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
|
if not modules then modules = { } end modules ['l-gzip'] = {
version = 1.001,
author = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
copyright = "PRAGMA ADE / ConTeXt Development Team",
license = "see context related readme files"
}
if gzip then
local suffix, suffixes = file.suffix, file.suffixes
function gzip.load(filename)
local f = io.open(filename,"rb")
if not f then
-- invalid file
elseif suffix(filename) == "gz" then
f:close()
local g = gzip.open(filename,"rb")
if g then
local str = g:read("*all")
g:close()
return str
end
else
local str = f:read("*all")
f:close()
return str
end
end
function gzip.save(filename,data)
if suffix(filename) ~= "gz" then
filename = filename .. ".gz"
end
local f = io.open(filename,"wb")
if f then
local s = zlib.compress(data or "",9,nil,15+16)
f:write(s)
f:close()
return #s
end
end
function gzip.suffix(filename)
local suffix, extra = suffixes(filename)
local gzipped = extra == "gz"
return suffix, gzipped
end
else
-- todo: fallback on flate
end
if flate then
local type = type
local find = string.find
local compress = flate.gz_compress
local decompress = flate.gz_decompress
local absmax = 128*1024*1024
local initial = 64*1024
local identifier = "^\x1F\x8B\x08"
function gzip.compressed(s)
return s and find(s,identifier)
end
function gzip.compress(s,level)
if s and not find(s,identifier) then -- the find check might go away
if not level then
level = 3
elseif level <= 0 then
return s
elseif level > 9 then
level = 9
end
return compress(s,level) or s
end
end
function gzip.decompress(s,size,iterate)
if s and find(s,identifier) then
if type(size) ~= "number" then
size = initial
end
if size > absmax then
size = absmax
end
if type(iterate) == "number" then
max = size * iterate
elseif iterate == nil or iterate == true then
iterate = true
max = absmax
end
if max > absmax then
max = absmax
end
while true do
local d = decompress(s,size)
if d then
return d
end
size = 2 * size
if not iterate or size > max then
return false
end
end
else
return s
end
end
end
|
