redis.tcl

   1 # Tcl clinet library - used by test-redis.tcl script for now
   2 # Copyright (C) 2009 Salvatore Sanfilippo
   3 # Released under the BSD license like Redis itself
   4 #
   5 # Example usage:
   6 #
   7 # set r [redis 127.0.0.1 6379]
   8 # $r lpush mylist foo
   9 # $r lpush mylist bar
  10 # $r lrange mylist 0 -1
  11 # $r close
  12 #
  13 # Non blocking usage example:
  14 #
  15 # proc handlePong {r type reply} {
  16 #     puts "PONG $type '$reply'"
  17 #     if {$reply ne "PONG"} {
  18 #         $r ping [list handlePong]
  19 #     }
  20 # }
  21 #
  22 # set r [redis]
  23 # $r blocking 0
  24 # $r get fo [list handlePong]
  25 #
  26 # vwait forever
  27
  28 package require Tcl 8.5
  29 package provide redis 0.1
  30
  31 namespace eval redis {}
  32 set ::redis::id 0
  33 array set ::redis::fd {}
  34 array set ::redis::blocking {}
  35 array set ::redis::callback {}
  36 array set ::redis::state {} ;# State in non-blocking reply reading
  37 array set ::redis::statestack {} ;# Stack of states, for nested mbulks
  38 array set ::redis::bulkarg {}
  39 array set ::redis::multibulkarg {}
  40
  41 # Flag commands requiring last argument as a bulk write operation
  42 foreach redis_bulk_cmd {
  43     set setnx rpush lpush lset lrem sadd srem sismember echo getset smove zadd zrem zscore zincrby append zrank zrevrank hget hdel hexists
  44 } {
  45     set ::redis::bulkarg($redis_bulk_cmd) {}
  46 }
  47
  48 # Flag commands requiring last argument as a bulk write operation
  49 foreach redis_multibulk_cmd {
  50     mset msetnx hset hsetnx hmset hmget
  51 } {
  52     set ::redis::multibulkarg($redis_multibulk_cmd) {}
  53 }
  54
  55 unset redis_bulk_cmd
  56 unset redis_multibulk_cmd
  57
  58 proc redis {{server 127.0.0.1} {port 6379}} {
  59     set fd [socket $server $port]
  60     fconfigure $fd -translation binary
  61     set id [incr ::redis::id]
  62     set ::redis::fd($id) $fd
  63     set ::redis::blocking($id) 1
  64     ::redis::redis_reset_state $id
  65     interp alias {} ::redis::redisHandle$id {} ::redis::__dispatch__ $id
  66 }
  67
  68 proc ::redis::__dispatch__ {id method args} {
  69     set fd $::redis::fd($id)
  70     set blocking $::redis::blocking($id)
  71     if {$blocking == 0} {
  72         if {[llength $args] == 0} {
  73             error "Please provide a callback in non-blocking mode"
  74         }
  75         set callback [lindex $args end]
  76         set args [lrange $args 0 end-1]
  77     }
  78     if {[info command ::redis::__method__$method] eq {}} {
  79         if {[info exists ::redis::bulkarg($method)]} {
  80             set cmd "$method "
  81             append cmd [join [lrange $args 0 end-1]]
  82             append cmd " [string length [lindex $args end]]\r\n"
  83             append cmd [lindex $args end]
  84             ::redis::redis_writenl $fd $cmd
  85         } elseif {[info exists ::redis::multibulkarg($method)]} {
  86             set cmd "*[expr {[llength $args]+1}]\r\n"
  87             append cmd "$[string length $method]\r\n$method\r\n"
  88             foreach a $args {
  89                 append cmd "$[string length $a]\r\n$a\r\n"
  90             }
  91             ::redis::redis_write $fd $cmd
  92             flush $fd
  93         } else {
  94             set cmd "$method "
  95             append cmd [join $args]
  96             ::redis::redis_writenl $fd $cmd
  97         }
  98         if {$blocking} {
  99             ::redis::redis_read_reply $fd
 100         } else {
 101             # Every well formed reply read will pop an element from this
 102             # list and use it as a callback. So pipelining is supported
 103             # in non blocking mode.
