configfiles/vim/.vim/autoload/tlib/hash.vim

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2015-10-15 22:38:56 +02:00
" @Author: Tom Link (mailto:micathom AT gmail com?subject=[vim])
" @License: GPL (see http://www.gnu.org/licenses/gpl.txt)
" @Revision: 276
if !exists('g:tlib#hash#use_crc32')
let g:tlib#hash#use_crc32 = '' "{{{2
endif
if !exists('g:tlib#hash#use_adler32')
let g:tlib#hash#use_adler32 = '' "{{{2
endif
function! tlib#hash#CRC32B(chars) "{{{3
if !empty(g:tlib#hash#use_crc32)
let use = g:tlib#hash#use_crc32
elseif has('ruby')
let use = 'ruby'
else
let use = 'vim'
endif
if exists('*tlib#hash#CRC32B_'. use)
return tlib#hash#CRC32B_{use}(a:chars)
else
throw "Unknown version of tlib#hash#CRC32B: ". use
endif
endf
function! tlib#hash#CRC32B_ruby(chars) "{{{3
if has('ruby')
let rv = ''
if !exists('s:loaded_ruby_zlib')
ruby require 'zlib'
let s:loaded_ruby_zlib = 1
endif
ruby VIM::command('let rv = "%08X"' % Zlib.crc32(VIM::evaluate("a:chars")))
return rv
else
throw "tlib#hash#CRC32B_ruby not supported in this version of vim"
endif
endf
function! tlib#hash#CRC32B_vim(chars) "{{{3
if !exists('s:crc_table')
let cfile = tlib#persistent#Filename('tlib', 'crc_table', 1)
let s:crc_table = tlib#persistent#Value(cfile, 'tlib#hash#CreateCrcTable', 0)
endif
let xFFFF_FFFF = repeat([1], 32)
let crc = tlib#bitwise#XOR([0], xFFFF_FFFF, 'bits')
for char in split(a:chars, '\zs')
let octet = char2nr(char)
let r1 = tlib#bitwise#ShiftRight(crc, 8)
let i0 = tlib#bitwise#AND(crc, xFFFF_FFFF, 'bits')
let i1 = tlib#bitwise#XOR(i0, octet, 'bits')
let i2 = tlib#bitwise#Bits2Num(tlib#bitwise#AND(i1, 0xff, 'bits'))
let r2 = s:crc_table[i2]
let crc = tlib#bitwise#XOR(r1, r2, 'bits')
endfor
let crc = tlib#bitwise#XOR(crc, xFFFF_FFFF, 'bits')
let rv = tlib#bitwise#Bits2Num(crc, 16)
if len(rv) < 8
let rv = repeat('0', 8 - len(rv)) . rv
endif
return rv
endf
" :nodoc:
function! tlib#hash#CreateCrcTable() "{{{3
let sum = 0.0
for exponent in [0, 1, 2, 4, 5, 7, 8, 10, 11, 12, 16, 22, 23, 26, 32]
let exp = tlib#bitwise#Bits2Num(repeat([0], 32 - exponent) + [1], 10.0)
let sum += exp
endfor
let divisor = tlib#bitwise#Num2Bits(sum)
let crc_table = []
for octet in range(256)
let remainder = tlib#bitwise#Num2Bits(octet)
for i in range(8)
if get(remainder, i) != 0
let remainder = tlib#bitwise#XOR(remainder, tlib#bitwise#ShiftLeft(divisor, i), "bits")
endif
endfor
let remainder = tlib#bitwise#ShiftRight(remainder, 8)
call add(crc_table, remainder)
endfor
return crc_table
endf
function! tlib#hash#Adler32(chars) "{{{3
if !empty(g:tlib#hash#use_adler32)
let use = g:tlib#hash#use_adler32
elseif exists('*or')
let use = 'vim'
else
let use = 'tlib'
endif
if exists('*tlib#hash#Adler32_'. use)
return tlib#hash#Adler32_{use}(a:chars)
else
throw "Unknown version of tlib#hash#Adler32_: ". use
endif
endf
function! tlib#hash#Adler32_vim(chars) "{{{3
if exists('*or')
let mod_adler = 65521
let a = 1
let b = 0
for index in range(len(a:chars))
let c = char2nr(a:chars[index])
let a = (a + c) % mod_adler
let b = (b + a) % mod_adler
endfor
let bb = b * float2nr(pow(2, 16))
let checksum = or(bb, a)
" TLogVAR checksum, a, b, bb
return printf("%08X", checksum)
else
throw "TLIB: Vim version doesn't support bitwise or()"
endif
endf
function! tlib#hash#Adler32_tlib(chars) "{{{3
let mod_adler = 65521
let a = 1
let b = 0
for index in range(len(a:chars))
let c = char2nr(a:chars[index])
let a = (a + c) % mod_adler
let b = (b + a) % mod_adler
endfor
let bb = tlib#bitwise#ShiftLeft(tlib#bitwise#Num2Bits(b), 16)
let checksum = tlib#bitwise#OR(bb, a, "bits")
return printf('%08s', tlib#bitwise#Bits2Num(checksum, 16))
endf