Merge pull request #522 from fyrz/RocksJava-Optimize-Filters-For-Hits

[RocksJava] OptimizeFiltersForHits

java/rocksjni/options.cc

@@ -1731,6 +1731,30 @@ void Java_org_rocksdb_Options_setMinPartialMergeOperands(
           static_cast<int32_t>(jmin_partial_merge_operands);
 }
 
+/*
+ * Class:     org_rocksdb_Options
+ * Method:    optimizeFiltersForHits
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_Options_optimizeFiltersForHits(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  return reinterpret_cast<rocksdb::Options*>(
+      jhandle)->optimize_filters_for_hits;
+}
+
+/*
+ * Class:     org_rocksdb_Options
+ * Method:    setOptimizeFiltersForHits
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_Options_setOptimizeFiltersForHits(
+    JNIEnv* env, jobject jobj, jlong jhandle,
+    jboolean joptimize_filters_for_hits) {
+  reinterpret_cast<rocksdb::Options*>(
+      jhandle)->optimize_filters_for_hits =
+          static_cast<bool>(joptimize_filters_for_hits);
+}
+
 /*
  * Method:    optimizeForPointLookup
  * Signature: (JJ)V
@@ -2778,6 +2802,30 @@ void Java_org_rocksdb_ColumnFamilyOptions_setMinPartialMergeOperands(
           static_cast<int32_t>(jmin_partial_merge_operands);
 }
 
+/*
+ * Class:     org_rocksdb_ColumnFamilyOptions
+ * Method:    optimizeFiltersForHits
+ * Signature: (J)Z
+ */
+jboolean Java_org_rocksdb_ColumnFamilyOptions_optimizeFiltersForHits(
+    JNIEnv* env, jobject jobj, jlong jhandle) {
+  return reinterpret_cast<rocksdb::ColumnFamilyOptions*>(
+      jhandle)->optimize_filters_for_hits;
+}
+
+/*
+ * Class:     org_rocksdb_ColumnFamilyOptions
+ * Method:    setOptimizeFiltersForHits
+ * Signature: (JZ)V
+ */
+void Java_org_rocksdb_ColumnFamilyOptions_setOptimizeFiltersForHits(
+    JNIEnv* env, jobject jobj, jlong jhandle,
+    jboolean joptimize_filters_for_hits) {
+  reinterpret_cast<rocksdb::ColumnFamilyOptions*>(
+      jhandle)->optimize_filters_for_hits =
+          static_cast<bool>(joptimize_filters_for_hits);
+}
+
 /////////////////////////////////////////////////////////////////////
 // rocksdb::DBOptions
 

java/src/main/java/org/rocksdb/ColumnFamilyOptions.java

@@ -580,6 +580,18 @@ public class ColumnFamilyOptions extends RocksObject
     return minPartialMergeOperands(nativeHandle_);
   }
 
+  @Override
+  public ColumnFamilyOptions setOptimizeFiltersForHits(
+      final boolean optimizeFiltersForHits) {
+    setOptimizeFiltersForHits(nativeHandle_, optimizeFiltersForHits);
+    return this;
+  }
+
+  @Override
+  public boolean optimizeFiltersForHits() {
+    return optimizeFiltersForHits(nativeHandle_);
+  }
+
   /**
    * Release the memory allocated for the current instance
    * in the c++ side.
@@ -721,6 +733,9 @@ public class ColumnFamilyOptions extends RocksObject
   private native void setMinPartialMergeOperands(
       long handle, int minPartialMergeOperands);
   private native int minPartialMergeOperands(long handle);
+  private native void setOptimizeFiltersForHits(long handle,
+      boolean optimizeFiltersForHits);
+  private native boolean optimizeFiltersForHits(long handle);
 
   MemTableConfig memTableConfig_;
   TableFormatConfig tableFormatConfig_;

java/src/main/java/org/rocksdb/ColumnFamilyOptionsInterface.java

@@ -975,6 +975,38 @@ public interface ColumnFamilyOptionsInterface {
    */
   int minPartialMergeOperands();
 
