cabal-install-3.12.1.0: The command-line interface for Cabal and Hackage.

Safe Haskell | None
Language | Haskell2010

Distribution.Client.FileMonitor

Contents

- Declaring files to monitor
- Creating and checking sets of monitored files
- Internal

Description

An abstraction to help with re-running actions when files or other input values they depend on have changed.

Synopsis

- data MonitorFilePath
  - = MonitorFile {
    - monitorKindFile :: !MonitorKindFile
    - monitorKindDir :: !MonitorKindDir
    - monitorPath :: !FilePath
    }
  - | MonitorFileGlob {
    - monitorKindFile :: !MonitorKindFile
    - monitorKindDir :: !MonitorKindDir
    - monitorPathGlob :: !RootedGlob
    }
- data MonitorKindFile
  - = FileExists
  - | FileModTime
  - | FileHashed
  - | FileNotExists
- data MonitorKindDir
  - = DirExists
  - | DirModTime
  - | DirNotExists
- data RootedGlob = RootedGlob FilePathRoot Glob
- monitorFile :: FilePath -> MonitorFilePath
- monitorFileHashed :: FilePath -> MonitorFilePath
- monitorNonExistentFile :: FilePath -> MonitorFilePath
- monitorFileExistence :: FilePath -> MonitorFilePath
- monitorDirectory :: FilePath -> MonitorFilePath
- monitorNonExistentDirectory :: FilePath -> MonitorFilePath
- monitorDirectoryExistence :: FilePath -> MonitorFilePath
- monitorFileOrDirectory :: FilePath -> MonitorFilePath
- monitorFileGlob :: RootedGlob -> MonitorFilePath
- monitorFileGlobExistence :: RootedGlob -> MonitorFilePath
- monitorFileSearchPath :: [FilePath] -> FilePath -> [MonitorFilePath]
- monitorFileHashedSearchPath :: [FilePath] -> FilePath -> [MonitorFilePath]
- data FileMonitor a b = FileMonitor {
  - fileMonitorCacheFile :: FilePath
  - fileMonitorKeyValid :: a -> a -> Bool
  - fileMonitorCheckIfOnlyValueChanged :: Bool
  }
- newFileMonitor :: Eq a => FilePath -> FileMonitor a b
- data MonitorChanged a b
  - = MonitorUnchanged b [MonitorFilePath]
  - | MonitorChanged (MonitorChangedReason a)
- data MonitorChangedReason a
  - = MonitoredFileChanged FilePath
  - | MonitoredValueChanged a
  - | MonitorFirstRun
  - | MonitorCorruptCache
- checkFileMonitorChanged :: (Binary a, Structured a, Binary b, Structured b) => FileMonitor a b -> FilePath -> a -> IO (MonitorChanged a b)
- updateFileMonitor :: (Binary a, Structured a, Binary b, Structured b) => FileMonitor a b -> FilePath -> Maybe MonitorTimestamp -> [MonitorFilePath] -> a -> b -> IO ()
- data MonitorTimestamp
- beginUpdateFileMonitor :: IO MonitorTimestamp
- data MonitorStateFileSet
- data MonitorStateFile
- data MonitorStateGlob

# Declaring files to monitor

data MonitorFilePath #

A description of a file (or set of files) to monitor for changes.

Where file paths are relative they are relative to a common directory (e.g. project root), not necessarily the process current directory.

Constructors

MonitorFile |

Fields

- monitorKindFile :: !MonitorKindFile
- monitorKindDir :: !MonitorKindDir
- monitorPath :: !FilePath

MonitorFileGlob |

Fields

- monitorKindFile :: !MonitorKindFile
- monitorKindDir :: !MonitorKindDir
- monitorPathGlob :: !RootedGlob

#### Instances

Instances details

Structured MonitorFilePath # |
Instance details Defined in Distribution.Client.FileMonitor Methods structure :: Proxy MonitorFilePath -> Structure # structureHash' :: Tagged MonitorFilePath MD5
Binary MonitorFilePath # |
Instance details Defined in Distribution.Client.FileMonitor Methods put :: MonitorFilePath -> Put # get :: Get MonitorFilePath # putList :: [MonitorFilePath] -> Put #
Generic MonitorFilePath # |

