/* * Copyright © 2019 Smoke Turner, LLC ([email protected]) * * Licensed 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 com.smoketurner.dropwizard.graphql; import com.codahale.metrics.Meter; import com.codahale.metrics.MetricRegistry; import com.google.common.cache.Cache; import com.google.common.cache.CacheBuilder; import com.google.common.cache.CacheBuilderSpec; import graphql.ExecutionInput; import graphql.execution.preparsed.PreparsedDocumentEntry; import graphql.execution.preparsed.PreparsedDocumentProvider; import java.util.concurrent.ExecutionException; import java.util.function.Function; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public class CachingPreparsedDocumentProvider implements PreparsedDocumentProvider { private static final Logger LOGGER = LoggerFactory.getLogger(CachingPreparsedDocumentProvider.class); private final Cache<String, PreparsedDocumentEntry> cache; private final Meter cacheMisses; /** * Constructor * * @param spec Specification for the cache * @param registry Metric registry */ public CachingPreparsedDocumentProvider(CacheBuilderSpec spec, MetricRegistry registry) { LOGGER.info("Query Cache: {}", spec); cache = CacheBuilder.from(spec).build(); cacheMisses = registry.meter(MetricRegistry.name(CachingPreparsedDocumentProvider.class, "cache-misses")); } @Override public PreparsedDocumentEntry getDocument( ExecutionInput executionInput, Function<ExecutionInput, PreparsedDocumentEntry> computeFunction) { final String query = executionInput.getQuery(); try { return cache.get( query, () -> { LOGGER.debug("Query cache miss: {}", query); cacheMisses.mark(); return computeFunction.apply(executionInput); }); } catch (ExecutionException e) { LOGGER.error("Unable to get document from cache", e); } // NO-OP return computeFunction.apply(executionInput); } }