org.jgroups.blocks.GridInputStream Maven / Gradle / Ivy
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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including
all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and
JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up
with different versions on classes on the class path).
The newest version!
package org.jgroups.blocks;
import org.jgroups.logging.Log;
import org.jgroups.logging.LogFactory;
import org.jgroups.annotations.Experimental;
import java.io.*;
/**
* @author Bela Ban
*/
@Experimental
public class GridInputStream extends InputStream {
final ReplCache cache;
final int chunk_size;
final String name;
protected final GridFile file; // file representing this input stream
int index=0; // index into the file for writing
int local_index=0;
byte[] current_buffer=null;
boolean end_reached=false;
final static Log log=LogFactory.getLog(GridInputStream.class);
GridInputStream(GridFile file, ReplCache cache, int chunk_size) throws FileNotFoundException {
this.file=file;
this.name=file.getPath();
this.cache=cache;
this.chunk_size=chunk_size;
}
public int read() throws IOException {
int bytes_remaining_to_read=getBytesRemainingInChunk();
if(bytes_remaining_to_read == 0) {
if(end_reached)
return -1;
current_buffer=fetchNextChunk();
local_index=0;
if(current_buffer == null)
return -1;
else if(current_buffer.length < chunk_size)
end_reached=true;
bytes_remaining_to_read=getBytesRemainingInChunk();
}
int retval=current_buffer[local_index++];
index++;
return retval;
}
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
public int read(byte[] b, int off, int len) throws IOException {
int bytes_read=0;
while(len > 0) {
int bytes_remaining_to_read=getBytesRemainingInChunk();
if(bytes_remaining_to_read == 0) {
if(end_reached)
return bytes_read > 0? bytes_read : -1;
current_buffer=fetchNextChunk();
local_index=0;
if(current_buffer == null)
return bytes_read > 0? bytes_read : -1;
else if(current_buffer.length < chunk_size)
end_reached=true;
bytes_remaining_to_read=getBytesRemainingInChunk();
}
int bytes_to_read=Math.min(len, bytes_remaining_to_read);
// bytes_to_read=Math.min(bytes_to_read, current_buffer.length - local_index);
System.arraycopy(current_buffer, local_index, b, off, bytes_to_read);
local_index+=bytes_to_read;
off+=bytes_to_read;
len-=bytes_to_read;
bytes_read+=bytes_to_read;
index+=bytes_to_read;
}
return bytes_read;
}
public long skip(long n) throws IOException {
throw new UnsupportedOperationException();
}
public int available() throws IOException {
throw new UnsupportedOperationException();
}
public void close() throws IOException {
local_index=index=0;
end_reached=false;
}
private int getBytesRemainingInChunk() {
// return chunk_size - local_index;
return current_buffer == null? 0 : current_buffer.length - local_index;
}
private byte[] fetchNextChunk() {
int chunk_number=getChunkNumber();
String key=name + ".#" + chunk_number;
byte[] val= cache.get(key);
if(log.isTraceEnabled())
log.trace("fetching index=" + index + ", key=" + key +": " + (val != null? val.length + " bytes" : "null"));
return val;
}
private int getChunkNumber() {
return index / chunk_size;
}
}