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Artifact 2201109c37fd96805ee9ded9be609aa3cf5d251ba3d01ebd155fe2e0b3fb0367:


#----------------------------------------------------------------------
#  Virtual File System for Version Control Systems
#
#  Copyright (c) 2014-2015, Peter Spjuth
#
#  License for vcsvfs package: Same as for Tcl
#----------------------------------------------------------------------

package require vfs
package provide vcsvfs 0.2

namespace eval vcsvfs {
    variable DataRefChan
    variable mpoints {}
    namespace eval fossil {}
    namespace eval svn {}
    namespace eval git {}
    namespace eval hg {}
}

# Create a command which when eval'd recreates known file systems
proc vcsvfs::serialize {} {
    variable ::vcsvfs::mpoints
    return [list vcsvfs::deserialize $mpoints]
}

# Pick up the command created by serialize
proc vcsvfs::deserialize {data} {
    variable ::vcsvfs::mpoints
    dict for {key value} $data {
        dict set mpoints $key $value
        # Handle if this is done again, do not mount it twice
        if {[string match *vcsvfs* [file system $key]]} {
            continue
        }
        vfs::filesystem mount $key [list vcsvfs::Vfs]
    }
}

# Create a Virtual File System showing a revision of a fossil checkout
#
# dir: Directory in a fossil checkout
# rev: Revision to mount
#
# Returns: path to the generated VFS
proc vcsvfs::fossil::mount {dir rev} {
    variable ::vcsvfs::mpoints
    set dir [file normalize $dir]

    # Fossil command must be run within the dir, so temporarily change pwd
    set oldpwd [pwd]
    cd $dir

    # The mount point will always be at the fossil root, even if
    # a sub directory was given.
    # Locate fossil root for the given directory.
    set info [exec fossil info]
    regexp -line {local-root:\s*(\S.*)} $info -> root
    set root [file normalize $root]
    cd $root

    # Getting files via manifest artifact
    # This is a quick and robust way to get the file tree and each file's sha
    # Other info is trickier and is handled below
    if {[catch {exec fossil artifact $rev} artifact]} {
        return -code error "No such fossil revision: $rev"
    }
    set commitTime 0
    set cTime now
    set finfo {}
    set todo [split $artifact \n]
    while {[llength $todo] > 0} {
        set line [lindex $todo 0]
        set todo [lrange $todo 1 end]
        # Expected format in a line:
        # B baseline
        # F tests/left.txt c1572b3809a1ba6ab2de9307c96b1cfeefdcf0ba
        # D 2015-02-23T23:30:07.509
        if {[regexp {^B (.*)} $line -> bUuid]} {
            # Pick up a baseline manifest and parse it first
            set artifact [exec fossil "artifact" $bUuid]
            set todo [concat [split $artifact \n] $todo]
            continue
        }
        if {[regexp {^D (.*)} $line -> cTime]} {
            # Remove decimals and middle T
            regsub {\.\d+} $cTime "" cTime
            regsub {T} $cTime " " cTime
            set commitTime [clock scan $cTime -gmt 1]
        }
        if {[regexp {^F (\S+) (\S+)} $line -> fName fSha]} {
            # File names can have spaces, coded with \s
            set fName [string map {\\s " "} $fName]
            dict set finfo $fName sha $fSha
            dict set finfo $fName mtimestr $cTime ;# Anything
            dict set finfo $fName type file
            dict set finfo $fName isfile 1
            dict set finfo $fName isdir 0
            # Setting size is delayed until needed since the needed
            # calls are relatively expensive.

            # Mark all known directory paths and build up file tree info
            set parentStr ""
            foreach dirPath [file split $fName] {
                dict set finfo $parentStr child $dirPath 1
                dict set finfo $parentStr isfile 0
                dict set finfo $parentStr isdir 1
                dict set finfo $parentStr type directory
                set parentStr [file join $parentStr $dirPath]
            }
        }
    }
    # Try to use "fossil ls -r, available in newer versions"
    set doneCollecting 0
    if { ! [catch {exec fossil ls -r $rev -v} lsdata]} {
        set lsdata [string trim $lsdata \n]
        foreach line [split $lsdata \n] {
            # Expected format in a line:
            # 2012-08-21 20:38:19  4563  tests/rev.test
            regexp {(\S+ \S+)\s+(\d+)\s+(.+)} $line -> fDate fSize fName
            dict set finfo $fName mtimestr $fDate
            dict set finfo $fName size $fSize
        }
        set doneCollecting 1
    }

