PApp-SQL/SQL.xs

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

#define is_dbh(sv) ((sv) && sv_isobject (sv) && sv_derived_from ((sv), "DBI::db"))

typedef struct lru_node {
  struct lru_node *next;
  struct lru_node *prev;
  U32 hash;
  SV *dbh;
  SV *sql;

  SV *sth;
#if 0 /* method cache */
  GV *execute;
  GV *bind_columns;
  GV *fetch;
#endif
} lru_node;

static lru_node lru_list;
static int lru_size;
static int lru_maxsize;

#define lru_init lru_list.next = &lru_list; lru_list.prev = &lru_list /* other fields are zero */

/* this is primitive, yet effective */
/* the returned value must never be zero (or bad things will happen) */
#define lru_hash do {   \
        hash = (((U32)dbh)>>2); \
        hash += *statement;\
        hash += len;            \
} while (0)

/* fetch and "use" */
/* could be done using a single call (we could call prepare!) */
static SV *lru_fetch(SV *dbh, SV *sql)
{
  lru_node *n;

  U32 hash;
  STRLEN len;
  char *statement = SvPV (sql, len);

  dbh = SvRV (dbh);

  lru_hash;

  /*fprintf (stderr, "F: %08lx %s\n", hash, SvPV_nolen (sql));/*D*/

  n = &lru_list;
  do {
    n = n->next;
    if (!n->hash)
      return 0;
  } while (n->hash != hash
           || !sv_eq (n->sql, sql)
           || n->dbh != dbh);

  /* found, so return to the start of the list */
  n->prev->next = n->next;
  n->next->prev = n->prev;

  n->next = lru_list.next;
  n->prev = &lru_list;
  lru_list.next->prev = n;
  lru_list.next = n;

  return n->sth;
}

static void lru_nukeone(void)
{
  lru_node *n;
  /* nuke at the end */

  n = lru_list.prev;

  lru_list.prev = n->prev;
  n->prev->next = &lru_list;

  /*fprintf (stderr, "N: %s\n", SvPV_nolen (n->sql));/*D*/

  SvREFCNT_dec (n->dbh);
  SvREFCNT_dec (n->sql);
  SvREFCNT_dec (n->sth);
  Safefree (n);
  
  lru_size--;
}

/* store a not-yet existing entry(!) */
static void lru_store(SV *dbh, SV *sql, SV *sth)
{
  lru_node *n;

  U32 hash;
  STRLEN len;
  char *statement = SvPV (sql, len);

  dbh = SvRV (dbh);

  lru_hash;

  /*fprintf (stderr, "S: %08lx %s\n", hash, SvPV_nolen (sql));/*D*/

  lru_size++;
  if (lru_size > lru_maxsize)
    lru_nukeone ();

  New (0, n, 1, lru_node);

  n->hash = hash;
  n->dbh = dbh; SvREFCNT_inc (dbh); /* note: this is the dbi hash itself, not the reference */
  n->sql = newSVsv (sql);
  n->sth = sth; SvREFCNT_inc (sth);

  n->next = lru_list.next;
  n->prev = &lru_list;
  lru_list.next->prev = n;
  lru_list.next = n;
}

static void lru_cachesize (int size)
{
  if (size >= 0)
    {
      lru_maxsize = size;
      while (lru_size > lru_maxsize)
        lru_nukeone ();
    }
}

static GV *sql_exec;
static GV *DBH;

MODULE = PApp::SQL              PACKAGE = PApp::SQL

PROTOTYPES: DISABLE

BOOT:
{
   sql_exec = gv_fetchpv ("PApp::SQL::sql_exec", TRUE, SVt_PV);
   DBH      = gv_fetchpv ("PApp::SQL::DBH"     , TRUE, SVt_PV);

