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util-sac.lua /size: 12 Kb last modification: 2020-07-01 14:35
1if
 not
 modules
 then
 modules
 =
 {
 }
 end
 modules
 [
'
util-sac
'
]
 =
 {
2    version
   =
 1
.
001
,
3    comment
   =
 "
companion to luat-lib.mkiv
"
,
4    author
    =
 "
Hans Hagen, PRAGMA-ADE, Hasselt NL
"
,
5    copyright
 =
 "
PRAGMA ADE / ConTeXt Development Team
"
,
6    license
   =
 "
see context related readme files
"
7}
8
9-- experimental string access (some 3 times faster than file access when messing
10-- with bytes)
11
12local
 byte
,
 sub
 =
 string
.
byte
,
 string
.
sub
13local
 tonumber
 =
 tonumber
14
15utilities
         =
 utilities
 or
 {
 }
16local
 streams
     =
 {
 }
17utilities
.
streams
 =
 streams
18
19function
 streams
.
open
(
filename
,
zerobased
)
20    local
 f
 =
 filename
 and
 io
.
loaddata
(
filename
)
21    if
 f
 then
22        return
 {
 f
,
 1
,
 #
f
,
 zerobased
 or
 false
 }
23    end
24end
25
26function
 streams
.
openstring
(
f
,
zerobased
)
27    if
 f
 then
28        return
 {
 f
,
 1
,
 #
f
,
 zerobased
 or
 false
 }
29    end
30end
31
32function
 streams
.
getstring
(
f
)
33    if
 f
 then
34        return
 f
[
1
]
35    end
36end
37
38function
 streams
.
close
(
)
39    -- dummy
40end
41
42function
 streams
.
size
(
f
)
43    return
 f
 and
 f
[
3
]
 or
 0
44end
45
46streams
.
getsize
 =
 streams
.
size
47
48function
 streams
.
setposition
(
f
,
i
)
49    if
 f
[
4
]
 then
50        -- zerobased
51        if
 i
 <
=
 0
 then
52            f
[
2
]
 =
 1
53        else
54            f
[
2
]
 =
 i
 +
 1
55        end
56    else
57        if
 i
 <
=
 1
 then
58            f
[
2
]
 =
 1
59        else
60            f
[
2
]
 =
 i
61        end
62    end
63end
64
65function
 streams
.
getposition
(
f
)
66    if
 f
[
4
]
 then
67        -- zerobased
68        return
 f
[
2
]
 -
 1
69    else
70        return
 f
[
2
]
71    end
72end
73
74function
 streams
.
look
(
f
,
n
,
chars
)
75    local
 b
 =
 f
[
2
]
76    local
 e
 =
 b
 +
 n
 -
 1
77    if
 chars
 then
78        return
 sub
(
f
[
1
]
,
b
,
e
)
79    else
80        return
 byte
(
f
[
1
]
,
b
,
e
)
81    end
82end
83
84function
 streams
.
skip
(
f
,
n
)
85    f
[
2
]
 =
 f
[
2
]
 +
 n
86end
87
88function
 streams
.
readbyte
(
f
)
89    local
 i
 =
 f
[
2
]
90    f
[
2
]
 =
 i
 +
 1
91    return
 byte
(
f
[
1
]
,
i
)
92end
93
94function
 streams
.
readbytes
(
f
,
n
)
95    local
 i
 =
 f
[
2
]
96    local
 j
 =
 i
 +
 n
97    f
[
2
]
 =
 j
98    return
 byte
(
f
[
1
]
,
i
,
j
-1
)
99end
100
101function
 streams
.
readbytetable
(
f
,
n
)
102    local
 i
 =
 f
[
2
]
103    local
 j
 =
 i
 +
 n
104    f
[
2
]
 =
 j
105    return
 {
 byte
(
f
[
1
]
,
i
,
j
-1
)
 }
106end
107
108function
 streams
.
skipbytes
(
f
,
n
)
109    f
[
2
]
 =
 f
[
2
]
 +
 n
110end
111
112function
 streams
.
