Compress-LZF/LZF.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

/* try to be compatible with older perls */
/* SvPV_nolen() macro first defined in 5.005_55 */
/* this is slow, not threadsafe, but works */
#include "patchlevel.h"
#if (PATCHLEVEL == 4) || ((PATCHLEVEL == 5) && (SUBVERSION < 55))
static STRLEN nolen_na;
# define SvPV_nolen(sv) SvPV ((sv), nolen_na)
#endif
#if PATCHLEVEL < 6
# define call_sv perl_call_sv
#endif

#include "lzf_c.c"
#include "lzf_d.c"

/* we re-use the storable header for our purposes */
#define MAGIC_LO        0
#define MAGIC_U         0 /* uncompressed data follows */
#define MAGIC_C         1 /* compressed data follows */
#define MAGIC_undef     2 /* the special value undef */
#define MAGIC_CR        3 /* storable (reference, freeze), compressed */
#define MAGIC_R         4 /* storable (reference, freeze) */
#define MAGIC_CR_deref  5 /* storable (NO reference, freeze), compressed */
#define MAGIC_R_deref   6 /* storable (NO reference, freeze) */
#define MAGIC_HI        7 /* room for one higher storable major */

#define IN_RANGE(v,l,h) ((unsigned int)((unsigned)(v) - (unsigned)(l)) <= (unsigned)(h) - (unsigned)(l))

static SV *serializer_package, *serializer_mstore, *serializer_mretrieve;
static CV *storable_mstore, *storable_mretrieve;

static SV *
compress_sv (SV *data, char cprepend, int uprepend)
{
  STRLEN usize, csize;
  char *src = (char *)SvPV (data, usize);

  if (usize)
    {
      SV *ret = NEWSV (0, usize + 1);
      unsigned char *dst;
      int skip = 0;

      SvPOK_only (ret);
      dst = (unsigned char *)SvPVX (ret);

      if (cprepend)
        dst[skip++] = cprepend;

      if (usize < 0x80)
        {
          dst[skip++] = usize;
        }
      else if (usize < 0x800) 
        {
          dst[skip++] = (( usize >>  6)         | 0xc0);
          dst[skip++] = (( usize        & 0x3f) | 0x80);
        }
      else if (usize < 0x10000) 
        {
          dst[skip++] = (( usize >> 12)         | 0xe0);
          dst[skip++] = (((usize >>  6) & 0x3f) | 0x80);
          dst[skip++] = (( usize        & 0x3f) | 0x80);
        }
      else if (usize < 0x200000) 
        {
          dst[skip++] = (( usize >> 18)         | 0xf0);
          dst[skip++] = (((usize >> 12) & 0x3f) | 0x80);
          dst[skip++] = (((usize >>  6) & 0x3f) | 0x80);
          dst[skip++] = (( usize        & 0x3f) | 0x80);
        }
      else if (usize < 0x4000000) 
        {
          dst[skip++] = (( usize >> 24)         | 0xf8);
          dst[skip++] = (((usize >> 18) & 0x3f) | 0x80);
          dst[skip++] = (((usize >> 12) & 0x3f) | 0x80);
          dst[skip++] = (((usize >>  6) & 0x3f) | 0x80);
          dst[skip++] = (( usize        & 0x3f) | 0x80);
        }
      else
        croak ("compress can only compress up to %ld bytes", 0x4000000-1);

      /* 11 bytes is the smallest compressible string */
      csize = usize < 11 ? 0 :
              lzf_compress (src, usize,
                                  dst + skip,
                                  usize - skip);

      if (csize)
        {
          SvCUR_set (ret, csize + skip);
        }
      else if (uprepend < 0)
        {
          SvREFCNT_dec (ret);
          ret = SvREFCNT_inc (data);
        }
      else
        {
          *dst++ = uprepend;

          Move ((void *)src, (void *)dst, usize, unsigned char);

