rdblue commented on code in PR #4672: URL: https://github.com/apache/iceberg/pull/4672#discussion_r862253608
########## api/src/main/java/org/apache/iceberg/expressions/ExpressionUtil.java: ########## @@ -0,0 +1,257 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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 org.apache.iceberg.expressions; + +import java.util.regex.Pattern; +import java.util.stream.Collectors; +import org.apache.iceberg.transforms.Transform; +import org.apache.iceberg.transforms.Transforms; +import org.apache.iceberg.types.Types; + +/** + * Expression utility methods. + */ +public class ExpressionUtil { + private static final Transform<CharSequence, Integer> HASH_FUNC = Transforms + .bucket(Types.StringType.get(), Integer.MAX_VALUE); + private static final Pattern DATE = Pattern.compile("\\d\\d\\d\\d-\\d\\d-\\d\\d"); + private static final Pattern TIME = Pattern.compile( + "\\d\\d:\\d\\d(:\\d\\d(.\\d{1,6})?)?"); + private static final Pattern TIMESTAMP = Pattern.compile( + "\\d\\d\\d\\d-\\d\\d-\\d\\dT\\d\\d:\\d\\d(:\\d\\d(.\\d{1,6})?)?([-+]\\d\\d:\\d\\d)?"); + + private ExpressionUtil() { + } + + /** + * Produces an unbound {@link Expression} with the same structure, but with data values replaced by descriptions. + * <p> + * Numbers are replaced with magnitude and type, string-like values are replaced by hashes, and date/time values are + * replaced by the type. + * + * @param expr an Expression to sanitize + * @return a sanitized Expression + */ + public static Expression sanitize(Expression expr) { + return ExpressionVisitors.visit(expr, ExpressionSanitizer.INSTANCE); + } + + /** + * Produces a sanitized expression string with the same structure, but with data values replaced by descriptions. + * <p> + * Numbers are replaced with magnitude and type, string-like values are replaced by hashes, and date/time values are + * replaced by the type. + * + * @param expr an Expression to sanitize + * @return a sanitized expression string + */ + public static String toSanitizedString(Expression expr) { + return ExpressionVisitors.visit(expr, StringSanitizer.INSTANCE); + } + + private static class ExpressionSanitizer extends ExpressionVisitors.ExpressionVisitor<Expression> { + private static final ExpressionSanitizer INSTANCE = new ExpressionSanitizer(); + + @Override + public Expression alwaysTrue() { + return Expressions.alwaysTrue(); + } + + @Override + public Expression alwaysFalse() { + return Expressions.alwaysFalse(); + } + + @Override + public Expression not(Expression result) { + return Expressions.not(result); + } + + @Override + public Expression and(Expression leftResult, Expression rightResult) { + return Expressions.and(leftResult, rightResult); + } + + @Override + public Expression or(Expression leftResult, Expression rightResult) { + return Expressions.or(leftResult, rightResult); + } + + @Override + public <T> Expression predicate(BoundPredicate<T> pred) { + throw new UnsupportedOperationException("Cannot sanitize bound predicate: " + pred); + } + + @Override + @SuppressWarnings("unchecked") + public <T> Expression predicate(UnboundPredicate<T> pred) { + switch (pred.op()) { + case IS_NULL: + case NOT_NULL: + case IS_NAN: + case NOT_NAN: + // unary predicates don't need to be sanitized + return pred; + case LT: + case LT_EQ: + case GT: + case GT_EQ: + case EQ: + case NOT_EQ: + case STARTS_WITH: + case NOT_STARTS_WITH: + return new UnboundPredicate<>(pred.op(), pred.term(), (T) sanitize(pred.literal())); + case IN: + case NOT_IN: + Iterable<String> iter = () -> pred.literals().stream().map(ExpressionUtil::sanitize).iterator(); + return new UnboundPredicate<>(pred.op(), pred.term(), (Iterable<T>) iter); + default: + throw new UnsupportedOperationException("Cannot sanitize unsupported predicate type: " + pred.op()); + } + } + } + + private static class StringSanitizer