readchar
(
f
)
113    local
 i
 =
 f
[
2
]
114    f
[
2
]
 =
 i
 +
 1
115    return
 sub
(
f
[
1
]
,
i
,
i
)
116end
117
118function
 streams
.
readstring
(
f
,
n
)
119    local
 i
 =
 f
[
2
]
120    local
 j
 =
 i
 +
 n
121    f
[
2
]
 =
 j
122    return
 sub
(
f
[
1
]
,
i
,
j
-1
)
123end
124
125function
 streams
.
readinteger1
(
f
)
  -- one byte
126    local
 i
 =
 f
[
2
]
127    f
[
2
]
 =
 i
 +
 1
128    local
 n
 =
 byte
(
f
[
1
]
,
i
)
129    if
 n
  >
=
 0x80
 then
130        return
 n
 -
 0x100
131    else
132        return
 n
133    end
134end
135
136streams
.
readcardinal1
 =
 streams
.
readbyte
  -- one byte
137streams
.
readcardinal
  =
 streams
.
readcardinal1
138streams
.
readinteger
   =
 streams
.
readinteger1
139
140function
 streams
.
readcardinal2
(
f
)
141    local
 i
 =
 f
[
2
]
142    local
 j
 =
 i
 +
 1
143    f
[
2
]
 =
 j
 +
 1
144    local
 a
,
 b
 =
 byte
(
f
[
1
]
,
i
,
j
)
145    return
 0x100
 *
 a
 +
 b
146end
147
148function
 streams
.
readcardinal2le
(
f
)
149    local
 i
 =
 f
[
2
]
150    local
 j
 =
 i
 +
 1
151    f
[
2
]
 =
 j
 +
 1
152    local
 b
,
 a
 =
 byte
(
f
[
1
]
,
i
,
j
)
153    return
 0x100
 *
 a
 +
 b
154end
155
156function
 streams
.
readinteger2
(
f
)
157    local
 i
 =
 f
[
2
]
158    local
 j
 =
 i
 +
 1
159    f
[
2
]
 =
 j
 +
 1
160    local
 a
,
 b
 =
 byte
(
f
[
1
]
,
i
,
j
)
161    if
 a
 >
=
 0x80
 then
162        return
 0x100
 *
 a
 +
 b
 -
 0x10000
163    else
164        return
 0x100
 *
 a
 +
 b
165    end
166end
167
168function
 streams
.
readinteger2le
(
f
)
169    local
 i
 =
 f
[
2
]
170    local
 j
 =
 i
 +
 1
171    f
[
2
]
 =
 j
 +
 1
172    local
 b
,
 a
 =
 byte
(
f
[
1
]
,
i
,
j
)
173    if
 a
 >
=
 0x80
 then
174        return
 0x100
 *
 a
 +
 b
 -
 0x10000
175    else
176        return
 0x100
 *
 a
 +
 b
177    end
178end
179
180function
 streams
.
readcardinal3
(
f
)
181    local
 i
 =
 f
[
2
]
182    local
 j
 =
 i
 +
 2
183    f
[
2
]
 =
 j
 +
 1
184    local
 a
,
 b
,
 c
 =
 byte
(
f
[
1
]
,
i
,
j
)
185    return
 0x10000
 *
 a
 +
 0x100
 *
 b
 +
 c
186end
187
188function
 streams
.
readcardinal3le
(
f
)
189    local
 i
 =
 f
[
2
]
190    local
 j
 =
 i
 +
 2
191    f
[
2
]
 =
 j
 +
 1
192    local
 c
,
 b
,
 a
 =
 byte
(
f
[
1
]
,
i
,
j
)
193    return
 0x10000
 *
 a
 +
 0x100
 *
 b
 +
 c
194end
195
196function
 streams
.
readinteger3
(
f
)
197    local
 i
 =
 f
[
2
]
198    local
 j
 =
 i
 +
 3
199    f
[
2
]
 =
 j
 +
 1
200    local
 a
,
 b
,
 c
 =
 byte
(
f
[
1
]
,
i
,
j
)
201    if
 a
 >
=
 0x80
 then
202        return
 0x10000
 *
 a
 +
 0x100
 *
 b
 +
 c
 -
 0x1000000
203    else
204        return
 0x10000
 *
 a
 +
 0x100
 *
 b
 +
 c
205    end
206end
207
208function
 streams
.
