Zarutian 2005-07-27-01:15 Here is a super simple peer-to-peer system:
set myIdentity empty
set listeningPortnr 8050
rename send old_send
proc log {message {level 5}} {
# redefine this proc to filter the firehose stream of log messages.
# levels
# 1 mind numbing detail
# 2 less numbing
# 3 noteworthy
# 4 milestone
# 5 landmark
puts "[clock seconds]:[set level]: $message"
}
proc send {chan data} {
log [info level 0] 1
catch {
puts $chan $data
flush $chan
}
}
proc appendToInBuffer {chan data} {
log [info level 0] 1
variable buffers
append buffers($chan) $data
append buffers($chan) "\n"
}
proc getInBuffer {chan} {
log [info level 0] 1
variable buffers
set buffers($chan)
}
proc emptyInBuffer {chan} {
log [info level 0] 1
variable buffers
catch {
unset buffers($chan)
}
}
proc inBufferReady {chan} {
log [info level 0] 1
variable buffers
return [info complete [set buffers($chan)]]
}
proc dropPeer {chan} {
log [info level 0] 1
close $chan
emptyInBuffer $chan
}
proc addToKnownPeers {identity ipnr portnr} {
log [info level 0] 1
variable knownPeers
lappend knownPeers [list $identity $ipnr $portnr [clock seconds]]
}
proc accept {chan ipnr portnr} {
log [info level 0] 2
fconfigure $chan -encoding utf-8
send $chan "hello $ipnr $portnr"
send $chan "comment This is a super simple peer to peer node"
send $chan "ready"
fileevent $chan readable [list handle_connection $chan $ipnr]
}
proc handle_connection {chan ipnr} {
log [info level 0] 2
appendToInBuffer $chan [gets $chan]
if {[inBufferReady $chan]} {
handle_gram [GetInBuffer $chan] $chan $ipnr
emptyInBuffer $chan
}
if {[eof $chan]} { dropPeer $chan }
}
proc handle_gram {gram chan ipnr} {
log [info level 0] 3
switch -exact -- [lindex $gram 0] {
"your_identity?" {
variable myIdentity
variable listeningPortnr
send $chan "peer_anounce [list $myIdentity] ?ip? $listeningPortnr"
return
}
"peer_anounce" {
set identity [lindex $gram 1]
set ip [lindex $gram 2]
if {$ip == "?ip?"} { set ip $ipnr }
set portnr [lindex $gram 3]
addToKnownPeers $identity $ip $portnr
return
}
"quit" {
send $chan "Goodbye!"
dropPeer $chan
return
}
}
}...work in progress