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https://issues.apache.org/jira/browse/PHOENIX-4237?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16203947#comment-16203947
]
ASF GitHub Bot commented on PHOENIX-4237:
-----------------------------------------
Github user JamesRTaylor commented on a diff in the pull request:
https://github.com/apache/phoenix/pull/275#discussion_r144620511
--- Diff:
phoenix-core/src/main/java/org/apache/phoenix/expression/function/CollationKeyFunction.java
---
@@ -0,0 +1,233 @@
+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 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
+ *
+ */
[email protected](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);
+ String localeISOCode = getLocaleISOCode(tuple, ptr);
+ Boolean useSpecialUpperCaseCollator =
getUseSpecialUpperCaseCollator(tuple, ptr);
+ Integer collatorStrength = getCollatorStrength(tuple,
ptr);
+ Integer collatorDecomposition =
getCollatorDecomposition(tuple, ptr);
+
+ Locale locale =
LocaleUtils.get().getLocaleByIsoCode(localeISOCode);
+
+ if(LOG.isDebugEnabled()) {
+ LOG.debug(String.format("Locale: " +
locale.toLanguageTag()));
+ }
+
+ LinguisticSort linguisticSort =
LinguisticSort.get(locale);
+
+ Collator collator =
BooleanUtils.isTrue(useSpecialUpperCaseCollator)
+ ?
linguisticSort.getUpperCaseCollator(false) : linguisticSort.getCollator();
+
+ if (collatorStrength != null) {
+ collator.setStrength(collatorStrength);
+ }
+
+ if (collatorDecomposition != null) {
+
collator.setDecomposition(collatorDecomposition);
+ }
+
+ if(LOG.isDebugEnabled()) {
+ LOG.debug(String.format("Collator: [strength:
%d, decomposition: %d], Special-Upper-Case: %s",
+ collator.getStrength(),
collator.getDecomposition(), BooleanUtils.isTrue(useSpecialUpperCaseCollator)));
+ }
+
+ byte[] collationKeyByteArray =
collator.getCollationKey(inputValue).toByteArray();
+
+ if(LOG.isDebugEnabled()) {
+ LOG.debug("Collation key bytes:" +
Arrays.toString(collationKeyByteArray));
+ }
+
+ // byte is signed in Java, but we need unsigned values
for comparison
+ //
https://www.programcreek.com/java-api-examples/index.php?api=java.text.CollationKey
+ // Byte.toUnsignedInt will convert a byte value between
[-128,127] to an int value
+ // between [0,255]
--- End diff --
Let's start with the tests. That conversion should not be necessary.
> Allow sorting on (Java) collation keys for non-English locales
> --------------------------------------------------------------
>
> Key: PHOENIX-4237
> URL: https://issues.apache.org/jira/browse/PHOENIX-4237
> Project: Phoenix
> Issue Type: Improvement
> Reporter: Shehzaad Nakhoda
> Fix For: 4.12.0
>
>
> Strings stored via Phoenix can be composed from a subset of the entire set of
> Unicode characters. The natural sort order for strings for different
> languages often differs from the order dictated by the binary representation
> of the characters of these strings. Java provides the idea of a Collator
> which given an input string and a (language) locale can generate a Collation
> Key which can then be used to compare strings in that natural order.
> Salesforce has recently open-sourced grammaticus. IBM has open-sourced ICU4J
> some time ago. These technologies can be combined to provide a robust new
> Phoenix function that can be used in an ORDER BY clause to sort strings
> according to the user's locale.
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