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Add LRU cache for generated parsers to FnInvisibleXml #2749

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Merged
ChristianGruen merged 2 commits into from
Sep 1, 2026
+41 −1
Merged

Add LRU cache for generated parsers to FnInvisibleXml #2749

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e021f09
add LRU cache for generated parsers
GuntherRademacher Sep 1, 2026
b2d4eba
minor changes
GuntherRademacher Sep 1, 2026
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42 changes: 41 additions & 1 deletion basex-core/src/main/java/org/basex/query/func/fn/FnInvisibleXml.java
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
import static org.basex.query.QueryError.*;

import java.io.*;
import java.util.*;

import org.basex.build.*;
import org.basex.core.*;
Expand Down Expand Up @@ -74,6 +75,17 @@ private final class Generator {
private static final Option[] NO_OPTS = new Blitz.Option[0];
/** Markup Blitz options for fail-on-error. */
private static final Option[] FAIL_OPTS = new Blitz.Option[] { Blitz.Option.FAIL_ON_ERROR };
/** Maximum number of parser cache entries. */
private static final int CACHE_SIZE = 15;
/** Generated parser cache. */
private static final LinkedHashMap<String, de.bottlecaps.markup.blitz.Parser> PARSERS =
new LinkedHashMap<>(CACHE_SIZE + 1, 1.0f, true) {
@Override
protected boolean removeEldestEntry(
final Map.Entry<String, de.bottlecaps.markup.blitz.Parser> eldest) {
return size() > CACHE_SIZE;
}
};

/**
* Generate a parser from an invisible XML grammar.
Expand All @@ -97,7 +109,7 @@ public FuncItem generate(final QueryContext qc) throws QueryException {
final de.bottlecaps.markup.blitz.Parser parser;
final Blitz.Option[] opts = options.get(IxmlOptions.FAIL_ON_ERROR) ? FAIL_OPTS : NO_OPTS;
try {
parser = xml ? Blitz.generateFromXml(grmmr, opts) : Blitz.generate(grmmr, opts);
parser = parser(grmmr, xml, opts);
} catch(final BlitzParseException ex) {
throw IXML_GRM_X_X_X.get(info, ex.getOffendingToken(), ex.getLine(), ex.getColumn());
} catch(final BlitzException ex) {
Expand All @@ -110,6 +122,34 @@ public FuncItem generate(final QueryContext qc) throws QueryException {
final FuncType ft = FuncType.get(parseFunction.seqType(), Types.STRING_O);
return new FuncItem(info, parseFunction, params, AnnList.EMPTY, ft, params.length, null);
}

/**
* Returns a cached parser.
* @param grammar grammar string
* @param xml XML grammar flag
* @param opts generation options
* @return parser
*/
private de.bottlecaps.markup.blitz.Parser parser(final String grammar, final boolean xml,
final Blitz.Option[] opts) {
final String key = grammar + "\0" + xml + "\0" + Arrays.toString(opts);
de.bottlecaps.markup.blitz.Parser parser;
synchronized(PARSERS) {
parser = PARSERS.get(key);
}
if(parser == null) {
parser = xml ? Blitz.generateFromXml(grammar, opts) : Blitz.generate(grammar, opts);
synchronized(PARSERS) {
final de.bottlecaps.markup.blitz.Parser cached = PARSERS.get(key);
if(cached != null) {
parser = cached;
} else {
PARSERS.put(key, parser);
}
}
}
return parser;
}
}

/**
Expand Down
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