    # Getting files via http fileage to aquire file times
    # Since dates are parsed from the age string they are rather imprecise
    # Use a while around it to be able to break free easily (faking goto)
    while { ! $doneCollecting} {
        set html [exec fossil http << "GET /fileage?name=$rev"]
        if { ! [regexp {Files in.*} $html html]} {
            # Not the expected format of response, skip
            break
        }
        if { ! [regexp {\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}} $html cTime2]} {
            # Not the expected format of response, skip
            break
        }
        # This is currently unused since we do not trust the formatted time in
        # the web page. The time stamp from the artifact is used later.
        set commitTime2 [clock scan $cTime2 -gmt 1]
        #puts "CT $commitTime  CT2 $commitTime2"
        # Rows in the HTML table
        foreach row [regexp -all -inline {<tr>.*?</tr>} $html] {
            # Columns in the HTML table
            set cols [regexp -all -inline {<td>(.*?)</td>} $row]
            set col1 [string trim [lindex $cols 1]]
            set col2 [string trim [lindex $cols 3]]
            # First column is age, in readable format
            # e.g. "current" "36.4 minutes" "97.0 days" "1.06 years"
            if {$col1 eq ""} continue
            if {$col1 eq "current"} {
                set fTime $commitTime
                set err 0
            } else {
                set value [lindex $col1 0]
                set unit [lindex $col1 1]
                set err 0
                switch -glob $unit {
                    second* {
                        set value [expr {int($value)}]
                        set unit second
                        set err 0
                    }
                    minute* {
                        # In general, try to underestimate the value. The web
                        # page rounds to one decimal.
                        set value [expr {int(($value-0.05)*60)}]
                        set unit second
                        set err 6
                    }
                    hour* {
                        set value [expr {int(($value-0.05)*60*60)}]
                        set unit second
                        set err 360
                    }
                    day* {
                        set value [expr {int(($value-0.05)*60*60*24)}]
                        set unit second
                        set err 8640
                    }
                    year* {
                        # Year has two decimals
                        set value [expr {int(($value-0.005)*60*60*24*365)}]
                        set unit second
                        set err [expr {6*60*24*365}]
                    }
                    default {
                        puts "Unhandled unit: $unit in '$col1'"
                        set value [expr {int($value)}]
                    }
                }
                set fTime [expr {$commitTime - $value}]
            }
            #puts "AGE $col1 -> $fTime"

            # Second column is file names, separated by <br>
            # Remove links
            regsub -all {<a .*?>} $col2 "" col2
            regsub -all {</a>} $col2 "" col2
            regsub -all {\n} $col2 "" col2
            regsub -all {<br>} $col2 "\n" col2
            set col2 [string trim $col2]
            foreach fName [split $col2 \n] {
                # Check that it matches something filled in from the artifact
                if {[dict exists $finfo $fName]} {
                    dict set finfo $fName mtime $fTime
                    # Store error estimate for debug help
                    dict set finfo $fName errX $err
                }
            }
        }
        # Kill surrounding while loop
        break
    }

    # As another step, get current file stamps from fossil ls.
    # Since ls show current checkout they might not be valid for the rev
    # being looked at. However if they are still present and older than the
    # ones from fileage they are likely correct.
    # Also, fileage and ls uses different criteria for which commit defines
    # the age (across merges), so things basically will be a best effort guess.
    if { ! $doneCollecting} {
        set allfiles [exec fossil ls --age .]
        foreach line [split $allfiles \n] {
            # Expected format in a line:
            # 2012-08-21 20:38:19  tests/rev.test
            regexp {(\S+ \S+)\s+(.+)} $line -> fDate fName
            set mTime [clock scan $fDate -gmt 1]
            if {[dict exists $finfo $fName mtime]} {
                set x [dict get $finfo $fName mtime]
                set e [dict get $finfo $fName errX]
                if {$mTime < $x} {
                    dict set finfo $fName mtime $mTime
                } elseif {abs($mTime - $x) < 3600} {
                    #puts "$fName   age $x   ls $mTime  diff [expr {$mTime - $x}]  err $e"
                }
            }
        }
    }

