/usr/share/tcltk/tcllib1.16/nns/server.tcl is in tcllib 1.16-dfsg-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 | # -*- tcl -*-
# ### ### ### ######### ######### #########
## Name Service - Server (Singleton)
# ### ### ### ######### ######### #########
## Requirements
package require Tcl 8.4
package require comm ; # Generic message transport
package require interp ; # Interpreter helpers.
package require logger ; # Tracing internal activity
package require nameserv::common ; # Common/shared utilities
namespace eval ::nameserv::server {}
# ### ### ### ######### ######### #########
## API: Start, Stop
proc ::nameserv::server::start {} {
variable comm
variable port
variable localonly
log::debug "start"
if {$comm ne ""} return
log::debug "start /granted"
set interp [interp::createEmpty]
foreach msg {
Bind
Release
Search
Search/Continuous/Start
Search/Continuous/Stop
ProtocolVersion
ProtocolFeatures
} {
interp alias $interp $msg {} ::nameserv::server::$msg
}
set comm [comm::comm new ::nameserv::server::COMM \
-interp $interp \
-port $port \
-listen 1 \
-local $localonly]
$comm hook lost ::nameserv::server::LOST
log::debug "UP @$port local-only $localonly"
return
}
proc ::nameserv::server::stop {} {
variable comm
variable names
variable data
log::debug "stop"
if {$comm eq ""} return
log::debug "stop /granted"
# This kills all existing connection and destroys the configured
# -interp as well.
$comm destroy
set comm ""
array unset names *
array unset data *
log::debug "DOWN"
return
}
proc ::nameserv::server::active? {} {
variable comm
return [expr {$comm ne ""}]
}
# ### ### ### ######### ######### #########
## INT: Protocol operations
proc ::nameserv::server::ProtocolVersion {} {return 1}
proc ::nameserv::server::ProtocolFeatures {} {return {Core Search/Continuous}}
proc ::nameserv::server::Bind {name cdata} {
variable comm
variable names
variable data
set id [$comm remoteid]
log::debug "bind ([list $name -> $cdata]), for $id"
if {[info exists data($name)]} {
log::debug "bind failed, \"$name\" is already bound"
return -code error "Name \"$name\" is already bound"
}
lappend names($id) $name
set data($name) $cdata
Search/Continuous/NotifyAdd $name $cdata
return
}
proc ::nameserv::server::Release {} {
variable comm
ReleaseId [$comm remoteid]
return
}
proc ::nameserv::server::Search {pattern} {
variable data
return [array get data $pattern]
}
proc ::nameserv::server::ReleaseId {id} {
variable names
variable data
variable searchi
log::debug "release id $id"
# Two steps. Release all searches the client may have open, then
# all names it may have bound. That last step may trigger
# notifications for searches by other clients. It must not trigger
# searches from the client just going away, hence their release
# first.
foreach k [array names searchi [list $id *]] {
Search/Release $k
}
if {[info exists names($id)]} {
set gone {}
foreach n $names($id) {
lappend gone $n $data($n)
catch {unset data($n)}
log::debug "release name <$n>"
}
unset names($id)
Search/Continuous/NotifyRelease $gone
}
return
}
# ### ### ### ######### ######### #########
## Support for continuous and async searches
proc ::nameserv::server::Search/Continuous/Start {tag pattern} {
variable data
variable searchi
variable searchp
variable comm
set id [$comm remoteid]
# Register the search, then generate the initial response.
# Non-unique tags are silently discarded. Clients will wait
# forever.
set k [list $id $tag]
log::debug "search <$k>"
if {[info exists searchi($k)]} {
log::debug "search already known"
return
}
log::debug "search added"
set searchi($k) $pattern
lappend searchp($pattern) $k
$comm send -async $id [list Search/Continuous/Change \
$tag add [array get data $pattern]]
return
}
proc ::nameserv::server::Search/Continuous/Stop {tag} {
Search/Release [list [$comm remoteid] $tag]
return
}
proc ::nameserv::server::Search/Release {k} {
variable searchi
variable searchp
# Remove search information from the data store
if {![info exists searchi($k)]} return
log::debug "release search <$k>"
set pattern $searchi($k)
unset searchi($k)
set pos [lsearch -exact $searchp($pattern) $k]
if {$pos < 0} return
set new [lreplace $searchp($pattern) $pos $pos]