+  /**
+   * <p>This flag specifies that the implementation should optimize the filters
+   * mainly for cases where keys are found rather than also optimize for keys
+   * missed. This would be used in cases where the application knows that
+   * there are very few misses or the performance in the case of misses is not
+   * important.</p>
+   *
+   * <p>For now, this flag allows us to not store filters for the last level i.e
+   * the largest level which contains data of the LSM store. For keys which
+   * are hits, the filters in this level are not useful because we will search
+   * for the data anyway.</p>
+   *
+   * <p><strong>NOTE</strong>: the filters in other levels are still useful
+   * even for key hit because they tell us whether to look in that level or go
+   * to the higher level.</p>
+   *
+   * <p>Default: false<p>
+   *
+   * @param optimizeFiltersForHits boolean value indicating if this flag is set.
+   * @return the reference to the current option.
+   */
+  Object setOptimizeFiltersForHits(boolean optimizeFiltersForHits);
+
+  /**
+   * <p>Returns the current state of the {@code optimize_filters_for_hits}
+   * setting.</p>
+   *
+   * @return boolean value indicating if the flag
+   *     {@code optimize_filters_for_hits} was set.
+   */
+  boolean optimizeFiltersForHits();
+
   /**
    * Default memtable memory budget used with the following methods:
    *

java/src/main/java/org/rocksdb/Options.java

@@ -1044,6 +1044,18 @@ public class Options extends RocksObject
     return this;
   }
 
+  @Override
+  public Options setOptimizeFiltersForHits(
+      final boolean optimizeFiltersForHits) {
+    setOptimizeFiltersForHits(nativeHandle_, optimizeFiltersForHits);
+    return this;
+  }
+
+  @Override
+  public boolean optimizeFiltersForHits() {
+    return optimizeFiltersForHits(nativeHandle_);
+  }
+
   /**
    * Release the memory allocated for the current instance
    * in the c++ side.
@@ -1268,6 +1280,9 @@ public class Options extends RocksObject
   private native void setMinPartialMergeOperands(
       long handle, int minPartialMergeOperands);
   private native int minPartialMergeOperands(long handle);
+  private native void setOptimizeFiltersForHits(long handle,
+      boolean optimizeFiltersForHits);
+  private native boolean optimizeFiltersForHits(long handle);
   // instance variables
   RocksEnv env_;
   MemTableConfig memTableConfig_;

java/src/test/java/org/rocksdb/ColumnFamilyOptionsTest.java

@@ -538,6 +538,21 @@ public class ColumnFamilyOptionsTest {
     }
   }
 
+  @Test
+  public void optimizeFiltersForHits() {
+    ColumnFamilyOptions opt = null;
+    try {
+      boolean aBoolean = rand.nextBoolean();
+      opt = new ColumnFamilyOptions();
+      opt.setOptimizeFiltersForHits(aBoolean);
+      assertThat(opt.optimizeFiltersForHits()).isEqualTo(aBoolean);
+    } finally {
+      if (opt != null) {
+        opt.dispose();
+      }
+    }
+  }
+
   @Test
   public void memTable() throws RocksDBException {
     ColumnFamilyOptions opt = null;

java/src/test/java/org/rocksdb/OptionsTest.java

@@ -500,6 +500,21 @@ public class OptionsTest {
     }
   }
 
+  @Test
+  public void optimizeFiltersForHits() {
+    Options opt = null;
+    try {
+      boolean aBoolean = rand.nextBoolean();
+      opt = new Options();
+      opt.setOptimizeFiltersForHits(aBoolean);
+      assertThat(opt.optimizeFiltersForHits()).isEqualTo(aBoolean);
+    } finally {
+      if (opt != null) {
+        opt.dispose();
+      }
+    }
+  }
+
   @Test
   public void createIfMissing() {
     Options opt = null;