    cd $oldpwd

    # Generate a mount point.
    set tail [string range $dir [string length $root] end]
    set mountpoint "${root} ($rev)"

    dict set mpoints $mountpoint "finfo" $finfo
    dict set mpoints $mountpoint "origroot" $root
    dict set mpoints $mountpoint "rev" $rev
    dict set mpoints $mountpoint "vcstype" fossil
    vfs::filesystem mount $mountpoint [list vcsvfs::Vfs]

    set result $mountpoint$tail
    #puts $result
    #puts [dict size $finfo]
    #puts [dict get $finfo [lindex $finfo 0]]
    return $result
}

proc vcsvfs::fossil::unmount {dir} {
    variable ::vcsvfs::mpoints
    # TBD: Find the mountpoint
    #dict unset mpoints $mountpoint
    #vfs::filesystem unmount $mountpoint
}

# Create a Virtual File System showing a revision of an SVN checkout
#
# dir: Directory in an SVN checkout
# rev: Revision to mount
#
# Returns: path to the generated VFS
proc vcsvfs::svn::mount {dir rev} {
    variable ::vcsvfs::mpoints
    set dir [file normalize $dir]

    # Command must be run within the dir, so temporarily change pwd
    set oldpwd [pwd]
    cd $dir

    # The mount point will normally be at the wc root, even if
    # a sub directory was given.
    # Locate root for the given directory.
    set info [exec svn info]
    if { ! [regexp -line {Working Copy Root Path:\s*(\S.*)} $info -> root]} {
        # Fallback to given dir
        set root .
    }
    # TBD: Always root at given dir, for speed
    set root .
    set root [file normalize $root]
    cd $root

    # Getting files via ls
    set allfiles [exec svn ls -R -r $rev]
    foreach line [split $allfiles \n] {
        # Each line is one file/dir name
        set fName $line
        if {[string index $fName end] eq "/"} {
            # This is a directory, strip the /
            set fName [string range $fName 0 end-1]
            dict set finfo $fName isfile 0
            dict set finfo $fName isdir 1
            dict set finfo $fName type directory
        } else {
            # This is a file
            dict set finfo $fName isfile 1
            dict set finfo $fName isdir 0
            dict set finfo $fName type file
        }
        # Mark all known directory paths and build up file tree info
        set parentStr ""
        foreach dirPath [file split $fName] {
            dict set finfo $parentStr child $dirPath 1
            dict set finfo $parentStr isfile 0
            dict set finfo $parentStr isdir 1
            dict set finfo $parentStr type directory
            set parentStr [file join $parentStr $dirPath]
        }
    }

    set xml [exec svn ls -R -r $rev --xml]
    # TBD real xml parser
    foreach line [split $xml \n] {
        if {[regexp {<name>(.*)</name>} $line -> fName]} {
            continue
        }
        if {[regexp {<date>(.*)</date>} $line -> fDate]} {
            dict set finfo $fName mtimestr $fDate
            continue
        }
        if {[regexp {<size>(.*)</size>} $line -> fSize]} {
            dict set finfo $fName size $fSize
            continue
        }
    }

    cd $oldpwd

    # Generate a mount point.
    set tail [string range $dir [string length $root] end]
    set mountpoint "${root} ($rev)"

    dict set mpoints $mountpoint "finfo" $finfo
    dict set mpoints $mountpoint "origroot" $root
    dict set mpoints $mountpoint "rev" $rev
    dict set mpoints $mountpoint "vcstype" svn
    vfs::filesystem mount $mountpoint [list vcsvfs::Vfs]

    set result $mountpoint$tail
    #puts $result
    #puts [dict size $finfo]
    #puts [dict get $finfo [lindex $finfo 0]]
    return $result
}

proc vcsvfs::svn::unmount {dir} {
    variable ::vcsvfs::mpoints
    # TBD: Find the mountpoint
    #dict unset mpoints $mountpoint
    #vfs::filesystem unmount $mountpoint
}

# Create a Virtual File System showing a revision of a HG checkout
#
# dir: Directory in an HG checkout
# rev: Revision to mount
#
# Returns: path to the generated VFS
proc vcsvfs::hg::mount {dir rev} {
    variable ::vcsvfs::mpoints
    set dir [file normalize $dir]

