Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.trino.sql.analyzer;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Sets;
import com.google.common.collect.Streams;
import io.trino.sql.analyzer.Analysis.Range;
import io.trino.sql.tree.AnchorPattern;
import io.trino.sql.tree.ExcludedPattern;
import io.trino.sql.tree.Expression;
import io.trino.sql.tree.FunctionCall;
import io.trino.sql.tree.Identifier;
import io.trino.sql.tree.LongLiteral;
import io.trino.sql.tree.MeasureDefinition;
import io.trino.sql.tree.NodeRef;
import io.trino.sql.tree.PatternRecognitionRelation;
import io.trino.sql.tree.PatternRecognitionRelation.RowsPerMatch;
import io.trino.sql.tree.PatternSearchMode;
import io.trino.sql.tree.RangeQuantifier;
import io.trino.sql.tree.RowPattern;
import io.trino.sql.tree.SkipTo;
import io.trino.sql.tree.SubsetDefinition;
import io.trino.sql.tree.VariableDefinition;
import java.util.HashSet;
import java.util.List;
import java.util.Optional;
import java.util.Set;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static com.google.common.collect.ImmutableSet.toImmutableSet;
import static io.trino.spi.StandardErrorCode.INVALID_LABEL;
import static io.trino.spi.StandardErrorCode.INVALID_PROCESSING_MODE;
import static io.trino.spi.StandardErrorCode.INVALID_RANGE;
import static io.trino.spi.StandardErrorCode.INVALID_ROW_PATTERN;
import static io.trino.spi.StandardErrorCode.NESTED_ROW_PATTERN_RECOGNITION;
import static io.trino.spi.StandardErrorCode.NOT_SUPPORTED;
import static io.trino.spi.StandardErrorCode.NUMERIC_VALUE_OUT_OF_RANGE;
import static io.trino.sql.analyzer.ExpressionTreeUtils.extractExpressions;
import static io.trino.sql.analyzer.SemanticExceptions.semanticException;
import static io.trino.sql.tree.PatternRecognitionRelation.RowsPerMatch.ALL_WITH_UNMATCHED;
import static io.trino.sql.tree.PatternRecognitionRelation.RowsPerMatch.WINDOW;
import static io.trino.sql.tree.ProcessingMode.Mode.FINAL;
import static io.trino.sql.util.AstUtils.preOrder;
public class PatternRecognitionAnalyzer
{
private PatternRecognitionAnalyzer() {}
public static PatternRecognitionAnalysis analyze(
List subsets,
List variableDefinitions,
List measures,
RowPattern pattern,
Optional skipTo)
{
// extract label names (Identifiers) from PATTERN and SUBSET clauses. create labels respecting SQL identifier semantics
Set primaryLabels = extractExpressions(ImmutableList.of(pattern), Identifier.class).stream()
.map(PatternRecognitionAnalyzer::label)
.collect(toImmutableSet());
List unionLabels = subsets.stream()
.map(SubsetDefinition::getName)
.map(PatternRecognitionAnalyzer::label)
.collect(toImmutableList());
// analyze SUBSET
Set unique = new HashSet<>();
for (SubsetDefinition subset : subsets) {
String label = label(subset.getName());
if (primaryLabels.contains(label)) {
throw semanticException(INVALID_LABEL, subset.getName(), "union pattern variable name: %s is a duplicate of primary pattern variable name", subset.getName());
}
if (!unique.add(label)) {
throw semanticException(INVALID_LABEL, subset.getName(), "union pattern variable name: %s is declared twice", subset.getName());
}
for (Identifier element : subset.getIdentifiers()) {
// TODO can there be repetitions in the list of subset elements? (currently repetitions are supported)
if (!primaryLabels.contains(label(element))) {
throw semanticException(INVALID_LABEL, element, "subset element: %s is not a primary pattern variable", element);
}
}
}
// analyze DEFINE
unique = new HashSet<>();
for (VariableDefinition definition : variableDefinitions) {
String label = label(definition.getName());
if (!primaryLabels.contains(label)) {
throw semanticException(INVALID_LABEL, definition.getName(), "defined variable: %s is not a primary pattern variable", definition.getName());
}
if (!unique.add(label)) {
throw semanticException(INVALID_LABEL, definition.getName(), "pattern variable with name: %s is defined twice", definition.getName());
}
// DEFINE clause only supports RUNNING semantics which is default
Expression expression = definition.getExpression();