Instance details

Defined in Distribution.Client.FileMonitor

Associated Types

type Rep MonitorFilePath |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorFilePath = D1 ('MetaData "MonitorFilePath" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "MonitorFile" 'PrefixI 'True) (S1 ('MetaSel ('Just "monitorKindFile") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindFile) :*: (S1 ('MetaSel ('Just "monitorKindDir") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindDir) :*: S1 ('MetaSel ('Just "monitorPath") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 FilePath))) :+: C1 ('MetaCons "MonitorFileGlob" 'PrefixI 'True) (S1 ('MetaSel ('Just "monitorKindFile") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindFile) :*: (S1 ('MetaSel ('Just "monitorKindDir") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindDir) :*: S1 ('MetaSel ('Just "monitorPathGlob") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 RootedGlob))))

Methods

from :: MonitorFilePath -> Rep MonitorFilePath x #

to :: Rep MonitorFilePath x -> MonitorFilePath #

Show MonitorFilePath # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorFilePath -> ShowS # show :: MonitorFilePath -> String # showList :: [MonitorFilePath] -> ShowS #
Eq MonitorFilePath # |
Instance details Defined in Distribution.Client.FileMonitor Methods (==) :: MonitorFilePath -> MonitorFilePath -> Bool # (/=) :: MonitorFilePath -> MonitorFilePath -> Bool #
type Rep MonitorFilePath # |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorFilePath = D1 ('MetaData "MonitorFilePath" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "MonitorFile" 'PrefixI 'True) (S1 ('MetaSel ('Just "monitorKindFile") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindFile) :*: (S1 ('MetaSel ('Just "monitorKindDir") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindDir) :*: S1 ('MetaSel ('Just "monitorPath") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 FilePath))) :+: C1 ('MetaCons "MonitorFileGlob" 'PrefixI 'True) (S1 ('MetaSel ('Just "monitorKindFile") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindFile) :*: (S1 ('MetaSel ('Just "monitorKindDir") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 MonitorKindDir) :*: S1 ('MetaSel ('Just "monitorPathGlob") 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 RootedGlob))))

data MonitorKindFile #

Constructors

FileExists |
FileModTime |
FileHashed |
FileNotExists |

#### Instances

Instances details

Structured MonitorKindFile # |
Instance details Defined in Distribution.Client.FileMonitor Methods structure :: Proxy MonitorKindFile -> Structure # structureHash' :: Tagged MonitorKindFile MD5
Binary MonitorKindFile # |
Instance details Defined in Distribution.Client.FileMonitor Methods put :: MonitorKindFile -> Put # get :: Get MonitorKindFile # putList :: [MonitorKindFile] -> Put #
Generic MonitorKindFile # |

Instance details

Defined in Distribution.Client.FileMonitor

Associated Types

type Rep MonitorKindFile |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorKindFile = D1 ('MetaData "MonitorKindFile" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) ((C1 ('MetaCons "FileExists" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "FileModTime" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "FileHashed" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "FileNotExists" 'PrefixI 'False) (U1 :: Type -> Type)))

Methods

from :: MonitorKindFile -> Rep MonitorKindFile x #

to :: Rep MonitorKindFile x -> MonitorKindFile #

Show MonitorKindFile # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorKindFile -> ShowS # show :: MonitorKindFile -> String # showList :: [MonitorKindFile] -> ShowS #
Eq MonitorKindFile # |
Instance details Defined in Distribution.Client.FileMonitor Methods (==) :: MonitorKindFile -> MonitorKindFile -> Bool # (/=) :: MonitorKindFile -> MonitorKindFile -> Bool #
type Rep MonitorKindFile # |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorKindFile = D1 ('MetaData "MonitorKindFile" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) ((C1 ('MetaCons "FileExists" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "FileModTime" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "FileHashed" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "FileNotExists" 'PrefixI 'False) (U1 :: Type -> Type)))

data MonitorKindDir #

Constructors

DirExists |
DirModTime |
DirNotExists |

#### Instances

Instances details

Structured MonitorKindDir # |
Instance details Defined in Distribution.Client.FileMonitor Methods structure :: Proxy MonitorKindDir -> Structure # structureHash' :: Tagged MonitorKindDir MD5
Binary MonitorKindDir # |
Instance details Defined in Distribution.Client.FileMonitor Methods put :: MonitorKindDir -> Put # get :: Get MonitorKindDir # putList :: [MonitorKindDir] -> Put #
Generic MonitorKindDir # |