    # Command must be run within the dir, so temporarily change pwd
    set oldpwd [pwd]
    cd $dir

    # The mount point will normally be at the wc root, even if
    # a sub directory was given.
    # Locate root for the given directory.
    set root [exec hg root]
    # TBD: Always root at given dir, for speed
    #set root .
    #set root [file normalize $root]
    #cd $root

    # Getting files via manifest
    set allfiles [exec hg manifest --debug -r $rev]
    # Expected line format:
    # sha1sum perms *? name
    foreach line [split $allfiles \n] {
        # Each line is one file name
        regexp {^(\S+)\s+\S+\s+\*?\s*(\S.*)$} $line -> sha fName
        dict set finfo $fName isfile 1
        dict set finfo $fName isdir 0
        dict set finfo $fName "sha" $sha
        dict set finfo $fName type file
        # Fake mtime and size from sha, to make same look same
        dict set finfo $fName mtime [scan [string range $sha 0 6] %x]
        dict set finfo $fName size  [scan [string range $sha 7 9] %x]
        # Mark all known directory paths and build up file tree info
        set parentStr ""
        foreach dirPath [file split $fName] {
            dict set finfo $parentStr child $dirPath 1
            dict set finfo $parentStr isfile 0
            dict set finfo $parentStr isdir 1
            dict set finfo $parentStr type directory
            set parentStr [file join $parentStr $dirPath]
        }
    }
    # TBD: Any way to get file sizes and mtimes from HG?

    # Try using the hglist extension
    set cmd [list hg ls --template "{size} {date} {name}\n" -a \
                     --recursive -r $rev]
    if { ! [catch {exec {*}$cmd} allfiles]} {
        # Expected line format:
        # size date name
        foreach line [split $allfiles \n] {
            if {[regexp {^(\d+)\s+(\d+)\S*\s+(\S.*)$} $line -> size mtime fName]} {
                # Check that it matches something filled in from the manifest
                if {[dict exists $finfo $fName]} {
                    dict set finfo $fName "mtime" $mtime
                    dict set finfo $fName "size"  $size
                }
            }
        }
    }

    cd $oldpwd

    # Generate a mount point.
    set tail [string range $dir [string length $root] end]
    set mountpoint "${root} ($rev)"

    dict set mpoints $mountpoint "finfo" $finfo
    dict set mpoints $mountpoint "origroot" $root
    dict set mpoints $mountpoint "rev" $rev
    dict set mpoints $mountpoint "vcstype" hg
    vfs::filesystem mount $mountpoint [list vcsvfs::Vfs]

    set result $mountpoint$tail
    return $result
}

proc vcsvfs::hg::unmount {dir} {
    variable ::vcsvfs::mpoints
    # TBD: Find the mountpoint
    #dict unset mpoints $mountpoint
    #vfs::filesystem unmount $mountpoint
}

# Create a Virtual File System showing a revision of a GIT checkout
#
# dir: Directory in an GIT checkout
# rev: Revision to mount
#
# Returns: path to the generated VFS
proc vcsvfs::git::mount {dir rev} {
    variable ::vcsvfs::mpoints
    set dir [file normalize $dir]

    # Command must be run within the dir, so temporarily change pwd
    set oldpwd [pwd]
    cd $dir

    # The mount point will be at the given dir
    set root $dir

    # Getting files via ls
    set allfiles [exec git ls-tree -r --long $rev .]
    foreach line [split $allfiles \n] {
        # Each line is:
        # <mode> SP <type> SP <object> SP <object size> TAB <file>
        regexp {(\S)+\s+(\S+)\s+(\S+)\s+(\S+)\t(.*)} $line -> \
                mode type sha size fName
        # TBD: check mode to see a link
        if {$type eq "tree"} {
            dict set finfo $fName isfile 0
            dict set finfo $fName isdir 1
            dict set finfo $fName "type" directory
        } else {
            # This is a file
            dict set finfo $fName isfile 1
            dict set finfo $fName isdir 0
            dict set finfo $fName "type" file
            dict set finfo $fName "sha" $sha
            dict set finfo $fName "size" $size
            # TBD: Delay this call until mtime is needed?
            set mtime [exec git log --pretty=format:%ct -n 1 $rev -- $fName]
            dict set finfo $fName "mtime" $mtime
        }
        # Mark all known directory paths and build up file tree info
        set parentStr ""
        foreach dirPath [file split $fName] {
            dict set finfo $parentStr child $dirPath 1
            dict set finfo $parentStr isfile 0
            dict set finfo $parentStr isdir 1
            dict set finfo $parentStr "type" directory
            set parentStr [file join $parentStr $dirPath]
        }
    }

