Enter 2003: The Beautiful Scenery/enter-parhaat-2003.iso/files/Python-2.2.1.exe/HTTP.TCL

Text File | 2000-05-30 | 21.7 KB | 882 lines

# http.tcl --
#
#    Client-side HTTP for GET, POST, and HEAD commands.
#    These routines can be used in untrusted code that uses
#    the Safesock security policy.  These procedures use a
#    callback interface to avoid using vwait, which is not
#    defined in the safe base.
#
# See the file "license.terms" for information on usage and
# redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: http.tcl,v 1.32.2.1 2000/05/31 01:28:57 sandeep Exp $

# Rough version history:
# 1.0    Old http_get interface
# 2.0    http:: namespace and http::geturl
# 2.1    Added callbacks to handle arriving data, and timeouts
# 2.2    Added ability to fetch into a channel
# 2.3    Added SSL support, and ability to post from a channel
#    This version also cleans up error cases and eliminates the
#    "ioerror" status in favor of raising an error

package provide http 2.3

namespace eval http {
    variable http
    array set http {
    -accept */*
    -proxyhost {}
    -proxyport {}
    -useragent {Tcl http client package 2.3}
    -proxyfilter http::ProxyRequired
    }

    variable formMap
    variable alphanumeric a-zA-Z0-9
    variable c
    variable i 0
    for {} {$i <= 256} {incr i} {
    set c [format %c $i]
    if {![string match \[$alphanumeric\] $c]} {
        set formMap($c) %[format %.2x $i]
    }
    }
    # These are handled specially
    array set formMap {
    " " +   \n %0d%0a
    }

    variable urlTypes
    array set urlTypes {
    http    {80 ::socket}
    }

    namespace export geturl config reset wait formatQuery register unregister
    # Useful, but not exported: data size status code
}

# http::register --
#
#     See documentaion for details.
#
# Arguments:
#     proto           URL protocol prefix, e.g. https
#     port            Default port for protocol
#     command         Command to use to create socket
# Results:
#     list of port and command that was registered.

proc http::register {proto port command} {
    variable urlTypes
    set urlTypes($proto) [list $port $command]
}

# http::unregister --
#
#     Unregisters URL protocol handler
#
# Arguments:
#     proto           URL protocol prefix, e.g. https
# Results:
#     list of port and command that was unregistered.

proc http::unregister {proto} {
    variable urlTypes
    if {![info exists urlTypes($proto)]} {
    return -code error "unsupported url type \"$proto\""
    }
    set old $urlTypes($proto)
    unset urlTypes($proto)
    return $old
}

# http::config --
#
#    See documentaion for details.
#
# Arguments:
#    args        Options parsed by the procedure.
# Results:
#        TODO

proc http::config {args} {
    variable http
    set options [lsort [array names http -*]]
    set usage [join $options ", "]
    if {[llength $args] == 0} {
    set result {}
    foreach name $options {
        lappend result $name $http($name)
    }
    return $result
    }
    regsub -all -- - $options {} options
    set pat ^-([join $options |])$
    if {[llength $args] == 1} {
    set flag [lindex $args 0]
    if {[regexp -- $pat $flag]} {
        return $http($flag)
    } else {
        return -code error "Unknown option $flag, must be: $usage"
    }
    } else {
    foreach {flag value} $args {
        if {[regexp -- $pat $flag]} {
        set http($flag) $value
        } else {
        return -code error "Unknown option $flag, must be: $usage"
        }
    }
    }
}

# http::Finish --
#
#    Clean up the socket and eval close time callbacks
#
# Arguments:
#    token        Connection token.
#    errormsg    (optional) If set, forces status to error.
#       skipCB      (optional) If set, don't call the -command callback.  This
#                   is useful when geturl wants to throw an exception instead
#                   of calling the callback.  That way, the same error isn't
#                   reported to two places.
#
# Side Effects:
#        Closes the socket

proc http::Finish { token {errormsg ""} {skipCB 0}} {
    variable $token
    upvar 0 $token state
    global errorInfo errorCode
    if {[string length $errormsg] != 0} {
    set state(error) [list $errormsg $errorInfo $errorCode]
    set state(status) error
    }
    catch {close $state(sock)}
    catch {after cancel $state(after)}
    if {[info exists state(-command)] && !$skipCB} {
    if {[catch {eval $state(-command) {$token}} err]} {
        if {[string length $errormsg] == 0} {
        set state(error) [list $err $errorInfo $errorCode]
        set state(status) error
        }
    }
    if {[info exist state(-command)]} {
        # Command callback may already have unset our state
        unset state(-command)
    }
    }
}

