source: tol/tolsh/tolsh.vfs/lib/tcllib1.10/transfer/ddest.tcl @ 8227d4c

# -*- tcl -*-
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##

# Class for the handling of stream destinations.

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## Requirements

package require snit

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## Implementation

snit::type ::transfer::data::destination {

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    ## API

    #                       Destination is ...
    option -channel  {} ; # an open & writable channel.
    option -file     {} ; # a writable file.
    option -variable {} ; # the named variable.

    method put   {chunk} {}
    method done  {}      {}
    method valid {mv}    {}

    method receive {sock done} {}

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    ## Implementation

    method put {chunk} {
        if {$xtype eq "file"} {
            set value [open $value w]
            set xtype  channel
            set close 1
        }

        switch -exact -- $xtype {
            variable {
                upvar \#0 $value var
                append var $chunk
            }
            channel {
                puts -nonewline $value $chunk
            }
        }
        return
    }

    method done {} {
        switch -exact -- $xtype {
            file - variable {}
            channel {
                if {$close} {close $value}
            }
        }
    }

    method valid {mv} {
        upvar 1 $mv message
        switch -exact -- $xtype {
            undefined {
                set message "Data destination is undefined"
                return 0
            }
            default {}
        }
        return 1
    }

    method receive {sock done} {
        set ntransfered 0
        set old [fconfigure $sock -blocking]
        fconfigure $sock -blocking 0
        fileevent $sock readable \
                [mymethod Read $sock $old $done]
        return
    }

    method Read {sock oldblock done} {
        set chunk [read $sock]
        if {[set l [string length $chunk]]} {
            $self put $chunk
            incr ntransfered $l
        }
        if {[eof $sock]} {
            $self done
            fileevent  $sock readable {}
            fconfigure $sock -blocking $oldblock

            lappend done $ntransfered
            uplevel #0 $done
        }
        return
    }

    # ### ### ### ######### ######### #########
    ## Internal helper commands.

    onconfigure -variable {newvalue} {
        set etype variable
        set xtype string

        if {![uplevel \#0 {info exists $newvalue}]} {
            return -code error "Bad variable \"$newvalue\", does not exist"
        }

        set value $newvalue
        return
    }

    onconfigure -channel {newvalue} {
        if {![llength [file channels $newvalue]]} {
            return -code error "Bad channel handle \"$newvalue\", does not exist"
        }
        set etype channel
        set xtype channel
        set value $newvalue
        return
    }

    onconfigure -file {newvalue} {
        if {![file exists $newvalue]} {
            set d [file dirname $newvalue]
            if {![file writable $d]} {
                return -code error "File \"$newvalue\" not creatable"
            }
            if {![file isdirectory $d]} {
                return -code error "File \"$newvalue\" not creatable"
            }
        } else {
            if {![file writable $newvalue]} {
                return -code error "File \"$newvalue\" not writable"
            }
            if {![file isfile $newvalue]} {
                return -code error "File \"$newvalue\" not a file"
            }
        }
        set etype channel
        set xtype file
        set value $newvalue
        return
    }

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    ## Data structures

    variable etype  undefined
    variable xtype  undefined
    variable value
    variable close 0

    variable ntransfered

    ##
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}

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## Ready

package provide transfer::data::destination 0.1