   /* apache might BOOT: twice :( */
   if (lru_size)
     lru_cachesize (0);

   lru_init;
   lru_cachesize (50);
}

int
cachesize(size = -1)
        int     size
        CODE:
        RETVAL = lru_maxsize;
        lru_cachesize (size);
        OUTPUT:
        RETVAL

void
sql_exec(...)
        ALIAS:
                sql_fetch    = 1
                sql_fetchall = 2
                sql_exists   = 4
        PPCODE:
{
        if (items == 0)
          croak ("Usage: sql_exec [database-handle,] [bind-var-refs,... ] \"sql-statement\", [arguments, ...]");
        else
          {
            int arg = 0;
            int bind_first, bind_last;
            int count;
            SV *dbh = ST(0);
            SV *sth;
            SV *sql;
            SV *execute;

            /* save our arguments against destruction through function calls */
            SP += items;
            
            /* first check wether we should use an explicit db handle */
            if (!is_dbh (dbh))
              {
                dbh = get_sv ("DBH", FALSE);
                if (!is_dbh (dbh))
                  {
                    dbh = GvSV(DBH);
                    if (!is_dbh (dbh))
                      croak ("sql_exec: no $DBH found in current package or in PApp::SQL::");
                  }
              }
            else
              arg++; /* we consumed one argument */

            /* count the remaining references (for bind_columns) */
            bind_first = arg;
            while (items > arg && SvROK (ST(arg)))
              arg++;

            bind_last = arg;

            /* consume the sql-statement itself */
            if (items <= arg)
              croak ("sql_exec: required argument \"sql-statement\" missing");

            if (!SvPOK (ST(arg)))
              croak ("sql_exec: sql-statement must be a string");

            sql = ST(arg); arg++;

            if (ix == 4)
              {
                SV *neu = sv_2mortal (newSVpv ("select count(*) > 0 from ", 0));
                sv_catsv (neu, sql);
                sv_catpv (neu, " limit 1");
                sql = neu;
                ix = 1; /* sql_fetch */
              }

            /* check cache for existing statement handle (NYI) */
            sth = lru_fetch (dbh, sql);
            if (!sth)
              {
                PUSHMARK (SP);
                EXTEND (SP, 2);
                PUSHs (dbh);
                PUSHs (sql);
                PUTBACK;
                count = call_method ("prepare", G_SCALAR);
                SPAGAIN;

                if (count != 1)
                  croak ("sql_exec: unable to prepare() statement '%s': %s",
                         SvPV_nolen (sql),
                         SvPV_nolen (get_sv ("DBI::errstr", TRUE)));

                sth = POPs;

                lru_store (dbh, sql, sth);
              }

            PUSHMARK (SP);
            EXTEND (SP, items - arg + 1);
            PUSHs (sth);
            while (items > arg)
              {
                PUSHs (ST(arg));
                arg++;
              }

            PUTBACK;
            /* { static GV *execute;
              if (!execute) execute = gv_fetchmethod_autoload(SvSTASH(SvRV(sth)), "execute", 0);
              count = call_sv(GvCV(execute), G_SCALAR);
             }*/
            count = call_method ("execute", G_SCALAR);
            SPAGAIN;

            if (count != 1)
              croak ("sql_exec: execute() didn't return any value ('%s'): %s",
                     SvPV_nolen (sql),
                     SvPV_nolen (get_sv ("DBI::errstr", TRUE)));

            execute = POPs;

            if (!SvTRUE (execute))
              croak ("sql_exec: unable to execute statement '%s' (%s)",
                     SvPV_nolen (sql),
                     SvPV_nolen (get_sv ("DBI::errstr", TRUE)));

            sv_setsv (GvSV(sql_exec), execute);

            if (bind_first != bind_last)
              {
                PUSHMARK (SP);
                EXTEND (SP, bind_last - bind_first + 2);
                PUSHs (sth);
                do {
                  PUSHs (ST(bind_first));
                  bind_first++;
                } while (bind_first != bind_last);

