carterkozak commented on a change in pull request #335: Import of LogstashLayout as JsonTemplateLayout URL: https://github.com/apache/logging-log4j2/pull/335#discussion_r405628150
########## File path: log4j-layout-json-template/src/main/java/org/apache/logging/log4j/layout/json/template/JsonTemplateLayout.java ########## @@ -0,0 +1,562 @@ +/* + * 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; + +import org.apache.logging.log4j.core.Layout; +import org.apache.logging.log4j.core.LogEvent; +import org.apache.logging.log4j.core.StringLayout; +import org.apache.logging.log4j.core.config.Configuration; +import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute; +import org.apache.logging.log4j.core.config.plugins.PluginBuilderFactory; +import org.apache.logging.log4j.core.config.plugins.PluginConfiguration; +import org.apache.logging.log4j.core.config.plugins.PluginElement; +import org.apache.logging.log4j.core.layout.ByteBufferDestination; +import org.apache.logging.log4j.core.layout.Encoder; +import org.apache.logging.log4j.core.layout.LockingStringBuilderEncoder; +import org.apache.logging.log4j.core.lookup.StrSubstitutor; +import org.apache.logging.log4j.core.util.Constants; +import org.apache.logging.log4j.core.util.KeyValuePair; +import org.apache.logging.log4j.core.util.StringEncoder; +import org.apache.logging.log4j.layout.json.template.resolver.EventResolverContext; +import org.apache.logging.log4j.layout.json.template.resolver.StackTraceElementObjectResolverContext; +import org.apache.logging.log4j.layout.json.template.resolver.TemplateResolver; +import org.apache.logging.log4j.layout.json.template.resolver.TemplateResolvers; +import org.apache.logging.log4j.layout.json.template.util.JsonWriter; +import org.apache.logging.log4j.layout.json.template.util.Recycler; +import org.apache.logging.log4j.layout.json.template.util.RecyclerFactory; +import org.apache.logging.log4j.layout.json.template.util.Uris; +import org.apache.logging.log4j.plugins.Node; +import org.apache.logging.log4j.plugins.Plugin; +import org.apache.logging.log4j.util.Strings; + +import java.nio.charset.Charset; +import java.util.Collections; +import java.util.Map; +import java.util.Objects; +import java.util.function.Supplier; + +@Plugin(name = "JsonTemplateLayout", + category = Node.CATEGORY, + elementType = Layout.ELEMENT_TYPE, + printObject = true) +public class JsonTemplateLayout implements StringLayout { + + private static final Map<String, String> CONTENT_FORMAT = + Collections.singletonMap("version", "1"); + + private final Charset charset; + + private final String contentType; + + private final TemplateResolver<LogEvent> eventResolver; + + private final String eventDelimiter; + + private final Recycler<Context> contextRecycler; + + // The class and fields are visible for tests. + static final class Context implements AutoCloseable { + + final JsonWriter jsonWriter; + + final Encoder<StringBuilder> encoder; + + private Context( + final JsonWriter jsonWriter, + final Encoder<StringBuilder> encoder) { + this.jsonWriter = jsonWriter; + this.encoder = encoder; + } + + @Override + public void close() { + jsonWriter.close(); + } + + } + + private JsonTemplateLayout(final Builder builder) { + this.charset = builder.charset; + this.contentType = "application/json; charset=" + charset; + this.eventDelimiter = builder.eventDelimiter; + final StrSubstitutor substitutor = builder.configuration.getStrSubstitutor(); + final JsonWriter jsonWriter = JsonWriter + .newBuilder() + .setMaxStringLength(builder.maxStringLength) + .setTruncatedStringSuffix(builder.truncatedStringSuffix) + .build(); + final TemplateResolver<StackTraceElement> stackTraceElementObjectResolver = + builder.stackTraceEnabled + ? createStackTraceElementResolver(builder, substitutor, jsonWriter) + : null; + this.eventResolver = createEventResolver( + builder, + substitutor, + jsonWriter, + stackTraceElementObjectResolver); + this.contextRecycler = createContextRecycler(builder, jsonWriter); + } + + private static