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/cvs/Compress-LZF/LZF.xs
Revision: 1.16
Committed: Tue Apr 20 02:37:29 2004 UTC (20 years, 1 month ago) by pcg
Branch: MAIN
Changes since 1.15: +1 -0 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 #include "EXTERN.h"
2 #include "perl.h"
3 #include "XSUB.h"
4
5 /* try to be compatible with older perls */
6 /* SvPV_nolen() macro first defined in 5.005_55 */
7 /* this is slow, not threadsafe, but works */
8 #include "patchlevel.h"
9 #if (PATCHLEVEL == 4) || ((PATCHLEVEL == 5) && (SUBVERSION < 55))
10 static STRLEN nolen_na;
11 # define SvPV_nolen(sv) SvPV ((sv), nolen_na)
12 #endif
13 #if PATCHLEVEL < 6
14 # define call_sv perl_call_sv
15 #endif
16
17 #include "lzf_c.c"
18 #include "lzf_d.c"
19
20 /* we re-use the storable header for our purposes */
21 #define MAGIC_LO 0
22 #define MAGIC_U 0 /* uncompressed data follows */
23 #define MAGIC_C 1 /* compressed data follows */
24 #define MAGIC_undef 2 /* the special value undef */
25 #define MAGIC_CR 3 /* storable (reference, freeze), compressed */
26 #define MAGIC_R 4 /* storable (reference, freeze) */
27 #define MAGIC_CR_deref 5 /* storable (NO reference, freeze), compressed */
28 #define MAGIC_R_deref 6 /* storable (NO reference, freeze) */
29 #define MAGIC_HI 7 /* room for one higher storable major */
30
31 #define IN_RANGE(v,l,h) ((unsigned int)((unsigned)(v) - (unsigned)(l)) <= (unsigned)(h) - (unsigned)(l))
32
33 static SV *serializer_package, *serializer_mstore, *serializer_mretrieve;
34 static CV *storable_mstore, *storable_mretrieve;
35
36 static SV *
37 compress_sv (SV *data, char cprepend, int uprepend)
38 {
39 STRLEN usize, csize;
40 char *src = (char *)SvPV (data, usize);
41
42 if (usize)
43 {
44 SV *ret = NEWSV (0, usize + 1);
45 unsigned char *dst;
46 int skip = 0;
47
48 SvPOK_only (ret);
49 dst = (unsigned char *)SvPVX (ret);
50
51 if (cprepend)
52 dst[skip++] = cprepend;
53
54 if (usize < 0x80)
55 {
56 dst[skip++] = usize;
57 }
58 else if (usize < 0x800)
59 {
60 dst[skip++] = (( usize >> 6) | 0xc0);
61 dst[skip++] = (( usize & 0x3f) | 0x80);
62 }
63 else if (usize < 0x10000)
64 {
65 dst[skip++] = (( usize >> 12) | 0xe0);
66 dst[skip++] = (((usize >> 6) & 0x3f) | 0x80);
67 dst[skip++] = (( usize & 0x3f) | 0x80);
68 }
69 else if (usize < 0x200000)
70 {
71 dst[skip++] = (( usize >> 18) | 0xf0);
72 dst[skip++] = (((usize >> 12) & 0x3f) | 0x80);
73 dst[skip++] = (((usize >> 6) & 0x3f) | 0x80);
74 dst[skip++] = (( usize & 0x3f) | 0x80);
75 }
76 else if (usize < 0x4000000)
77 {
78 dst[skip++] = (( usize >> 24) | 0xf8);
79 dst[skip++] = (((usize >> 18) & 0x3f) | 0x80);
80 dst[skip++] = (((usize >> 12) & 0x3f) | 0x80);
81 dst[skip++] = (((usize >> 6) & 0x3f) | 0x80);
82 dst[skip++] = (( usize & 0x3f) | 0x80);
83 }
84 else
85 croak ("compress can only compress up to %ld bytes", 0x4000000-1);
86
87 /* 11 bytes is the smallest compressible string */
88 csize = usize < 11 ? 0 :
89 lzf_compress (src, usize,
90 dst + skip,
91 usize - skip);
92
93 if (csize)
94 {
95 SvCUR_set (ret, csize + skip);
96 }
97 else if (uprepend < 0)
98 {
99 SvREFCNT_dec (ret);
100 ret = SvREFCNT_inc (data);
101 }
102 else
103 {
104 *dst++ = uprepend;
