How do sourcetree know there are changes on origin?

[giammin]

How do sourcetree know there are changes on origin and display the number of new commit in the toolbar Pull button

[Seth · Accepted solution]

SourceTree can be (and is by default) configured to issue a "git fetch" command every few minutes.

In the options dialog, see "Check default remotes for updates every __ minutes".

[Johannes Kilian]

By polling the connected server .... I'm not quite sure if the numbers can be determined if you use another hosting service as Bitbucket Server (as I don't use any other)

[giammin]

i'm interested in the git command it uses

[Johannes Kilian]

I haven't any great expertise here, but If I look at the "atlassian-bitbucket-access.log" log file (within BITBUCKET_HOME), I see the following:

172.16.0.120 | http | i@13J5DP6x17x2603224x0 | - | 2016-03-04 00:17:44,994 
| "GET /scm/myProj/configdata.git/info/refs HTTP/1.1" 
| "" "git/1.9.5.msysgit.0" | - | - | - | - | - | - | 

This seems to be used to get the state of the remote repository (see: https://git-scm.com/book/be/v2/Git-Internals-Transfer-Protocols - info/refs)

Comparing this data with your local repository, SourceTree might determine the asked information.

[Johannes Kilian]

You also might have a look here: http://stackoverflow.com/questions/3258243/check-if-pull-needed-in-git and http://stackoverflow.com/questions/2016901/viewing-unpushed-git-commits