| /* |
| * 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.lucene.gradle; |
| |
| import java.io.IOException; |
| import java.io.Reader; |
| import java.io.StringWriter; |
| import java.io.Writer; |
| import java.nio.charset.StandardCharsets; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| import java.util.function.Supplier; |
| |
| public class SpillWriter extends Writer { |
| private final static int MAX_BUFFERED = 2 * 1024; |
| private final StringWriter buffer = new StringWriter(MAX_BUFFERED); |
| |
| private final Supplier<Path> spillPathSupplier; |
| private Writer spill; |
| private Path spillPath; |
| |
| public SpillWriter(Supplier<Path> spillPathSupplier) { |
| this.spillPathSupplier = spillPathSupplier; |
| } |
| |
| @Override |
| public void write(char[] cbuf, int off, int len) throws IOException { |
| getSink(len).write(cbuf, off, len); |
| } |
| |
| @Override |
| public void write(int c) throws IOException { |
| getSink(1).write(c); |
| } |
| |
| @Override |
| public void write(char[] cbuf) throws IOException { |
| getSink(cbuf.length).write(cbuf); |
| } |
| |
| @Override |
| public void write(String str) throws IOException { |
| getSink(str.length()).write(str); |
| } |
| |
| @Override |
| public void write(String str, int off, int len) throws IOException { |
| getSink(len).write(str, off, len); |
| } |
| |
| @Override |
| public Writer append(CharSequence csq) throws IOException { |
| getSink(csq.length()).append(csq); |
| return this; |
| } |
| |
| @Override |
| public Writer append(CharSequence csq, int start, int end) throws IOException { |
| getSink(Math.max(0, end - start)).append(csq, start, end); |
| return this; |
| } |
| |
| @Override |
| public Writer append(char c) throws IOException { |
| getSink(1).append(c); |
| return this; |
| } |
| |
| private Writer getSink(int expectedWriteChars) throws IOException { |
| if (spill == null) { |
| if (buffer.getBuffer().length() + expectedWriteChars <= MAX_BUFFERED) { |
| return buffer; |
| } |
| |
| spillPath = spillPathSupplier.get(); |
| spill = Files.newBufferedWriter(spillPath, StandardCharsets.UTF_8); |
| spill.append(buffer.getBuffer()); |
| buffer.getBuffer().setLength(0); |
| } |
| |
| return spill; |
| } |
| |
| @Override |
| public void flush() throws IOException { |
| getSink(0).flush(); |
| } |
| |
| @Override |
| public void close() throws IOException { |
| buffer.close(); |
| if (spill != null) { |
| spill.close(); |
| Files.delete(spillPath); |
| } |
| } |
| |
| public void copyTo(Writer writer) throws IOException { |
| if (spill != null) { |
| flush(); |
| try (Reader reader = Files.newBufferedReader(spillPath, StandardCharsets.UTF_8)) { |
| reader.transferTo(writer); |
| } |
| } else { |
| writer.append(buffer.getBuffer()); |
| } |
| } |
| |
| public long length() throws IOException { |
| flush(); |
| if (spill != null) { |
| return Files.size(spillPath); |
| } else { |
| return buffer.getBuffer().length(); |
| } |
| } |
| } |