Instance details

Defined in Distribution.Client.FileMonitor

Associated Types

type Rep MonitorKindDir |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorKindDir = D1 ('MetaData "MonitorKindDir" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "DirExists" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "DirModTime" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "DirNotExists" 'PrefixI 'False) (U1 :: Type -> Type)))

Methods

from :: MonitorKindDir -> Rep MonitorKindDir x #

to :: Rep MonitorKindDir x -> MonitorKindDir #

Show MonitorKindDir # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorKindDir -> ShowS # show :: MonitorKindDir -> String # showList :: [MonitorKindDir] -> ShowS #
Eq MonitorKindDir # |
Instance details Defined in Distribution.Client.FileMonitor Methods (==) :: MonitorKindDir -> MonitorKindDir -> Bool # (/=) :: MonitorKindDir -> MonitorKindDir -> Bool #
type Rep MonitorKindDir # |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorKindDir = D1 ('MetaData "MonitorKindDir" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "DirExists" 'PrefixI 'False) (U1 :: Type -> Type) :+: (C1 ('MetaCons "DirModTime" 'PrefixI 'False) (U1 :: Type -> Type) :+: C1 ('MetaCons "DirNotExists" 'PrefixI 'False) (U1 :: Type -> Type)))

data RootedGlob #

A file path specified by globbing, relative to some root directory.

Constructors

RootedGlob |

Fields

- FilePathRoot

  what the glob is relative to

- Glob

  the glob

#### Instances

Instances details

Parsec RootedGlob # |
Instance details Defined in Distribution.Client.Glob Methods parsec :: CabalParsing m => m RootedGlob #
Pretty RootedGlob # |
Instance details Defined in Distribution.Client.Glob Methods pretty :: RootedGlob -> Doc # prettyVersioned :: CabalSpecVersion -> RootedGlob -> Doc #
Structured RootedGlob # |
Instance details Defined in Distribution.Client.Glob Methods structure :: Proxy RootedGlob -> Structure # structureHash' :: Tagged RootedGlob MD5
Binary RootedGlob # |
Instance details Defined in Distribution.Client.Glob Methods put :: RootedGlob -> Put # get :: Get RootedGlob # putList :: [RootedGlob] -> Put #
Generic RootedGlob # |

Instance details

Defined in Distribution.Client.Glob

Associated Types

type Rep RootedGlob |

Instance details

Defined in Distribution.Client.Glob

type Rep RootedGlob = D1 ('MetaData "RootedGlob" "Distribution.Client.Glob" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "RootedGlob" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 FilePathRoot) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Glob)))

Methods

from :: RootedGlob -> Rep RootedGlob x #

to :: Rep RootedGlob x -> RootedGlob #

Show RootedGlob # |
Instance details Defined in Distribution.Client.Glob Methods showsPrec :: Int -> RootedGlob -> ShowS # show :: RootedGlob -> String # showList :: [RootedGlob] -> ShowS #
Eq RootedGlob # |
Instance details Defined in Distribution.Client.Glob Methods (==) :: RootedGlob -> RootedGlob -> Bool # (/=) :: RootedGlob -> RootedGlob -> Bool #
type Rep RootedGlob # |

Instance details

Defined in Distribution.Client.Glob

type Rep RootedGlob = D1 ('MetaData "RootedGlob" "Distribution.Client.Glob" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "RootedGlob" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 FilePathRoot) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Glob)))

monitorFile :: FilePath -> MonitorFilePath #

Monitor a single file for changes, based on its modification time. The monitored file is considered to have changed if it no longer exists or if its modification time has changed.

monitorFileHashed :: FilePath -> MonitorFilePath #

Monitor a single file for changes, based on its modification time and content hash. The monitored file is considered to have changed if it no longer exists or if its modification time and content hash have changed.

monitorNonExistentFile :: FilePath -> MonitorFilePath #

Monitor a single non-existent file for changes. The monitored file is considered to have changed if it exists.

monitorFileExistence :: FilePath -> MonitorFilePath #

Monitor a single file for existence only. The monitored file is considered to have changed if it no longer exists.

monitorDirectory :: FilePath -> MonitorFilePath #

Monitor a single directory for changes, based on its modification time. The monitored directory is considered to have changed if it no longer exists or if its modification time has changed.

