com.hazelcast.org.codehaus.commons.compiler.io.Readers Maven / Gradle / Ivy
/*
* Janino - An embedded Java[TM] compiler
*
* Copyright (c) 2018, 2019 Arno Unkrig. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
* following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the
* following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other materials provided with the distribution.
* 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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package com.hazelcast.org.codehaus.commons.compiler.io;
import java.io.FilterReader;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.util.Arrays;
import java.util.Iterator;
import com.hazelcast.org.codehaus.commons.compiler.util.LineAndColumnTracker;
import com.hazelcast.org.codehaus.commons.nullanalysis.NotNullByDefault;
import com.hazelcast.org.codehaus.commons.nullanalysis.Nullable;
/**
* Utiltity methods related to {@link Reader}.
*/
public final
class Readers {
private Readers() {}
/**
* Any attempts to read return an "end-of-input" condition.
*/
public static final Reader EMPTY_READER = new StringReader("");
/**
* @return {@link FilterReader} that runs the runnable right before the first character is read
*/
public static Reader
onFirstChar(Reader in, final Runnable runnable) {
return new FilterReader(in) {
private boolean hadChars;
@Override public int
read() throws IOException {
this.aboutToRead();
return super.read();
}
@Override @NotNullByDefault(false) public int
read(char[] cbuf, int off, int len) throws IOException {
this.aboutToRead();
return super.read(cbuf, off, len);
}
@Override public long
skip(long n) throws IOException {
this.aboutToRead();
return super.skip(n);
}
private void
aboutToRead() {
if (!this.hadChars) {
runnable.run();
this.hadChars = true;
}
}
};
}
/**
* @return A {@link FilterReader} that tracks line and column numbers while characters are being read
*/
public static Reader
trackLineAndColumn(Reader in, final LineAndColumnTracker tracker) {
return new FilterReader(in) {
@Override public int
read() throws IOException {
int c = super.read();
if (c >= 0) tracker.consume((char) c);
return c;
}
@Override @NotNullByDefault(false) public int
read(char[] cbuf, final int off, int len) throws IOException {
if (len <= 0) return 0;
int c = this.read();
if (c < 0) return -1;
cbuf[off] = (char) c;
return 1;
}
@Override public long
skip(final long n) throws IOException {
if (n <= 0) return 0;
int c = this.read();
if (c < 0) return 0;
return 1;
}
@Override public boolean markSupported() { return false; }
@Override public void mark(int readAheadLimit) throws IOException { throw new IOException(); }
@Override public void reset() throws IOException { throw new IOException(); }
};
}
public static Reader
concat(Reader... delegates) { return Readers.concat(Arrays.asList(delegates)); }
/**
* @return Reads from the first element of the delegates, then, after EOI, from the second until EOI,
* and so forth
*/
public static Reader
concat(final Iterable delegates) {
return new Reader() {
private final Iterator delegateIterator = delegates.iterator();
private Reader currentDelegate = Readers.EMPTY_READER;
/**
* Closes all delegates.
*/
@Override public void
close() throws IOException { for (Reader delegate : delegates) delegate.close(); }
@Override public int
read() throws IOException {
for (;;) {
int result = this.currentDelegate.read();
if (result != -1) return result;
if (!this.delegateIterator.hasNext()) return -1;
this.currentDelegate = (Reader) this.delegateIterator.next();
}
}
@Override public long
skip(long n) throws IOException {
for (;;) {
long result = this.currentDelegate.skip(n);
if (result != -1L) return result;
if (!this.delegateIterator.hasNext()) return 0;
this.currentDelegate = (Reader) this.delegateIterator.next();
}
}
@Override public int
read(@Nullable final char[] cbuf, final int off, final int len) throws IOException {
for (;;) {
int result = this.currentDelegate.read(cbuf, off, len);
if (result != -1L) return result;
if (!this.delegateIterator.hasNext()) return -1;
this.currentDelegate = (Reader) this.delegateIterator.next();
}
}
};
}
/**
* @return A {@link Reader} that copies the bytes being passed through to a given {@link Writer}; this is in
* analogy with the UNIX "tee" command
*/
public static Reader
teeReader(Reader in, final Writer out, final boolean closeWriterOnEoi) {
return new FilterReader(in) {
@Override public void
close() throws IOException {
this.in.close();
out.close();
}
@Override public int
read() throws IOException {
int c = this.in.read();
if (c == -1) {
if (closeWriterOnEoi) {
out.close();
} else {
out.flush();
}
} else {
out.write(c);
}
return c;
}
@Override public int
read(@Nullable char[] cbuf, int off, int len) throws IOException {
int bytesRead = this.in.read(cbuf, off, len);
if (bytesRead == -1) {
if (closeWriterOnEoi) {
out.close();
} else {
out.flush();
}
} else {
out.write(cbuf, off, bytesRead);
}
return bytesRead;
}
};
}
public static String
readAll(Reader in) throws IOException {
StringWriter sw = new StringWriter();
Readers.copy(in, sw);
return sw.toString();
}
public static void
copy(Reader in, Writer out) throws IOException {
char[] buffer = new char[8192];
for (;;) {
int n = in.read(buffer);
if (n == -1) break;
out.write(buffer, 0, n);
}
}
}
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