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-rw-r--r--Documentation/git-remote-helpers.txt186
1 files changed, 155 insertions, 31 deletions
diff --git a/Documentation/git-remote-helpers.txt b/Documentation/git-remote-helpers.txt
index 930b4034ac..f5836e46d0 100644
--- a/Documentation/git-remote-helpers.txt
+++ b/Documentation/git-remote-helpers.txt
@@ -24,22 +24,141 @@ output. Because a remote helper runs as an independent process from
git, there is no need to re-link git to add a new helper, nor any
need to link the helper with the implementation of git.
-Every helper must support the "capabilities" command, which git will
-use to determine what other commands the helper will accept. Other
-commands generally concern facilities like discovering and updating
-remote refs, transporting objects between the object database and
-the remote repository, and updating the local object store.
-
-Helpers supporting the 'fetch' capability can discover refs from the
-remote repository and transfer objects reachable from those refs to
-the local object store. Helpers supporting the 'push' capability can
-transfer local objects to the remote repository and update remote refs.
+Every helper must support the "capabilities" command, which git
+uses to determine what other commands the helper will accept. Those
+other commands can be used to discover and update remote refs,
+transport objects between the object database and the remote repository,
+and update the local object store.
Git comes with a "curl" family of remote helpers, that handle various
transport protocols, such as 'git-remote-http', 'git-remote-https',
'git-remote-ftp' and 'git-remote-ftps'. They implement the capabilities
'fetch', 'option', and 'push'.
+INPUT FORMAT
+------------
+
+Git sends the remote helper a list of commands on standard input, one
+per line. The first command is always the 'capabilities' command, in
+response to which the remote helper must print a list of the
+capabilities it supports (see below) followed by a blank line. The
+response to the capabilities command determines what commands Git uses
+in the remainder of the command stream.
+
+The command stream is terminated by a blank line. In some cases
+(indicated in the documentation of the relevant commands), this blank
+line is followed by a payload in some other protocol (e.g., the pack
+protocol), while in others it indicates the end of input.
+
+Capabilities
+~~~~~~~~~~~~
+
+Each remote helper is expected to support only a subset of commands.
+The operations a helper supports are declared to git in the response
+to the `capabilities` command (see COMMANDS, below).
+
+'option'::
+ For specifying settings like `verbosity` (how much output to
+ write to stderr) and `depth` (how much history is wanted in the
+ case of a shallow clone) that affect how other commands are
+ carried out.
+
+'connect'::
+ For fetching and pushing using git's native packfile protocol
+ that requires a bidirectional, full-duplex connection.
+
+'push'::
+ For listing remote refs and pushing specified objects from the
+ local object store to remote refs.
+
+'fetch'::
+ For listing remote refs and fetching the associated history to
+ the local object store.
+
+'import'::
+ For listing remote refs and fetching the associated history as
+ a fast-import stream.
+
+'refspec' <refspec>::
+ This modifies the 'import' capability, allowing the produced
+ fast-import stream to modify refs in a private namespace
+ instead of writing to refs/heads or refs/remotes directly.
+ It is recommended that all importers providing the 'import'
+ capability use this.
++
+A helper advertising the capability
+`refspec refs/heads/*:refs/svn/origin/branches/*`
+is saying that, when it is asked to `import refs/heads/topic`, the
+stream it outputs will update the `refs/svn/origin/branches/topic`
+ref.
++
+This capability can be advertised multiple times. The first
+applicable refspec takes precedence. The left-hand of refspecs
+advertised with this capability must cover all refs reported by
+the list command. If no 'refspec' capability is advertised,
+there is an implied `refspec *:*`.
+
+Capabilities for Pushing
+~~~~~~~~~~~~~~~~~~~~~~~~
+'connect'::
+ Can attempt to connect to 'git receive-pack' (for pushing),
+ 'git upload-pack', etc for communication using the
+ packfile protocol.
++
+Supported commands: 'connect'.
+
+'push'::
+ Can discover remote refs and push local commits and the
+ history leading up to them to new or existing remote refs.
++
+Supported commands: 'list for-push', 'push'.
+
+If a helper advertises both 'connect' and 'push', git will use
+'connect' if possible and fall back to 'push' if the helper requests
+so when connecting (see the 'connect' command under COMMANDS).