# http::reset --
#
#    See documentaion for details.
#
# Arguments:
#    token    Connection token.
#    why    Status info.
#
# Side Effects:
#       See Finish

proc http::reset { token {why reset} } {
    variable $token
    upvar 0 $token state
    set state(status) $why
    catch {fileevent $state(sock) readable {}}
    catch {fileevent $state(sock) writable {}}
    Finish $token
    if {[info exists state(error)]} {
    set errorlist $state(error)
    unset state
    eval error $errorlist
    }
}

# http::geturl --
#
#    Establishes a connection to a remote url via http.
#
# Arguments:
#       url        The http URL to goget.
#       args        Option value pairs. Valid options include:
#                -blocksize, -validate, -headers, -timeout
# Results:
#    Returns a token for this connection.
#    This token is the name of an array that the caller should
#    unset to garbage collect the state.

proc http::geturl { url args } {
    variable http
    variable urlTypes

    # Initialize the state variable, an array.  We'll return the
    # name of this array as the token for the transaction.

    if {![info exists http(uid)]} {
    set http(uid) 0
    }
    set token [namespace current]::[incr http(uid)]
    variable $token
    upvar 0 $token state
    reset $token

    # Process command options.

    array set state {
    -blocksize     8192
    -queryblocksize 8192
    -validate     0
    -headers     {}
    -timeout     0
    -type           application/x-www-form-urlencoded
    -queryprogress    {}
    state        header
    meta        {}
    currentsize    0
    totalsize    0
    querylength    0
    queryoffset    0
        type            text/html
        body            {}
    status        ""
    http            ""
    }
    set options {-blocksize -channel -command -handler -headers \
        -progress -query -queryblocksize -querychannel -queryprogress\
        -validate -timeout -type}
    set usage [join $options ", "]
    regsub -all -- - $options {} options
    set pat ^-([join $options |])$
    foreach {flag value} $args {
    if {[regexp $pat $flag]} {
        # Validate numbers
        if {[info exists state($flag)] && \
            [string is integer -strict $state($flag)] && \
            ![string is integer -strict $value]} {
        unset $token
        return -code error "Bad value for $flag ($value), must be integer"
        }
        set state($flag) $value
    } else {
        unset $token
        return -code error "Unknown option $flag, can be: $usage"
    }
    }

    # Make sure -query and -querychannel aren't both specified

    set isQueryChannel [info exists state(-querychannel)]
    set isQuery [info exists state(-query)]
    if {$isQuery && $isQueryChannel} {
    unset $token
    return -code error "Can't combine -query and -querychannel options!"
    }

    # Validate URL, determine the server host and port, and check proxy case

    if {![regexp -nocase {^(([^:]*)://)?([^/:]+)(:([0-9]+))?(/.*)?$} $url \
        x prefix proto host y port srvurl]} {
    unset $token
    return -code error "Unsupported URL: $url"
    }
    if {[string length $proto] == 0} {
    set proto http
    set url ${proto}://$url
    }
    if {![info exists urlTypes($proto)]} {
    unset $token
    return -code error "Unsupported URL type \"$proto\""
    }
    set defport [lindex $urlTypes($proto) 0]
    set defcmd [lindex $urlTypes($proto) 1]

    if {[string length $port] == 0} {
    set port $defport
    }
    if {[string length $srvurl] == 0} {
    set srvurl /
    }
    if {[string length $proto] == 0} {
    set url http://$url
    }
    set state(url) $url
    if {![catch {$http(-proxyfilter) $host} proxy]} {
    set phost [lindex $proxy 0]
    set pport [lindex $proxy 1]
    }

    # If a timeout is specified we set up the after event
    # and arrange for an asynchronous socket connection.

    if {$state(-timeout) > 0} {
    set state(after) [after $state(-timeout) \
        [list http::reset $token timeout]]
    set async -async
    } else {
    set async ""
    }

    # If we are using the proxy, we must pass in the full URL that
    # includes the server name.

    if {[info exists phost] && [string length $phost]} {
    set srvurl $url
    set conStat [catch {eval $defcmd $async {$phost $pport}} s]
    } else {
    set conStat [catch {eval $defcmd $async {$host $port}} s]
    }
    if {$conStat} {

    # something went wrong while trying to establish the connection
    # Clean up after events and such, but DON'T call the command callback
    # (if available) because we're going to throw an exception from here
    # instead.
    Finish $token "" 1
    cleanup $token
    return -code error $s
    }
    set state(sock) $s

