{{ message }}
Repository navigation
Expand file tree
/
Copy pathoctavezmat.m
More file actions
398 lines (334 loc) · 10.8 KB
/
Copy pathoctavezmat.m
File metadata and controls
398 lines (334 loc) · 10.8 KB
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
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
function varargout = octavezmat(varargin)
%
% output = octavezmat(input, iscompress, zipmethod)
% or
% [output, info] = octavezmat(input, iscompress, zipmethod)
% unzipdata = octavezmat(zipdata, info)
%
% File-based zlib/gzip compression for Octave when Java is not available
%
% Author: Qianqian Fang (q.fang <at> neu.edu)
%
% input:
% input: the input data, can be a string, a numerical vector or array
% iscompress: (optional) if iscompress is 1, compress the input,
% if 0, decompress the input. Default value is 1.
% if one defines iscompress as the info struct (2nd output),
% it will perform decompression and recover the original input.
% method: (optional) compression method:
% 'zlib': zlib compression (default)
% 'gzip': gzip compression
%
% output:
% output: the compressed/decompressed byte stream as uint8 vector
% info: (optional) a struct with 'type', 'size', 'method', 'status'
%
% examples:
% [bytes, info] = octavezmat(eye(10), 1, 'zlib');
% orig = octavezmat(bytes, info);
%
% license:
% BSD or GPL version 3, see LICENSE_{BSD,GPLv3}.txt files for details
%
% -- this function is part of JSONLab toolbox (http://neurojson.org/jsonlab)
%
if (nargin < 1)
fprintf(1, 'Format: output = octavezmat(data, iscompress, zipmethod)\n');
return
end
iscompress = 1;
zipmethod = 'zlib';
data = varargin{1};
% Handle info struct input for decompression
inputinfo = [];
if (nargin >= 2)
if (isstruct(varargin{2}))
inputinfo = varargin{2};
iscompress = 0;
if (isfield(inputinfo, 'method'))
zipmethod = inputinfo.method;
end
else
iscompress = varargin{2};
end
end
if (nargin >= 3)
zipmethod = varargin{3};
end
% Store original info
origtype = class(data);
origsize = size(data);
% Convert to uint8
if (ischar(data))
data = uint8(data);
elseif (islogical(data))
data = uint8(data);
elseif (isa(data, 'string'))
data = uint8(char(data));
else
data = typecast(data(:), 'uint8');
end
data = data(:)';
% Normalize method name
if (strcmp(zipmethod, 'deflate'))
zipmethod = 'zlib';
end
% Dispatch to appropriate file-based function
if (iscompress)
if (strcmp(zipmethod, 'zlib'))
varargout{1} = file_zlib_encode(data);
elseif (strcmp(zipmethod, 'gzip'))
varargout{1} = file_gzip_encode(data);
else
error('Unsupported method: %s', zipmethod);
end
else
if (strcmp(zipmethod, 'zlib'))
varargout{1} = file_zlib_decode(data);
elseif (strcmp(zipmethod, 'gzip'))
varargout{1} = file_gzip_decode(data);
else
error('Unsupported method: %s', zipmethod);
end
end
% Build info struct
if (nargout > 1)
varargout{2} = struct('type', origtype, 'size', origsize, ...
