From eda0dcdd97fc675b4ac0424492d3f9228e5913dd Mon Sep 17 00:00:00 2001
From: Adam Retter <adam.retter@googlemail.com>
Date: Fri, 5 Dec 2014 13:41:39 +0000
Subject: [PATCH] Exposed IncreasedParallelism option to Java API as
 setIncreasedParallelism

---
 java/org/rocksdb/DBOptions.java          |  8 ++++++++
 java/org/rocksdb/DBOptionsInterface.java | 15 +++++++++++++++
 java/org/rocksdb/Options.java            |  8 ++++++++
 java/rocksjni/options.cc                 | 23 +++++++++++++++++++++++
 4 files changed, 54 insertions(+)

diff --git a/java/org/rocksdb/DBOptions.java b/java/org/rocksdb/DBOptions.java
index 600369dec8..e3614f463b 100644
--- a/java/org/rocksdb/DBOptions.java
+++ b/java/org/rocksdb/DBOptions.java
@@ -72,6 +72,13 @@ public class DBOptions extends RocksObject implements DBOptionsInterface {
     return dbOptions;
   }
 
+  @Override
+  public DBOptions setIncreaseParallelism(int totalThreads) {
+    assert (isInitialized());
+    setIncreaseParallelism(nativeHandle_, totalThreads);
+    return this;
+  }
+
   @Override
   public DBOptions setCreateIfMissing(boolean flag) {
     assert(isInitialized());
@@ -547,6 +554,7 @@ public class DBOptions extends RocksObject implements DBOptionsInterface {
   private native void newDBOptions();
   private native void disposeInternal(long handle);
 
+  private native void setIncreaseParallelism(long handle, int totalThreads);
   private native void setCreateIfMissing(long handle, boolean flag);
   private native boolean createIfMissing(long handle);
   private native void setCreateMissingColumnFamilies(
diff --git a/java/org/rocksdb/DBOptionsInterface.java b/java/org/rocksdb/DBOptionsInterface.java
index 19ffe375d2..39ba13d25f 100644
--- a/java/org/rocksdb/DBOptionsInterface.java
+++ b/java/org/rocksdb/DBOptionsInterface.java
@@ -7,6 +7,21 @@ package org.rocksdb;
 
 public interface DBOptionsInterface {
 
+  /**
+   * <p>By default, RocksDB uses only one background thread for flush and
+   * compaction. Calling this function will set it up such that total of
+   * `total_threads` is used.</p>
+   *
+   * <p>You almost definitely want to call this function if your system is
+   * bottlenecked by RocksDB.</p>
+   *
+   * @param The total number of threads to be used by RocksDB. A good value
+   *            is the number of cores.
+   *
+   * @return the instance of the current Options
+   */
+  Object setIncreaseParallelism(int totalThreads);
+
   /**
    * If this value is set to true, then the database will be created
    * if it is missing during {@code RocksDB.open()}.
diff --git a/java/org/rocksdb/Options.java b/java/org/rocksdb/Options.java
index 7781b80a6d..ac4037508e 100644
--- a/java/org/rocksdb/Options.java
+++ b/java/org/rocksdb/Options.java
@@ -43,6 +43,13 @@ public class Options extends RocksObject
     env_ = RocksEnv.getDefault();
   }
 
+  @Override
+  public Options setIncreaseParallelism(int totalThreads) {
+    assert(isInitialized());
+    setIncreaseParallelism(nativeHandle_, totalThreads);
+    return this;
+  }
+
   @Override
   public Options setCreateIfMissing(boolean flag) {
     assert(isInitialized());
@@ -1032,6 +1039,7 @@ public class Options extends RocksObject
   private native void prepareForBulkLoad(long handle);
 
   // DB native handles
+  private native void setIncreaseParallelism(long handle, int totalThreads);
   private native void setCreateIfMissing(long handle, boolean flag);
   private native boolean createIfMissing(long handle);
   private native void setCreateMissingColumnFamilies(
diff --git a/java/rocksjni/options.cc b/java/rocksjni/options.cc
index d139b1a57b..667d74508c 100644
--- a/java/rocksjni/options.cc
+++ b/java/rocksjni/options.cc
@@ -68,6 +68,17 @@ void Java_org_rocksdb_Options_disposeInternal(
   delete reinterpret_cast<rocksdb::Options*>(handle);
 }
 
+/*
+ * Class:     org_rocksdb_Options
+ * Method:    setIncreaseParallelism
+ * Signature: (JI)V
+ */
+void Java_org_rocksdb_Options_setIncreaseParallelism(
+    JNIEnv * evnv, jobject jobj, jlong jhandle, jint totalThreads) {
+  reinterpret_cast<rocksdb::Options*>
+      (jhandle)->IncreaseParallelism(static_cast<int>(totalThreads));
+}
+
 /*
  * Class:     org_rocksdb_Options
  * Method:    setCreateIfMissing
@@ -2816,6 +2827,18 @@ void Java_org_rocksdb_DBOptions_disposeInternal(
   delete reinterpret_cast<rocksdb::DBOptions*>(handle);
 }
 
+/*
+ * Class:     org_rocksdb_DBOptions
+ * Method:    setIncreaseParallelism
+ * Signature: (JI)V
+ */
+void Java_org_rocksdb_DBOptions_setIncreaseParallelism(
+    JNIEnv * env, jobject jobj, jlong jhandle, jint totalThreads) {
+  reinterpret_cast<rocksdb::DBOptions*>
+      (jhandle)->IncreaseParallelism(static_cast<int>(totalThreads));
+}
+
+
 /*
  * Class:     org_rocksdb_DBOptions
  * Method:    setCreateIfMissing