extends ExpressionVisitors.ExpressionVisitor<String> { + private static final StringSanitizer INSTANCE = new StringSanitizer(); + + @Override + public String alwaysTrue() { + return "true"; + } + + @Override + public String alwaysFalse() { + return "false"; + } + + @Override + public String not(String result) { + return "NOT (" + result + ")"; + } + + @Override + public String and(String leftResult, String rightResult) { + return "(" + leftResult + " AND " + rightResult + ")"; + } + + @Override + public String or(String leftResult, String rightResult) { + return "(" + leftResult + " OR " + rightResult + ")"; + } + + @Override + public <T> String predicate(BoundPredicate<T> pred) { + throw new UnsupportedOperationException("Cannot sanitize bound predicate: " + pred); + } + + public String termToString(UnboundTerm<?> term) { + if (term instanceof UnboundTransform) { + return ((UnboundTransform<?, ?>) term).transform() + "(" + termToString(term.ref()) + ")"; + } else if (term instanceof NamedReference) { + return ((NamedReference<?>) term).name(); + } else { + throw new UnsupportedOperationException("Unsupported term: " + term); + } + } + + @Override + public <T> String predicate(UnboundPredicate<T> pred) { + String term = termToString(pred.term()); + switch (pred.op()) { + case IS_NULL: + return term + " IS NULL"; + case NOT_NULL: + return term + " IS NOT NULL"; + case IS_NAN: + return "is_nan(" + term + ")"; + case NOT_NAN: + return "not_nan(" + term + ")"; + case LT: + return term + " < " + sanitize(pred.literal()); + case LT_EQ: + return term + " <= " + sanitize(pred.literal()); + case GT: + return term + " > " + sanitize(pred.literal()); + case GT_EQ: + return term + " >= " + sanitize(pred.literal()); + case EQ: + return term + " = " + sanitize(pred.literal()); + case NOT_EQ: + return term + " != " + sanitize(pred.literal()); + case IN: + return term + " IN " + pred.literals().stream() + .map(ExpressionUtil::sanitize) + .collect(Collectors.joining(", ", "(", ")")); + case NOT_IN: + return term + " NOT IN " + pred.literals().stream() + .map(ExpressionUtil::sanitize) + .collect(Collectors.joining(", ", "(", ")")); + case STARTS_WITH: + return term + " STARTS WITH " + sanitize(pred.literal()); + case NOT_STARTS_WITH: + return term + " NOT STARTS WITH " + sanitize(pred.literal()); + default: + throw new UnsupportedOperationException("Cannot sanitize unsupported predicate type: " + pred.op()); + } + } + } + + private static String sanitize(Literal<?> literal) { + if (literal instanceof Literals.StringLiteral) { + CharSequence value = ((Literals.StringLiteral) literal).value(); + if (DATE.matcher(value).matches()) { + return "(date)"; + } else if (TIME.matcher(value).matches()) { + return "(time)"; + } else if (TIMESTAMP.matcher(value).matches()) { + return "(timestamp)"; + } else { + return sanitizeString(value); + } + } else if (literal instanceof Literals.DateLiteral) { + return "(date)"; + } else if (literal instanceof Literals.TimeLiteral) { + return "(time)"; + } else if (literal instanceof Literals.TimestampLiteral) { + return "(timestamp)"; + } else if (literal instanceof Literals.IntegerLiteral) { + return sanitizeNumber(((Literals.IntegerLiteral) literal).value(), "int"); + } else if (literal instanceof Literals.LongLiteral) { + return sanitizeNumber(((Literals.LongLiteral) literal).value(), "int"); Review Comment: Good catch! I used `int` or `float` in both cases because the type is determined by what you pass in to create the literal, not the actual type of data in a table (because the expression is unbound). Since the types are floating anyway, I didn't think it made much sense to be strict. What really matters is the magnitude of the value. If you have a `4-digit-int` it doesn't matter if it was passed in as a long or passed in as an int. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
