config: New command for storing configuration in the git-annex branch.

Any config names can be set using this; git-annex commands will only look
at specific ones that make sense and are worth the overhead of querying the
branch.

This might also be useful for storing whatever other config-type stuff the
user might want to shove into the git-annex branch.

This commit was sponsored by Jochen Bartl on Patreon.

11 files changed, 190 insertions, 2 deletions

diff --git a/Annex.hs b/Annex.hs
index 1ee6e837f1..18b4f48c9f 100644
--- a/Annex.hs
+++ b/Annex.hs
@@ -114,6 +114,7 @@ data AnnexState = AnnexState
 	, checkignorehandle :: Maybe (Maybe CheckIgnoreHandle)
 	, forcebackend :: Maybe String
 	, globalnumcopies :: Maybe NumCopies
+	, globalconfig :: Maybe (M.Map String String)
 	, forcenumcopies :: Maybe NumCopies
 	, limit :: ExpandableMatcher Annex
 	, uuidmap :: Maybe UUIDMap
@@ -165,6 +166,7 @@ newState c r = do
 		, checkignorehandle = Nothing
 		, forcebackend = Nothing
 		, globalnumcopies = Nothing
+		, globalconfig = Nothing
 		, forcenumcopies = Nothing
 		, limit = BuildingMatcher []
 		, uuidmap = Nothing
diff --git a/Annex/Branch.hs b/Annex/Branch.hs
index c90958ab05..9d963f98b0 100644
--- a/Annex/Branch.hs
+++ b/Annex/Branch.hs
@@ -233,7 +233,7 @@ getHistorical date file =
 getRef :: Ref -> FilePath -> Annex String
 getRef ref file = withIndex $ decodeBS <$> catFile ref file
 
-{- Applies a function to modifiy the content of a file.
+{- Applies a function to modify the content of a file.
  -
  - Note that this does not cause the branch to be merged, it only
  - modifes the current content of the file on the branch.
diff --git a/CHANGELOG b/CHANGELOG
index 57994f1560..14dad2bfec 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -6,6 +6,7 @@ git-annex (6.20170102) UNRELEASED; urgency=medium
   * Remove -j short option for --json-progress; that option was already
     taken for --json.
   * vicfg: Include the numcopies configuation.
+  * config: New command for storing configuration in the git-annex branch.
 
  -- Joey Hess <id@joeyh.name>  Fri, 06 Jan 2017 15:22:06 -0400
 
diff --git a/CmdLine/GitAnnex.hs b/CmdLine/GitAnnex.hs
index 394bd173bf..99cf564cc1 100644
--- a/CmdLine/GitAnnex.hs
+++ b/CmdLine/GitAnnex.hs
@@ -84,6 +84,7 @@ import qualified Command.GroupWanted
 import qualified Command.Required
 import qualified Command.Schedule
 import qualified Command.Ungroup
+import qualified Command.Config
 import qualified Command.Vicfg
 import qualified Command.Sync
 import qualified Command.Mirror
@@ -158,6 +159,7 @@ cmds testoptparser testrunner =
 	, Command.Required.cmd
 	, Command.Schedule.cmd
 	, Command.Ungroup.cmd
+	, Command.Config.cmd
 	, Command.Vicfg.cmd
 	, Command.LookupKey.cmd
 	, Command.CalcKey.cmd
diff --git a/Command/Config.hs b/Command/Config.hs
new file mode 100644
index 0000000000..690c8d2888
--- /dev/null
+++ b/Command/Config.hs
@@ -0,0 +1,65 @@
+{- git-annex command
+ -
+ - Copyright 2017 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.Config where
+
+import Command
+import Logs.Config
+
+cmd :: Command
+cmd = command "config" SectionSetup "configuration stored in git-annex branch"
+	paramNothing (seek <$$> optParser)
+
+data Action
+	= SetConfig ConfigName ConfigValue
+	| GetConfig ConfigName
+	| UnsetConfig ConfigName
+
+type Name = String
+type Value = String
+
+optParser :: CmdParamsDesc -> Parser Action
+optParser _ = setconfig <|> getconfig <|> unsetconfig
+  where
+	setconfig = SetConfig
+		<$> strOption
+			( long "set"
+			<> help "set configuration"
+			<> metavar paramName
+			)
+		<*> strArgument
+			( metavar paramValue
+			)
+	getconfig = GetConfig <$> strOption
+		( long "get"
+		<> help "get configuration"
+		<> metavar paramName
+		)
+	unsetconfig = UnsetConfig <$> strOption
+		( long "unset"
+		<> help "unset configuration"
+		<> metavar paramName
+		)
+
+seek :: Action -> CommandSeek
+seek (SetConfig name val) = commandAction $ do
+	showStart name val
+	next $ next $ do
+		setGlobalConfig name val
+		return True
+seek (UnsetConfig name) = commandAction $ do
+	showStart name "unset"
+	next $ next $ do
+		unsetGlobalConfig name
+		return True
+seek (GetConfig name) = commandAction $ do
+	mv <- getGlobalConfig name
+	case mv of
+		Nothing -> stop
+		Just v -> do
+			liftIO $ putStrLn v
+			stop
diff --git a/Logs.hs b/Logs.hs
index a3dd968880..38bd1c0683 100644
--- a/Logs.hs
+++ b/Logs.hs
@@ -63,6 +63,9 @@ uuidLog = "uuid.log"
 numcopiesLog :: FilePath
 numcopiesLog = "numcopies.log"
 
