"

 COPYRIGHT (c) 1997 by eXept Software AG

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

"{ Package: 'stx:libbasic2' }"

Object subclass:#DirectoryContents

	instanceVariableNames:'directory timeStamp contents'

	classVariableNames:'CachedDirectories LockSema ReadersList'

	poolDictionaries:''

	category:'System-Support'

!

Object subclass:#DirectoryContentsItem

	instanceVariableNames:'info fileName'

	classVariableNames:'CachedRemoteMountPoints CachedRemoteMountPointsTimeStamp'

	poolDictionaries:''

	privateIn:DirectoryContents

!

!DirectoryContents class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1997 by eXept Software AG

              All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    DirectoryContents provides a cached view onto a fileDirectory.

    Notice:

        This class is not available in other ST-systems;

        Applications using it may not be portable.

    [author:]

        Claus Atzkern

    [see also:]

        Filename

        FileStream DirectoryStream OperatingSystem

"

! !

!DirectoryContents class methodsFor:'initialization'!

initialize

    "setup lock-mechanism

    "

    LockSema    := RecursionLock new.

    ReadersList := Dictionary new.

! !

!DirectoryContents class methodsFor:'instance creation'!

new

    ^ self basicNew initialize

! !

!DirectoryContents class methodsFor:'accessing'!

directoryNamed:aDirectory

    "returns the DirectoryContents for a directory named 

     aDirectoryName, aString, nil or Filename

    "

    |directory contents max lockRead pathName addToList|

    (aDirectory notNil and:[(directory := aDirectory asFilename) exists]) ifFalse:[

        ^ nil

    ].

    directory := directory asAbsoluteFilename.

    contents := nil.

    LockSema critical:[

        CachedDirectories notNil ifTrue:[

            contents := self directoryAt:directory.

            contents isNil ifTrue:[

                max := self maxCachedDirectories.

                CachedDirectories size > max ifTrue:[

                    CachedDirectories := CachedDirectories select:[:aDir|

                        (aDir size > 32 and:[aDir isObsolete not])

                    ]

                ].

                CachedDirectories size > max ifTrue:[

                    CachedDirectories removeFirst

                ]

            ].

        ].

        contents isNil ifTrue:[

            ReadersList isNil ifTrue:[ReadersList := Dictionary new].

            pathName := directory pathName.

            lockRead := ReadersList at:pathName ifAbsentPut:[Semaphore forMutualExclusion].

        ]

    ].

    contents notNil ifTrue:[^ contents].

    addToList := false.

    lockRead critical:[

        [  "/ test whether another task got the semaphore and

           "/ has read the directory contents

           (contents := self directoryAt:directory) isNil ifTrue:[

                "/ read the directory contents

                contents  := self new directory:directory.

                "/ only cache if the mod'Time is valid.

                addToList := contents timeStamp notNil.

            ]

        ] ensure:[

            LockSema critical:[

                addToList ifTrue:[

                    CachedDirectories isNil ifTrue:[

                        CachedDirectories := OrderedCollection new

                    ].

                    CachedDirectories add:contents

                ].

                (lockRead isEmpty and:[ReadersList notNil]) ifTrue:[

                    ReadersList removeKey:pathName ifAbsent:nil

                ]

            ]

        ]

    ].    

    ^ contents

! !

!DirectoryContents class methodsFor:'cache flushing'!

flushCache

    "flush list of rememebred directory contents"

    LockSema critical:[ CachedDirectories := nil ].

    "

     self flushCache

    "

    "Created: / 11.2.2000 / 00:13:59 / cg"

!

flushCachedDirectoryFor:aDirectoryOrString

    "remove directory from cache

    "

    |index directory|

    (CachedDirectories notNil and:[aDirectoryOrString notNil]) ifTrue:[

        directory := aDirectoryOrString asFilename.

        (directory isSymbolicLink not

        and:[ directory isDirectory]) ifTrue:[

            LockSema critical:[

                CachedDirectories notNil ifTrue:[

                    directory := directory asAbsoluteFilename.

                    index := CachedDirectories findFirst:[:d | d directory = directory ].

                    index ~~ 0 ifTrue:[

                        CachedDirectories removeAtIndex:index.