          SvCUR_set (ret, usize + 1);
        }

      return ret;
    }
  else
    return newSVpv ("", 0);
}

static SV *
decompress_sv (SV *data, int skip)
{
  STRLEN usize, csize;
  unsigned char *src = (unsigned char *)SvPV (data, csize) + skip;

  if (csize)
    {
      void *dst;
      SV *ret;

      csize -= skip;

      if (src[0])
        {
          if (!(src[0] & 0x80))
            {
              csize -= 1;
              usize =                 *src++ & 0xff;
            }
          else if (!(src[0] & 0x20))
            {
              csize -= 2;
              usize =                 *src++ & 0x1f;
              usize = (usize << 6) | (*src++ & 0x3f);
            }
          else if (!(src[0] & 0x10))
            {
              csize -= 3;
              usize =                 *src++ & 0x0f;
              usize = (usize << 6) | (*src++ & 0x3f);
              usize = (usize << 6) | (*src++ & 0x3f);
            }
          else if (!(src[0] & 0x08))
            {
              csize -= 4;
              usize =                 *src++ & 0x07;
              usize = (usize << 6) | (*src++ & 0x3f);
              usize = (usize << 6) | (*src++ & 0x3f);
              usize = (usize << 6) | (*src++ & 0x3f);
            }
          else if (!(src[0] & 0x04))
            {
              csize -= 5;
              usize =                 *src++ & 0x03;
              usize = (usize << 6) | (*src++ & 0x3f);
              usize = (usize << 6) | (*src++ & 0x3f);
              usize = (usize << 6) | (*src++ & 0x3f);
              usize = (usize << 6) | (*src++ & 0x3f);
            }
          else
            croak ("compressed data corrupted (invalid length)");
                    
          ret = NEWSV (0, usize);
          SvPOK_only (ret);
          dst = SvPVX (ret);

          if (lzf_decompress (src, csize, dst, usize) != usize)
            croak ("compressed data corrupted (size mismatch)", csize, skip, usize);
        }
      else
        {
          usize = csize - 1;
          ret = NEWSV (0, usize);
          SvPOK_only (ret);

          Move ((void *)(src + 1), (void *)SvPVX (ret), usize, unsigned char);
      }

      SvCUR_set (ret, usize);

      return ret;
    }
  else
    return newSVpvn ("", 0);
}

static void
need_storable(void)
{
#if PATCHLEVEL < 6
  char req[8192];
  sprintf (req, "require %s;", SvPV_nolen (serializer_package));
  perl_eval_pv (req, 1);
#else
  load_module (PERL_LOADMOD_NOIMPORT, serializer_package, Nullsv);
#endif

  storable_mstore    = GvCV (gv_fetchpv (SvPV_nolen (serializer_mstore   ), TRUE, SVt_PVCV));
  storable_mretrieve = GvCV (gv_fetchpv (SvPV_nolen (serializer_mretrieve), TRUE, SVt_PVCV));
}

MODULE = Compress::LZF   PACKAGE = Compress::LZF

BOOT:
        serializer_package   = newSVpv ("Storable", 0);
        serializer_mstore    = newSVpv ("Storable::mstore", 0);
        serializer_mretrieve = newSVpv ("Storable::mretrieve", 0);

void
set_serializer(package, mstore, mretrieve)
        SV *    package
        SV *    mstore
        SV *    mretrieve
        PROTOTYPE: $$$
        PPCODE:
        SvSetSV (serializer_package  , package  );
        SvSetSV (serializer_mstore   , mstore   );
        SvSetSV (serializer_mretrieve, mretrieve);
        storable_mstore =
        storable_mretrieve = 0;

void
compress(data)
        SV *    data
        PROTOTYPE: $
        PPCODE:
        XPUSHs (sv_2mortal (compress_sv (data, 0, MAGIC_U)));

void
decompress(data)
        SV *    data
        PROTOTYPE: $
        PPCODE:
        XPUSHs (sv_2mortal (decompress_sv (data, 0)));

void
sfreeze(sv)
        SV *    sv
        ALIAS:
        sfreeze_cr = 1
        sfreeze_c  = 2
        PROTOTYPE: $
        PPCODE:

        SvGETMAGIC (sv);

        if (!SvOK (sv))
          XPUSHs (sv_2mortal (newSVpvn ("\02", 1))); /* 02 == MAGIC_undef */
        else if (SvROK (sv)
              || (SvTYPE(sv) != SVt_IV
                 && SvTYPE(sv) != SVt_NV
                 && SvTYPE(sv) != SVt_PV
                 && SvTYPE(sv) != SVt_PVMG)) /* mstore */
          {
            int deref = !SvROK (sv);

            if (!storable_mstore)
              need_storable ();

            if (deref)
              sv = newRV_noinc (sv);

            PUSHMARK (SP);
            XPUSHs (sv);
            PUTBACK;

            if (1 != call_sv ((SV *)storable_mstore, G_SCALAR))
              croak ("Storable::mstore didn't return a single scalar");

            SPAGAIN;

            sv = POPs;

            if (SvPVX (sv)[0] != MAGIC_R)
              croak ("Storable format changed, need newer version of Compress::LZF");

            if (deref)
              SvPVX (sv)[0] = MAGIC_R_deref;

            if (ix) /* compress */
              sv = sv_2mortal (compress_sv (sv, deref ? MAGIC_CR_deref : MAGIC_CR, -1));

            XPUSHs (sv);
          }
        else if (SvPOKp (sv) && IN_RANGE (SvPVX (sv)[0], MAGIC_LO, MAGIC_HI))
          XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, MAGIC_U))); /* need to prefix only */
        else if (ix == 2) /* compress always */
          XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, -1)));
        else /* don't compress */
          XPUSHs (sv_2mortal (SvREFCNT_inc (sv)));

void
sthaw(sv)
        SV *    sv
        PROTOTYPE: $
        PPCODE:

        int deref = 0;

        SvGETMAGIC (sv);
        if (SvPOK (sv) && IN_RANGE (SvPV_nolen (sv)[0], MAGIC_LO, MAGIC_HI))
          {
            switch (SvPVX (sv)[0])
              {
                case MAGIC_undef:
                  XPUSHs (sv_2mortal (NEWSV (0, 0)));
                  break;

                case MAGIC_U:
                  XPUSHs (sv_2mortal (decompress_sv (sv, 0)));
                  break;

                case MAGIC_C:
                  XPUSHs (sv_2mortal (decompress_sv (sv, 1)));
                  break;

                case MAGIC_R_deref:
                  deref = 1;
                  SvPVX (sv)[0] = MAGIC_R;
                  goto handle_MAGIC_R;

                case MAGIC_CR_deref:
                  deref = 1;
                case MAGIC_CR:
                  sv = sv_2mortal (decompress_sv (sv, 1)); /* mortal could be optimized */
                  if (deref)
                    if (SvPVX (sv)[0] == MAGIC_R_deref)
                      SvPVX (sv)[0] = MAGIC_R;
                    else
                      croak ("Compress::LZF::sthaw(): invalid data, maybe you need a newer version of Compress::LZF?");

                case MAGIC_R:
                handle_MAGIC_R:
                  if (!storable_mstore)
                    need_storable ();

                  PUSHMARK (SP);
                  XPUSHs (sv);
                  PUTBACK;

                  if (1 != call_sv ((SV *)storable_mretrieve, G_SCALAR))
                    croak ("Storable::mstore didn't return a single scalar");