+configLog :: FilePath
+configLog = "config.log"
+
 remoteLog :: FilePath
 remoteLog = "remote.log"
 
diff --git a/doc/git-annex-config.mdwn b/doc/git-annex-config.mdwn
new file mode 100644
index 0000000000..1e1819bb7f
--- /dev/null
+++ b/doc/git-annex-config.mdwn
@@ -0,0 +1,56 @@
+# NAME
+
+git-annex config - configuration stored in git-annex branch
+
+# SYNOPSIS
+
+git annex config --set name value
+
+git annex config --get name
+
+git annex config --unset name
+
+# DESCRIPTION
+
+Set or get configuration settings stored in the git-annex branch.
+
+Unlike `git config` settings, these settings can be seen
+in all clones of the repository, once they have gotten their
+git-annex branches in sync.
+
+# SUPPORTED SETTINGS
+
+git-annex does not check the git-annex branch for all settings.
+Only a few make sense to be able to set such that all clones of a
+repository see the setting, and so git-annex only looks for these:
+
+These settings can be overridden on a per-repository basis using
+`git config`:
+
+None yet!
+
+# EXAMPLE
+
+Suppose you want to prevent git annex sync from committing changes
+to files, so a manual git commit workflow is used in all clones of the
+repository. Then run:
+
+	git annex config --set annex.autocommit false
+
+If you change your mind, you can get back to the default behavior:
+
+	git annex config --unset annex.autocommit
+
+# SEE ALSO
+
+[[git-annex]](1)
+
+git-config(1)
+
+[[git-annex-vicfg]](1)
+
+# AUTHOR
+
+Joey Hess <id@joeyh.name>
+
+Warning: Automatically converted into a man page by mdwn2man. Edit with care.
diff --git a/doc/git-annex-sync.mdwn b/doc/git-annex-sync.mdwn
index d60033de45..f0dce81143 100644
--- a/doc/git-annex-sync.mdwn
+++ b/doc/git-annex-sync.mdwn
@@ -42,7 +42,9 @@ by running "git annex sync" on the remote.
 
 * `--commit`, `--no-commit`
 
-  A commit is done by default. Use --no-commit to avoid committing local changes.
+  A commit is done by default (unless annex.autocommit is set to false).
+  
+  Use --no-commit to avoid committing local changes.
 
 * `--message=msg`
 
diff --git a/doc/git-annex.mdwn b/doc/git-annex.mdwn
index ca1ac3620f..af6342164f 100644
--- a/doc/git-annex.mdwn
+++ b/doc/git-annex.mdwn
@@ -280,6 +280,12 @@ subdirectories).
 
   See [[git-annex-schedule]](1) for details.
 
+* `config`
+
+  Get and set other configuration stored in git-annex branch.
+  
+  See [[git-annex-config]](1) for details.
+
 * `vicfg`
 
   Opens EDITOR on a temp file containing most of the above configuration
@@ -1000,6 +1006,9 @@ Here are all the supported configuration settings.
   Set to false to prevent the git-annex assistant and git-annex sync
   from automatically committing changes to files in the repository.
 
+  To configure the behavior in all repositories, this can be set in
+  [[git-annex-config]].
+
 * `annex.startupscan`
 
   Set to false to prevent the git-annex assistant from scanning the
diff --git a/doc/internals.mdwn b/doc/internals.mdwn
index 329961ccdb..78d0c8d472 100644
--- a/doc/internals.mdwn
+++ b/doc/internals.mdwn
@@ -100,6 +100,16 @@ Records the global numcopies setting.
 
 The file format is simply a timestamp followed by a number.
 
+## `config.log`
+
+Records global configuration settings, which can be overridden by values
+in `.git/config`.
+
+The file format is a timestamp, followed by the name of the configuration,
+followed by the value. For example:
+
+	1317929189.157237s annex.autocommit false
+
 ## `remote.log`
 
 Holds persistent configuration settings for [[special_remotes]] such as
diff --git a/doc/todo/wishlist__58___per-repository_autocommit__61__false/comment_1_851483817d97de212932203c2e830293._comment b/doc/todo/wishlist__58___per-repository_autocommit__61__false/comment_1_851483817d97de212932203c2e830293._comment
new file mode 100644
index 0000000000..7e5d850385
--- /dev/null
+++ b/doc/todo/wishlist__58___per-repository_autocommit__61__false/comment_1_851483817d97de212932203c2e830293._comment
@@ -0,0 +1,38 @@
+[[!comment format=mdwn
+ username="joey"
+ subject="""comment 1"""
+ date="2017-01-30T18:13:42Z"
+ content="""
+This could be put in the git-annex branch similarly to the `git annex
+numcopies` configuration so all clones see it.
+
+As well as --no-commit, --content is the other option that I think 
+might make sense to have a clone-wide setting for. sync's --no-pull and
+--no-push seem much less likely to need such a setting.
+
+I've been leaning toward eventually turning sync --content on by default,
+and such a clone-wide configuration would be useful to let users get back
+the current behavior.
+
+Hmm, this could be generalized all the way to having a file in the
+git-annex branch that stores default settings for `annex.*` configs.
+But then git-annex would have to pull that file out of the git-annex branch
+every time it's run, which would slow down commands that get run a lot in
+succession. So that's a generalization too far.
+
+Still, looking through the configs, I can see some other things
+that it would similarly make sense to sometimes want to set clone-wide,
+including: annex.genmetadata, annex.used-refspec, annex.diskreserve, 
+annex.addsmallfiles.
+
+So, we have some configs that are each only used by a few commands,
+that make sense to be allowed to be set clone-wide. We can make the file
+in the git-annex branch be only read by commands that look at those
+configs, and can consider when implementing each whether it would slow
+down any command too much to have it need to read the git-annex branch
+file.
+
+I've added a `git annex config` command that can set such clone-wide
+configurations. I have not yet made git annex sync look at it for
+annex.autocommit.
+"""]]