From 2da53b1e06655792569505796ee3f91bf9bcbfd3 Mon Sep 17 00:00:00 2001
From: Yueh-Hsuan Chiang <yhchiang@fb.com>
Date: Thu, 14 Aug 2014 10:58:09 -0700
Subject: [PATCH] [Java] Add purgeOldBackups API

Summary:
1. Check status of CreateNewBackup. If status is not OK, then throw.
2. Add purgeOldBackups API

Test Plan:
make test
make sample

Reviewers: haobo, sdong, zzbennett, swapnilghike, yhchiang

Reviewed By: yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21753
---
 java/org/rocksdb/BackupableDB.java | 10 ++++++++++
 java/rocksjni/backupablejni.cc     | 21 ++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/java/org/rocksdb/BackupableDB.java b/java/org/rocksdb/BackupableDB.java
index 90d4a2a9a..108c4deb5 100644
--- a/java/org/rocksdb/BackupableDB.java
+++ b/java/org/rocksdb/BackupableDB.java
@@ -47,6 +47,15 @@ public class BackupableDB extends RocksDB {
   public void createNewBackup(boolean flushBeforeBackup) {
     createNewBackup(nativeHandle_, flushBeforeBackup);
   }
+  
+  /**
+   * Deletes old backups, keeping latest numBackupsToKeep alive.
+   * 
+   * @param numBackupsToKeep Number of latest backups to keep.
+   */
+  public void purgeOldBackups(int numBackupsToKeep) {
+    purgeOldBackups(nativeHandle_, numBackupsToKeep);
+  }
 
 
   /**
@@ -77,4 +86,5 @@ public class BackupableDB extends RocksDB {
 
   protected native void open(long rocksDBHandle, long backupDBOptionsHandle);
   protected native void createNewBackup(long handle, boolean flag);
+  protected native void purgeOldBackups(long handle, int numBackupsToKeep);
 }
diff --git a/java/rocksjni/backupablejni.cc b/java/rocksjni/backupablejni.cc
index 8413d5ea2..2aa1d0b1d 100644
--- a/java/rocksjni/backupablejni.cc
+++ b/java/rocksjni/backupablejni.cc
@@ -40,7 +40,26 @@ void Java_org_rocksdb_BackupableDB_open(
  */
 void Java_org_rocksdb_BackupableDB_createNewBackup(
     JNIEnv* env, jobject jbdb, jlong jhandle, jboolean jflag) {
-  reinterpret_cast<rocksdb::BackupableDB*>(jhandle)->CreateNewBackup(jflag);
+  rocksdb::Status s =
+      reinterpret_cast<rocksdb::BackupableDB*>(jhandle)->CreateNewBackup(jflag);
+  if (!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
+}
+
+/*
+ * Class:     org_rocksdb_BackupableDB
+ * Method:    purgeOldBackups
+ * Signature: (JI)V
+ */
+void Java_org_rocksdb_BackupableDB_purgeOldBackups(
+    JNIEnv* env, jobject jbdb, jlong jhandle, jboolean jnumBackupsToKeep) {
+  rocksdb::Status s =
+      reinterpret_cast<rocksdb::BackupableDB*>(jhandle)->
+      PurgeOldBackups(jnumBackupsToKeep);
+  if (!s.ok()) {
+    rocksdb::RocksDBExceptionJni::ThrowNew(env, s);
+  }
 }
 
 ///////////////////////////////////////////////////////////////////////////