    # Wait for the connection to complete

    if {$state(-timeout) > 0} {
    fileevent $s writable [list http::Connect $token]
    http::wait $token

    if {[string equal $state(status) "error"]} {
        # something went wrong while trying to establish the connection
        # Clean up after events and such, but DON'T call the command
        # callback (if available) because we're going to throw an
        # exception from here instead.
        set err [lindex $state(error) 0]
        cleanup $token
        return -code error $err
    } elseif {![string equal $state(status) "connect"]} {
        # Likely to be connection timeout
        return $token
    }
    set state(status) ""
    }

    # Send data in cr-lf format, but accept any line terminators

    fconfigure $s -translation {auto crlf} -buffersize $state(-blocksize)

    # The following is disallowed in safe interpreters, but the socket
    # is already in non-blocking mode in that case.

    catch {fconfigure $s -blocking off}
    set how GET
    if {$isQuery} {
    set state(querylength) [string length $state(-query)]
    if {$state(querylength) > 0} {
        set how POST
        set contDone 0
    } else {
        # there's no query data
        unset state(-query)
        set isQuery 0
    }
    } elseif {$state(-validate)} {
    set how HEAD
    } elseif {$isQueryChannel} {
    set how POST
    # The query channel must be blocking for the async Write to
    # work properly.
    fconfigure $state(-querychannel) -blocking 1 -translation binary
    set contDone 0
    }

    if {[catch {
    puts $s "$how $srvurl HTTP/1.0"
    puts $s "Accept: $http(-accept)"
    puts $s "Host: $host"
    puts $s "User-Agent: $http(-useragent)"
    foreach {key value} $state(-headers) {
        regsub -all \[\n\r\]  $value {} value
        set key [string trim $key]
        if {[string equal $key "Content-Length"]} {
        set contDone 1
        set state(querylength) $value
        }
        if {[string length $key]} {
        puts $s "$key: $value"
        }
    }
    if {$isQueryChannel && $state(querylength) == 0} {
        # Try to determine size of data in channel
        # If we cannot seek, the surrounding catch will trap us

        set start [tell $state(-querychannel)]
        seek $state(-querychannel) 0 end
        set state(querylength) \
            [expr {[tell $state(-querychannel)] - $start}]
        seek $state(-querychannel) $start
    }

    # Flush the request header and set up the fileevent that will
    # either push the POST data or read the response.
    #
    # fileevent note:
    #
    # It is possible to have both the read and write fileevents active
    # at this point.  The only scenario it seems to affect is a server
    # that closes the connection without reading the POST data.
    # (e.g., early versions TclHttpd in various error cases).
    # Depending on the platform, the client may or may not be able to
    # get the response from the server because of the error it will
    # get trying to write the post data.  Having both fileevents active
    # changes the timing and the behavior, but no two platforms
    # (among Solaris, Linux, and NT)  behave the same, and none
    # behave all that well in any case.  Servers should always read thier
    # POST data if they expect the client to read their response.

    if {$isQuery || $isQueryChannel} {
        puts $s "Content-Type: $state(-type)"
        if {!$contDone} {
        puts $s "Content-Length: $state(querylength)"
        }
        puts $s ""
        fconfigure $s -translation {auto binary}
        fileevent $s writable [list http::Write $token]
    } else {
        puts $s ""
        flush $s
        fileevent $s readable [list http::Event $token]
    }

    if {! [info exists state(-command)]} {

        # geturl does EVERYTHING asynchronously, so if the user
        # calls it synchronously, we just do a wait here.

        wait $token
        if {[string equal $state(status) "error"]} {
        # Something went wrong, so throw the exception, and the
        # enclosing catch will do cleanup.
        return -code error [lindex $state(error) 0]
        }
    }
    } err]} {
    # The socket probably was never connected,
    # or the connection dropped later.

    # Clean up after events and such, but DON'T call the command callback
    # (if available) because we're going to throw an exception from here
    # instead.