    cd $oldpwd

    # Generate a mount point.
    set tail [string range $dir [string length $root] end]
    set mountpoint "${root} ($rev)"

    dict set mpoints $mountpoint "finfo" $finfo
    dict set mpoints $mountpoint "origroot" $root
    dict set mpoints $mountpoint "rev" $rev
    dict set mpoints $mountpoint "vcstype" git
    vfs::filesystem mount $mountpoint [list vcsvfs::Vfs]

    set result $mountpoint$tail
    #puts $result
    #puts [dict size $finfo]
    #puts [dict get $finfo [lindex $finfo 0]]
    return $result
}

proc vcsvfs::git::unmount {dir} {
    variable ::vcsvfs::mpoints
    # TBD: Find the mountpoint
    #dict unset mpoints $mountpoint
    #vfs::filesystem unmount $mountpoint
}

# Handler for Reflected Channel
proc vcsvfs::DataRefChan {id cmd chId args} {
    variable DataRefChan
    switch $cmd {
        initialize {
            set mode [lindex $args 0]
            return "initialize finalize watch read"
        }
        finalize {
            unset DataRefChan($id,data)
            return
        }
        watch {
            #set eventSpec [lindex $args 0]
            return
        }
        read {
            set count [lindex $args 0]
            set si $DataRefChan($id,ptr)
            set newPtr [expr {$si + $count}]
            set ei [expr {$newPtr - 1}]
            set data [string range $DataRefChan($id,data) $si $ei]
            set DataRefChan($id,ptr) $newPtr
            return $data
        }
    }
}

# Set up a Reflected Channel which reads the provided data
proc vcsvfs::CreateDataRefChan {data} {
    variable DataRefChan
    set t 0
    while {[info exists DataRefChan($t,data)]} {
        incr t
    }
    set DataRefChan($t,data) $data
    set DataRefChan($t,ptr) 0
    set chId [chan create r [list vcsvfs::DataRefChan $t]]
    return $chId
}

# This is used before closing a pipe from a command.
# It should read all data to avoid errors from the command.
proc vcsvfs::ReadAllBeforeClose {chId} {
    read $chId
}

# Helper for glob matching in directory
proc vcsvfs::MatchInDirectory {finfo relative actual args} {
    set pattern [lindex $args 0]
    set types [lindex $args 1]
    set allowFile 0
    set allowDir 0
    if {[vfs::matchDirectories $types]} {set allowDir 1}
    if {[vfs::matchFiles $types]} {set allowFile 1}

    set result {}
    if {[dict exists $finfo $relative child]} {
        set childD [dict get $finfo $relative child]
    } else {
        # Empty dir
        return {}
    }
    foreach child [dict keys $childD] {
        if { ! [string match $pattern $child]} continue
        set local [file join $relative $child]
        if {[dict get $finfo $local isfile] && !$allowFile} continue
        if {[dict get $finfo $local isdir] && !$allowDir} continue
        lappend result [file join $actual $child]
    }
    return $result
}

# Extract file data from Fossil revision
proc vcsvfs::fossil::openFile {rootD relative mode} {
    set oldpwd [pwd]
    cd [dict get $rootD "origroot"]
    set rev [dict get $rootD rev]
    # Which way of extracting file data is best?
    # fossil finfo -p -r $rev $relative
    # set sha [dict get $finfor sha]
    # fossil artifact $sha
    # fossil cat $relative -r $rev
    # Read through a pipe to get requested mode
    set chId [open [list |fossil cat $relative -r $rev] $mode]
    cd $oldpwd

    return [list $chId [list vcsvfs::ReadAllBeforeClose $chId]]
}

# Extract file data from Subversion revision
proc vcsvfs::svn::openFile {rootD relative mode} {
    set oldpwd [pwd]
    cd [dict get $rootD "origroot"]
    set rev [dict get $rootD rev]
    # Read through a pipe to get requested mode
    set chId [open [list |svn cat -r $rev $relative] $mode]
    cd $oldpwd