readinteger3le
(
f
)
209    local
 i
 =
 f
[
2
]
210    local
 j
 =
 i
 +
 3
211    f
[
2
]
 =
 j
 +
 1
212    local
 c
,
 b
,
 a
 =
 byte
(
f
[
1
]
,
i
,
j
)
213    if
 a
 >
=
 0x80
 then
214        return
 0x10000
 *
 a
 +
 0x100
 *
 b
 +
 c
 -
 0x1000000
215    else
216        return
 0x10000
 *
 a
 +
 0x100
 *
 b
 +
 c
217    end
218end
219
220function
 streams
.
readcardinal4
(
f
)
221    local
 i
 =
 f
[
2
]
222    local
 j
 =
 i
 +
 3
223    f
[
2
]
 =
 j
 +
 1
224    local
 a
,
 b
,
 c
,
 d
 =
 byte
(
f
[
1
]
,
i
,
j
)
225    return
 0x1000000
 *
 a
 +
 0x10000
 *
 b
 +
 0x100
 *
 c
 +
 d
226end
227
228function
 streams
.
readcardinal4le
(
f
)
229    local
 i
 =
 f
[
2
]
230    local
 j
 =
 i
 +
 3
231    f
[
2
]
 =
 j
 +
 1
232    local
 d
,
 c
,
 b
,
 a
 =
 byte
(
f
[
1
]
,
i
,
j
)
233    return
 0x1000000
 *
 a
 +
 0x10000
 *
 b
 +
 0x100
 *
 c
 +
 d
234end
235
236function
 streams
.
readinteger4
(
f
)
237    local
 i
 =
 f
[
2
]
238    local
 j
 =
 i
 +
 3
239    f
[
2
]
 =
 j
 +
 1
240    local
 a
,
 b
,
 c
,
 d
 =
 byte
(
f
[
1
]
,
i
,
j
)
241    if
 a
 >
=
 0x80
 then
242        return
 0x1000000
 *
 a
 +
 0x10000
 *
 b
 +
 0x100
 *
 c
 +
 d
 -
 0x100000000
243    else
244        return
 0x1000000
 *
 a
 +
 0x10000
 *
 b
 +
 0x100
 *
 c
 +
 d
245    end
246end
247
248function
 streams
.
readinteger4le
(
f
)
249    local
 i
 =
 f
[
2
]
250    local
 j
 =
 i
 +
 3
251    f
[
2
]
 =
 j
 +
 1
252    local
 d
,
 c
,
 b
,
 a
 =
 byte
(
f
[
1
]
,
i
,
j
)
253    if
 a
 >
=
 0x80
 then
254        return
 0x1000000
 *
 a
 +
 0x10000
 *
 b
 +
 0x100
 *
 c
 +
 d
 -
 0x100000000
255    else
256        return
 0x1000000
 *
 a
 +
 0x10000
 *
 b
 +
 0x100
 *
 c
 +
 d
257    end
258end
259
260function
 streams
.
readfixed2
(
f
)
261    local
 i
 =
 f
[
2
]
262    local
 j
 =
 i
 +
 1
263    f
[
2
]
 =
 j
 +
 1
264    local
 a
,
 b
 =
 byte
(
f
[
1
]
,
i
,
j
)
265    if
 a
 >
=
 0x80
 then
266        return
 tonumber
(
(
a
 -
 0x100
)
 .
.
 "
.
"
 .
.
 b
)
 or
 0
267    else
268        return
 tonumber
(
(
a
        )
 .
.
 "
.
"
 .
.
 b
)
 or
 0
269    end
270end
271
272function
 streams
.
readfixed4
(
f
)
273    local
 i
 =
 f
[
2
]
274    local
 j
 =
 i
 +
 3
275    f
[
2
]
 =
 j
 +
 1
276    local
 a
,
 b
,
 c
,
 d
 =
 byte
(
f
[
1
]
,
i
,
j
)
277    if
 a
 >
=
 0x80
 then
278        return
 tonumber
(
(
0x100
 *
 a
 +
 b
 -
 0x10000
)
 .
