Issue 49: added toRedisHASHes function (#49)

doc/rdd.md

@@ -137,6 +137,14 @@ sc.toRedisHASH(hashRDD, hashName, ttl)
 
 By default, Hashes won't have any expiry set.
 
+Use the following to store an RDD into multiple hashs:
+
+```scala
+sc.toRedisHASHes(hashRDD, ttl)
+```
+
+The `hashRDD` is a rdd of tuples (`hashname`, `map[field name, field value]`)
+
 #### Lists
 Use the following to store an RDD in a Redis List:
 

src/main/scala/com/redislabs/provider/redis/redisFunctions.scala

@@ -5,6 +5,7 @@ import com.redislabs.provider.redis.util.ConnectionUtils.withConnection
 import com.redislabs.provider.redis.util.PipelineUtils._
 import org.apache.spark.SparkContext
 import org.apache.spark.rdd.RDD
+import scala.collection.JavaConversions.mapAsJavaMap
 
 /**
   * RedisContext extends sparkContext's functionality with redis functions
@@ -264,6 +265,19 @@ class RedisContext(@transient val sc: SparkContext) extends Serializable {
     kvs.foreachPartition(partition => setHash(hashName, partition, ttl, redisConfig, readWriteConfig))
   }
 
+  /**
+   * Write RDD of (hash name, hash KVs)
+   *
+   * @param kvs      RDD of tuples (hash name, Map(hash field name, hash field value))
+   * @param ttl      time to live
+   */
+  def toRedisHASHes(kvs: RDD[(String, Map[String, String])], ttl: Int = 0)
+                  (implicit
+                   redisConfig: RedisConfig = RedisConfig.fromSparkConf(sc.getConf),
+                   readWriteConfig: ReadWriteConfig = ReadWriteConfig.fromSparkConf(sc.getConf)) {
+    kvs.foreachPartition(partition => setHash(partition, ttl, redisConfig, readWriteConfig))
+  }
+
   /**
     * @param kvs      Pair RDD of K/V
     * @param zsetName target zset's name which hold all the kvs
@@ -401,6 +415,33 @@ object RedisContext extends Serializable {
     conn.close()
   }
 
+  /**
+   * @param hashes hashName: map of k/vs to be saved in the target host
+   * @param ttl time to live
+   */
+  def setHash(hashes: Iterator[(String, Map[String,String])],
+              ttl: Int,
+              redisConfig: RedisConfig,
+              readWriteConfig: ReadWriteConfig) {
+    implicit val rwConf: ReadWriteConfig = readWriteConfig
+
+    hashes
+      .map { case (key, hashFields) =>
+        (redisConfig.getHost(key), (key, hashFields))
+      }
+      .toArray
+      .groupBy(_._1)
+      .foreach { case (node, arr) =>
+        withConnection(node.endpoint.connect()) { conn =>
+          foreachWithPipeline(conn, arr) { (pipeline, a) =>
+            val (key, hashFields) = a._2
+            pipeline.hmset(key, hashFields)
+            if (ttl > 0) pipeline.expire(key, ttl)
+          }
+        }
+      }
+  }
+
   /**
     * @param zsetName
     * @param arr k/vs which should be saved in the target host

src/test/scala/com/redislabs/provider/redis/rdd/RedisRddExtraSuite.scala

@@ -42,10 +42,30 @@ trait RedisRddExtraSuite extends SparkRedisSuite with Keys with Matchers {
     verifyList("list2", list2)
   }
 
+  test("toRedisHASHes") {
+    val map1 = Map("k1" -> "v1", "k2" -> "v2")
+    val map2 = Map("k3" -> "v3", "k4" -> "v4")
+    val hashes = Seq(
+      ("hash1", map1),
+      ("hash2", map2)
+    )
+    val rdd = sc.parallelize(hashes)
+    sc.toRedisHASHes(rdd)
+
+    verifyHash("hash1", map1)
+    verifyHash("hash2", map2)
+  }
+
   def verifyList(list: String, vals: Seq[String]): Unit = {
     withConnection(redisConfig.getHost(list).endpoint.connect()) { conn =>
       conn.lrange(list, 0, vals.size).asScala should be(vals.toList)
     }
   }
 
+  def verifyHash(hash: String, vals: Map[String, String]): Unit = {
+    withConnection(redisConfig.getHost(hash).endpoint.connect()) { conn =>
+      conn.hgetAll(hash).asScala should be(vals)
+    }
+  }
+
 }