'method', zipmethod, 'status', 0);
end
% Restore original type and shape if decompressing with info
if (~isempty(inputinfo) && isfield(inputinfo, 'type'))
if (strcmp(inputinfo.type, 'logical'))
varargout{1} = logical(varargout{1});
elseif (strcmp(inputinfo.type, 'char'))
varargout{1} = char(varargout{1});
else
varargout{1} = typecast(varargout{1}, inputinfo.type);
end
varargout{1} = reshape(varargout{1}, inputinfo.size);
end
% ==========================================================================
% File-based ZLIB compression/decompression
% ==========================================================================
function compressed = file_zlib_encode(data)
% ZLIB compression using file-based zip
data = uint8(data(:))';
fname = tempname;
tmpfile = fname;
zipfile = [fname '.zip'];
fd = fopen(tmpfile, 'wb');
fwrite(fd, data, 'uint8');
fclose(fd);
zip(zipfile, tmpfile);
delete(tmpfile);
fd = fopen(zipfile, 'rb');
zipdata = fread(fd, [1 inf], 'uint8=>uint8');
fclose(fd);
delete(zipfile);
% Extract raw DEFLATE from ZIP and wrap in ZLIB format
deflate_data = extract_deflate_from_zip(zipdata);
compressed = wrap_zlib(deflate_data, data);
% --------------------------------------------------------------------------
function data = file_zlib_decode(compressed)
% ZLIB decompression using file-based unzip
compressed = uint8(compressed(:))';
% Strip ZLIB header (2 bytes) and Adler-32 trailer (4 bytes) to get raw DEFLATE
if (length(compressed) > 6)
deflate_data = compressed(3:end - 4);
else
deflate_data = compressed;
end
fname = tempname;
zipfile = [fname '.zip'];
% Use unique output directory to avoid file conflicts
outdir = tempname;
mkdir(outdir);
% Create ZIP with CRC=0 (unzip will warn but still extract)
zipdata = wrap_deflate_in_zip(deflate_data, [], uint32(0));
fd = fopen(zipfile, 'wb');
fwrite(fd, zipdata, 'uint8');
fclose(fd);
% Try to unzip - may produce CRC warning but should still extract
try
unzip(zipfile, outdir);
catch
% Even if unzip throws error, file might still be extracted
end
if (exist(zipfile, 'file'))
delete(zipfile);
end
% Look for the output file - it's named 'data' in our ZIP (from wrap_deflate_in_zip)
outfile = fullfile(outdir, 'data');
if (exist(outfile, 'file') ~= 2)
% Try to find any file in outdir
d = dir(outdir);
for i = 1:length(d)
if (~d(i).isdir)
outfile = fullfile(outdir, d(i).name);
break
end
end
end
if (exist(outfile, 'file') ~= 2)
if (exist(outdir, 'dir'))
rmdir(outdir, 's');
end
error('failed to decompress zlib data');
end
fd = fopen(outfile, 'rb');
if (fd < 0)
if (exist(outdir, 'dir'))
rmdir(outdir, 's');
end
error('failed to open decompressed file');
end
data = fread(fd, [1 inf], 'uint8=>uint8');
fclose(fd);
% Cleanup
if (exist(outdir, 'dir'))
delete(fullfile(outdir, '*'));
rmdir(outdir);
end
% ==========================================================================
% File-based GZIP compression/decompression
% ==========================================================================
function compressed = file_gzip_encode(data)
% GZIP compression using file I/O with 'wbz' mode
data = uint8(data(:))';
fname = tempname;
gzfile = [fname '.gz'];
fd = fopen(gzfile, 'wbz');
fwrite(fd, data, 'uint8');
fclose(fd);
fd = fopen(gzfile, 'rb');
compressed = fread(fd, [1 inf], 'uint8=>uint8');
fclose(fd);
delete(gzfile);
% --------------------------------------------------------------------------
function data = file_gzip_decode(compressed)
% GZIP decompression using file I/O with 'rbz' mode
compressed = uint8(compressed(:))';
fname = tempname;
gzfile = [fname '.gz'];
fd = fopen(gzfile, 'wb');
fwrite(fd, compressed, 'uint8');
fclose(fd);
fd = fopen(gzfile, 'rbz');
data = fread(fd, [1 inf], 'uint8=>uint8');
fclose(fd);
delete(gzfile);
% ==========================================================================
% ZIP format helper functions
% ==========================================================================
function deflate_data = extract_deflate_from_zip(zipdata)
% Extract raw DEFLATE stream from ZIP archive
deflate_data = zipdata;
if (length(zipdata) > 30 && zipdata(1) == 80 && zipdata(2) == 75 && ...
zipdata(3) == 3 && zipdata(4) == 4)
fname_len = double(zipdata(27)) + double(zipdata(28)) * 256;
extra_len = double(zipdata(29)) + double(zipdata(30)) * 256;
comp_size = double(zipdata(19)) + double(zipdata(20)) * 256 + ...
