Index: ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDTFJSONTuple.java =================================================================== --- ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDTFJSONTuple.java (revision 1207574) +++ ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDTFJSONTuple.java (working copy) @@ -19,6 +19,8 @@ package org.apache.hadoop.hive.ql.udf.generic; import java.util.ArrayList; +import java.util.LinkedHashMap; +import java.util.Map; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; @@ -55,6 +57,28 @@ boolean pathParsed = false; boolean seenErrors = false; + //An LRU cache using a linked hash map + static class HashCache extends LinkedHashMap { + + private static final int CACHE_SIZE = 16; + private static final int INIT_SIZE = 32; + private static final float LOAD_FACTOR = 0.6f; + + HashCache() { + super(INIT_SIZE, LOAD_FACTOR); + } + + private static final long serialVersionUID = 1; + + @Override + protected boolean removeEldestEntry(Map.Entry eldest) { + return size() > CACHE_SIZE; + } + + } + + static Map jsonObjectCache = new HashCache(); + @Override public void close() throws HiveException { } @@ -124,7 +148,11 @@ return; } try { - JSONObject jsonObj = new JSONObject(jsonStr); + JSONObject jsonObj = jsonObjectCache.get(jsonStr); + if (jsonObj == null) { + jsonObj = new JSONObject(jsonStr); + jsonObjectCache.put(jsonStr, jsonObj); + } for (int i = 0; i < numCols; ++i) { if (jsonObj.isNull(paths[i])) {