monitorNonExistentDirectory :: FilePath -> MonitorFilePath #

Monitor a single non-existent directory for changes. The monitored directory is considered to have changed if it exists.

monitorDirectoryExistence :: FilePath -> MonitorFilePath #

Monitor a single directory for existence. The monitored directory is considered to have changed only if it no longer exists.

monitorFileOrDirectory :: FilePath -> MonitorFilePath #

Monitor a single file or directory for changes, based on its modification time. The monitored file is considered to have changed if it no longer exists or if its modification time has changed.

monitorFileGlob :: RootedGlob -> MonitorFilePath #

Monitor a set of files (or directories) identified by a file glob. The monitored glob is considered to have changed if the set of files matching the glob changes (i.e. creations or deletions), or for files if the modification time and content hash of any matching file has changed.

monitorFileGlobExistence :: RootedGlob -> MonitorFilePath #

Monitor a set of files (or directories) identified by a file glob for existence only. The monitored glob is considered to have changed if the set of files matching the glob changes (i.e. creations or deletions).

monitorFileSearchPath :: [FilePath] -> FilePath -> [MonitorFilePath] #

Creates a list of files to monitor when you search for a file which unsuccessfully looked in `notFoundAtPaths` before finding it at `foundAtPath`.

monitorFileHashedSearchPath :: [FilePath] -> FilePath -> [MonitorFilePath] #

Similar to `monitorFileSearchPath`, but also instructs us to monitor the hash of the found file.

# Creating and checking sets of monitored files

data FileMonitor a b #

A monitor for detecting changes to a set of files. It can be used to efficiently test if any of a set of files (specified individually or by glob patterns) has changed since some snapshot. In addition, it also checks for changes in a value (of type `a`), and when there are no changes in either it returns a saved value (of type `b`).

The main use case looks like this: suppose we have some expensive action that depends on certain pure inputs and reads some set of files, and produces some pure result. We want to avoid re-running this action when it would produce the same result. So we need to monitor the files the action looked at, the other pure input values, and we need to cache the result. Then at some later point, if the input value didn't change, and none of the files changed, then we can re-use the cached result rather than re-running the action.

This can be achieved using a `FileMonitor`. Each `FileMonitor` instance saves state in a disk file, so the file for that has to be specified, making sure it is unique. The pattern is to use `checkFileMonitorChanged` to see if there's been any change. If there is, re-run the action, keeping track of the files, then use `updateFileMonitor` to record the current set of files to monitor, the current input value for the action, and the result of the action.

The typical occurrence of this pattern is captured by `rerunIfChanged` and the `Rebuild` monad. More complicated cases may need to use `checkFileMonitorChanged` and `updateFileMonitor` directly.

Constructors

FileMonitor |

Fields

- fileMonitorCacheFile :: FilePath

  The file where this `FileMonitor` should store its state.

- fileMonitorKeyValid :: a -> a -> Bool

  Compares a new cache key with old one to determine if a corresponding cached value is still valid.

  Typically this is just an equality test, but in some circumstances it can make sense to do things like subset comparisons.

  The first arg is the new value, the second is the old cached value.

- fileMonitorCheckIfOnlyValueChanged :: Bool

  When this mode is enabled, if `checkFileMonitorChanged` returns `MonitoredValueChanged` then we have the guarantee that no files changed, that the value change was the only change. In the default mode no such guarantee is provided which is slightly faster.

newFileMonitor #

Arguments

:: Eq a |
=> FilePath | The file to cache the state of the file monitor. Must be unique.
-> FileMonitor a b |

Define a new file monitor.

It's best practice to define file monitor values once, and then use the same value for `checkFileMonitorChanged` and `updateFileMonitor` as this ensures you get the same types `a` and `b` for reading and writing.

The path of the file monitor itself must be unique because it keeps state on disk and these would clash.

data MonitorChanged a b #

The result of `checkFileMonitorChanged`: either the monitored files or value changed (and it tells us which it was) or nothing changed and we get the cached result.

Constructors

MonitorUnchanged b [MonitorFilePath] | The monitored files and value did not change. The cached result is `b`. The set of monitored files is also returned. This is useful for composing or nesting `FileMonitor`s.
MonitorChanged (MonitorChangedReason a) | The monitor found that something changed. The reason is given.

