package org.apache.maven.index.reader;
/*
* 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.
*/
import java.io.Closeable;
import java.io.IOException;
import java.text.ParseException;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;
import java.util.UUID;
import org.apache.maven.index.reader.WritableResourceHandler.WritableResource;
import static org.apache.maven.index.reader.Utils.loadProperties;
import static org.apache.maven.index.reader.Utils.storeProperties;
/**
* Maven 2 Index writer that writes chunk and maintains published property file.
* <p/>
* <strong>Currently no incremental update is supported, as the deleteion states should be maintained by
* caller</strong>. Hence, this writer will always produce the "main" chunk only.
*
* @since 5.1.2
*/
public class IndexWriter
implements Closeable
{
private static final int INDEX_V1 = 1;
private final WritableResourceHandler local;
private final Properties localIndexProperties;
private final boolean incremental;
private final String nextChunkCounter;
private final String nextChunkName;
public IndexWriter(final WritableResourceHandler local, final String indexId, final boolean incrementalSupported)
throws IOException
{
if (local == null) {
throw new NullPointerException("local resource handler null");
}
if (indexId == null) {
throw new NullPointerException("indexId null");
}
this.local = local;
Properties indexProperties = loadProperties(local.locate(Utils.INDEX_FILE_PREFIX + ".properties"));
if (incrementalSupported && indexProperties != null) {
this.localIndexProperties = indexProperties;
// existing index, this is incremental publish, and we will add new chunk
String localIndexId = localIndexProperties.getProperty("nexus.index.id");
if (localIndexId == null || !localIndexId.equals(indexId)) {
throw new IllegalArgumentException(
"index already exists and indexId mismatch or unreadable: " + localIndexId + ", " +
indexId);
}
this.incremental = true;
this.nextChunkCounter = calculateNextChunkCounter();
this.nextChunkName = Utils.INDEX_FILE_PREFIX + "." + nextChunkCounter + ".gz";
}
else {
// non-existing index, create published index from scratch
this.localIndexProperties = new Properties();
this.localIndexProperties.setProperty("nexus.index.id", indexId);
this.localIndexProperties.setProperty("nexus.index.chain-id", UUID.randomUUID().toString());
this.incremental = false;
this.nextChunkCounter = null;
this.nextChunkName = Utils.INDEX_FILE_PREFIX + ".gz";
}
}
/**
* Returns the index context ID that published index has set.
*/
public String getIndexId() {
return localIndexProperties.getProperty("nexus.index.id");
}
/**
* Returns the {@link Date} when index was last published or {@code null} if this is first publishing. In other
* words,returns {@code null} when {@link #isIncremental()} returns {@code false}. After this writer is closed, the
* return value is updated to "now" (in {@link #close() method}.
*/
public Date getPublishedTimestamp() {
try {
String timestamp = localIndexProperties.getProperty("nexus.index.timestamp");
if (timestamp != null) {
return Utils.INDEX_DATE_FORMAT.parse(timestamp);
}
return null;
}
catch (ParseException e) {
throw new RuntimeException("Corrupt date", e);
}
}
/**
* Returns {@code true} if incremental publish is about to happen.
*/
public boolean isIncremental() {
return incremental;
}
/**
* Returns the chain id of published index. If {@link #isIncremental()} is {@code false}, this is the newly generated
* chain ID.
*/
public String getChainId() {
return localIndexProperties.getProperty("nexus.index.chain-id");
}
/**
* Returns the next chunk name about to be published.
*/
public String getNextChunkName() {
return nextChunkName;
}
/**
* Writes out the record iterator and returns the written record count.
*/
public int writeChunk(final Iterator<Map<String, String>> iterator) throws IOException {
int written;
WritableResource writableResource = local.locate(nextChunkName);
try {
final ChunkWriter chunkWriter = new ChunkWriter(nextChunkName, writableResource.write(), INDEX_V1, new Date());
try {
written = chunkWriter.writeChunk(iterator);
}
finally {
chunkWriter.close();
}
if (incremental) {
// TODO: update main gz file
}
return written;
}
finally {
writableResource.close();
}
}
/**
* Closes the underlying {@link ResourceHandler} and synchronizes published index properties, so remote clients
* becomes able to consume newly published index. If sync is not desired (ie. due to aborted publish), then this
* method should NOT be invoked, but rather the {@link ResourceHandler} that caller provided in constructor of
* this class should be closed manually.
*/
public void close() throws IOException {
try {
if (incremental) {
localIndexProperties.setProperty("nexus.index.last-incremental", nextChunkCounter);
}
localIndexProperties.setProperty("nexus.index.timestamp", Utils.INDEX_DATE_FORMAT.format(new Date()));
storeProperties(local.locate(Utils.INDEX_FILE_PREFIX + ".properties"), localIndexProperties);
}
finally {
local.close();
}
}
/**
* Calculates the chunk names that needs to be fetched.
*/
private String calculateNextChunkCounter() {
String lastChunkCounter = localIndexProperties.getProperty("nexus.index.last-incremental");
if (lastChunkCounter != null) {
return String.valueOf(Integer.parseInt(lastChunkCounter) + 1);
}
else {
return "1";
}
}
}