package com.github.ltsopensource.core.commons.io;
import java.io.InputStream;
/**
* @author Robert HG (254963746@qq.com)
*/
public class UnsafeByteArrayInputStream extends InputStream {
protected byte buf[];
protected int pos;
protected int mark = 0;
protected int count;
public UnsafeByteArrayInputStream(byte buf[]) {
this.buf = buf;
this.pos = 0;
this.count = buf.length;
}
public UnsafeByteArrayInputStream(byte buf[], int offset, int length) {
this.buf = buf;
this.pos = offset;
this.count = Math.min(offset + length, buf.length);
this.mark = offset;
}
public int read() {
return (pos < count) ? (buf[pos++] & 0xff) : -1;
}
public int read(byte b[], int off, int len) {
if (b == null) {
throw new NullPointerException();
} else if (off < 0 || len < 0 || len > b.length - off) {
throw new IndexOutOfBoundsException();
}
if (pos >= count) {
return -1;
}
int avail = count - pos;
if (len > avail) {
len = avail;
}
if (len <= 0) {
return 0;
}
System.arraycopy(buf, pos, b, off, len);
pos += len;
return len;
}
public long skip(long n) {
long k = count - pos;
if (n < k) {
k = n < 0 ? 0 : n;
}
pos += k;
return k;
}
public int available() {
return count - pos;
}
public boolean markSupported() {
return true;
}
public void mark(int readAheadLimit) {
mark = pos;
}
public void reset() {
pos = mark;
}
}