if {[llength $new]} {
# Shorten the callback list.
set searchp($pattern) $new
} else {
# Nothing monitors that pattern anymore, remove it completely.
unset searchp($pattern)
}
return
}
proc ::nameserv::server::Search/Continuous/NotifyAdd {name val} {
variable searchp
# Abort quickly if there are no searches waiting.
if {![array size searchp]} return
foreach p [array names searchp] {
if {![string match $p $name]} continue
Notify $p add [list $name $val]
}
return
}
proc ::nameserv::server::Search/Continuous/NotifyRelease {gone} {
variable searchp
# Abort quickly if there are no searches waiting.
if {![array size searchp]} return
array set m $gone
foreach p [array names searchp] {
set response [array get m $p]
if {![llength $response]} continue
Notify $p remove $response
}
return
}
proc ::nameserv::server::Notify {p type response} {
variable searchp
variable comm
foreach item $searchp($p) {
foreach {id tag} $item break
$comm send -async $id \
[list Search/Continuous/Change $tag $type $response]
}
return
}
# ### ### ### ######### ######### #########
## Initialization - In-memory database
namespace eval ::nameserv::server {
# Database
# search = list (id tag) : Searches are identified by client and a tag.
#
# array (id -> list (name)) : Names under which a connection is known.
# array (name -> data) : Data associated with a name.
#
# array (pattern -> list (search)) : Per pattern the list of searches using it.
# array (search -> pattern) : Pattern per active search.
#
# searchp <~~> names
# searchi <~~> data
variable names ; array set names {}
variable data ; array set data {}
variable searchp ; array set searchp {}
variable searchi ; array set searchi {}
}
# ### ### ### ######### ######### #########
## INT: Connection management
proc ::nameserv::server::LOST {args} {
# Currently just to see when a client goes away.
upvar 1 id id chan chan reason reason
ReleaseId $id
return
}
# ### ### ### ######### ######### #########
## Initialization - System state
namespace eval ::nameserv::server {
# Object command of the communication channel of the server.
# If present re-configuration is not possible.
variable comm {}
}
# ### ### ### ######### ######### #########
## API: Configuration management (host, port)
proc ::nameserv::server::cget {option} {
return [configure $option]
}
proc ::nameserv::server::configure {args} {
variable localonly
variable port
variable comm
if {![llength $args]} {
return [list -localonly $localonly -port $port]
}
if {[llength $args] == 1} {
# cget
set opt [lindex $args 0]
switch -exact -- $opt {
-localonly { return $localonly }
-port { return $port }
default {
return -code error "bad option \"$opt\", expected -localonly, or -port"
}
}
}
# Note: Should -port be made configurable after communication has
# started it might be necessary to provide code to re-initialize
# the connections to all known clients using the new
# configuration.
while {[llength $args]} {
set opt [lindex $args 0]
switch -exact -- $opt {
-localonly {
if {[llength $args] < 2} {
return -code error "value for \"$opt\" is missing"
}
# Todo: Check boolean
set new [lindex $args 1]
set args [lrange $args 2 end]
if {$new == $localonly} continue
set localonly $new
if {$comm eq ""} continue
$comm configure -local $localonly
}
-port {
if {$comm ne ""} {
return -code error "Unable to configure an active server"
}
if {[llength $args] < 2} {
return -code error "value for \"$opt\" is missing"
}
# Todo: Check non-zero unsigned short integer
set port [lindex $args 1]
set args [lrange $args 2 end]
}
default {
return -code error "bad option \"$opt\", expected -localonly, or -port"
}
}
}
return
}
# ### ### ### ######### ######### #########
## Initialization - Tracing, Configuration
logger::initNamespace ::nameserv::server
namespace eval ::nameserv::server {
# Port the server will listen on, and boolean flag determining
# acceptance of non-local connections.
variable port [nameserv::common::port]
variable localonly 1
}
# ### ### ### ######### ######### #########
## Ready
package provide nameserv::server 0.3.2
##
# ### ### ### ######### ######### #########
|