aQute.libg.cafs

Class CAFS

java.lang.Object

aQute.libg.cafs.CAFS

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.lang.Iterable<SHA1>

public class CAFS
extends java.lang.Object
implements java.io.Closeable, java.lang.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(java.io.File home, boolean create) Constructor for a Content Addressable File Store

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
boolean	exists(byte[] sha1)
boolean	isEmpty()
java.util.Iterator<SHA1>	iterator()
java.io.InputStream	read(SHA1 sha1) Read the contents of a sha 1 key.
void	reindex()
SHA1	write(java.io.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(java.io.File home,
    boolean create)
     throws java.lang.Exception

Constructor for a Content Addressable File Store

Parameters:

home -

create -

Throws:

java.lang.Exception

Method Detail

write

public SHA1 write(java.io.InputStream in)
           throws java.lang.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:

java.lang.Exception - if anything goes wrong

read

public java.io.InputStream read(SHA1 sha1)
                         throws java.lang.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:

java.lang.Exception

exists

public boolean exists(byte[] sha1)
               throws java.lang.Exception

Throws:

java.lang.Exception

reindex

public void reindex()
             throws java.lang.Exception

Throws:

java.lang.Exception

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Throws:

java.io.IOException

iterator

public java.util.Iterator<SHA1> iterator()

Specified by:

iterator in interface java.lang.Iterable<SHA1>

isEmpty

public boolean isEmpty()
                throws java.io.IOException

Throws:

java.io.IOException