#### Instances

Instances details

(Show b, Show a) => Show (MonitorChanged a b) # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorChanged a b -> ShowS # show :: MonitorChanged a b -> String # showList :: [MonitorChanged a b] -> ShowS #

data MonitorChangedReason a #

What kind of change `checkFileMonitorChanged` detected.

Constructors

MonitoredFileChanged FilePath | One of the files changed (existence, file type, mtime or file content, depending on the `MonitorFilePath` in question)
MonitoredValueChanged a | The pure input value changed. The previous cached key value is also returned. This is sometimes useful when using a `fileMonitorKeyValid` function that is not simply `(==)`, when invalidation can be partial. In such cases it can make sense to `updateFileMonitor` with a key value that's a combination of the new and old (e.g. set union).
MonitorFirstRun | There was no saved monitor state, cached value etc. Ie the file for the `FileMonitor` does not exist.
MonitorCorruptCache | There was existing state, but we could not read it. This typically happens when the code has changed compared to an existing `FileMonitor` cache file and type of the input value or cached value has changed such that we cannot decode the values. This is completely benign as we can treat is just as if there were no cache file and re-run.

#### Instances

Instances details

Functor MonitorChangedReason # |
Instance details Defined in Distribution.Client.FileMonitor Methods fmap :: (a -> b) -> MonitorChangedReason a -> MonitorChangedReason b # (<$) :: a -> MonitorChangedReason b -> MonitorChangedReason a #
Show a => Show (MonitorChangedReason a) # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorChangedReason a -> ShowS # show :: MonitorChangedReason a -> String # showList :: [MonitorChangedReason a] -> ShowS #
Eq a => Eq (MonitorChangedReason a) # |
Instance details Defined in Distribution.Client.FileMonitor Methods (==) :: MonitorChangedReason a -> MonitorChangedReason a -> Bool # (/=) :: MonitorChangedReason a -> MonitorChangedReason a -> Bool #

checkFileMonitorChanged #

Arguments

:: (Binary a, Structured a, Binary b, Structured b) |
=> FileMonitor a b | cache file path
-> FilePath | root directory
-> a | guard or key value
-> IO (MonitorChanged a b) | did the key or any paths change?

Test if the input value or files monitored by the `FileMonitor` have changed. If not, return the cached value.

See `FileMonitor` for a full explanation.

updateFileMonitor #

Arguments

:: (Binary a, Structured a, Binary b, Structured b) |
=> FileMonitor a b | cache file path
-> FilePath | root directory
-> Maybe MonitorTimestamp | timestamp when the update action started
-> [MonitorFilePath] | files of interest relative to root
-> a | the current key value
-> b | the current result value
-> IO () |

Update the input value and the set of files monitored by the `FileMonitor`, plus the cached value that may be returned in future.

This takes a snapshot of the state of the monitored files right now, so `checkFileMonitorChanged` will look for file system changes relative to this snapshot.

This is typically done once the action has been completed successfully and we have the action's result and we know what files it looked at. See `FileMonitor` for a full explanation.

If we do take the snapshot after the action has completed then we have a problem. The problem is that files might have changed while the action was running but after the action read them. If we take the snapshot after the action completes then we will miss these changes. The solution is to record a timestamp before beginning execution of the action and then we make the conservative assumption that any file that has changed since then has already changed, ie the file monitor state for these files will be such that `checkFileMonitorChanged` will report that they have changed.

So if you do use `updateFileMonitor` after the action (so you can discover the files used rather than predicting them in advance) then use `beginUpdateFileMonitor` to get a timestamp and pass that. Alternatively, if you take the snapshot in advance of the action, or you're not monitoring any files then you can use `Nothing` for the timestamp parameter.

data MonitorTimestamp #

A timestamp to help with the problem of file changes during actions. See `updateFileMonitor` for details.

beginUpdateFileMonitor :: IO MonitorTimestamp #

Record a timestamp at the beginning of an action, and when the action completes call `updateFileMonitor` passing it the timestamp. See `updateFileMonitor` for details.

# Internal

data MonitorStateFileSet #

The state necessary to determine whether a set of monitored files has changed. It consists of two parts: a set of specific files to be monitored (index by their path), and a list of globs, which monitor may files at once.

