Java tutorial
/* * Copyright 2016 The Simple File Server Authors * * 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 org.sfs.nodes.data; import com.google.common.base.Function; import com.google.common.base.Optional; import io.vertx.core.Handler; import io.vertx.core.MultiMap; import io.vertx.core.http.HttpServerResponse; import io.vertx.core.json.JsonObject; import org.sfs.Server; import org.sfs.SfsRequest; import org.sfs.VertxContext; import org.sfs.auth.Authenticate; import org.sfs.filesystem.volume.DigestBlob; import org.sfs.nodes.LocalNode; import org.sfs.rx.HandleServerToBusy; import org.sfs.rx.Holder2; import org.sfs.rx.Terminus; import org.sfs.util.MessageDigestFactory; import org.sfs.validate.ValidateActionAdminOrSystem; import org.sfs.validate.ValidateNodeIsDataNode; import org.sfs.validate.ValidateParamBetweenLong; import org.sfs.validate.ValidateParamComputedDigest; import org.sfs.validate.ValidateParamExists; import rx.Observable; import java.util.regex.Matcher; import static com.google.common.base.Charsets.UTF_8; import static com.google.common.base.Optional.absent; import static com.google.common.base.Optional.of; import static com.google.common.collect.FluentIterable.from; import static com.google.common.collect.Iterables.toArray; import static java.lang.Long.MAX_VALUE; import static java.lang.Long.parseLong; import static java.net.HttpURLConnection.HTTP_NOT_FOUND; import static java.net.HttpURLConnection.HTTP_OK; import static org.sfs.rx.Defer.aVoid; import static org.sfs.util.KeepAliveHttpServerResponse.DELIMITER_BUFFER; import static org.sfs.util.MessageDigestFactory.fromValueIfExists; import static org.sfs.util.SfsHttpQueryParams.COMPUTED_DIGEST; import static org.sfs.util.SfsHttpQueryParams.LENGTH; import static org.sfs.util.SfsHttpQueryParams.OFFSET; import static org.sfs.util.SfsHttpQueryParams.POSITION; import static org.sfs.util.SfsHttpQueryParams.VOLUME; public class ChecksumBlob implements Handler<SfsRequest> { @Override public void handle(final SfsRequest httpServerRequest) { VertxContext<Server> vertxContext = httpServerRequest.vertxContext(); aVoid().flatMap(new Authenticate(httpServerRequest)) .flatMap(new ValidateActionAdminOrSystem(httpServerRequest)) .map(new ValidateNodeIsDataNode<>(vertxContext)).map(aVoid -> httpServerRequest) .map(new ValidateParamExists(VOLUME)).map(new ValidateParamExists(POSITION)) .map(new ValidateParamBetweenLong(POSITION, 0, MAX_VALUE)) .map(new ValidateParamBetweenLong(LENGTH, 0, MAX_VALUE)) .map(new ValidateParamBetweenLong(OFFSET, 0, MAX_VALUE)).map(new ValidateParamComputedDigest()) .flatMap(httpServerRequest1 -> { MultiMap params = httpServerRequest1.params(); final Iterable<MessageDigestFactory> iterable = from(params.names()) .transform(new Function<String, Optional<MessageDigestFactory>>() { @Override public Optional<MessageDigestFactory> apply(String param) { Matcher matcher = COMPUTED_DIGEST.matcher(param); if (matcher.matches()) { String digestName = matcher.group(1); return fromValueIfExists(digestName); } return absent(); } }).filter(Optional::isPresent).transform(input -> input.get()); MultiMap queryParams = httpServerRequest1.params(); String volumeId = queryParams.get(VOLUME); long position = parseLong(queryParams.get(POSITION)); Optional<Long> oOffset; if (queryParams.contains(OFFSET)) { oOffset = of(parseLong(queryParams.get(OFFSET))); } else { oOffset = absent(); } Optional<Long> oLength; if (queryParams.contains(LENGTH)) { oLength = of(parseLong(queryParams.get(LENGTH))); } else { oLength = absent(); } // let the client know we're alive by sending pings on the response stream httpServerRequest1.startProxyKeepAlive(); LocalNode localNode = new LocalNode(vertxContext, vertxContext.verticle().nodes().volumeManager()); return localNode .checksum(volumeId, position, oOffset, oLength, toArray(iterable, MessageDigestFactory.class)) .map(digestBlobOptional -> new Holder2<>(httpServerRequest1, digestBlobOptional)); }).flatMap(holder -> httpServerRequest.stopKeepAlive().map(aVoid -> holder)) .onErrorResumeNext(throwable -> httpServerRequest.stopKeepAlive() .flatMap(aVoid -> Observable.<Holder2<SfsRequest, Optional<DigestBlob>>>error(throwable))) .single().onErrorResumeNext(new HandleServerToBusy<>()) .subscribe(new Terminus<Holder2<SfsRequest, Optional<DigestBlob>>>(httpServerRequest) { @Override public void onNext(Holder2<SfsRequest, Optional<DigestBlob>> holder) { Optional<DigestBlob> oJsonDigestBlob = holder.value1(); JsonObject jsonResponse = new JsonObject(); if (oJsonDigestBlob.isPresent()) { jsonResponse.put("code", HTTP_OK).put("blob", oJsonDigestBlob.get().toJsonObject()); } else { jsonResponse.put("code", HTTP_NOT_FOUND); } HttpServerResponse httpResponse = holder.value0().response(); httpResponse.write(jsonResponse.encode(), UTF_8.toString()).write(DELIMITER_BUFFER); } }); } }