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/*
* Copyright (c) 2013 Google Inc.
*
* 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.api.client.util;
import java.io.FilterInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
/**
* Provides utility methods for working with byte arrays and I/O streams.
*
* @since 1.14
* @author Yaniv Inbar
* @deprecated use Guava's com.google.common.io.ByteStreams
*/
@Deprecated
public final class ByteStreams {
private static final int BUF_SIZE = 0x1000; // 4K
/**
* Copies all bytes from the input stream to the output stream. Does not close or flush either
* stream.
*
* @param from the input stream to read from
* @param to the output stream to write to
* @return the number of bytes copied
*/
public static long copy(InputStream from, OutputStream to) throws IOException {
Preconditions.checkNotNull(from);
Preconditions.checkNotNull(to);
byte[] buf = new byte[BUF_SIZE];
long total = 0;
while (true) {
int r = from.read(buf);
if (r == -1) {
break;
}
to.write(buf, 0, r);
total += r;
}
return total;
}
/**
* Wraps an input stream, limiting the number of bytes which can be read.
*
* @param in the input stream to be wrapped
* @param limit the maximum number of bytes to be read
* @return a length-limited {@link InputStream}
*/
public static InputStream limit(InputStream in, long limit) {
return new LimitedInputStream(in, limit);
}
private static final class LimitedInputStream extends FilterInputStream {
private long left;
private long mark = -1;
LimitedInputStream(InputStream in, long limit) {
super(in);
Preconditions.checkNotNull(in);
Preconditions.checkArgument(limit >= 0, "limit must be non-negative");
left = limit;
}
@Override
public int available() throws IOException {
return (int) Math.min(in.available(), left);
}
// it's okay to mark even if mark isn't supported, as reset won't work
@Override
public synchronized void mark(int readLimit) {
in.mark(readLimit);
mark = left;
}
@Override
public int read() throws IOException {
if (left == 0) {
return -1;
}
int result = in.read();
if (result != -1) {
--left;
}
return result;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (left == 0) {
return -1;
}
len = (int) Math.min(len, left);
int result = in.read(b, off, len);
if (result != -1) {
left -= result;
}
return result;
}
@Override
public synchronized void reset() throws IOException {
if (!in.markSupported()) {
throw new IOException("Mark not supported");
}
if (mark == -1) {
throw new IOException("Mark not set");
}
in.reset();
left = mark;
}
@Override
public long skip(long n) throws IOException {
n = Math.min(n, left);
long skipped = in.skip(n);
left -= skipped;
return skipped;
}
}
/**
* Reads some bytes from an input stream and stores them into the buffer array {@code b}.
*
* This method blocks until {@code len} bytes of input data have been read into the array, or
* end of file is detected. The number of bytes read is returned, possibly zero. Does not close
* the stream.
*
*
A caller can detect EOF if the number of bytes read is less than {@code len}. All subsequent
* calls on the same stream will return zero.
*
*
If {@code b} is null, a {@code NullPointerException} is thrown. If {@code off} is negative,
* or {@code len} is negative, or {@code off+len} is greater than the length of the array {@code
* b}, then an {@code IndexOutOfBoundsException} is thrown. If {@code len} is zero, then no bytes
* are read. Otherwise, the first byte read is stored into element {@code b[off]}, the next one
* into {@code b[off+1]}, and so on. The number of bytes read is, at most, equal to {@code len}.
*
* @param in the input stream to read from
* @param b the buffer into which the data is read
* @param off an int specifying the offset into the data
* @param len an int specifying the number of bytes to read
* @return the number of bytes read
*/
public static int read(InputStream in, byte[] b, int off, int len) throws IOException {
Preconditions.checkNotNull(in);
Preconditions.checkNotNull(b);
if (len < 0) {
throw new IndexOutOfBoundsException("len is negative");
}
int total = 0;
while (total < len) {
int result = in.read(b, off + total, len - total);
if (result == -1) {
break;
}
total += result;
}
return total;
}
private ByteStreams() {}
}