    return [list $chId [list vcsvfs::ReadAllBeforeClose $chId]]
}

# Extract file data from HG revision
proc vcsvfs::hg::openFile {rootD relative mode} {
    set oldpwd [pwd]
    cd [dict get $rootD "origroot"]
    set rev [dict get $rootD rev]
    # Read through a pipe to get requested mode
    set chId [open [list |hg cat -r $rev $relative] $mode]
    cd $oldpwd

    return [list $chId [list vcsvfs::ReadAllBeforeClose $chId]]
}

# Some notes about git commands that can be good to have
proc vcsvfs::git::openFile {rootD relative mode} {
    set oldpwd [pwd]
    cd [dict get $rootD "origroot"]
    set sha [dict get $rootD finfo $relative sha]
    #git cat-file
    #git show <rev>^{tree}
    # example: git show HEAD^^^:apa

    # Read through a pipe to get requested mode
    set chId [open [list |git cat-file blob $sha] $mode]
    cd $oldpwd

    return [list $chId [list vcsvfs::ReadAllBeforeClose $chId]]
}

# Fossil may delay filling in size, this takes car of that
proc vcsvfs::fossil::size {finfo} {
    # Use "fossil whatis" on its sha
    # Expected format in a line:
    # size:    629 bytes
    set whatis [exec fossil whatis [dict get $finfo sha]]
    regexp {size:\s+(\d+)} $whatis -> fSize
    return $fSize
}

# Parse a time string from Fossil
proc vcsvfs::fossil::mTime {finfo} {
    set mtimestr [dict get $finfo mtimestr]
    # TBD parse to mtime correct?
    set mtime [clock scan $mtimestr -gmt 1]
    return $mtime
}

# Parse a time string from Subversion
proc vcsvfs::svn::mTime {finfo} {
    set mtimestr [dict get $finfo mtimestr]
    # TBD parse to mtime correct?
    # Remove any decimals from time string
    regsub {\.\d+Z} $mtimestr "" mtimestr
    set mtime [clock scan $mtimestr -gmt 1]
    return $mtime
}

# The handler for the mounted VFS
proc vcsvfs::Vfs {subcmd root relative actual args} {
    variable mpoints
    #puts "\nVfs called:"
    #puts " Su $subcmd"
    #puts " Ro $root"
    #puts " Re $relative"
    #puts " Ac $actual"
    #puts " Ar $args"

    set rootD [dict get $mpoints $root]
    set origroot [dict get $rootD origroot]
    set finfo [dict get $rootD finfo]
    set vcstype [dict get $rootD vcstype]

    if { ! [dict exists $finfo $relative]} {
        # Unknown path
        vfs::filesystem posixerror $::vfs::posix(EACCES)
        return -code error $::vfs::posix(EACCES)
    }
    set finfor [dict get $finfo $relative]
    #puts " $finfor"

    switch $subcmd {
        access {
            set mode [vfs::accessMode [lindex $args 0]]
            # Only read supported
            if {$mode ne "R"} {
                vfs::filesystem posixerror $::vfs::posix(EACCES)
                return -code error $::vfs::posix(EACCES)
            }
            return
        }
        fileattributes {
            #set index [lindex $args 0]
            #set value [lindex $args 1]
            return
        }
        matchindirectory {
            return [vcsvfs::MatchInDirectory $finfo $relative $actual {*}$args]
        }
        open {
            set mode [lindex $args 0]
            if {$mode == {}} {set mode r}
            #set permissions [lindex $args 1]
            if {$mode ne "r" && $mode ne "rb"} {
                # Read only
                vfs::filesystem posixerror $::vfs::posix(EACCES)
                return -code error $::vfs::posix(EACCES)
            }