.
 "
.
"
 .
.
 (
0x100
 *
 c
 +
 d
)
)
 or
 0
279    else
280        return
 tonumber
(
(
0x100
 *
 a
 +
 b
          )
 .
.
 "
.
"
 .
.
 (
0x100
 *
 c
 +
 d
)
)
 or
 0
281    end
282end
283
284if
 bit32
 then
285
286    local
 extract
 =
 bit32
.
extract
287    local
 band
    =
 bit32
.
band
288
289    function
 streams
.
read2dot14
(
f
)
290        local
 i
 =
 f
[
2
]
291        local
 j
 =
 i
 +
 1
292        f
[
2
]
 =
 j
 +
 1
293        local
 a
,
 b
 =
 byte
(
f
[
1
]
,
i
,
j
)
294        if
 a
 >
=
 0x80
 then
295            local
 n
 =
 -
(
0x100
 *
 a
 +
 b
)
296            return
 -
 (
extract
(
n
,
14
,
2
)
 +
 (
band
(
n
,
0x3FFF
)
 /
 16384
.
0
)
)
297        else
298            local
 n
 =
   0x100
 *
 a
 +
 b
299            return
   (
extract
(
n
,
14
,
2
)
 +
 (
band
(
n
,
0x3FFF
)
 /
 16384
.
0
)
)
300        end
301    end
302
303end
304
305function
 streams
.
skipshort
(
f
,
n
)
306    f
[
2
]
 =
 f
[
2
]
 +
 2
*
(
n
 or
 1
)
307end
308
309function
 streams
.
skiplong
(
f
,
n
)
310    f
[
2
]
 =
 f
[
2
]
 +
 4
*
(
n
 or
 1
)
311end
312
313if
 sio
 and
 sio
.
readcardinal2
 then
314
315    local
 readcardinal1
  =
 sio
.
readcardinal1
316    local
 readcardinal2
  =
 sio
.
readcardinal2
317    local
 readcardinal3
  =
 sio
.
readcardinal3
318    local
 readcardinal4
  =
 sio
.
readcardinal4
319    local
 readinteger1
   =
 sio
.
readinteger1
320    local
 readinteger2
   =
 sio
.
readinteger2
321    local
 readinteger3
   =
 sio
.
readinteger3
322    local
 readinteger4
   =
 sio
.
readinteger4
323    local
 readfixed2
     =
 sio
.
readfixed2
324    local
 readfixed4
     =
 sio
.
readfixed4
325    local
 read2dot14
     =
 sio
.
read2dot14
326    local
 readbytes
      =
 sio
.
readbytes
327    local
 readbytetable
  =
 sio
.
readbytetable
328
329    function
 streams
.
readcardinal1
(
f
)
330        local
 i
 =
 f
[
2
]
331        f
[
2
]
 =
 i
 +
 1
332        return
 readcardinal1
(
f
[
1
]
,
i
)
333    end
334    function
 streams
.
readcardinal2
(
f
)
335        local
 i
 =
 f
[
2
]
336        f
[
2
]
 =
 i
 +
 2
337        return
 readcardinal2
(
f
[
1
]
,
i
)
338    end
339    function
 streams
.
readcardinal3
(
f
)
340        local
 i
 =
 f
[
2
]
341        f
[
2
]
 =
 i
 +
 3
342        return
 readcardinal3
(
f
[
1
]
,
i
)
343    end
344    function
 streams
.
readcardinal4
(
f
)
345        local
 i
 =
 f
[
2
]
346        f
[
2
]
 =
 i
 +
 4
347        return
 readcardinal4
(
f
[
1
]
,
i
)
348    end
349    function
 streams
.
readinteger1
(
f
)
350        local
 i
 =
 f
[
2
]
351        f
[
2
]
 =
 i
 +
 1
352        return
 readinteger1
(
f
[
1
]
,
i
)
353    end
354    function
 streams
.
