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/*
* Copyright (C) 2007 The Guava 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 com.google.common.io;
import com.google.common.base.Function;
import com.google.common.collect.Lists;
import java.io.BufferedReader;
import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.nio.CharBuffer;
import java.util.Arrays;
import java.util.List;
/**
* Unit tests for {@link LineBuffer} and {@link LineReader}.
*
* @author Chris Nokleberg
*/
@AndroidIncompatible // occasionally very slow
public class LineBufferTest extends IoTestCase {
public void testProcess() throws IOException {
bufferHelper("");
bufferHelper("\n", "\n");
bufferHelper("\r\n", "\r\n");
bufferHelper("\n\r", "\n", "\r");
bufferHelper("\r", "\r");
bufferHelper("\n\n", "\n", "\n");
bufferHelper("\r\n\r\n", "\r\n", "\r\n");
bufferHelper("\r\r", "\r", "\r");
bufferHelper("\ra\r\n\n\r\r", "\r", "a\r\n", "\n", "\r", "\r");
bufferHelper("no newlines at all", "no newlines at all");
bufferHelper("two lines\nbut no newline at end", "two lines\n", "but no newline at end");
bufferHelper(
"\nempty first line\nno newline at end", "\n", "empty first line\n", "no newline at end");
bufferHelper("three\rlines\rno newline at end", "three\r", "lines\r", "no newline at end");
bufferHelper("mixed\nline\rendings\r\n", "mixed\n", "line\r", "endings\r\n");
}
private static final int[] CHUNK_SIZES = {1, 2, 3, Integer.MAX_VALUE};
private static void bufferHelper(String input, String... expect) throws IOException {
List<String> expectProcess = Arrays.asList(expect);
List<String> expectRead =
Lists.transform(
expectProcess,
new Function<String, String>() {
@Override
public String apply(String value) {
return value.replaceAll("[\\r\\n]", "");
}
});
for (int chunk : CHUNK_SIZES) {
chunk = Math.max(1, Math.min(chunk, input.length()));
assertEquals(expectProcess, bufferHelper(input, chunk));
assertEquals(expectRead, readUsingJava(input, chunk));
assertEquals(expectRead, readUsingReader(input, chunk, true));
assertEquals(expectRead, readUsingReader(input, chunk, false));
}
}
private static List<String> bufferHelper(String input, int chunk) throws IOException {
final List<String> lines = Lists.newArrayList();
LineBuffer lineBuf =
new LineBuffer() {
@Override
protected void handleLine(String line, String end) {
lines.add(line + end);
}
};
char[] chars = input.toCharArray();
int off = 0;
while (off < chars.length) {
int len = Math.min(chars.length, off + chunk) - off;
lineBuf.add(chars, off, len);
off += len;
}
lineBuf.finish();
return lines;
}
private static List<String> readUsingJava(String input, int chunk) throws IOException {
BufferedReader r = new BufferedReader(getChunkedReader(input, chunk));
List<String> lines = Lists.newArrayList();
String line;
while ((line = r.readLine()) != null) {
lines.add(line);
}
r.close();
return lines;
}
private static List<String> readUsingReader(String input, int chunk, boolean asReader)
throws IOException {
Readable readable =
asReader ? getChunkedReader(input, chunk) : getChunkedReadable(input, chunk);
LineReader r = new LineReader(readable);
List<String> lines = Lists.newArrayList();
String line;
while ((line = r.readLine()) != null) {
lines.add(line);
}
return lines;
}
// Returns a Readable that is *not* a Reader.
private static Readable getChunkedReadable(String input, int chunk) {
final Reader reader = getChunkedReader(input, chunk);
return new Readable() {
@Override
public int read(CharBuffer cbuf) throws IOException {
return reader.read(cbuf);
}
};
}
private static Reader getChunkedReader(String input, final int chunk) {
return new FilterReader(new StringReader(input)) {
@Override
public int read(char[] cbuf, int off, int len) throws IOException {
return super.read(cbuf, off, Math.min(chunk, len));
}
};
}
}
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