X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=topgit.git;a=blobdiff_plain;f=README;h=b99b03680fb7fced0e1dc2f0e699f73b141745f5;hp=0d21544b29fad50fdc829efd6ddc81e5c26d208b;hb=d33fe8bccb78adca51fa87626cd80bd064676d1f;hpb=4ebcd08612c5bcbb53a5e9e44f576c12e827bbcb diff --git a/README b/README index 0d21544..b99b036 100644 --- a/README +++ b/README @@ -184,6 +184,24 @@ SYNOPSIS tg: Updating base with t/gitweb/nifty-links changes... tg: Updating t/whatever against new base... + ## Clone a TopGit-controlled repository + $ git clone URL repo + $ cd repo + $ tg remote --populate origin + ... + $ git fetch + $ tg update + + ## Add a TopGit remote to a repository and push to it + $ git remote add foo URL + $ tg remote foo + $ git push foo + + ## Update from a non-default TopGit remote + $ git fetch foo + $ tg -r foo summary + $ tg -r foo update + USAGE ----- @@ -215,6 +233,10 @@ tg create it will detect that you are on a topic branch base ref and resume the topic branch creation operation. + In an alternative use case, if '-r BRANCH' is given instead + of dependency list, the topic branch is created based on + the given remote branch. + tg delete ~~~~~~~~~ Remove a TopGit-controlled topic branch of given name @@ -250,10 +272,26 @@ tg patch TODO: tg patch -i to base at index instead of branch, -w for working tree +tg remote +~~~~~~~~~ + Register given remote as TopGit-controlled. This will create + the namespace for the remote branch bases and teach 'git fetch' + and 'git push' to operate on them. + + It takes a mandatory remote name argument, and optional + '--populate' switch - use that for your origin-style remote, + it will seed the local topic branch system based on the + remote topic branches. '--populate' will also make 'tg remote' + automatically fetch the remote and 'tg update' to look at + branches of this remote for updates by default. + tg summary ~~~~~~~~~~ Show overview of all TopGit-tracked topic branches and their - up-to-date status ('0' marks that it introduces no own changes, + up-to-date status ('>' marks the current topic branch, + '0' marks that it introduces no own changes, + 'l'/'r' marks that it is local-only or has remote mate, + 'L'/'R' marks that it is ahead/out-of-date wrt. its remote mate, 'D' marks that it is out-of-date wrt. its dependencies, '!' marks that it has missing dependencies (even recursively), 'B' marks that it is out-of-date wrt. its base). @@ -336,21 +374,37 @@ tg export TODO: For quilt exporting, use a temporary branch and remove it when done - this would allow producing conflict-less series +tg import +~~~~~~~~~ + Import commits within the given revision range into TopGit, + creating one topic branch per commit, the dependencies forming + a linear sequence starting on your current branch. + + The branch names are auto-guessed from the commit messages + and prefixed by t/ by default; use '-p PREFIX' to specify + an alternative prefix (even an empty one). + tg update ~~~~~~~~~ Update the current topic branch wrt. changes in the branches - it depends on. This is made in two phases - first, + it depends on and remote branches. + This is performed in two phases - first, changes within the dependencies are merged to the base, - then the base is merged into the topic branch. The output - will guide you in case of conflicts. + then the base is merged into the topic branch. + The output will guide you in case of conflicts. In case your dependencies are not up-to-date, tg update will first recurse into them and update these. + If a remote branch update brings dependencies on branches + not yet instantiated locally, you can either bring in all + the new branches from the remote using 'tg remote --populate' + or only pick out the missing ones using 'tg create -r' + ('tg summary' will point out branches with incomplete + dependencies by showing an '!' near to them). + TODO: tg update -a for updating all topic branches -TODO: Some infrastructure for sharing topic branches between - repositories easily TODO: tg depend for adding/removing dependencies smoothly TODO: tg rename @@ -401,3 +455,50 @@ is not called if the hook was not executable beforehand). Another automagically installed piece is .git/info/attributes specifier for an 'ours' merge strategy for the files .topmsg and .topdeps, and the (intuitive) 'ours' merge strategy definition in .git/config. + + +REMOTE HANDLING +--------------- + +There are three issues with accessing topic branches in remote repositories: + + (i) Fetching/pushing accurate picture of the remote topic branch setup + (ii) Referring to remote topic branches from your local repository + (iii) Developing some of the remote topic branches locally + +(ii) and (iii) are fairly interconnected problems, while (i) is largely +independent. The issue is to accurately reflect the current state of the +quickly changing topic branches set - this can be easily done +with the current facilities like 'git remote prune' and 'git push --mirror' - +and to properly upload also the bases of the topic branches. +For this, we need to modify the fetch/push refspecs to also include +the refs/top-bases/ ref namespace; we shall provide a special 'tg remote' +command to set up an existing remote for TopGit usage. + +About (ii) and (iii), there are two somewhat contradicting design +considerations: + + (a) Hacking on multiple independent TopGit remotes in a single + repository + (b) Having a self-contained topic system in local refs space + +To us, (a) does not appear to be very convincing, while (b) is quite desirable +for 'git-log topic' etc. working, 'git push' automatically creating +self-contained topic system in the remote repository, and increased conceptual +simplicity. + +Thus, we choose to instantiate all the topic branches of given remote locally; +this is performed by 'tg remote --populate'. +'tg update' will also check if a branch can be updated from its corresponding +remote branch. The logic is somewhat involved if we should DTRT. +First, we update the base, handling the remote branch as if it was the first +dependency; thus, conflict resolutions made in the remote branch will be +carried over to our local base automagically. Then, the base is merged into +remote branch and the result is merged to local branch - again, to carry over +remote conflict resolutions. In the future, this order might be adjustable +per-update in case local changes are diverging more than the remote ones. + +All commands by default refer to the remote that 'tg remote --populate' +was called on the last time ('topgit.remote' configuration variable). You can +manually run any command with a different base remote by passing '-r REMOTE' +_before_ the subcommand name.