extractExpressions(ImmutableList.of(expression), FunctionCall.class).stream()
.filter(functionCall -> functionCall.getProcessingMode().map(mode -> mode.getMode() == FINAL).orElse(false))
.findFirst()
.ifPresent(functionCall -> {
throw semanticException(INVALID_PROCESSING_MODE, functionCall.getProcessingMode().get(), "FINAL semantics is not supported in DEFINE clause");
});
}
// record primary labels without definitions. they are implicitly associated with `true` condition
Set undefinedLabels = Sets.difference(primaryLabels, unique);
// validate pattern quantifiers
ImmutableMap.Builder, Range> ranges = ImmutableMap.builder();
preOrder(pattern)
.filter(RangeQuantifier.class::isInstance)
.map(RangeQuantifier.class::cast)
.forEach(quantifier -> {
Optional atLeast = quantifier.getAtLeast().map(LongLiteral::getParsedValue);
atLeast.ifPresent(value -> {
if (value < 0) {
throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier lower bound must be greater than or equal to 0");
}
if (value > Integer.MAX_VALUE) {
throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier lower bound must not exceed " + Integer.MAX_VALUE);
}
});
Optional atMost = quantifier.getAtMost().map(LongLiteral::getParsedValue);
atMost.ifPresent(value -> {
if (value < 1) {
throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier upper bound must be greater than or equal to 1");
}
if (value > Integer.MAX_VALUE) {
throw semanticException(NUMERIC_VALUE_OUT_OF_RANGE, quantifier, "Pattern quantifier upper bound must not exceed " + Integer.MAX_VALUE);
}
});
if (atLeast.isPresent() && atMost.isPresent()) {
if (atLeast.get() > atMost.get()) {
throw semanticException(INVALID_RANGE, quantifier, "Pattern quantifier lower bound must not exceed upper bound");
}
}
ranges.put(NodeRef.of(quantifier), new Range(atLeast.map(Math::toIntExact), atMost.map(Math::toIntExact)));
});
// validate AFTER MATCH SKIP
Set allLabels = ImmutableSet.builder()
.addAll(primaryLabels)
.addAll(unionLabels)
.build();
skipTo.flatMap(SkipTo::getIdentifier)
.ifPresent(identifier -> {
String label = label(identifier);
if (!allLabels.contains(label)) {
throw semanticException(INVALID_LABEL, identifier, "%s is not a primary or union pattern variable", identifier);
}
});
// check no prohibited nesting: cannot nest one row pattern recognition within another
List expressions = Streams.concat(
measures.stream()
.map(MeasureDefinition::getExpression),
variableDefinitions.stream()
.map(VariableDefinition::getExpression))
.collect(toImmutableList());
expressions.forEach(expression -> preOrder(expression)
.filter(child -> child instanceof PatternRecognitionRelation || child instanceof RowPattern)
.findFirst()
.ifPresent(nested -> {
throw semanticException(NESTED_ROW_PATTERN_RECOGNITION, nested, "nested row pattern recognition in row pattern recognition");
}));
return new PatternRecognitionAnalysis(allLabels, undefinedLabels, ranges.buildOrThrow());
}
public static void validateNoPatternSearchMode(Optional patternSearchMode)
{
patternSearchMode.ifPresent(mode -> {
throw semanticException(NOT_SUPPORTED, mode, "Pattern search modifier: %s is not allowed in MATCH_RECOGNIZE clause", mode.getMode());
});
}
public static void validatePatternExclusions(Optional rowsPerMatch, RowPattern pattern)
{
// exclusion syntax is not allowed in row pattern if ALL ROWS PER MATCH WITH UNMATCHED ROWS is specified
if (rowsPerMatch.isPresent() && (rowsPerMatch.get() == ALL_WITH_UNMATCHED || rowsPerMatch.get() == WINDOW)) {
preOrder(pattern)
.filter(ExcludedPattern.class::isInstance)
.findFirst()
.ifPresent(exclusion -> {
throw semanticException(INVALID_ROW_PATTERN, exclusion, "Pattern exclusion syntax is not allowed when ALL ROWS PER MATCH WITH UNMATCHED ROWS is specified");
});
}
}
public static void validateNoPatternAnchors(RowPattern pattern)
{
preOrder(pattern)
.filter(AnchorPattern.class::isInstance)
.findFirst()
.ifPresent(anchor -> {
throw semanticException(INVALID_ROW_PATTERN, anchor, "Anchor pattern syntax is not allowed in window");
});
}
private static String label(Identifier identifier)
{
return identifier.getCanonicalValue();
}
}