                  SPAGAIN;

                  if (deref)
                    {
                      SETs (sv_2mortal (SvREFCNT_inc (SvRV (TOPs))));

                      if (SvPVX (sv)[0] == MAGIC_R)
                        SvPVX (sv)[0] = MAGIC_R_deref;
                    }
                  else
                    XPUSHs (POPs); /* this is a nop, hopefully */

                  break; 

                default:
                  croak ("Compress::LZF::sthaw(): invalid data, maybe you need a newer version of Compress::LZF?");
              }
          }
        else
          XPUSHs (sv_2mortal (newSVsv (sv)));
Revision:	1.14
Committed:	Thu Sep 5 04:44:55 2002 UTC (21 years, 8 months ago) by root
Branch:	MAIN
Changes since 1.13:	+25 -4 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#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	root	1.2	#if PATCHLEVEL < 6
14			# define call_sv perl_call_sv
15			#endif
16	root	1.1
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	root	1.4	#define MAGIC_undef 2 /* the special value undef */
25			#define MAGIC_CR 3 /* storable (reference, freeze), compressed */
26	root	1.1	#define MAGIC_R 4 /* storable (reference, freeze) */
27	root	1.9	#define MAGIC_CR_deref 5 /* storable (NO reference, freeze), compressed */
28	root	1.10	#define MAGIC_R_deref 6 /* storable (NO reference, freeze) */
29	root	1.1	#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	root	1.14	static SV serializer_package, serializer_mstore, *serializer_mretrieve;
34	root	1.1	static CV storable_mstore, storable_mretrieve;
35
36			static SV *
37	root	1.10	compress_sv (SV *data, char cprepend, int uprepend)
38	root	1.1	{
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	root	1.10	else if (uprepend < 0)
98	root	1.1	{
99			SvREFCNT_dec (ret);
100			ret = SvREFCNT_inc (data);
101			}
102			else
103			{
104	root	1.10	*dst++ = uprepend;
105	root	1.1
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	root	1.13	croak ("compressed data corrupted (invalid length)");
169	root	1.1
170			ret = NEWSV (0, usize);
171			SvPOK_only (ret);
172			dst = SvPVX (ret);
173
174			if (lzf_decompress (src, csize, dst, usize) != usize)
175	root	1.13	croak ("compressed data corrupted (size mismatch)", csize, skip, usize);
176	root	1.1	}
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	root	1.2	#if PATCHLEVEL < 6
198	root	1.14	char req[8192];
199			sprintf (req, "require %s;", SvPV_nolen (serializer_package));
200			perl_eval_pv (req, 1);
201	root	1.2	#else
202	root	1.14	load_module (PERL_LOADMOD_NOIMPORT, serializer_package, Nullsv);
203	root	1.2	#endif
204	root	1.1
205	root	1.14	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	root	1.1	}
208
209			MODULE = Compress::LZF PACKAGE = Compress::LZF
210	root	1.14
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	root	1.1
229			void
230			compress(data)
231			SV * data
232			PROTOTYPE: $
233			PPCODE:
234	root	1.10	XPUSHs (sv_2mortal (compress_sv (data, 0, MAGIC_U)));
235	root	1.1
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	root	1.10	SvGETMAGIC (sv);
253
254	root	1.4	if (!SvOK (sv))
255			XPUSHs (sv_2mortal (newSVpvn ("\02", 1))); /* 02 == MAGIC_undef */
256	root	1.12	else if (SvROK (sv)