TemplateResolver<StackTraceElement> createStackTraceElementResolver( + final Builder builder, + final StrSubstitutor substitutor, + final JsonWriter jsonWriter) { + final StackTraceElementObjectResolverContext stackTraceElementObjectResolverContext = + StackTraceElementObjectResolverContext + .newBuilder() + .setSubstitutor(substitutor) + .setJsonWriter(jsonWriter) + .build(); + final String stackTraceElementTemplate = readStackTraceElementTemplate(builder); + return TemplateResolvers.ofTemplate(stackTraceElementObjectResolverContext, stackTraceElementTemplate); + } + + private TemplateResolver<LogEvent> createEventResolver( + final Builder builder, + final StrSubstitutor substitutor, + final JsonWriter jsonWriter, + final TemplateResolver<StackTraceElement> stackTraceElementObjectResolver) { + final String eventTemplate = readEventTemplate(builder); + final float maxByteCountPerChar = builder.charset.newEncoder().maxBytesPerChar(); + final int maxStringByteCount = + Math.toIntExact(Math.round( + maxByteCountPerChar * builder.maxStringLength)); + final EventResolverContext resolverContext = EventResolverContext + .newBuilder() + .setSubstitutor(substitutor) + .setJsonWriter(jsonWriter) + .setRecyclerFactory(builder.recyclerFactory) + .setMaxStringByteCount(maxStringByteCount) + .setLocationInfoEnabled(builder.locationInfoEnabled) + .setStackTraceEnabled(builder.stackTraceEnabled) + .setStackTraceElementObjectResolver(stackTraceElementObjectResolver) + .setMdcKeyPattern(builder.mdcKeyPattern) + .setNdcPattern(builder.ndcPattern) + .setEventTemplateAdditionalFields(builder.eventTemplateAdditionalFields.additionalFields) + .build(); + return TemplateResolvers.ofTemplate(resolverContext, eventTemplate); + } + + private static String readEventTemplate(final Builder builder) { + return readTemplate( + builder.eventTemplate, + builder.eventTemplateUri, + builder.charset); + } + + private static String readStackTraceElementTemplate(final Builder builder) { + return readTemplate( + builder.stackTraceElementTemplate, + builder.stackTraceElementTemplateUri, + builder.charset); + } + + private static String readTemplate( + final String template, + final String templateUri, + final Charset charset) { + return Strings.isBlank(template) + ? Uris.readUri(templateUri, charset) + : template; + } + + private static Recycler<Context> createContextRecycler( + final Builder builder, + final JsonWriter jsonWriter) { + final Supplier<Context> supplier = + createContextSupplier(builder.charset, jsonWriter); + return builder + .recyclerFactory + .create(supplier, Context::close); + } + + private static Supplier<Context> createContextSupplier( + final Charset charset, + final JsonWriter jsonWriter) { + return () -> { + final JsonWriter clonedJsonWriter = jsonWriter.clone(); + final Encoder<StringBuilder> encoder = + Constants.ENABLE_DIRECT_ENCODERS + ? new LockingStringBuilderEncoder(charset) + : null; + return new Context(clonedJsonWriter, encoder); + }; + } + + @Override + public byte[] toByteArray(final LogEvent event) { + final String eventJson = toSerializable(event); + return StringEncoder.toBytes(eventJson, charset); + } + + @Override + public String toSerializable(final LogEvent event) { + final Context context = acquireContext(); + final JsonWriter jsonWriter = context.jsonWriter; + final StringBuilder stringBuilder = jsonWriter.getStringBuilder(); + try { + eventResolver.resolve(event, jsonWriter); + stringBuilder.append(eventDelimiter); + return stringBuilder.toString(); + } finally { + contextRecycler.release(context); + } + } + + @Override + public void encode(final LogEvent event, final ByteBufferDestination destination) { + + // Acquire a context. + final Context context = acquireContext(); Review comment: no changes requested, but it might be helpful to implement Closeable (without throwing an IOException) to use structured try-with-resources blocks around context use. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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