                    ]

                ]

            ]

        ]

    ].

!

lowSpaceCleanup

    "flush list of remembered directory contents when low on memory"

    self flushCache

    "

     self lowSpaceCleanup

    "

    "Created: / 18.2.1998 / 18:17:05 / cg"

    "Modified: / 24.9.1998 / 17:51:15 / cg"

!

preSnapshot

    "flush list of rememebred directory contents' before saving an image"

    self flushCache.

! !

!DirectoryContents class methodsFor:'constants'!

maxCachedDirectories

    "returns number of maximum cached directories

    "

    ^ 20

    "Modified: / 25.2.1998 / 19:56:24 / cg"

! !

!DirectoryContents class methodsFor:'private'!

directoryAt:aFilename

    "checks whether directory already exists and is valid.

     If true the directory is returned otherwise nil

    "

    |index directory absoluteFilename|

    directory := nil.

    LockSema critical:[

        CachedDirectories notNil ifTrue:[

            absoluteFilename := aFilename asFilename asAbsoluteFilename.

            index := CachedDirectories findFirst:[:d| d directory = absoluteFilename ].

            index ~~ 0 ifTrue:[

                directory := CachedDirectories at:index.

                directory isObsolete ifTrue:[

                    CachedDirectories removeAtIndex:index.

                    directory := nil.

                ]

            ]

        ]

    ].

    ^ directory

! !

!DirectoryContents class methodsFor:'queries'!

directoryNamed:aDirectoryName detect:aTwoArgBlock

    "evaluate the block, [:filename :isDirectory] on the directory

     contents of a directory named aDirectoryName, until the block

     returns true. If nothing detected false is returned

    "

    |directory dir|

    directory := aDirectoryName asFilename.

    directory exists ifFalse:[

        ^ false

    ].

    (dir := self directoryAt:directory) notNil ifTrue:[

        dir contentsDo:[:aFile :isDir|

            (aTwoArgBlock value:aFile value:isDir) ifTrue:[^ true]

        ].

        ^ false

    ].

    [

        directory directoryContentsDo:[:fn |

            |file|

            file := directory construct:fn.

            (aTwoArgBlock value:file value:(file isDirectory)) ifTrue:[

                ^ true

            ]

        ].

    ] on:FileStream openErrorSignal do:[:ex|

          "cannot open directory"

          ^ false

    ].

"/    dir := DirectoryStream directoryNamed:(directory pathName).

"/

"/    dir isNil ifFalse:[

"/        [

"/            [dir atEnd] whileFalse:[

"/                (name := dir nextLine) notNil ifTrue:[

"/                    name := directory construct:name.

"/

"/                    (aTwoArgBlock value:name value:(name isDirectory)) ifTrue:[

"/                        ^ true

"/                    ]

"/                ]

"/            ].

"/        ] valueNowOrOnUnwindDo:[

"/            dir close.

"/        ]

"/    ].

    ^ false

    "Modified: / 24.9.1998 / 21:14:58 / cg"

! !

!DirectoryContents class methodsFor:'utilities'!

contentsItemForFileName:aFilenameOrString 

    | aFilename directory directoryContents|

    aFilename := aFilenameOrString asFilename.

    directory := aFilename directory.

    directoryContents := self directoryNamed:directory.

    directoryContents isNil ifTrue:[

        aFilename exists ifTrue:[

            ^ (DirectoryContentsItem new fileName:aFilename) info:aFilename info.

        ].

        ^ nil

    ].

    directoryContents itemsDo:[:fileItemThere |

        fileItemThere fileName = aFilename ifTrue:[

            fileItemThere updateInfo.

            ^ fileItemThere.

        ]

    ].

    ^ (DirectoryContentsItem new fileName:aFilename) info:aFilename info.

    "

     DirectoryContents contentsItemForFileName:'/etc/passwd'

     DirectoryContents contentsItemForFileName:'/'

    "

! !

!DirectoryContents methodsFor:'accessing'!

directory

    "returns the directoy name as Filename

    "

    ^ directory

!

modificationTime

    "get the last modification time of the directory

    "

    ^ directory modificationTime

!

timeStamp

    "get the last timeStamp (when the directory info was read) of the directory

    "

    ^ timeStamp

! !