257			\|\| (SvTYPE(sv) != SVt_IV
258			&& SvTYPE(sv) != SVt_NV
259			&& SvTYPE(sv) != SVt_PV
260			&& SvTYPE(sv) != SVt_PVMG)) /* mstore */
261	root	1.1	{
262	root	1.9	int deref = !SvROK (sv);
263
264	root	1.1	if (!storable_mstore)
265			need_storable ();
266
267	root	1.9	if (deref)
268			sv = newRV_noinc (sv);
269
270	root	1.1	PUSHMARK (SP);
271			XPUSHs (sv);
272			PUTBACK;
273
274			if (1 != call_sv ((SV *)storable_mstore, G_SCALAR))
275			croak ("Storable::mstore didn't return a single scalar");
276
277			SPAGAIN;
278
279			sv = POPs;
280
281			if (SvPVX (sv)[0] != MAGIC_R)
282			croak ("Storable format changed, need newer version of Compress::LZF");
283
284	root	1.10	if (deref)
285			SvPVX (sv)[0] = MAGIC_R_deref;
286
287	root	1.1	if (ix) /* compress */
288	root	1.10	sv = sv_2mortal (compress_sv (sv, deref ? MAGIC_CR_deref : MAGIC_CR, -1));
289	root	1.9
290	root	1.10	XPUSHs (sv);
291	root	1.1	}
292	root	1.13	else if (SvPOKp (sv) && IN_RANGE (SvPVX (sv)[0], MAGIC_LO, MAGIC_HI))
293	root	1.10	XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, MAGIC_U))); /* need to prefix only */
294	root	1.1	else if (ix == 2) /* compress always */
295	root	1.10	XPUSHs (sv_2mortal (compress_sv (sv, MAGIC_C, -1)));
296	root	1.1	else /* don't compress */
297			XPUSHs (sv_2mortal (SvREFCNT_inc (sv)));
298
299			void
300			sthaw(sv)
301			SV * sv
302			PROTOTYPE: $
303			PPCODE:
304
305	root	1.9	int deref = 0;
306
307	root	1.7	SvGETMAGIC (sv);
308	root	1.6	if (SvPOK (sv) && IN_RANGE (SvPV_nolen (sv)[0], MAGIC_LO, MAGIC_HI))
309	root	1.1	{
310			switch (SvPVX (sv)[0])
311			{
312	root	1.4	case MAGIC_undef:
313			XPUSHs (sv_2mortal (NEWSV (0, 0)));
314			break;
315
316	root	1.1	case MAGIC_U:
317			XPUSHs (sv_2mortal (decompress_sv (sv, 0)));
318			break;
319
320			case MAGIC_C:
321			XPUSHs (sv_2mortal (decompress_sv (sv, 1)));
322			break;
323
324	root	1.10	case MAGIC_R_deref:
325			deref = 1;
326			SvPVX (sv)[0] = MAGIC_R;
327			goto handle_MAGIC_R;
328
329	root	1.9	case MAGIC_CR_deref:
330			deref = 1;
331	root	1.1	case MAGIC_CR:
332			sv = sv_2mortal (decompress_sv (sv, 1)); /* mortal could be optimized */
333	root	1.10	if (deref)
334			if (SvPVX (sv)[0] == MAGIC_R_deref)
335	root	1.9	SvPVX (sv)[0] = MAGIC_R;
336	root	1.10	else
337			croak ("Compress::LZF::sthaw(): invalid data, maybe you need a newer version of Compress::LZF?");
338
339	root	1.1	case MAGIC_R:
340	root	1.10	handle_MAGIC_R:
341	root	1.1	if (!storable_mstore)
342			need_storable ();
343
344			PUSHMARK (SP);
345			XPUSHs (sv);
346			PUTBACK;
347
348			if (1 != call_sv ((SV *)storable_mretrieve, G_SCALAR))
349			croak ("Storable::mstore didn't return a single scalar");
350
351			SPAGAIN;
352
353	root	1.9	if (deref)
354			{
355	root	1.10	SETs (sv_2mortal (SvREFCNT_inc (SvRV (TOPs))));
356	root	1.9
357			if (SvPVX (sv)[0] == MAGIC_R)
358	root	1.10	SvPVX (sv)[0] = MAGIC_R_deref;
359	root	1.9	}
360	root	1.10	else
361			XPUSHs (POPs); /* this is a nop, hopefully */
362	root	1.1
363			break;
364
365			default:
366			croak ("Compress::LZF::sthaw(): invalid data, maybe you need a newer version of Compress::LZF?");
367			}
368			}
369			else
370	root	1.11	XPUSHs (sv_2mortal (newSVsv (sv)));