    # if state(status) is error, it means someone's already called Finish
    # to do the above-described clean up.
    if {[string equal $state(status) "error"]} {
        Finish $token $err 1
    }
    cleanup $token
    return -code error $err
    }

    return $token
}

# Data access functions:
# Data - the URL data
# Status - the transaction status: ok, reset, eof, timeout
# Code - the HTTP transaction code, e.g., 200
# Size - the size of the URL data

proc http::data {token} {
    variable $token
    upvar 0 $token state
    return $state(body)
}
proc http::status {token} {
    variable $token
    upvar 0 $token state
    return $state(status)
}
proc http::code {token} {
    variable $token
    upvar 0 $token state
    return $state(http)
}
proc http::ncode {token} {
    variable $token
    upvar 0 $token state
    if {[regexp {[0-9]{3}} $state(http) numeric_code]} {
    return $numeric_code
    } else {
    return $state(http)
    }
}
proc http::size {token} {
    variable $token
    upvar 0 $token state
    return $state(currentsize)
}

proc http::error {token} {
    variable $token
    upvar 0 $token state
    if {[info exists state(error)]} {
    return $state(error)
    }
    return ""
}

# http::cleanup
#
#    Garbage collect the state associated with a transaction
#
# Arguments
#    token    The token returned from http::geturl
#
# Side Effects
#    unsets the state array

proc http::cleanup {token} {
    variable $token
    upvar 0 $token state
    if {[info exist state]} {
    unset state
    }
}

# http::Connect
#
#    This callback is made when an asyncronous connection completes.
#
# Arguments
#    token    The token returned from http::geturl
#
# Side Effects
#    Sets the status of the connection, which unblocks
#     the waiting geturl call

proc http::Connect {token} {
    variable $token
    upvar 0 $token state
    global errorInfo errorCode
    if {[eof $state(sock)] ||
    [string length [fconfigure $state(sock) -error]]} {
        Finish $token "connect failed [fconfigure $state(sock) -error]" 1
    } else {
    set state(status) connect
    fileevent $state(sock) writable {}
    }
    return
}

# http::Write
#
#    Write POST query data to the socket
#
# Arguments
#    token    The token for the connection
#
# Side Effects
#    Write the socket and handle callbacks.

proc http::Write {token} {
    variable $token
    upvar 0 $token state
    set s $state(sock)

    # Output a block.  Tcl will buffer this if the socket blocks

    set done 0
    if {[catch {

    # Catch I/O errors on dead sockets

    if {[info exists state(-query)]} {

        # Chop up large query strings so queryprogress callback
        # can give smooth feedback

        puts -nonewline $s \
            [string range $state(-query) $state(queryoffset) \
            [expr {$state(queryoffset) + $state(-queryblocksize) - 1}]]
        incr state(queryoffset) $state(-queryblocksize)
        if {$state(queryoffset) >= $state(querylength)} {
        set state(queryoffset) $state(querylength)
        set done 1
        }
    } else {

        # Copy blocks from the query channel

        set outStr [read $state(-querychannel) $state(-queryblocksize)]
        puts -nonewline $s $outStr
        incr state(queryoffset) [string length $outStr]
        if {[eof $state(-querychannel)]} {
        set done 1
        }
    }
    } err]} {
    # Do not call Finish here, but instead let the read half of
    # the socket process whatever server reply there is to get.

    set state(posterror) $err
    set done 1
    }
    if {$done} {
    catch {flush $s}
    fileevent $s writable {}
    fileevent $s readable [list http::Event $token]
    }

    # Callback to the client after we've completely handled everything

    if {[string length $state(-queryprogress)]} {
    eval $state(-queryprogress) [list $token $state(querylength)\
        $state(queryoffset)]
    }
}

# http::Event
#
#    Handle input on the socket
#
# Arguments
#    token    The token returned from http::geturl
#
# Side Effects
#    Read the socket and handle callbacks.

 proc http::Event {token} {
    variable $token
    upvar 0 $token state
    set s $state(sock)

     if {[eof $s]} {
    Eof $token
    return
    }
    if {[string equal $state(state) "header"]} {
    if {[catch {gets $s line} n]} {
        Finish $token $n
    } elseif {$n == 0} {
        set state(state) body
        if {![regexp -nocase ^text $state(type)]} {
        # Turn off conversions for non-text data
        fconfigure $s -translation binary
        if {[info exists state(-channel)]} {
            fconfigure $state(-channel) -translation binary
        }
        }
        if {[info exists state(-channel)] &&
            ![info exists state(-handler)]} {
        # Initiate a sequence of background fcopies
        fileevent $s readable {}
        CopyStart $s $token
        }
    } elseif {$n > 0} {
        if {[regexp -nocase {^content-type:(.+)$} $line x type]} {
        set state(type) [string trim $type]
        }
        if {[regexp -nocase {^content-length:(.+)$} $line x length]} {
        set state(totalsize) [string trim $length]
        }
        if {[regexp -nocase {^([^:]+):(.+)$} $line x key value]} {
        lappend state(meta) $key [string trim $value]
        } elseif {[regexp ^HTTP $line]} {
        set state(http) $line
        }
    }
    } else {
    if {[catch {
        if {[info exists state(-handler)]} {
        set n [eval $state(-handler) {$s $token}]
        } else {
        set block [read $s $state(-blocksize)]
        set n [string length $block]
        if {$n >= 0} {
            append state(body) $block
        }
        }
        if {$n >= 0} {
        incr state(currentsize) $n
        }
    } err]} {
        Finish $token $err
    } else {
        if {[info exists state(-progress)]} {
        eval $state(-progress) {$token $state(totalsize) $state(currentsize)}
        }
    }
    }
}