!DirectoryContents methodsFor:'enumerating'!

contentsAndBaseNamesDo:aThreeArgBlock

    "evaluate the block on each file; the argument to the block is the

     filename, the baseName and true in case of a directory

     block arguments: [:fileName :aBaseName :isDirectory|

    "

    self itemsDo:[:eachItem |

        aThreeArgBlock 

            value:(eachItem fileName) 

            value:(eachItem baseName ) 

            value:(eachItem isDirectory)

    ].

!

contentsDo:aTwoArgBlock

    "evaluate the block on each file; the argument to the block is the

     filename and true in case of a directory

     block arguments: [:fileName :isDirectory|

    "

    self itemsDo:[:eachItem |

        aTwoArgBlock

            value:(eachItem fileName) 

            value:(eachItem isDirectory)

    ].

!

directoriesAndBasenamesDo:aTwoArgBlock

    "evaluate block on each directory; a Filename and Basename.

     The directories are sorted

    "

    self itemsDo:[:eachItem |

        eachItem isDirectory ifTrue:[

            aTwoArgBlock value:(eachItem fileName) value:(eachItem baseName)

        ]

    ]

!

directoriesDo:aOneArgBlock

    "evaluate block on each directory; a Filename. The directories are sorted

    "

    self itemsDo:[:eachItem |

        eachItem isDirectory ifTrue:[

            aOneArgBlock value:(eachItem fileName) 

        ]

    ].

!

filesAndBasenamesDo:aTwoArgBlock

    "evaluate block on each file; a Filename and a Basename.

     The files are sorted.

    "

    self itemsDo:[:eachItem |

        eachItem isDirectory ifFalse:[

            aTwoArgBlock value:(eachItem fileName) value:(eachItem baseName)

        ]

    ]

!

filesDo:aOneArgBlock

    "evaluate block on each file; a Filename. The files are sorted.

    "

    self itemsDo:[:eachItem |

        eachItem isDirectory ifFalse:[

            aOneArgBlock value:(eachItem fileName)

        ]

    ]

!

itemsDo:aBlock

    "evaluate the block on each contentsItem, which contains the fileName and type info"

    contents do:[:eachItem |

        aBlock value:eachItem.

    ].

! !

!DirectoryContents methodsFor:'instance creation'!

directory:aFilename

    "instance creation; setup attributes"

    |t dircontents|

    directory := aFilename asFilename.

    t := Timestamp now. "/ directory modificationTime.

    [

        dircontents := directory directoryContents.

        dircontents sort.

        contents  := dircontents collect:[:eachBasename | DirectoryContentsItem new fileName:(directory construct:eachBasename)].

"/        dircontents := directory directoryContentsAsFilenames.

"/        dircontents sort:[:a :b | a baseName < b baseName].

"/        contents  := dircontents 

"/                    collect:[:eachFilename | DirectoryContentsItem new fileName:eachFilename].

    ] on:FileStream openErrorSignal do:[:ex|

        contents := #().

    ].

    timeStamp := t.

! !

!DirectoryContents methodsFor:'printing'!

printOn:aStream

    aStream nextPutAll:'DirectoryContents of: '.

    directory printOn:aStream.

! !

!DirectoryContents methodsFor:'private'!

updateContents

    "ensure that the file-info os present for every item"

    contents do:[:eachItem |

        eachItem updateInfo.

    ].

! !

!DirectoryContents methodsFor:'queries'!

isObsolete

    "returns true if the directory contents represented by the receiver is obsolete

     (i.e. if the fileSystems directory has been changed in the meanwhile)

    "

    |mt|

    directory exists ifFalse:[^ true].

    timeStamp isNil ifTrue:[^ true].

    (mt := directory modificationTime) isNil ifTrue:[^ true].

    "/ ignores milliseconds in the comparison

    timeStamp < mt ifTrue:[^ true].

    timeStamp getSeconds = mt getSeconds ifTrue:[^ true].

    ^ false

    "Modified: / 23.8.2001 / 16:50:51 / cg"

!