                PUTBACK;
                count = call_method ("bind_columns", G_SCALAR);
                SPAGAIN;

                if (count != 1)
                  croak ("sql_exec: bind_columns() didn't return any value ('%s'): %s",
                         SvPV_nolen (sql),
                         SvPV_nolen (get_sv ("DBI::errstr", TRUE)));

                if (!SvOK (POPs))
                  croak ("sql_exec: bind_columns() didn't return a true ('%s'): %s",
                         SvPV_nolen (sql),
                         SvPV_nolen (get_sv ("DBI::errstr", TRUE)));
              }

            /* free our arguments from the stack */
            SP -= items;

            if (ix == 1)
              { /* sql_fetch */
                SV *row;

                PUSHMARK (SP);
                XPUSHs (sth);
                PUTBACK;
                count = call_method ("fetchrow_arrayref", G_SCALAR);
                SPAGAIN;

                if (count != 1)
                  abort ();

                row = POPs;

                if (SvROK (row))
                  {
                    AV *av;

                    switch (GIMME_V)
                      {
                        case G_VOID:
                          /* no thing */
                          break;
                        case G_SCALAR:
                          /* the first element */
                          XPUSHs (*av_fetch ((AV *)SvRV (row), 0, 1));
                          break;
                        case G_ARRAY:
                          av = (AV *)SvRV (row);
                          count = AvFILL (av) + 1;
                          EXTEND (SP, count);
                          for (arg = 0; arg < count; arg++)
                            PUSHs (AvARRAY (av)[arg]);

                          break;
                        default:
                          abort ();
                      }
                 }
              }
            else if (ix == 2)
              { /* sql_fetchall */
                SV *rows;

                PUSHMARK (SP);
                XPUSHs (sth);
                PUTBACK;
                count = call_method ("fetchall_arrayref", G_SCALAR);
                SPAGAIN;

                if (count != 1)
                  abort ();

                rows = POPs;

                if (SvROK (rows))
                  {
                    AV *av = (AV *)SvRV (rows);
                    count = AvFILL (av) + 1;

                    if (count)
                      {
                        int columns = AvFILL ((AV *)SvRV (AvARRAY(av)[0])) + 1; /* columns? */

                        EXTEND (SP, count);
                        if (columns == 1)
                          for (arg = 0; arg < count; arg++)
                            PUSHs (AvARRAY ((AV *)SvRV (AvARRAY (av)[arg]))[0]);
                        else
                          for (arg = 0; arg < count; arg++)
                            PUSHs (AvARRAY (av)[arg]);
                      }
                 }
              }
            else
              XPUSHs (sth);

            if (ix || GIMME_V == G_VOID)
              {
                PUSHMARK (SP);
                XPUSHs (sth);
                PUTBACK;
                (void) call_method ("finish", G_DISCARD);
                SPAGAIN;
              }
          }
}


