Merge pull request #1568 from Okapist/read-data-by-column-name-optimi…

…zation

Optimize read data by column name

clickhouse-data/src/main/java/com/clickhouse/data/ClickHouseSimpleRecord.java

@@ -1,7 +1,9 @@
 package com.clickhouse.data;
 
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Default implementation of {@link com.clickhouse.data.ClickHouseRecord},
@@ -13,6 +15,7 @@ public class ClickHouseSimpleRecord implements ClickHouseRecord {
 
     private final List<ClickHouseColumn> columns;
     private ClickHouseValue[] values;
+    private Map<String, Integer> columnsIndexes = null;
 
     /**
      * Creates a record object to wrap given values.
@@ -83,19 +86,25 @@ public ClickHouseValue getValue(int index) {
 
     @Override
     public ClickHouseValue getValue(String name) {
+        if(columnsIndexes == null)
+            columnsIndexes = new HashMap<>(columns.size());
+
+        return getValue(columnsIndexes.computeIfAbsent(name, this::computeColumnIndex));
+    }
+
+    @Override
+    public int size() {
+        return values.length;
+    }
+
+    private int computeColumnIndex(String name) {
         int index = 0;
         for (ClickHouseColumn c : columns) {
             if (c.getColumnName().equalsIgnoreCase(name)) {
-                return getValue(index);
+                return index;
             }
             index++;
         }
-
         throw new IllegalArgumentException(ClickHouseUtils.format("Unable to find column [%s]", name));
     }
-
-    @Override
-    public int size() {
-        return values.length;
-    }
 }