diff options
Diffstat (limited to 'tcllib/modules/crc/crc32.tcl')
| -rw-r--r-- | tcllib/modules/crc/crc32.tcl | 377 |
1 files changed, 377 insertions, 0 deletions
diff --git a/tcllib/modules/crc/crc32.tcl b/tcllib/modules/crc/crc32.tcl new file mode 100644 index 0000000..ffc1f36 --- /dev/null +++ b/tcllib/modules/crc/crc32.tcl @@ -0,0 +1,377 @@ +# crc32.tcl -- Copyright (C) 2002 Pat Thoyts <patthoyts@users.sourceforge.net> +# +# CRC32 Cyclic Redundancy Check. +# (for algorithm see http://www.rad.com/networks/1994/err_con/crc.htm) +# +# From http://mini.net/tcl/2259.tcl +# Written by Wayland Augur and Pat Thoyts. +# +# ------------------------------------------------------------------------- +# See the file "license.terms" for information on usage and redistribution +# of this file, and for a DISCLAIMER OF ALL WARRANTIES. +# ------------------------------------------------------------------------- + +package require Tcl 8.2 + +namespace eval ::crc { + variable accel + array set accel {critcl 0 trf 0} + + namespace export crc32 + + variable crc32_tbl [list 0x00000000 0x77073096 0xEE0E612C 0x990951BA \ + 0x076DC419 0x706AF48F 0xE963A535 0x9E6495A3 \ + 0x0EDB8832 0x79DCB8A4 0xE0D5E91E 0x97D2D988 \ + 0x09B64C2B 0x7EB17CBD 0xE7B82D07 0x90BF1D91 \ + 0x1DB71064 0x6AB020F2 0xF3B97148 0x84BE41DE \ + 0x1ADAD47D 0x6DDDE4EB 0xF4D4B551 0x83D385C7 \ + 0x136C9856 0x646BA8C0 0xFD62F97A 0x8A65C9EC \ + 0x14015C4F 0x63066CD9 0xFA0F3D63 0x8D080DF5 \ + 0x3B6E20C8 0x4C69105E 0xD56041E4 0xA2677172 \ + 0x3C03E4D1 0x4B04D447 0xD20D85FD 0xA50AB56B \ + 0x35B5A8FA 0x42B2986C 0xDBBBC9D6 0xACBCF940 \ + 0x32D86CE3 0x45DF5C75 0xDCD60DCF 0xABD13D59 \ + 0x26D930AC 0x51DE003A 0xC8D75180 0xBFD06116 \ + 0x21B4F4B5 0x56B3C423 0xCFBA9599 0xB8BDA50F \ + 0x2802B89E 0x5F058808 0xC60CD9B2 0xB10BE924 \ + 0x2F6F7C87 0x58684C11 0xC1611DAB 0xB6662D3D \ + 0x76DC4190 0x01DB7106 0x98D220BC 0xEFD5102A \ + 0x71B18589 0x06B6B51F 0x9FBFE4A5 0xE8B8D433 \ + 0x7807C9A2 0x0F00F934 0x9609A88E 0xE10E9818 \ + 0x7F6A0DBB 0x086D3D2D 0x91646C97 0xE6635C01 \ + 0x6B6B51F4 0x1C6C6162 0x856530D8 0xF262004E \ + 0x6C0695ED 0x1B01A57B 0x8208F4C1 0xF50FC457 \ + 0x65B0D9C6 0x12B7E950 0x8BBEB8EA 0xFCB9887C \ + 0x62DD1DDF 0x15DA2D49 0x8CD37CF3 0xFBD44C65 \ + 0x4DB26158 0x3AB551CE 0xA3BC0074 0xD4BB30E2 \ + 0x4ADFA541 0x3DD895D7 0xA4D1C46D 0xD3D6F4FB \ + 0x4369E96A 0x346ED9FC 0xAD678846 0xDA60B8D0 \ + 0x44042D73 0x33031DE5 0xAA0A4C5F 0xDD0D7CC9 \ + 0x5005713C 0x270241AA 0xBE0B1010 0xC90C2086 \ + 0x5768B525 0x206F85B3 0xB966D409 0xCE61E49F \ + 0x5EDEF90E 0x29D9C998 0xB0D09822 0xC7D7A8B4 \ + 0x59B33D17 0x2EB40D81 0xB7BD5C3B 0xC0BA6CAD \ + 0xEDB88320 0x9ABFB3B6 0x03B6E20C 0x74B1D29A \ + 0xEAD54739 0x9DD277AF 0x04DB2615 0x73DC1683 \ + 0xE3630B12 0x94643B84 0x0D6D6A3E 0x7A6A5AA8 \ + 0xE40ECF0B 0x9309FF9D 0x0A00AE27 0x7D079EB1 \ + 0xF00F9344 0x8708A3D2 0x1E01F268 0x6906C2FE \ + 0xF762575D 0x806567CB 0x196C3671 0x6E6B06E7 \ + 0xFED41B76 0x89D32BE0 0x10DA7A5A 0x67DD4ACC \ + 0xF9B9DF6F 0x8EBEEFF9 0x17B7BE43 0x60B08ED5 \ + 0xD6D6A3E8 0xA1D1937E 0x38D8C2C4 0x4FDFF252 \ + 0xD1BB67F1 0xA6BC5767 0x3FB506DD 0x48B2364B \ + 0xD80D2BDA 0xAF0A1B4C 0x36034AF6 0x41047A60 \ + 0xDF60EFC3 0xA867DF55 0x316E8EEF 0x4669BE79 \ + 0xCB61B38C 0xBC66831A 0x256FD2A0 0x5268E236 \ + 0xCC0C7795 0xBB0B4703 0x220216B9 0x5505262F \ + 0xC5BA3BBE 0xB2BD0B28 0x2BB45A92 0x5CB36A04 \ + 0xC2D7FFA7 0xB5D0CF31 0x2CD99E8B 0x5BDEAE1D \ + 0x9B64C2B0 0xEC63F226 0x756AA39C 0x026D930A \ + 0x9C0906A9 0xEB0E363F 0x72076785 0x05005713 \ + 0x95BF4A82 0xE2B87A14 0x7BB12BAE 0x0CB61B38 \ + 0x92D28E9B 0xE5D5BE0D 0x7CDCEFB7 0x0BDBDF21 \ + 0x86D3D2D4 0xF1D4E242 0x68DDB3F8 0x1FDA836E \ + 0x81BE16CD 0xF6B9265B 0x6FB077E1 0x18B74777 \ + 0x88085AE6 0xFF0F6A70 0x66063BCA 0x11010B5C \ + 0x8F659EFF 0xF862AE69 0x616BFFD3 0x166CCF45 \ + 0xA00AE278 0xD70DD2EE 0x4E048354 0x3903B3C2 \ + 0xA7672661 0xD06016F7 0x4969474D 0x3E6E77DB \ + 0xAED16A4A 0xD9D65ADC 0x40DF0B66 0x37D83BF0 \ + 0xA9BCAE53 0xDEBB9EC5 0x47B2CF7F 0x30B5FFE9 \ + 0xBDBDF21C 0xCABAC28A 0x53B39330 0x24B4A3A6 \ + 0xBAD03605 0xCDD70693 0x54DE5729 0x23D967BF \ + 0xB3667A2E 0xC4614AB8 0x5D681B02 0x2A6F2B94 \ + 0xB40BBE37 0xC30C8EA1 0x5A05DF1B 0x2D02EF8D] + + # calculate the sign bit for the current platform. + variable signbit + if {![info exists signbit]} { + variable v + for {set v 1} {int($v) != 0} {set signbit $v; set v [expr {$v<<1}]} {} + unset v + } + + variable uid ; if {![info exists uid]} {set uid 0} +} + +# ------------------------------------------------------------------------- + +# crc::Crc32Init -- +# +# Create and initialize a crc32 context. This is cleaned up +# when we we call Crc32Final to obtain the result. +# +proc ::crc::Crc32Init {{seed 0xFFFFFFFF}} { + variable uid + variable accel + set token [namespace current]::[incr uid] + upvar #0 $token state + array set state [list sum $seed] + # If the initial seed is set to some other value we cannot use Trf. + if {$accel(trf) && $seed == 0xFFFFFFFF} { + set s {} + switch -exact -- $::tcl_platform(platform) { + windows { set s [open NUL w] } + unix { set s [open /dev/null w] } + } + if {$s != {}} { + fconfigure $s -translation binary -buffering none + ::crc-zlib -attach $s -mode write \ + -write-type variable \ + -write-destination ${token}(trfwrite) + array set state [list trfread 0 trfwrite 0 trf $s] + } + } + return $token +} + +# crc::Crc32Update -- +# +# This is called to add more data into the checksum. You may +# call this as many times as you require. Note that passing in +# "ABC" is equivalent to passing these letters in as separate +# calls -- hence this proc permits summing of chunked data. +# +# If we have a C-based implementation available, then we will +# use it here in preference to the pure-Tcl implementation. +# +proc ::crc::Crc32Update {token data} { + variable accel + upvar #0 $token state + set sum $state(sum) + if {$accel(critcl)} { + set sum [Crc32_c $data $sum] + } elseif {[info exists state(trf)]} { + puts -nonewline $state(trf) $data + return + } else { + set sum [Crc32_tcl $data $sum] + } + set state(sum) [expr {$sum ^ 0xFFFFFFFF}] + return +} + +# crc::Crc32Final -- +# +# This procedure is used to close the context and returns the +# checksum value. Once this procedure has been called the checksum +# context is freed and cannot be used again. +# +proc ::crc::Crc32Final {token} { + upvar #0 $token state + if {[info exists state(trf)]} { + close $state(trf) + binary scan $state(trfwrite) i sum + set sum [expr {$sum & 0xFFFFFFFF}] + } else { + set sum [expr {($state(sum) ^ 0xFFFFFFFF) & 0xFFFFFFFF}] + } + unset state + return $sum +} + +# crc::Crc32_tcl -- +# +# The pure-Tcl implementation of a table based CRC-32 checksum. +# The seed should always be 0xFFFFFFFF to begin with, but for +# successive chunks of data the seed should be set to the result +# of the last chunk. +# +proc ::crc::Crc32_tcl {data {seed 0xFFFFFFFF}} { + variable crc32_tbl + variable signbit + set signmask [expr {~$signbit>>7}] + set crcval $seed + + binary scan $data c* nums + foreach {n} $nums { + set ndx [expr {($crcval ^ $n) & 0xFF}] + set lkp [lindex $crc32_tbl $ndx] + set crcval [expr {($lkp ^ ($crcval >> 8 & $signmask)) & 0xFFFFFFFF}] + } + + return [expr {$crcval ^ 0xFFFFFFFF}] +} + +# crc::Crc32_c -- +# +# A C version of the CRC-32 code using the same table. This is +# designed to be compiled using critcl. +# +if {[package provide critcl] != {}} { + namespace eval ::crc { + critcl::ccommand Crc32_c {dummy interp objc objv} { + int r = TCL_OK; + unsigned long t = 0xFFFFFFFFL; + + if (objc < 2 || objc > 3) { + Tcl_WrongNumArgs(interp, 1, objv, "data ?seed?"); + return TCL_ERROR; + } + + if (objc == 3) { + r = Tcl_GetLongFromObj(interp, objv[2], (long *)&t); + } + + if (r == TCL_OK) { + int cn, size, ndx; + unsigned char *data; + unsigned long lkp; + Tcl_Obj *tblPtr, *lkpPtr; + + tblPtr = Tcl_GetVar2Ex(interp, "::crc::crc32_tbl", NULL, + TCL_LEAVE_ERR_MSG ); + if (tblPtr == NULL) { + r = TCL_ERROR; + } + if (r == TCL_OK) { + data = Tcl_GetByteArrayFromObj(objv[1], &size); + } + for (cn = 0; r == TCL_OK && cn < size; cn++) { + ndx = (t ^ data[cn]) & 0xFF; + r = Tcl_ListObjIndex(interp, tblPtr, ndx, &lkpPtr); + if (r == TCL_OK) { + r = Tcl_GetLongFromObj(interp, lkpPtr, (long*) &lkp); + } + if (r == TCL_OK) { + t = lkp ^ (t >> 8); + } + } + } + + if (r == TCL_OK) { + Tcl_SetObjResult(interp, Tcl_NewLongObj(t ^ 0xFFFFFFFF)); + } + return r; + } + } +} + +# LoadAccelerator -- +# +# This package can make use of a number of compiled extensions to +# accelerate the digest computation. This procedure manages the +# use of these extensions within the package. During normal usage +# this should not be called, but the test package manipulates the +# list of enabled accelerators. +# +proc ::crc::LoadAccelerator {name} { + variable accel + set r 0 + switch -exact -- $name { + critcl { + if {![catch {package require tcllibc}] + || ![catch {package require crcc}]} { + set r [expr {[info commands ::crc::Crc32_c] != {}}] + } + } + trf { + if {![catch {package require Trf}]} { + set r [expr {![catch {::crc-zlib aa} msg]}] + } + } + default { + return -code error "invalid accelerator package:\ + must be one of [join [array names accel] {, }]" + } + } + set accel($name) $r +} + +# crc::Pop -- +# +# Pop the nth element off a list. Used in options processing. +# +proc ::crc::Pop {varname {nth 0}} { + upvar $varname args + set r [lindex $args $nth] + set args [lreplace $args $nth $nth] + return $r +} + +# crc::crc32 -- +# +# Provide a Tcl implementation of a crc32 checksum similar to the +# cksum and sum unix commands. +# +# Options: +# -filename name - return a checksum for the specified file. +# -format string - return the checksum using this format string. +# -seed value - seed the algorithm using value (default is 0xffffffff) +# +proc ::crc::crc32 {args} { + array set opts [list -filename {} -format %u -seed 0xffffffff \ + -channel {} -chunksize 4096 -timeout 30000] + while {[string match -* [set option [lindex $args 0]]]} { + switch -glob -- $option { + -file* { set opts(-filename) [Pop args 1] } + -for* { set opts(-format) [Pop args 1] } + -chan* { set opts(-channel) [Pop args 1] } + -chunk* { set opts(-chunksize) [Pop args 1] } + -time* { set opts(-timeout) [Pop args 1] } + -seed { set opts(-seed) [Pop args 1] } + -impl* { set junk [Pop args 1] } + default { + if {[llength $args] == 1} { break } + if {[string compare $option "--"] == 0} { Pop args; break } + set err [join [lsort [array names opts -*]] ", "] + return -code error "bad option \"$option\": must be $err" + } + } + Pop args + } + + # If a file was given - open it + if {$opts(-filename) != {}} { + set opts(-channel) [open $opts(-filename) r] + fconfigure $opts(-channel) -translation binary + } + + if {$opts(-channel) == {}} { + + if {[llength $args] != 1} { + return -code error "wrong # args: should be \ + \"crc32 ?-format string? ?-seed value? \ + -channel chan | -file name | data\"" + } + set tok [Crc32Init $opts(-seed)] + Crc32Update $tok [lindex $args 0] + set r [Crc32Final $tok] + + } else { + + set r $opts(-seed) + set tok [Crc32Init $opts(-seed)] + while {![eof $opts(-channel)]} { + Crc32Update $tok [read $opts(-channel) $opts(-chunksize)] + } + set r [Crc32Final $tok] + + if {$opts(-filename) != {}} { + close $opts(-channel) + } + } + + return [format $opts(-format) $r] +} + +# ------------------------------------------------------------------------- + +# Try and load a compiled extension to help (note - trf is fastest) +namespace eval ::crc { + variable e {} + foreach e {trf critcl} { + if {[LoadAccelerator $e]} break + } + unset e +} + +package provide crc32 1.3.2 + +# ------------------------------------------------------------------------- +# +# Local variables: +# mode: tcl +# indent-tabs-mode: nil +# End: |