/*
* Copyright (C) 2008 The Android Open Source Project
*
* 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.android.internal.os;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;
import java.util.Formatter;
import java.util.Locale;
/**
* A print stream which logs output line by line.
*
* {@hide}
*/
abstract class LoggingPrintStream extends PrintStream {
private final StringBuilder builder = new StringBuilder();
/**
* A buffer that is initialized when raw bytes are first written to this
* stream. It may contain the leading bytes of multi-byte characters.
* Between writes this buffer is always ready to receive data; ie. the
* position is at the first unassigned byte and the limit is the capacity.
*/
private ByteBuffer encodedBytes;
/**
* A buffer that is initialized when raw bytes are first written to this
* stream. Between writes this buffer is always clear; ie. the position is
* zero and the limit is the capacity.
*/
private CharBuffer decodedChars;
/**
* Decodes bytes to characters using the system default charset. Initialized
* when raw bytes are first written to this stream.
*/
private CharsetDecoder decoder;
protected LoggingPrintStream() {
super(new OutputStream() {
public void write(int oneByte) throws IOException {
throw new AssertionError();
}
});
}
/**
* Logs the given line.
*/
protected abstract void log(String line);
@Override
public synchronized void flush() {
flush(true);
}
/**
* Searches buffer for line breaks and logs a message for each one.
*
* @param completely true if the ending chars should be treated as a line
* even though they don't end in a line break
*/
private void flush(boolean completely) {
int length = builder.length();
int start = 0;
int nextBreak;
// Log one line for each line break.
while (start < length
&& (nextBreak = builder.indexOf("\n", start)) != -1) {
log(builder.substring(start, nextBreak));
start = nextBreak + 1;
}
if (completely) {
// Log the remainder of the buffer.
if (start < length) {
log(builder.substring(start));
}
builder.setLength(0);
} else {
// Delete characters leading up to the next starting point.
builder.delete(0, start);
}
}
public void write(int oneByte) {
write(new byte[] { (byte) oneByte }, 0, 1);
}
@Override
public void write(byte[] buffer) {
write(buffer, 0, buffer.length);
}
@Override
public synchronized void write(byte bytes[], int start, int count) {
if (decoder == null) {
encodedBytes = ByteBuffer.allocate(80);
decodedChars = CharBuffer.allocate(80);
decoder = Charset.defaultCharset().newDecoder()
.onMalformedInput(CodingErrorAction.REPLACE)
.onUnmappableCharacter(CodingErrorAction.REPLACE);
}
int end = start + count;
while (start < end) {
// copy some bytes from the array to the long-lived buffer. This
// way, if we end with a partial character we don't lose it.
int numBytes = Math.min(encodedBytes.remaining(), end - start);
encodedBytes.put(bytes, start, numBytes);
start += numBytes;
encodedBytes.flip();
CoderResult coderResult;
do {
// decode bytes from the byte buffer into the char buffer
coderResult = decoder.decode(encodedBytes, decodedChars, false);
// copy chars from the char buffer into our string builder
decodedChars.flip();
builder.append(decodedChars);
decodedChars.clear();
} while (coderResult.isOverflow());
encodedBytes.compact();
}
flush(false);
}
/** Always returns false. */
@Override
public boolean checkError() {
return false;
}
/** Ignored. */
@Override
protected void setError() { /* ignored */ }
/** Ignored. */
@Override
public void close() { /* ignored */ }
@Override
public PrintStream format(String format, Object... args) {
return format(Locale.getDefault(), format, args);
}
@Override
public PrintStream printf(String format, Object... args) {
return format(format, args);
}
@Override
public PrintStream printf(Locale l, String format, Object... args) {
return format(l, format, args);
}
private final Formatter formatter = new Formatter(builder, null);
@Override
public synchronized PrintStream format(
Locale l, String format, Object... args) {
if (format == null) {
throw new NullPointerException("format");
}
formatter.format(l, format, args);
flush(false);
return this;
}
@Override
public synchronized void print(char[] charArray) {
builder.append(charArray);
flush(false);
}
@Override
public synchronized void print(char ch) {
builder.append(ch);
if (ch == '\n') {
flush(false);
}
}
@Override
public synchronized void print(double dnum) {
builder.append(dnum);
}
@Override
public synchronized void print(float fnum) {
builder.append(fnum);
}
@Override
public synchronized void print(int inum) {
builder.append(inum);
}
@Override
public synchronized void print(long lnum) {
builder.append(lnum);
}
@Override
public synchronized void print(Object obj) {
builder.append(obj);
flush(false);
}
@Override
public synchronized void print(String str) {
builder.append(str);
flush(false);
}
@Override
public synchronized void print(boolean bool) {
builder.append(bool);
}
@Override
public synchronized void println() {
flush(true);
}
@Override
public synchronized void println(char[] charArray) {
builder.append(charArray);
flush(true);
}
@Override
public synchronized void println(char ch) {
builder.append(ch);
flush(true);
}
@Override
public synchronized void println(double dnum) {
builder.append(dnum);
flush(true);
}
@Override
public synchronized void println(float fnum) {
builder.append(fnum);
flush(true);
}
@Override
public synchronized void println(int inum) {
builder.append(inum);
flush(true);
}
@Override
public synchronized void println(long lnum) {
builder.append(lnum);
flush(true);
}
@Override
public synchronized void println(Object obj) {
builder.append(obj);
flush(true);
}
@Override
public synchronized void println(String s) {
if (builder.length() == 0 && s != null) {
// Optimization for a simple println.
int length = s.length();
int start = 0;
int nextBreak;
// Log one line for each line break.
while (start < length
&& (nextBreak = s.indexOf('\n', start)) != -1) {
log(s.substring(start, nextBreak));
start = nextBreak + 1;
}
if (start < length) {
log(s.substring(start));
}
} else {
builder.append(s);
flush(true);
}
}
@Override
public synchronized void println(boolean bool) {
builder.append(bool);
flush(true);
}
@Override
public synchronized PrintStream append(char c) {
print(c);
return this;
}
@Override
public synchronized PrintStream append(CharSequence csq) {
builder.append(csq);
flush(false);
return this;
}
@Override
public synchronized PrintStream append(
CharSequence csq, int start, int end) {
builder.append(csq, start, end);
flush(false);
return this;
}
}