Github user JamesRTaylor commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/275#discussion_r145230698
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/expression/function/CollationKeyFunction.java
---
@@ -0,0 +1,221 @@
+package org.apache.phoenix.expression.function;
+
+import java.sql.SQLException;
+import java.text.Collator;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+
+import org.apache.commons.lang.BooleanUtils;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
+import org.apache.phoenix.expression.Expression;
+import org.apache.phoenix.parse.FunctionParseNode;
+import org.apache.phoenix.schema.tuple.Tuple;
+import org.apache.phoenix.schema.types.PBoolean;
+import org.apache.phoenix.schema.types.PDataType;
+import org.apache.phoenix.schema.types.PInteger;
+import org.apache.phoenix.schema.types.PIntegerArray;
+import org.apache.phoenix.schema.types.PUnsignedIntArray;
+import org.apache.phoenix.schema.types.PVarbinary;
+import org.apache.phoenix.schema.types.PVarchar;
+import org.apache.phoenix.schema.types.PhoenixArray;
+import org.apache.phoenix.util.VarBinaryFormatter;
+
+import com.force.db.i18n.LinguisticSort;
+import com.force.i18n.LocaleUtils;
+
+import com.ibm.icu.impl.jdkadapter.CollatorICU;
+import com.ibm.icu.util.ULocale;
+
+/**
+ * A Phoenix Function that calculates a collation key for an input string
based
+ * on a caller-provided locale and collator strength and decomposition
settings.
+ *
+ * It uses the open-source grammaticus and i18n packages to obtain the
collators
+ * it needs.
+ *
+ * @author snakhoda
+ *
+ */
+@FunctionParseNode.BuiltInFunction(name = CollationKeyFunction.NAME, args
= {
+ // input string
+ @FunctionParseNode.Argument(allowedTypes = { PVarchar.class }),
+ // ISO Code for Locale
+ @FunctionParseNode.Argument(allowedTypes = { PVarchar.class },
isConstant = true),
+ // whether to use special upper case collator
+ @FunctionParseNode.Argument(allowedTypes = { PBoolean.class },
defaultValue = "false", isConstant = true),
+ // collator strength
+ @FunctionParseNode.Argument(allowedTypes = { PInteger.class },
defaultValue = "null", isConstant = true),
+ // collator decomposition
+ @FunctionParseNode.Argument(allowedTypes = { PInteger.class },
defaultValue = "null", isConstant = true) })
+public class CollationKeyFunction extends ScalarFunction {
+
+ private static final Log LOG =
LogFactory.getLog(CollationKeyFunction.class);
+
+ public static final String NAME = "COLLKEY";
+
+ public CollationKeyFunction() {
+ }
+
+ public CollationKeyFunction(List<Expression> children) throws
SQLException {
+ super(children);
+ }
+
+ @Override
+ public boolean evaluate(Tuple tuple, ImmutableBytesWritable ptr) {
+ try {
+ String inputValue = getInputValue(tuple, ptr);
--- End diff --
The evaluate method is called for every row during processing, so we want
to have as little code here as possible. You can create a Collator local
variable and move all the code that sets it up to an init() method. You'd call
the init() method in the CollationKeyFunction(List<Expression> children)
constructor and in an overridden readFields method like this (see InstrFunction
for an example):
@Override
public void readFields(DataInput input) throws IOException {
super.readFields(input);
init();
}
---
