JingsongLi commented on a change in pull request #10381: [FLINK-14513][hive]
Implement listPartitionsByFilter to HiveCatalog
URL: https://github.com/apache/flink/pull/10381#discussion_r355248962
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File path:
flink-connectors/flink-connector-hive/src/main/java/org/apache/flink/table/catalog/hive/util/HiveTableUtil.java
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@@ -175,4 +186,93 @@ public static boolean requireRelyConstraint(byte trait) {
return (trait & HIVE_CONSTRAINT_RELY) != 0;
}
+ /**
+ * Generates a filter string for partition columns from the given
filter expressions.
+ *
+ * @param partColOffset The number of non-partition columns -- used to
shift field reference index
+ * @param partColNames The names of all partition columns
+ * @param expressions The filter expressions in CNF form
+ * @return an Optional filter string equivalent to the expressions,
which is empty if the expressions can't be handled
+ */
+ public static Optional<String> makePartitionFilter(int partColOffset,
List<String> partColNames, List<Expression> expressions) {
+ List<String> filters = new ArrayList<>(expressions.size());
+ ExpressionExtractor extractor = new
ExpressionExtractor(partColOffset, partColNames);
+ for (Expression expression : expressions) {
+ String str = expression.accept(extractor);
+ if (str == null) {
+ return Optional.empty();
+ }
+ filters.add(str);
+ }
+ return Optional.of(String.join(" and ", filters));
+ }
+
+ private static class ExpressionExtractor implements
ExpressionVisitor<String> {
+
+ private static final Map<FunctionDefinition, String>
FUNC_TO_STR = new HashMap<>();
+
+ static {
+ FUNC_TO_STR.put(BuiltInFunctionDefinitions.EQUALS, "=");
+ FUNC_TO_STR.put(BuiltInFunctionDefinitions.NOT_EQUALS,
"<>");
+
FUNC_TO_STR.put(BuiltInFunctionDefinitions.GREATER_THAN, ">");
+
FUNC_TO_STR.put(BuiltInFunctionDefinitions.GREATER_THAN_OR_EQUAL, ">=");
+ FUNC_TO_STR.put(BuiltInFunctionDefinitions.LESS_THAN,
"<");
+
FUNC_TO_STR.put(BuiltInFunctionDefinitions.LESS_THAN_OR_EQUAL, "<=");
+ }
+
+ // used to shift field reference index
+ private final int partColOffset;
+ private final List<String> partColNames;
+
+ ExpressionExtractor(int partColOffset, List<String>
partColNames) {
+ this.partColOffset = partColOffset;
+ this.partColNames = partColNames;
+ }
+
+ private String funcToString(BuiltInFunctionDefinition funcDef) {
+ return FUNC_TO_STR.containsKey(funcDef) ?
FUNC_TO_STR.get(funcDef) : funcDef.getName();
+ }
+
+ @Override
+ public String visit(CallExpression call) {
+ FunctionDefinition funcDef =
call.getFunctionDefinition();
+ if (funcDef instanceof BuiltInFunctionDefinition) {
+ List<String> operands = new ArrayList<>();
+ for (Expression child : call.getChildren()) {
+ String operand = child.accept(this);
+ if (operand == null) {
+ return null;
+ }
+ operands.add(operand);
+ }
+ if (funcDef == BuiltInFunctionDefinitions.CAST)
{
+ return String.format("cast(%s as %s)",
operands.get(0), operands.get(1));
+ }
+ return "(" + String.join(" " +
funcToString((BuiltInFunctionDefinition) funcDef) + " ", operands) + ")";
Review comment:
It is very dangerous here, maybe hive not support our built-in functions.
So I prefer use white list to support instead of throwing runtime exceptions.
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