double(zipdata(21)) * 65536 + double(zipdata(22)) * 16777216;
data_start = 31 + fname_len + extra_len;
if (data_start + comp_size - 1 <= length(zipdata))
deflate_data = zipdata(data_start:data_start + comp_size - 1);
end
end
% --------------------------------------------------------------------------
function zlib_data = wrap_zlib(deflate_data, original_data)
% Wrap raw DEFLATE in ZLIB format (header + deflate + adler32)
header = uint8([120, 156]); % 0x78 0x9C = default compression
checksum = adler32(original_data);
trailer = uint8([bitand(bitshift(checksum, -24), 255), ...
bitand(bitshift(checksum, -16), 255), ...
bitand(bitshift(checksum, -8), 255), ...
bitand(checksum, 255)]);
zlib_data = [header, deflate_data(:)', trailer];
% --------------------------------------------------------------------------
function checksum = adler32(data)
% Compute Adler-32 checksum
data = uint8(data(:))';
a = uint32(1);
b = uint32(0);
MOD = uint32(65521);
for i = 1:length(data)
a = mod(a + uint32(data(i)), MOD);
b = mod(b + a, MOD);
end
checksum = uint32(bitor(bitshift(b, 16), a));
% --------------------------------------------------------------------------
function crc = crc32(data)
% Compute CRC-32 checksum
data = uint8(data(:))';
crc = uint32(4294967295); % 0xFFFFFFFF
% CRC-32 polynomial table
persistent crc_table
if (isempty(crc_table))
crc_table = zeros(1, 256, 'uint32');
poly = uint32(3988292384); % 0xEDB88320
for i = 0:255
c = uint32(i);
for j = 1:8
if (bitand(c, 1))
c = bitxor(bitshift(c, -1), poly);
else
c = bitshift(c, -1);
end
end
crc_table(i + 1) = c;
end
end
for i = 1:length(data)
idx = bitand(bitxor(crc, uint32(data(i))), 255) + 1;
crc = bitxor(bitshift(crc, -8), crc_table(idx));
end
crc = bitxor(crc, uint32(4294967295)); % final XOR
% --------------------------------------------------------------------------
function zipdata = wrap_deflate_in_zip(deflate_data, orig_data, crc32val)
% Wrap raw DEFLATE data in a minimal ZIP archive
deflate_data = uint8(deflate_data(:))';
comp_size = length(deflate_data);
if (nargin < 2 || isempty(orig_data))
uncomp_size = comp_size * 10;
else
uncomp_size = length(orig_data);
end
if (nargin < 3 || isempty(crc32val))
crc32val = uint32(0);
end
filename = uint8('data');
fname_len = length(filename);
lh = uint8(zeros(1, 30));
lh(1:4) = [80, 75, 3, 4];
lh(5:6) = [20, 0];
lh(7:8) = [0, 0];
lh(9:10) = [8, 0];
lh(11:14) = [0, 0, 0, 0];
lh(15:18) = typecast(crc32val, 'uint8');
lh(19:22) = typecast(uint32(comp_size), 'uint8');
lh(23:26) = typecast(uint32(uncomp_size), 'uint8');
lh(27:28) = typecast(uint16(fname_len), 'uint8');
lh(29:30) = [0, 0];
ch = uint8(zeros(1, 46));
ch(1:4) = [80, 75, 1, 2];
ch(5:6) = [20, 0];
ch(7:8) = [20, 0];
ch(9:10) = [0, 0];
ch(11:12) = [8, 0];
ch(13:16) = [0, 0, 0, 0];
ch(17:20) = typecast(crc32val, 'uint8');
ch(21:24) = typecast(uint32(comp_size), 'uint8');
ch(25:28) = typecast(uint32(uncomp_size), 'uint8');
ch(29:30) = typecast(uint16(fname_len), 'uint8');
ch(31:46) = zeros(1, 16, 'uint8');
local_size = 30 + fname_len + comp_size;
central_size = 46 + fname_len;
ec = uint8(zeros(1, 22));
ec(1:4) = [80, 75, 5, 6];
ec(5:8) = [0, 0, 0, 0];
ec(9:10) = [1, 0];
ec(11:12) = [1, 0];
ec(13:16) = typecast(uint32(central_size), 'uint8');
ec(17:20) = typecast(uint32(local_size), 'uint8');
ec(21:22) = [0, 0];
zipdata = [lh, filename, deflate_data, ch, filename, ec];
You can’t perform that action at this time.