Next: , Previous: Adding Files, Up: Tutorial



2.7 Committing Work

Satisfied with the work he's done, Jim wants to save his changes. He chooses jp.co.juicebot.jb7 as a branch name. (See Naming Conventions for more information about appropriate branch names.) He then commits his working copy, which causes monotone to process the MT/work file and record the file contents, manifest, and revision into the database.

     $ monotone --db=jim.db --branch=jp.co.juicebot.jb7 commit --message='initial checkin of project'
     monotone: beginning commit
     monotone: manifest 2098eddbe833046174de28172a813150a6cbda7b
     monotone: revision 2e24d49a48adf9acf3a1b6391a080008cbef9c21
     monotone: branch jp.co.juicebot.jb7
     monotone: committed revision 2e24d49a48adf9acf3a1b6391a080008cbef9c21

Monotone did a number of things when committing the new revision. First, we can see from the output that monotone generated a manifest of the tree Jim committed. The manifest is stored inside the database, but Jim can print it out if he wants to see the exact state of all the files referenced by the revision he committed:

     $ monotone cat manifest
     3b12b2d0b31439bd50976633db1895cff8b19da0  include/jb.h
     2650ffc660dd00a08b659b883b65a060cac7e560  src/apple.c
     e8f147e5b4d5667f3228b7bba1c5c1e639f5db9f  src/banana.c

The column on the left contains cryptographic hashes of the files listed in the column on the right. Such a hash is also called the “file ID” of the file. The file ID identifies the state of each file stored in Jim's tree. The manifest is just a plain text file, identical to the output from the popular sha1sum unix command.

When monotone committed Jim's revision, it also erased the MT/work file, and wrote a new file called MT/revision, which contains the working copy's new base revision ID. Jim can use this revision ID in the future, as an argument to the checkout command, if he wishes to return to this revision:

     $ cat MT/revision
     2e24d49a48adf9acf3a1b6391a080008cbef9c21

Finally, monotone also generated a number of certificates, attached to the new revision. These certs store metadata about the commit. Jim can ask monotone for a list of certs on this revision.

     $ monotone ls certs 2e24d49a48adf9acf3a1b6391a080008cbef9c21
     -----------------------------------------------------------------
     Key   : jim@juicebot.co.jp
     Sig   : ok
     Name  : branch
     Value : jp.co.juicebot.jb7
     -----------------------------------------------------------------
     Key   : jim@juicebot.co.jp
     Sig   : ok
     Name  : date
     Value : 2004-10-26T02:53:08
     -----------------------------------------------------------------
     Key   : jim@juicebot.co.jp
     Sig   : ok
     Name  : author
     Value : jim@juicebot.co.jp
     -----------------------------------------------------------------
     Key   : jim@juicebot.co.jp
     Sig   : ok
     Name  : changelog
     Value : initial checkin of project

The output of this command has a block for each cert found. Each block has 4 significant pieces of information. The first indicates the signer of the cert, in this case jim@juicebot.co.jp. The second indicates whether this cert is “ok”, meaning whether the rsa signature provided is correct for the cert data. The third is the cert name, and the fourth is the cert value. This list shows us that monotone has confirmed that, according to jim@juicebot.co.jp, the revision 2e24d49a48adf9acf3a1b6391a080008cbef9c21 is a member of the branch jp.co.juicebot.jb7, written by jim@juicebot.co.jp, with the given date and changelog.

It is important to keep in mind that revisions are not “in” or “out” of a branch in any global sense, nor are any of these cert values true or false in any global sense. Each cert indicates that some person – in this case Jim – would like to associate a revision with some value; it is up to you to decide if you want to accept that association.

Jim can now check the status of his branch using the “heads” command, which lists all the head revisions in the branch:

     $ monotone heads
     branch 'jp.co.juicebot.jb7' is currently merged:
     2e24d49a48adf9acf3a1b6391a080008cbef9c21 jim@juicebot.co.jp 2004-10-26T02:53:08

The output of this command tells us that there is only one current “head” revision in the branch jp.co.juicebot.jb7, and it is the revision Jim just committed. A head revision is one without any descendents. Since Jim has not committed any changes to this revision yet, it has no descendents.