+
+Capabilities for Fetching
+~~~~~~~~~~~~~~~~~~~~~~~~~
+'connect'::
+ Can try to connect to 'git upload-pack' (for fetching),
+ 'git receive-pack', etc for communication using the
+ packfile protocol.
++
+Supported commands: 'connect'.
+
+'fetch'::
+ Can discover remote refs and transfer objects reachable from
+ them to the local object store.
++
+Supported commands: 'list', 'fetch'.
+
+'import'::
+ Can discover remote refs and output objects reachable from
+ them as a stream in fast-import format.
++
+Supported commands: 'list', 'import'.
+
+If a helper advertises 'connect', git will use it if possible and
+fall back to another capability if the helper requests so when
+connecting (see the 'connect' command under COMMANDS).
+When choosing between 'fetch' and 'import', git prefers 'fetch'.
+Other frontends may have some other order of preference.
+
+'refspec' <refspec>::
+ This modifies the 'import' capability.
++
+A helper advertising
+`refspec refs/heads/*:refs/svn/origin/branches/*`
+in its capabilities is saying that, when it handles
+`import refs/heads/topic`, the stream it outputs will update the
+`refs/svn/origin/branches/topic` ref.
++
+This capability can be advertised multiple times. The first
+applicable refspec takes precedence. The left-hand of refspecs
+advertised with this capability must cover all refs reported by
+the list command. If no 'refspec' capability is advertised,
+there is an implied `refspec *:*`.
+
INVOCATION
----------
@@ -48,6 +167,9 @@ arguments. The first argument specifies a remote repository as in git;
it is either the name of a configured remote or a URL. The second
argument specifies a URL; it is usually of the form
'<transport>://<address>', but any arbitrary string is possible.
+The 'GIT_DIR' environment variable is set up for the remote helper
+and can be used to determine where to store additional data or from
+which directory to invoke auxiliary git commands.
When git encounters a URL of the form '<transport>://<address>', where
'<transport>' is a protocol that it cannot handle natively, it
@@ -119,7 +241,22 @@ Supported if the helper has the "fetch" capability.
'push' +<src>:<dst>::
Pushes the given local <src> commit or branch to the
remote branch described by <dst>. A batch sequence of
- one or more push commands is terminated with a blank line.
+ one or more 'push' commands is terminated with a blank line
+ (if there is only one reference to push, a single 'push' command
+ is followed by a blank line). For example, the following would
+ be two batches of 'push', the first asking the remote-helper
+ to push the local ref 'master' to the remote ref 'master' and
+ the local 'HEAD' to the remote 'branch', and the second
+ asking to push ref 'foo' to ref 'bar' (forced update requested
+ by the '+').
++
+------------
+push refs/heads/master:refs/heads/master
+push HEAD:refs/heads/branch
+\n
+push +refs/heads/foo:refs/heads/bar
+\n
+------------
+
Zero or more protocol options may be entered after the last 'push'
command, before the batch's terminating blank line.
@@ -144,6 +281,11 @@ Supported if the helper has the "push" capability.
Especially useful for interoperability with a foreign versioning
system.
+
+Just like 'push', a batch sequence of one or more 'import' is
+terminated with a blank line. For each batch of 'import', the remote
+helper should produce a fast-import stream terminated by a 'done'
+command.
++
Supported if the helper has the "import" capability.
'connect' <service>::
@@ -168,26 +310,6 @@ completing a valid response for the current command.
Additional commands may be supported, as may be determined from
capabilities reported by the helper.
-CAPABILITIES
-------------
-
-'fetch'::
-'option'::
-'push'::
-'import'::
-'connect'::
- This helper supports the corresponding command with the same name.
-
-'refspec' 'spec'::
- When using the import command, expect the source ref to have
- been written to the destination ref. The earliest applicable
- refspec takes precedence. For example
- "refs/heads/{asterisk}:refs/svn/origin/branches/{asterisk}" means
- that, after an "import refs/heads/name", the script has written to
- refs/svn/origin/branches/name. If this capability is used at
- all, it must cover all refs reported by the list command; if
- it is not used, it is effectively "{asterisk}:{asterisk}"
-
REF LIST ATTRIBUTES
-------------------
@@ -240,6 +362,8 @@ SEE ALSO
--------
linkgit:git-remote[1]
+linkgit:git-remote-testgit[1]
+
GIT
---
Part of the linkgit:git[1] suite