[SPARK-14394][SQL] Generate AggregateHashMap class for LongTypes during TungstenAggregate codegen

## What changes were proposed in this pull request?

This PR adds support for generating the `AggregateHashMap` class in `TungstenAggregate` if the aggregate group by keys/value are of `LongType`. Note that currently this generate aggregate is not actually used.

NB: This currently only supports `LongType` keys/values (please see `isAggregateHashMapSupported` in `TungstenAggregate`) and will be generalized to other data types in a subsequent PR.

## How was this patch tested?

Manually inspected the generated code. This is what the generated map looks like for 2 keys:

```java
/* 068 */   public class agg_GeneratedAggregateHashMap {
/* 069 */     private org.apache.spark.sql.execution.vectorized.ColumnarBatch batch;
/* 070 */     private int[] buckets;
/* 071 */     private int numBuckets;
/* 072 */     private int maxSteps;
/* 073 */     private int numRows = 0;
/* 074 */     private org.apache.spark.sql.types.StructType schema =
/* 075 */     new org.apache.spark.sql.types.StructType()
/* 076 */     .add("k1", org.apache.spark.sql.types.DataTypes.LongType)
/* 077 */     .add("k2", org.apache.spark.sql.types.DataTypes.LongType)
/* 078 */     .add("sum", org.apache.spark.sql.types.DataTypes.LongType);
/* 079 */
/* 080 */     public agg_GeneratedAggregateHashMap(int capacity, double loadFactor, int maxSteps) {
/* 081 */       assert (capacity > 0 && ((capacity & (capacity - 1)) == 0));
/* 082 */       this.maxSteps = maxSteps;
/* 083 */       numBuckets = (int) (capacity / loadFactor);
/* 084 */       batch = org.apache.spark.sql.execution.vectorized.ColumnarBatch.allocate(schema,
/* 085 */         org.apache.spark.memory.MemoryMode.ON_HEAP, capacity);
/* 086 */       buckets = new int[numBuckets];
/* 087 */       java.util.Arrays.fill(buckets, -1);
/* 088 */     }
/* 089 */
/* 090 */     public agg_GeneratedAggregateHashMap() {
/* 091 */       new agg_GeneratedAggregateHashMap(1 << 16, 0.25, 5);
/* 092 */     }
/* 093 */
/* 094 */     public org.apache.spark.sql.execution.vectorized.ColumnarBatch.Row findOrInsert(long agg_key, long agg_key1) {
/* 095 */       long h = hash(agg_key, agg_key1);
/* 096 */       int step = 0;
/* 097 */       int idx = (int) h & (numBuckets - 1);
/* 098 */       while (step < maxSteps) {
/* 099 */         // Return bucket index if it's either an empty slot or already contains the key
/* 100 */         if (buckets[idx] == -1) {
/* 101 */           batch.column(0).putLong(numRows, agg_key);
/* 102 */           batch.column(1).putLong(numRows, agg_key1);
/* 103 */           batch.column(2).putLong(numRows, 0);
/* 104 */           buckets[idx] = numRows++;
/* 105 */           return batch.getRow(buckets[idx]);
/* 106 */         } else if (equals(idx, agg_key, agg_key1)) {
/* 107 */           return batch.getRow(buckets[idx]);
/* 108 */         }
/* 109 */         idx = (idx + 1) & (numBuckets - 1);
/* 110 */         step++;
/* 111 */       }
/* 112 */       // Didn't find it
/* 113 */       return null;
/* 114 */     }
/* 115 */
/* 116 */     private boolean equals(int idx, long agg_key, long agg_key1) {
/* 117 */       return batch.column(0).getLong(buckets[idx]) == agg_key && batch.column(1).getLong(buckets[idx]) == agg_key1;
/* 118 */     }
/* 119 */
/* 120 */     // TODO: Improve this Hash Function
/* 121 */     private long hash(long agg_key, long agg_key1) {
/* 122 */       return agg_key ^ agg_key1;
/* 123 */     }
/* 124 */
/* 125 */   }
```

Author: Sameer Agarwal <sameer@databricks.com>

Closes #12161 from sameeragarwal/tungsten-aggregate.

0 files changed, 0 insertions, 0 deletions