105
106 Move ((void *)src, (void *)dst, usize, unsigned char);
107
108 SvCUR_set (ret, usize + 1);
109 }
110
111 return ret;
112 }
113 else
114 return newSVpv ("", 0);
115 }
116
117 static SV *
118 decompress_sv (SV *data, int skip)
119 {
120 STRLEN usize, csize;
121 unsigned char *src = (unsigned char *)SvPV (data, csize) + skip;
122
123 if (csize)
124 {
125 void *dst;
126 SV *ret;
127
128 csize -= skip;
129
130 if (src[0])
131 {
132 if (!(src[0] & 0x80))
133 {
134 csize -= 1;
135 usize = *src++ & 0xff;
136 }
137 else if (!(src[0] & 0x20))
138 {
139 csize -= 2;
140 usize = *src++ & 0x1f;
141 usize = (usize << 6) | (*src++ & 0x3f);
142 }
143 else if (!(src[0] & 0x10))
144 {
145 csize -= 3;
146 usize = *src++ & 0x0f;
147 usize = (usize << 6) | (*src++ & 0x3f);
148 usize = (usize << 6) | (*src++ & 0x3f);
149 }
150 else if (!(src[0] & 0x08))
151 {
152 csize -= 4;
153 usize = *src++ & 0x07;
154 usize = (usize << 6) | (*src++ & 0x3f);
155 usize = (usize << 6) | (*src++ & 0x3f);
156 usize = (usize << 6) | (*src++ & 0x3f);
157 }
158 else if (!(src[0] & 0x04))
159 {
160 csize -= 5;
161 usize = *src++ & 0x03;
162 usize = (usize << 6) | (*src++ & 0x3f);
163 usize = (usize << 6) | (*src++ & 0x3f);
164 usize = (usize << 6) | (*src++ & 0x3f);
165 usize = (usize << 6) | (*src++ & 0x3f);
166 }
167 else
168 croak ("compressed data corrupted (invalid length)");
169
170 ret = NEWSV (0, usize);
171 SvPOK_only (ret);
172 dst = SvPVX (ret);
173
174 if (lzf_decompress (src, csize, dst, usize) != usize)
175 croak ("compressed data corrupted (size mismatch)", csize, skip, usize);
176 }
177 else
178 {
179 usize = csize - 1;
180 ret = NEWSV (0, usize);
181 SvPOK_only (ret);
182
183 Move ((void *)(src + 1), (void *)SvPVX (ret), usize, unsigned char);
184 }
185
186 SvCUR_set (ret, usize);
187
188 return ret;
189 }
190 else
191 return newSVpvn ("", 0);
192 }
193
194 static void
195 need_storable(void)
196 {
197 #if PATCHLEVEL < 6
198 char req[8192];
199 sprintf (req, "require %s;", SvPV_nolen (serializer_package));
200 perl_eval_pv (req, 1);
201 #else
202 load_module (PERL_LOADMOD_NOIMPORT, serializer_package, Nullsv);
203 #endif
204
205 storable_mstore = GvCV (gv_fetchpv (SvPV_nolen (serializer_mstore ), TRUE, SVt_PVCV));
206 storable_mretrieve = GvCV (gv_fetchpv (SvPV_nolen (serializer_mretrieve), TRUE, SVt_PVCV));
207 }
208
209 MODULE = Compress::LZF PACKAGE = Compress::LZF
210
211 BOOT:
212 serializer_package = newSVpv ("Storable", 0);
213 serializer_mstore = newSVpv ("Storable::mstore", 0);
214 serializer_mretrieve = newSVpv ("Storable::mretrieve", 0);
215
216 void
217 set_serializer(package, mstore, mretrieve)
218 SV * package
219 SV * mstore
220 SV * mretrieve
221 PROTOTYPE: $$$
222 PPCODE:
223 SvSetSV (serializer_package , package );
224 SvSetSV (serializer_mstore , mstore );
225 SvSetSV (serializer_mretrieve, mretrieve);
226 storable_mstore =
227 storable_mretrieve = 0;
228
229 void
230 compress(data)
231 SV * data
232 PROTOTYPE: $
233 PPCODE:
234 XPUSHs (sv_2mortal (compress_sv (data, 0, MAGIC_U)));
235
236 void
237 decompress(data)
238 SV * data
239 PROTOTYPE: $
240 PPCODE:
241 XPUSHs (sv_2mortal (decompress_sv (data, 0)));
242
243 void