            return [vcsvfs::${vcstype}::openFile $rootD $relative $mode]
        }
        stat {
            set res [dict create dev 0 ino 0 "mode" 0 nlink 0 uid 0 gid 0 \
                             size 0 atime 0 mtime 0 ctime 0 type file]
            dict set res type [dict get $finfor type]
            if {[dict get $finfor isfile]} {
                # Fill in any postponed info
                if { ! [dict exists $finfor mtime]} {
                    set mtime [vcsvfs::${vcstype}::mTime $finfor]
                    dict set finfor "mtime" $mtime
                    # Cache in main dictionary too
                    dict set mpoints $root "finfo" $relative "mtime" $mtime
                }
                if { ! [dict exists $finfor size]} {
                    set size [vcsvfs::${vcstype}::size $finfor]
                    dict set finfor "size" $size
                    # Cache in main dictionary too
                    dict set mpoints $root "finfo" $relative "size" $size
                }
                dict set res "mtime" [dict get $finfor "mtime"]
                dict set res "size"  [dict get $finfor "size"]
            }
            return $res
        }
        createdirectory - deletefile - removedirectory - utime {
            # Read-only, always error
        }
    }
    vfs::filesystem posixerror $::vfs::posix(EACCES)
    return -code error $::vfs::posix(EACCES)
}

##################################################################
# Test structure
##################################################################
if 0 {
# File traversing stuff from wiki...
proc ftw_1 {{dirs .}} {
    while {[llength $dirs]} {
        set dirs [lassign $dirs name]
        lappend dirs {*}[glob -nocomplain -directory $name -type d *]
        puts $name
    }
}
proc ls-l { dir } {
    # Get the current year, because the date format depends on it.
    set thisYear [clock format [clock seconds] -format %Y]
    # Walk the files in the given directory, accumulating lines
    # in $retval
    set retval {}
    set sep {}
    # In Tcl older than 8.3 use 'glob [file join $dir *]'
    foreach fileName [lsort [glob -dir $dir *]] {
        append retval $sep
        set sep \n
        # Get status of the file
        #file stat $fileName stat
        # use 'file lstat' instead: if the file is a symbolic link we don't want info about its target
        file lstat $fileName stat
        # Put in one character for file type.  Use - for a plain file.
        set type -
        if { [info exists stat(type)]
             && [string compare file $stat(type)] } {
            set type [string index $stat(type) 0]
        }
        append retval $type
        # Decode $stat(mode) into permissions the way that ls does it.
        foreach { mask pairs } {
            00400 { 00400 r }
            00200 { 00200 w }
            04100 { 04100 s 04000 S 00100 x }
            00040 { 00040 r }
            00020 { 00020 w }
            02010 { 02010 s 02000 S 00010 x }
            00004 { 00004 r }
            00002 { 00002 w }
            01001 { 01001 t 01000 T 00001 x }
        } {
            set value [expr $stat(mode) & $mask]
            set bit -
            foreach { x b } $pairs {
                if { $value == $x } {
                    set bit $b
                }
            }
            append retval $bit
        }
        # Put in link count, user ID, and size.  Note that the UID
        # will be numeric.  If you know how to back-translate this
        # from Tcl, please feel free to edit it in!
        # LV writes - use file userid and file groupid to convert the numbers back to names.
        #   I don't know what version of Tcl added those commands...
        append retval [format %4d $stat(nlink)] { }
        array set attribs [file attributes $fileName]
        if {[info exists attribs(-owner)]} {
            append retval [format %-8s $attribs(-owner)]
            append retval [format %-8s $attribs(-group)]
        } else {
            append retval [format %8d $stat(uid)]
            append retval [format %8d $stat(gid)]
        }
        append retval [format %9d $stat(size)]
        # Put in the date.  The current year is formatted differently
        # from prior years.
        set year [clock format $stat(mtime) -format "%Y"]
        if { $year == $thisYear } {
            set modified [clock format $stat(mtime) -format "%h %e %H:%M"]
        } else {
            set modified [clock format $stat(mtime) -format "%h %e  %Y"]
        }
        # glennj: see note below
        append retval { } $modified { }
        # Finally, put in the file name, stripping off the directory.
        append retval [file tail $fileName]
        if {[string compare $stat(type) link] == 0} {
            append retval " -> [file readlink $fileName]"
        }
        if {$type eq "-"} {
            set ch [open $fileName]
            set x [read $ch]
            set x [string range $x 0 4]
            close $ch
            append retval " = '$x'"
        }
        unset stat attribs
    }
    return $retval
}


set d [vcsvfs::fossil::mount ~/src/eskil f96b0fd915]
puts "------------- GLOB:"
puts [join [glob -dir $d *] \n]
puts "------------- FTW:"
ftw_1 [list $d]
puts "------------- LS:"
puts [ls-l $d]
}