Example usage for org.apache.spark.unsafe KVIterator KVIterator

Introduction

In this page you can find the example usage for org.apache.spark.unsafe KVIterator KVIterator.

Prototype

KVIterator

Source Link

Usage

From source file:edu.ucla.cs.wis.bigdatalog.spark.storage.map.UnsafeFixedWidthMonotonicAggregationMap.java

License:Apache License

/**
 * Returns an iterator over the keys and values in this map. This uses destructive iterator of
 * BytesToBytesMap. So it is illegal to call any other method on this map after `iterator()` has
 * been called./*from w  w w  . j a  v  a  2 s.  com*/
 * <p>
 * For efficiency, each call returns the same object.
 */
public KVIterator<UnsafeRow, UnsafeRow> iterator() {
    return new KVIterator<UnsafeRow, UnsafeRow>() {

        private final edu.ucla.cs.wis.bigdatalog.spark.storage.map.BytesToBytesMap.MapIterator mapLocationIterator = map
                .iterator();
        private final UnsafeRow key = new UnsafeRow();
        private final UnsafeRow value = new UnsafeRow();

        @Override
        public boolean next() {
            if (mapLocationIterator.hasNext()) {
                final edu.ucla.cs.wis.bigdatalog.spark.storage.map.BytesToBytesMap.Location loc = mapLocationIterator
                        .next();
                final MemoryLocation keyAddress = loc.getKeyAddress();
                final MemoryLocation valueAddress = loc.getValueAddress();
                key.pointTo(keyAddress.getBaseObject(), keyAddress.getBaseOffset(), groupingKeySchema.length(),
                        loc.getKeyLength());
                value.pointTo(valueAddress.getBaseObject(), valueAddress.getBaseOffset(),
                        aggregationBufferSchema.length(), loc.getValueLength());
                return true;
            } else {
                return false;
            }
        }

        @Override
        public UnsafeRow getKey() {
            return key;
        }

        @Override
        public UnsafeRow getValue() {
            return value;
        }

        @Override
        public void close() {
            // Do nothing.
        }
    };
}

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