aboutsummaryrefslogtreecommitdiff
path: root/CmdLine/Action.hs
blob: c1dd12b51e8e7c570319275227a6a28a5b86735f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
{- git-annex command-line actions
 -
 - Copyright 2010-2015 Joey Hess <id@joeyh.name>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

{-# LANGUAGE CPP #-}

module CmdLine.Action where

import Annex.Common
import qualified Annex
import Annex.Concurrent
import Types.Command
import Messages.Concurrent
import Messages.Internal
import Types.Messages

import Control.Concurrent.Async
import Control.Exception (throwIO)
import Data.Either

#ifdef WITH_CONCURRENTOUTPUT
import qualified System.Console.Regions as Regions
#endif

{- Runs a command, starting with the check stage, and then
 - the seek stage. Finishes by running the continutation, and 
 - then showing a count of any failures. -}
performCommandAction :: Command -> CommandSeek -> Annex () -> Annex ()
performCommandAction Command { cmdcheck = c, cmdname = name } seek cont = do
	mapM_ runCheck c
	Annex.changeState $ \s -> s { Annex.errcounter = 0 }
	seek
	finishCommandActions
	cont
	showerrcount =<< Annex.getState Annex.errcounter
  where
	showerrcount 0 = noop
	showerrcount cnt = error $ name ++ ": " ++ show cnt ++ " failed"

{- Runs one of the actions needed to perform a command.
 - Individual actions can fail without stopping the whole command,
 - including by throwing IO errors (but other errors terminate the whole
 - command).
 - 
 - When concurrency is enabled, a thread is forked off to run the action
 - in the background, as soon as a free slot is available.
 
 - This should only be run in the seek stage.
 -}
commandAction :: CommandStart -> Annex ()
commandAction a = withOutputType go 
  where
	go o@(ConcurrentOutput n _) = do
		ws <- Annex.getState Annex.workers
		(st, ws') <- if null ws
			then do
				st <- dupState
				return (st, replicate (n-1) (Left st))
			else do
				l <- liftIO $ drainTo (n-1) ws
				findFreeSlot l
		w <- liftIO $ async
			$ snd <$> Annex.run st (inOwnConsoleRegion o run)
		Annex.changeState $ \s -> s { Annex.workers = Right w:ws' }
	go _  =	run
	run = void $ includeCommandAction a

{- Waits for any forked off command actions to finish.
 -
 - Merge together the cleanup actions of all the AnnexStates used by
 - threads, into the current Annex's state, so they'll run at shutdown.
 -
 - Also merge together the errcounters of the AnnexStates.
 -}
finishCommandActions :: Annex ()
finishCommandActions = do
	ws <- Annex.getState Annex.workers
	Annex.changeState $ \s -> s { Annex.workers = [] }
	l <- liftIO $ drainTo 0 ws
	forM_ (lefts l) mergeState

{- Wait for Asyncs from the list to finish, replacing them with their
 - final AnnexStates, until the list of remaining Asyncs is not larger
 - than the specified size, then returns the new list.
 -
 - If the action throws an exception, it is propigated, but first
 - all other actions are waited for, to allow for a clean shutdown.
 -}
drainTo
	:: Int
	-> [Either Annex.AnnexState (Async Annex.AnnexState)]
	-> IO [Either Annex.AnnexState (Async Annex.AnnexState)]
drainTo sz l
	| null as || sz >= length as = return l
	| otherwise = do
		(done, ret) <- waitAnyCatch as
		let as' = filter (/= done) as
		case ret of
			Left e -> do
				void $ drainTo 0 (map Left sts ++ map Right as')
				throwIO e
			Right st -> do
				drainTo sz $ map Left (st:sts) ++ map Right as'
  where
	(sts, as) = partitionEithers l

findFreeSlot :: [Either Annex.AnnexState (Async Annex.AnnexState)] -> Annex (Annex.AnnexState, [Either Annex.AnnexState (Async Annex.AnnexState)])
findFreeSlot = go []
  where
	go c [] = do
		st <- dupState
		return (st, c)
	go c (Left st:rest) = return (st, c ++ rest)
	go c (v:rest) = go (v:c) rest

{- Like commandAction, but without the concurrency. -}
includeCommandAction :: CommandStart -> CommandCleanup
includeCommandAction a = account =<< tryIO (callCommandAction a)
  where
	account (Right True) = return True
	account (Right False) = incerr
	account (Left err) = do
		toplevelWarning True (show err)
		implicitMessage showEndFail
		incerr
	incerr = do
		Annex.incError
		return False

{- Runs a single command action through the start, perform and cleanup
 - stages, without catching errors. Useful if one command wants to run
 - part of another command. -}
callCommandAction :: CommandStart -> CommandCleanup
callCommandAction = fromMaybe True <$$> callCommandAction' 

{- Like callCommandAction, but returns Nothing when the command did not
 - perform any action. -}
callCommandAction' :: CommandStart -> Annex (Maybe Bool)
callCommandAction' = start
  where
	start   = stage $ maybe skip perform
	perform = stage $ maybe failure cleanup
	cleanup = stage $ status
	stage = (=<<)
	skip = return Nothing
	failure = implicitMessage showEndFail >> return (Just False)
	status r = implicitMessage (showEndResult r) >> return (Just r)

{- Do concurrent output when that has been requested. -}
allowConcurrentOutput :: Annex a -> Annex a
#ifdef WITH_CONCURRENTOUTPUT
allowConcurrentOutput a = go =<< Annex.getState Annex.concurrentjobs
  where
	go Nothing = a
	go (Just n) = ifM (liftIO concurrentOutputSupported)
		( Regions.displayConsoleRegions $
			goconcurrent (ConcurrentOutput n True)
		, goconcurrent (ConcurrentOutput n False)
		)
	goconcurrent o = bracket_ (setup o) cleanup a
	setup = Annex.setOutput
	cleanup = do
		finishCommandActions
		Annex.setOutput NormalOutput
#else
allowConcurrentOutput = id
#endif