#### Instances

Instances details

Structured MonitorStateFileSet # |
Instance details Defined in Distribution.Client.FileMonitor Methods structure :: Proxy MonitorStateFileSet -> Structure # structureHash' :: Tagged MonitorStateFileSet MD5
Binary MonitorStateFileSet # |
Instance details Defined in Distribution.Client.FileMonitor Methods put :: MonitorStateFileSet -> Put # get :: Get MonitorStateFileSet # putList :: [MonitorStateFileSet] -> Put #
Generic MonitorStateFileSet # |

Instance details

Defined in Distribution.Client.FileMonitor

Associated Types

type Rep MonitorStateFileSet |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorStateFileSet = D1 ('MetaData "MonitorStateFileSet" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "MonitorStateFileSet" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 [MonitorStateFile]) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 [MonitorStateGlob])))

Methods

from :: MonitorStateFileSet -> Rep MonitorStateFileSet x #

to :: Rep MonitorStateFileSet x -> MonitorStateFileSet #

Show MonitorStateFileSet # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorStateFileSet -> ShowS # show :: MonitorStateFileSet -> String # showList :: [MonitorStateFileSet] -> ShowS #
type Rep MonitorStateFileSet # |

Instance details

Defined in Distribution.Client.FileMonitor

type Rep MonitorStateFileSet = D1 ('MetaData "MonitorStateFileSet" "Distribution.Client.FileMonitor" "cabal-install-3.12.1.0-G554PkJj2SpDqyarXp9tbt" 'False) (C1 ('MetaCons "MonitorStateFileSet" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 [MonitorStateFile]) :*: S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'SourceStrict 'DecidedStrict) (Rec0 [MonitorStateGlob])))

data MonitorStateFile #

The state necessary to determine whether a monitored file has changed.

This covers all the cases of `MonitorFilePath` except for globs which is covered separately by `MonitorStateGlob`.

The `Maybe ModTime` is to cover the case where we already consider the file to have changed, either because it had already changed by the time we did the snapshot (i.e. too new, changed since start of update process) or it no longer exists at all.

#### Instances

Instances details

Structured MonitorStateFile # |
Instance details Defined in Distribution.Client.FileMonitor Methods structure :: Proxy MonitorStateFile -> Structure # structureHash' :: Tagged MonitorStateFile MD5
Binary MonitorStateFile # |
Instance details Defined in Distribution.Client.FileMonitor Methods put :: MonitorStateFile -> Put # get :: Get MonitorStateFile # putList :: [MonitorStateFile] -> Put #
Generic MonitorStateFile # |

Instance details

Defined in Distribution.Client.FileMonitor

Associated Types

type Rep MonitorStateFile |
Instance details Defined in Distribution.Client.FileMonitor type Rep MonitorStateFile

Methods

from :: MonitorStateFile -> Rep MonitorStateFile x #

to :: Rep MonitorStateFile x -> MonitorStateFile #

Show MonitorStateFile # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorStateFile -> ShowS # show :: MonitorStateFile -> String # showList :: [MonitorStateFile] -> ShowS #
type Rep MonitorStateFile # |
Instance details Defined in Distribution.Client.FileMonitor type Rep MonitorStateFile

data MonitorStateGlob #

The state necessary to determine whether the files matched by a globbing match have changed.

#### Instances

Instances details

Structured MonitorStateGlob # |
Instance details Defined in Distribution.Client.FileMonitor Methods structure :: Proxy MonitorStateGlob -> Structure # structureHash' :: Tagged MonitorStateGlob MD5
Binary MonitorStateGlob # |
Instance details Defined in Distribution.Client.FileMonitor Methods put :: MonitorStateGlob -> Put # get :: Get MonitorStateGlob # putList :: [MonitorStateGlob] -> Put #
Generic MonitorStateGlob # |

Instance details

Defined in Distribution.Client.FileMonitor

Associated Types

type Rep MonitorStateGlob |
Instance details Defined in Distribution.Client.FileMonitor type Rep MonitorStateGlob

Methods

from :: MonitorStateGlob -> Rep MonitorStateGlob x #

to :: Rep MonitorStateGlob x -> MonitorStateGlob #

Show MonitorStateGlob # |
Instance details Defined in Distribution.Client.FileMonitor Methods showsPrec :: Int -> MonitorStateGlob -> ShowS # show :: MonitorStateGlob -> String # showList :: [MonitorStateGlob] -> ShowS #
type Rep MonitorStateGlob # |
Instance details Defined in Distribution.Client.FileMonitor type Rep MonitorStateGlob