33,23 @@ jlong Java_org_rocksdb_HashSkipListMemTableConfig_newMemTableFactoryHandle(
   return 0;
 }
 
+/*
+ * Class:     org_rocksdb_HashSpdbMemTableConfig
+ * Method:    newMemTableFactoryHandle
+ * Signature: (JII)J
+ */
+jlong Java_org_rocksdb_HashSpdbMemTableConfig_newMemTableFactoryHandle(
+    JNIEnv* env, jobject /*jobj*/, jlong jbucket_count) {
+  ROCKSDB_NAMESPACE::Status s =
+      ROCKSDB_NAMESPACE::JniUtil::check_if_jlong_fits_size_t(jbucket_count);
+  if (s.ok()) {
+    return GET_CPLUSPLUS_POINTER(ROCKSDB_NAMESPACE::NewHashSpdbRepFactory(
+        static_cast<size_t>(jbucket_count)));
+  }
+  ROCKSDB_NAMESPACE::IllegalArgumentExceptionJni::ThrowNew(env, s);
+  return 0;
+}
+
 /*
  * Class:     org_rocksdb_HashLinkedListMemTableConfig
  * Method:    newMemTableFactoryHandle

java/samples/src/main/java/RocksDBSample.java

@@ -79,6 +79,9 @@ public static void main(final String[] args) {
       options.setMemTableConfig(new SkipListMemTableConfig());
       assert (options.memTableFactoryName().equals("SkipListFactory"));
 
+      options.setMemTableConfig(new HashSpdbMemTableConfig().setBucketCount(1000000));
+      assert (options.memTableFactoryName().equals("HashSpdbMemTableConfig"));
+
       options.setTableFormatConfig(new PlainTableConfig());
       // Plain-Table requires mmap read
       options.setAllowMmapReads(true);

java/src/main/java/org/rocksdb/HashSpdbMemTableConfig.java

@@ -0,0 +1,38 @@
+// Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+package org.rocksdb;
+
+/**
+ * The config for hash spdbd memtable representation.
+ */
+public class HashSpdbMemTableConfig extends MemTableConfig {
+  public static final int DEFAULT_BUCKET_COUNT = 1000000;
+
+  /**
+   * HashSpdbMemTableConfig constructor
+   */
+  public HashSpdbMemTableConfig() {
+    bucketCount_ = DEFAULT_BUCKET_COUNT;
+  }
+
+  /**
+   * Set the number of hash buckets used in the hash spdb memtable.
+   * Default = 1000000.
+   *
+   * @param count the number of hash buckets used in the hash
+   *    spdb memtable.
+   * @return the reference to the current HashSpdbMemTableConfig.
+   */
+  public HashSpdbMemTableConfig setBucketCount(final long count) {
+    bucketCount_ = count;
+    return this;
+  }
+
+  @Override
+  protected long newMemTableFactoryHandle() {
+    return newMemTableFactoryHandle(bucketCount_);
+  }
+
+  private native long newMemTableFactoryHandle(long bucketCount) throws IllegalArgumentException;
+
+  private long bucketCount_;
+}

java/src/test/java/org/rocksdb/MemTableTest.java

@@ -41,6 +41,24 @@ public void hashSkipListMemTable() throws RocksDBException {
     }
   }
 
+  @Test
+  public void hashSpdbMemTable() throws RocksDBException {
+    try (final Options options = new Options()) {
+      // Test HashSpdbMemTableConfig
+      HashSpdbMemTableConfig memTableConfig = new HashSpdbMemTableConfig();
+      assertThat(memTableConfig.bucketCount()).isEqualTo(1000000);
+      memTableConfig.setBucketCount(2000000);
+      assertThat(memTableConfig.bucketCount()).isEqualTo(2000000);
+      assertThat(memTableConfig.height()).isEqualTo(4);
+      memTableConfig.setHeight(5);
+      assertThat(memTableConfig.height()).isEqualTo(5);
+      assertThat(memTableConfig.branchingFactor()).isEqualTo(4);
+      memTableConfig.setBranchingFactor(6);
+      assertThat(memTableConfig.branchingFactor()).isEqualTo(6);
+      options.setMemTableConfig(memTableConfig);
+    }
+  }
+
   @Test
   public void skipListMemTable() throws RocksDBException {
     try(final Options options = new Options()) {