# http::CopyStart
#
#    Error handling wrapper around fcopy
#
# Arguments
#    s    The socket to copy from
#    token    The token returned from http::geturl
#
# Side Effects
#    This closes the connection upon error

 proc http::CopyStart {s token} {
    variable $token
    upvar 0 $token state
    if {[catch {
    fcopy $s $state(-channel) -size $state(-blocksize) -command \
        [list http::CopyDone $token]
    } err]} {
    Finish $token $err
    }
}

# http::CopyDone
#
#    fcopy completion callback
#
# Arguments
#    token    The token returned from http::geturl
#    count    The amount transfered
#
# Side Effects
#    Invokes callbacks

 proc http::CopyDone {token count {error {}}} {
    variable $token
    upvar 0 $token state
    set s $state(sock)
    incr state(currentsize) $count
    if {[info exists state(-progress)]} {
    eval $state(-progress) {$token $state(totalsize) $state(currentsize)}
    }
    # At this point the token may have been reset
    if {[string length $error]} {
    Finish $token $error
    } elseif {[catch {eof $s} iseof] || $iseof} {
    Eof $token
    } else {
    CopyStart $s $token
    }
}

# http::Eof
#
#    Handle eof on the socket
#
# Arguments
#    token    The token returned from http::geturl
#
# Side Effects
#    Clean up the socket

 proc http::Eof {token} {
    variable $token
    upvar 0 $token state
    if {[string equal $state(state) "header"]} {
    # Premature eof
    set state(status) eof
    } else {
    set state(status) ok
    }
    set state(state) eof
    Finish $token
}

# http::wait --
#
#    See documentaion for details.
#
# Arguments:
#    token    Connection token.
#
# Results:
#        The status after the wait.

proc http::wait {token} {
    variable $token
    upvar 0 $token state

    if {![info exists state(status)] || [string length $state(status)] == 0} {
    # We must wait on the original variable name, not the upvar alias
    vwait $token\(status)
    }

    return $state(status)
}

# http::formatQuery --
#
#    See documentaion for details.
#    Call http::formatQuery with an even number of arguments, where
#    the first is a name, the second is a value, the third is another
#    name, and so on.
#
# Arguments:
#    args    A list of name-value pairs.
#
# Results:
#        TODO

proc http::formatQuery {args} {
    set result ""
    set sep ""
    foreach i $args {
    append result $sep [mapReply $i]
    if {[string compare $sep "="]} {
        set sep =
    } else {
        set sep &
    }
    }
    return $result
}

# http::mapReply --
#
#    Do x-www-urlencoded character mapping
#
# Arguments:
#    string    The string the needs to be encoded
#
# Results:
#       The encoded string

 proc http::mapReply {string} {
    variable formMap

    # The spec says: "non-alphanumeric characters are replaced by '%HH'"
    # 1 leave alphanumerics characters alone
    # 2 Convert every other character to an array lookup
    # 3 Escape constructs that are "special" to the tcl parser
    # 4 "subst" the result, doing all the array substitutions

    set alphanumeric    a-zA-Z0-9
    regsub -all \[^$alphanumeric\] $string {$formMap(&)} string
    regsub -all \n $string {\\n} string
    regsub -all \t $string {\\t} string
    regsub -all {[][{})\\]\)} $string {\\&} string
    return [subst $string]
}

# http::ProxyRequired --
#    Default proxy filter.
#
# Arguments:
#    host    The destination host
#
# Results:
#       The current proxy settings

 proc http::ProxyRequired {host} {
    variable http
    if {[info exists http(-proxyhost)] && [string length $http(-proxyhost)]} {
    if {![info exists http(-proxyport)] || ![string length $http(-proxyport)]} {
        set http(-proxyport) 8080
    }
    return [list $http(-proxyhost) $http(-proxyport)]
    } else {
    return {}
    }
}