244 sfreeze(sv)
245 SV * sv
246 ALIAS:
247 sfreeze_cr = 1
248 sfreeze_c = 2
249 PROTOTYPE: $
250 PPCODE:
251
252 SvGETMAGIC (sv);
253
254 if (!SvOK (sv))
255 XPUSHs (sv_2mortal (newSVpvn ("\02", 1))); /* 02 == MAGIC_undef */
256 else if (SvROK (sv)
257 || (SvTYPE(sv) != SVt_IV
258 && SvTYPE(sv) != SVt_NV
259 && SvTYPE(sv) != SVt_PV
260 && SvTYPE(sv) != SVt_PVIV
261 && SvTYPE(sv) != SVt_PVNV
262 && SvTYPE(sv) != SVt_PVMG)) /* mstore */
263 {
264 int deref = !SvROK (sv);
265
266 if (!storable_mstore)
267 need_storable ();
268
269 if (deref)
270 sv = newRV_noinc (sv);
271
272 PUSHMARK (SP);
273 XPUSHs (sv);
274 PUTBACK;
275
276 if (1 != call_sv ((SV *)storable_mstore, G_SCALAR))
277 croak ("Storable::mstore didn't return a single scalar");
278
279 SPAGAIN;
280
281 sv = POPs;
282
283 if (SvPVX (sv)[0] != MAGIC_R)
284 croak ("Storable format changed, need newer version of Compress::LZF");
285
286 if (deref)
287 SvPVX (sv)[0] = MAGIC_R_deref;
288
289 if (ix) /* compress */
290 sv = sv_2mortal (compress_sv (sv, deref ? MAGIC_CR_deref : MAGIC_CR, -1));
291
292 XPUSHs (sv);
293 }
294 else if (SvPOKp (sv) && IN_RANGE (SvPVX (sv)[0], MAGIC_LO, MAGIC_HI))
295 XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, MAGIC_U))); /* need to prefix only */
296 else if (ix == 2) /* compress always */
297 XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, -1)));
298 else if (SvNIOK (sv)) /* don't compress */
299 {
300 STRLEN len;
301 char *s = SvPV (sv, len);
302 XPUSHs (sv_2mortal (newSVpvn (s, len)));
303 }
304 else /* don't compress */
305 XPUSHs (sv_2mortal (newSVsv (sv)));
306
307 void
308 sthaw(sv)
309 SV * sv
310 PROTOTYPE: $
311 PPCODE:
312
313 int deref = 0;
314
315 SvGETMAGIC (sv);
316 if (SvPOK (sv) && IN_RANGE (SvPV_nolen (sv)[0], MAGIC_LO, MAGIC_HI))
317 {
318 switch (SvPVX (sv)[0])
319 {
320 case MAGIC_undef:
321 XPUSHs (sv_2mortal (NEWSV (0, 0)));
322 break;
323
324 case MAGIC_U:
325 XPUSHs (sv_2mortal (decompress_sv (sv, 0)));
326 break;
327
328 case MAGIC_C:
329 XPUSHs (sv_2mortal (decompress_sv (sv, 1)));
330 break;
331
332 case MAGIC_R_deref:
333 deref = 1;
334 SvPVX (sv)[0] = MAGIC_R;
335 goto handle_MAGIC_R;
336
337 case MAGIC_CR_deref:
338 deref = 1;
339 case MAGIC_CR:
340 sv = sv_2mortal (decompress_sv (sv, 1)); /* mortal could be optimized */
341 if (deref)
342 if (SvPVX (sv)[0] == MAGIC_R_deref)
343 SvPVX (sv)[0] = MAGIC_R;
344 else
345 croak ("Compress::LZF::sthaw(): invalid data, maybe you need a newer version of Compress::LZF?");
346
347 case MAGIC_R:
348 handle_MAGIC_R:
349 if (!storable_mstore)
350 need_storable ();
351
352 PUSHMARK (SP);
353 XPUSHs (sv);
354 PUTBACK;
355
356 if (1 != call_sv ((SV *)storable_mretrieve, G_SCALAR))
357 croak ("Storable::mstore didn't return a single scalar");
358
359 SPAGAIN;
360
361 if (deref)
362 {
363 SETs (sv_2mortal (SvREFCNT_inc (SvRV (TOPs))));
364
365 if (SvPVX (sv)[0] == MAGIC_R)
366 SvPVX (sv)[0] = MAGIC_R_deref;
367 }
368 else
369 XPUSHs (POPs); /* this is a nop, hopefully */
370
371 break;
372
373 default:
374 croak ("Compress::LZF::sthaw(): invalid data, maybe you need a newer version of Compress::LZF?");
375 }
376 }
377 else
378 XPUSHs (sv_2mortal (newSVsv (sv)));
379