aQute.libg.cafs

Class CAFS

java.lang.Object

aQute.libg.cafs.CAFS

All Implemented Interfaces:

Closeable, AutoCloseable, 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

Constructors

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

Method Summary

Modifier and Type	Method and Description
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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

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

Specified by:

close in interface AutoCloseable

Throws:

IOException

iterator

public Iterator<SHA1> iterator()

Specified by:

iterator in interface Iterable<SHA1>

isEmpty

public boolean isEmpty()
                throws IOException

Throws:

IOException