 104             lappend ::redis::callback($id) $callback
 105             fileevent $fd readable [list ::redis::redis_readable $fd $id]
 106         }
 107     } else {
 108         uplevel 1 [list ::redis::__method__$method $id $fd] $args
 109     }
 110 }
 111
 112 proc ::redis::__method__blocking {id fd val} {
 113     set ::redis::blocking($id) $val
 114     fconfigure $fd -blocking $val
 115 }
 116
 117 proc ::redis::__method__close {id fd} {
 118     catch {close $fd}
 119     catch {unset ::redis::fd($id)}
 120     catch {unset ::redis::blocking($id)}
 121     catch {unset ::redis::state($id)}
 122     catch {unset ::redis::statestack($id)}
 123     catch {unset ::redis::callback($id)}
 124     catch {interp alias {} ::redis::redisHandle$id {}}
 125 }
 126
 127 proc ::redis::__method__channel {id fd} {
 128     return $fd
 129 }
 130
 131 proc ::redis::redis_write {fd buf} {
 132     puts -nonewline $fd $buf
 133 }
 134
 135 proc ::redis::redis_writenl {fd buf} {
 136     redis_write $fd $buf
 137     redis_write $fd "\r\n"
 138     flush $fd
 139 }
 140
 141 proc ::redis::redis_readnl {fd len} {
 142     set buf [read $fd $len]
 143     read $fd 2 ; # discard CR LF
 144     return $buf
 145 }
 146
 147 proc ::redis::redis_bulk_read {fd} {
 148     set count [redis_read_line $fd]
 149     if {$count == -1} return {}
 150     set buf [redis_readnl $fd $count]
 151     return $buf
 152 }
 153
 154 proc ::redis::redis_multi_bulk_read fd {
 155     set count [redis_read_line $fd]
 156     if {$count == -1} return {}
 157     set l {}
 158     for {set i 0} {$i < $count} {incr i} {
 159         lappend l [redis_read_reply $fd]
 160     }
 161     return $l
 162 }
 163
 164 proc ::redis::redis_read_line fd {
 165     string trim [gets $fd]
 166 }
 167
 168 proc ::redis::redis_read_reply fd {
 169     set type [read $fd 1]
 170     switch -exact -- $type {
 171         : -
 172         + {redis_read_line $fd}
 173         - {return -code error [redis_read_line $fd]}
 174         $ {redis_bulk_read $fd}
 175         * {redis_multi_bulk_read $fd}
 176         default {return -code error "Bad protocol, $type as reply type byte"}
 177     }
 178 }
 179
 180 proc ::redis::redis_reset_state id {
 181     set ::redis::state($id) [dict create buf {} mbulk -1 bulk -1 reply {}]
 182     set ::redis::statestack($id) {}
 183 }
 184
 185 proc ::redis::redis_call_callback {id type reply} {
 186     set cb [lindex $::redis::callback($id) 0]
 187     set ::redis::callback($id) [lrange $::redis::callback($id) 1 end]
 188     uplevel #0 $cb [list ::redis::redisHandle$id $type $reply]
 189     ::redis::redis_reset_state $id
 190 }
 191
 192 # Read a reply in non-blocking mode.
 193 proc ::redis::redis_readable {fd id} {
 194     if {[eof $fd]} {
 195         redis_call_callback $id eof {}
 196         ::redis::__method__close $id $fd
 197         return
 198     }
 199     if {[dict get $::redis::state($id) bulk] == -1} {
 200         set line [gets $fd]
 201         if {$line eq {}} return ;# No complete line available, return
 202         switch -exact -- [string index $line 0] {
 203             : -
 204             + {redis_call_callback $id reply [string range $line 1 end-1]}
 205             - {redis_call_callback $id err [string range $line 1 end-1]}
 206             $ {
 207                 dict set ::redis::state($id) bulk \
 208                     [expr [string range $line 1 end-1]+2]
 209                 if {[dict get $::redis::state($id) bulk] == 1} {
 210                     # We got a $-1, hack the state to play well with this.
 211                     dict set ::redis::state($id) bulk 2
 212                     dict set ::redis::state($id) buf "\r\n"
 213                     ::redis::redis_readable $fd $id
 214                 }
 215             }
 216             * {
 217                 dict set ::redis::state($id) mbulk [string range $line 1 end-1]
 218                 # Handle *-1
 219                 if {[dict get $::redis::state($id) mbulk] == -1} {
 220                     redis_call_callback $id reply {}
 221                 }
 222             }
 223             default {
 224                 redis_call_callback $id err \
 225                     "Bad protocol, $type as reply type byte"
 226             }
 227         }
 228     } else {
 229         set totlen [dict get $::redis::state($id) bulk]
 230         set buflen [string length [dict get $::redis::state($id) buf]]
 231         set toread [expr {$totlen-$buflen}]
 232         set data [read $fd $toread]
 233         set nread [string length $data]
 234         dict append ::redis::state($id) buf $data
 235         # Check if we read a complete bulk reply
 236         if {[string length [dict get $::redis::state($id) buf]] ==
 237             [dict get $::redis::state($id) bulk]} {
 238             if {[dict get $::redis::state($id) mbulk] == -1} {
 239                 redis_call_callback $id reply \
 240                     [string range [dict get $::redis::state($id) buf] 0 end-2]
 241             } else {
 242                 dict with ::redis::state($id) {
 243                     lappend reply [string range $buf 0 end-2]
 244                     incr mbulk -1
 245                     set bulk -1
 246                 }
 247                 if {[dict get $::redis::state($id) mbulk] == 0} {
 248                     redis_call_callback $id reply \
 249                         [dict get $::redis::state($id) reply]
 250                 }
 251             }
 252         }
 253     }
 254 }