readinteger2
(
f
)
355        local
 i
 =
 f
[
2
]
356        f
[
2
]
 =
 i
 +
 2
357        return
 readinteger2
(
f
[
1
]
,
i
)
358    end
359    function
 streams
.
readinteger3
(
f
)
360        local
 i
 =
 f
[
2
]
361        f
[
2
]
 =
 i
 +
 3
362        return
 readinteger3
(
f
[
1
]
,
i
)
363    end
364    function
 streams
.
readinteger4
(
f
)
365        local
 i
 =
 f
[
2
]
366        f
[
2
]
 =
 i
 +
 4
367        return
 readinteger4
(
f
[
1
]
,
i
)
368    end
369    function
 streams
.
readfixed2
(
f
)
 -- needs recent luatex
370        local
 i
 =
 f
[
2
]
371        f
[
2
]
 =
 i
 +
 2
372        return
 readfixed2
(
f
[
1
]
,
i
)
373    end
374    function
 streams
.
readfixed4
(
f
)
 -- needs recent luatex
375        local
 i
 =
 f
[
2
]
376        f
[
2
]
 =
 i
 +
 4
377        return
 readfixed4
(
f
[
1
]
,
i
)
378    end
379    function
 streams
.
read2dot4
(
f
)
380        local
 i
 =
 f
[
2
]
381        f
[
2
]
 =
 i
 +
 2
382        return
 read2dot4
(
f
[
1
]
,
i
)
383    end
384    function
 streams
.
readbytes
(
f
,
n
)
385        local
 i
 =
 f
[
2
]
386        local
 s
 =
 f
[
3
]
387        local
 p
 =
 i
 +
 n
388        if
 p
 >
 s
 then
389            f
[
2
]
 =
 s
 +
 1
390        else
391            f
[
2
]
 =
 p
392        end
393        return
 readbytes
(
f
[
1
]
,
i
,
n
)
394    end
395    function
 streams
.
readbytetable
(
f
,
n
)
396        local
 i
 =
 f
[
2
]
397        local
 s
 =
 f
[
3
]
398        local
 p
 =
 i
 +
 n
399        if
 p
 >
 s
 then
400            f
[
2
]
 =
 s
 +
 1
401        else
402            f
[
2
]
 =
 p
403        end
404        return
 readbytetable
(
f
[
1
]
,
i
,
n
)
405    end
406
407    streams
.
readbyte
       =
 streams
.
readcardinal1
408    streams
.
readsignedbyte
 =
 streams
.
readinteger1
409    streams
.
readcardinal
   =
 streams
.
readcardinal1
410    streams
.
readinteger
    =
 streams
.
readinteger1
411
412end
413
414if
 sio
 and
 sio
.
readcardinaltable
 then
415
416    local
 readcardinaltable
 =
 sio
.
readcardinaltable
417    local
 readintegertable
  =
 sio
.
readintegertable
418
419    function
 utilities
.
streams
.
readcardinaltable
(
f
,
n
,
b
)
420        local
 i
 =
 f
[
2
]
421        local
 s
 =
 f
[
3
]
422        local
 p
 =
 i
 +
 n
 *
 b
423        if
 p
 >
 s
 then
424            f
[
2
]
 =
 s
 +
 1
425        else
426            f
[
2
]
 =
 p
427        end
428        return
 readcardinaltable
(
f
[
1
]
,
i
,
n
,
b
)
429    end
430
431    function
 utilities
.
streams
.
readintegertable
(
f
,
n
,
b
)
432        local
 i
 =
 f
[
2
]
433        local
 s
 =
 f
[
3
]
434        local
 p
 =
 i
 +
  n
 *
 b
435        if
 p
 >
 s
 then
436            f
[
2
]
 =
 s
 +
 1
437        else
438            f
[
2
]
 =
 p
439        end
440        return
 readintegertable
(
f
[
1
]
,
i
,
n
,
b
)
441    end
442
443else
444
445    local
 readcardinal1
 =
 streams
.
readcardinal1
446    local
 readcardinal2
 =
 streams
.
