Example usage for org.apache.lucene.util.automaton Operations concatenate

Introduction

In this page you can find the example usage for org.apache.lucene.util.automaton Operations concatenate.

Prototype

static public Automaton concatenate(Automaton a1, Automaton a2) 

Source Link

Document

Returns an automaton that accepts the concatenation of the languages of the given automata.

Usage

From source file:org.elasticsearch.xpack.core.security.authz.permission.FieldPermissions.java

License:Open Source License

private static Automaton initializePermittedFieldsAutomaton(final String[] grantedFields,
        final String[] deniedFields) {
    Automaton grantedFieldsAutomaton;//from  ww  w .j a  v  a 2  s.c  o m
    if (grantedFields == null || Arrays.stream(grantedFields).anyMatch(Regex::isMatchAllPattern)) {
        grantedFieldsAutomaton = Automatons.MATCH_ALL;
    } else {
        // an automaton that includes metadata fields, including join fields created by the _parent field such
        // as _parent#type
        Automaton metaFieldsAutomaton = Operations.concatenate(Automata.makeChar('_'),
                Automata.makeAnyString());
        grantedFieldsAutomaton = Operations.union(Automatons.patterns(grantedFields), metaFieldsAutomaton);
    }

    Automaton deniedFieldsAutomaton;
    if (deniedFields == null || deniedFields.length == 0) {
        deniedFieldsAutomaton = Automatons.EMPTY;
    } else {
        deniedFieldsAutomaton = Automatons.patterns(deniedFields);
    }

    grantedFieldsAutomaton = MinimizationOperations.minimize(grantedFieldsAutomaton,
            Operations.DEFAULT_MAX_DETERMINIZED_STATES);
    deniedFieldsAutomaton = MinimizationOperations.minimize(deniedFieldsAutomaton,
            Operations.DEFAULT_MAX_DETERMINIZED_STATES);

    if (subsetOf(deniedFieldsAutomaton, grantedFieldsAutomaton) == false) {
        throw new ElasticsearchSecurityException("Exceptions for field permissions must be a subset of the "
                + "granted fields but " + Strings.arrayToCommaDelimitedString(deniedFields)
                + " is not a subset of " + Strings.arrayToCommaDelimitedString(grantedFields));
    }

    grantedFieldsAutomaton = Automatons.minusAndMinimize(grantedFieldsAutomaton, deniedFieldsAutomaton);
    return grantedFieldsAutomaton;
}

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