aQute.libg.cafs
Class CAFS

java.lang.Object
  aQute.libg.cafs.CAFS

All Implemented Interfaces:

Closeable, Iterable<SHA1>

public class CAFS
extends Object
implements Closeable, Iterable<SHA1>

CAFS implements a SHA-1 based file store. The basic idea is that every file in the universe has a unique SHA-1. Hard to believe but people smarter than me have come to that conclusion. This class maintains a compressed store of SHA-1 identified files. So if you have the SHA-1, you can get the contents. This makes it easy to store a SHA-1 instead of the whole file or maintain a naming scheme. An added advantage is that it is always easy to verify you get the right stuff. The SHA-1 Content Addressable File Store is the core underlying idea in Git.

Constructor Summary

CAFS(File home, boolean create)
Constructor for a Content Addressable File Store

Method Summary

void	close()
boolean	exists(byte[] sha1)
boolean	isEmpty()
Iterator<SHA1>	iterator()
InputStream	read(SHA1 sha1) Read the contents of a sha 1 key.
void	reindex()
SHA1	write(InputStream in) Store an input stream in the CAFS while calculating and returning the SHA-1 code.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CAFS

public CAFS(File home,
            boolean create)
     throws Exception

Constructor for a Content Addressable File Store

Parameters:

home -

create -

Throws:

Exception

Method Detail

write

public SHA1 write(InputStream in)
           throws Exception

Store an input stream in the CAFS while calculating and returning the SHA-1 code.

Parameters:

in - The input stream to store.

Returns:

The SHA-1 code.

Throws:

Exception - if anything goes wrong

read

public InputStream read(SHA1 sha1)
                 throws Exception

Read the contents of a sha 1 key.

Parameters:

sha1 - The key

Returns:

An Input Stream on the content or null of key not found

Throws:

Exception

exists

public boolean exists(byte[] sha1)
               throws Exception

Throws:

Exception

reindex

public void reindex()
             throws Exception

Throws:

Exception

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Throws:

IOException

iterator

public Iterator<SHA1> iterator()

Specified by:

iterator in interface Iterable<SHA1>

isEmpty

public boolean isEmpty()
                throws IOException

Throws:

IOException