readcardinal2
447    local
 readcardinal3
 =
 streams
.
readcardinal3
448    local
 readcardinal4
 =
 streams
.
readcardinal4
449
450    function
 streams
.
readcardinaltable
(
f
,
n
,
b
)
451        local
 i
 =
 f
[
2
]
452        local
 s
 =
 f
[
3
]
453        local
 p
 =
 i
 +
 n
 *
 b
454        if
 p
 >
 s
 then
455            f
[
2
]
 =
 s
 +
 1
456        else
457            f
[
2
]
 =
 p
458        end
459        local
 t
 =
 {
 }
460            if
 b
 =
=
 1
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readcardinal1
(
f
[
1
]
,
i
)
 end
461        elseif
 b
 =
=
 2
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readcardinal2
(
f
[
1
]
,
i
)
 end
462        elseif
 b
 =
=
 3
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readcardinal3
(
f
[
1
]
,
i
)
 end
463        elseif
 b
 =
=
 4
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readcardinal4
(
f
[
1
]
,
i
)
 end
 end
464        return
 t
465    end
466
467    local
 readinteger1
 =
 streams
.
readinteger1
468    local
 readinteger2
 =
 streams
.
readinteger2
469    local
 readinteger3
 =
 streams
.
readinteger3
470    local
 readinteger4
 =
 streams
.
readinteger4
471
472    function
 streams
.
readintegertable
(
f
,
n
,
b
)
473        local
 i
 =
 f
[
2
]
474        local
 s
 =
 f
[
3
]
475        local
 p
 =
 i
 +
 n
 *
 b
476        if
 p
 >
 s
 then
477            f
[
2
]
 =
 s
 +
 1
478        else
479            f
[
2
]
 =
 p
480        end
481        local
 t
 =
 {
 }
482            if
 b
 =
=
 1
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readinteger1
(
f
[
1
]
,
i
)
 end
483        elseif
 b
 =
=
 2
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readinteger2
(
f
[
1
]
,
i
)
 end
484        elseif
 b
 =
=
 3
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readinteger3
(
f
[
1
]
,
i
)
 end
485        elseif
 b
 =
=
 4
 then
 for
 i
=
1
,
n
 do
 t
[
i
]
 =
 readinteger4
(
f
[
1
]
,
i
)
 end
 end
486        return
 t
487    end
488
489end
490
491-- For practical reasons we put this here. It's less efficient but ok when we don't
492-- have much access.
493
494do
495
496    local
 files
 =
 utilities
.
files
497
498    if
 files
 then
499
500        local
 openfile
     =
 files
.
open
501        local
 openstream
   =
 streams
.
open
502        local
 openstring
   =
 streams
.
openstring
503
504        local
 setmetatable
 =
 setmetatable
505
506        function
 io
.
newreader
(
str
,
method
)
507            local
 f
,
 m
508            if
 method
 =
=
 "
string
"
 then
509                f
 =
 openstring
(
str
)
510                m
 =
 streams
511            elseif
 method
 =
=
 "
stream
"
 then
512                f
 =
 openstream
(
str
)
513                m
 =
 streams
514            else
515                f
 =
 openfile
(
str
,
"
rb
"
)
516                m
 =
 files
517            end
518            if
 f
 then
519                local
 t
 =
 {
 }
520                setmetatable
(
t
,
 {
521                    __index
 =
 function
(
t
,
k
)
522                        local
 r
 =
 m
[
k
]
523                        if
 k
 =
=
 "
close
"
 then
524                            if
 f
 then
525                                m
.
close
(
f
)
526                                f
 =
 nil
527                            end
528                            return
 function
(
)
 end
529                        elseif
 r
 then
530                            local
 v
 =
 function
(
_
,
a
,
b
)
 return
 r
(
f
,
a
,
b
)
 end
531                            t
[
k
]
 =
 v
532                            return
 v
533                        else
534                            print
(
"
unknown key
"
,
k
)
535                        end
536                    end
537                }
 )
538                return
 t
539            end
540        end
541
542    end
543
544end
545
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