log4j-layout-json-template/src/main/java/org/apache/logging/log4j/layout/json/template/resolver/StackTraceStringResolver.java

/*
 * 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.logging.log4j.layout.json.template.resolver;

import org.apache.logging.log4j.layout.json.template.util.TruncatingBufferedPrintWriter;
import org.apache.logging.log4j.layout.json.template.util.JsonWriter;
import org.apache.logging.log4j.layout.json.template.util.Recycler;

import java.util.function.Supplier;

final class StackTraceStringResolver implements StackTraceResolver {

    private final Recycler<TruncatingBufferedPrintWriter> writerRecycler;

    StackTraceStringResolver(final EventResolverContext context) {
        final Supplier<TruncatingBufferedPrintWriter> writerSupplier =
                () -> TruncatingBufferedPrintWriter.ofCapacity(
                        context.getMaxStringByteCount());
        this.writerRecycler = context
                .getRecyclerFactory()
                .create(writerSupplier, TruncatingBufferedPrintWriter::close);
    }

    @Override
    public void resolve(
            final Throwable throwable,
            final JsonWriter jsonWriter) {
        final TruncatingBufferedPrintWriter writer = writerRecycler.acquire();
        try {
            throwable.printStackTrace(writer);
            jsonWriter.writeString(writer.getBuffer(), 0, writer.getPosition());
        } finally {
            writerRecycler.release(writer);
        }
    }

}