Revision:	1.2
Committed:	Tue Oct 24 04:21:45 2000 UTC (23 years, 7 months ago) by root
Branch:	MAIN
Changes since 1.1:	+1 -1 lines
Log Message:	* empty log message *
#	Content
1	#include "EXTERN.h"
2	#include "perl.h"
3	#include "XSUB.h"
4
5	#define is_dbh(sv) ((sv) && sv_isobject (sv) && sv_derived_from ((sv), "DBI::db"))
6
7	typedef struct lru_node {
8	struct lru_node *next;
9	struct lru_node *prev;
10	U32 hash;
11	SV *dbh;
12	SV *sql;
13
14	SV *sth;
15	#if 0 /* method cache */
16	GV *execute;
17	GV *bind_columns;
18	GV *fetch;
19	#endif
20	} lru_node;
21
22	static lru_node lru_list;
23	static int lru_size;
24	static int lru_maxsize;
25
26	#define lru_init lru_list.next = &lru_list; lru_list.prev = &lru_list /* other fields are zero */
27
28	/* this is primitive, yet effective */
29	/* the returned value must never be zero (or bad things will happen) */
30	#define lru_hash do { \
31	hash = (((U32)dbh)>>2); \
32	hash += *statement;\
33	hash += len; \
34	} while (0)
35
36	/* fetch and "use" */
37	/* could be done using a single call (we could call prepare!) */
38	static SV lru_fetch(SV dbh, SV *sql)
39	{
40	lru_node *n;
41
42	U32 hash;
43	STRLEN len;
44	char *statement = SvPV (sql, len);
45
46	dbh = SvRV (dbh);
47
48	lru_hash;
49
50	/fprintf (stderr, "F: %08lx %s\n", hash, SvPV_nolen (sql));/D*/
51
52	n = &lru_list;
53	do {
54	n = n->next;
55	if (!n->hash)
56	return 0;
57	} while (n->hash != hash
58	\|\| !sv_eq (n->sql, sql)
59	\|\| n->dbh != dbh);
60
61	/* found, so return to the start of the list */
62	n->prev->next = n->next;
63	n->next->prev = n->prev;
64
65	n->next = lru_list.next;
66	n->prev = &lru_list;
67	lru_list.next->prev = n;
68	lru_list.next = n;
69
70	return n->sth;
71	}
72
73	static void lru_nukeone(void)
74	{
75	lru_node *n;
76	/* nuke at the end */
77
78	n = lru_list.prev;
79
80	lru_list.prev = n->prev;
81	n->prev->next = &lru_list;
82
83	/fprintf (stderr, "N: %s\n", SvPV_nolen (n->sql));/D*/
84
85	SvREFCNT_dec (n->dbh);
86	SvREFCNT_dec (n->sql);
87	SvREFCNT_dec (n->sth);
88	Safefree (n);
89
90	lru_size--;
91	}
92
93	/* store a not-yet existing entry(!) */
94	static void lru_store(SV dbh, SV sql, SV *sth)
95	{
96	lru_node *n;
97
98	U32 hash;
99	STRLEN len;
100	char *statement = SvPV (sql, len);
101
102	dbh = SvRV (dbh);
103
104	lru_hash;
105
106	/fprintf (stderr, "S: %08lx %s\n", hash, SvPV_nolen (sql));/D*/
107
108	lru_size++;
109	if (lru_size > lru_maxsize)
110	lru_nukeone ();
111
112	New (0, n, 1, lru_node);
113
114	n->hash = hash;
115	n->dbh = dbh; SvREFCNT_inc (dbh); /* note: this is the dbi hash itself, not the reference */
116	n->sql = newSVsv (sql);
117	n->sth = sth; SvREFCNT_inc (sth);
118
119	n->next = lru_list.next;
120	n->prev = &lru_list;
121	lru_list.next->prev = n;
122	lru_list.next = n;
123	}
124
125	static void lru_cachesize (int size)
126	{
127	if (size >= 0)
128	{
129	lru_maxsize = size;
130	while (lru_size > lru_maxsize)
131	lru_nukeone ();
132	}
133	}
134
135	static GV *sql_exec;
136	static GV *DBH;
137
138	MODULE = PApp::SQL PACKAGE = PApp::SQL
139
140	PROTOTYPES: DISABLE
141
142	BOOT:
143	{
144	sql_exec = gv_fetchpv ("PApp::SQL::sql_exec", TRUE, SVt_PV);
145	DBH = gv_fetchpv ("PApp::SQL::DBH" , TRUE, SVt_PV);
146
147	/* apache might BOOT: twice :( */
148	if (lru_size)
149	lru_cachesize (0);
150
151	lru_init;
152	lru_cachesize (50);
153	}
154
155	int
156	cachesize(size = -1)
157	int size
158	CODE:
159	RETVAL = lru_maxsize;
160	lru_cachesize (size);
161	OUTPUT:
162	RETVAL
163
164	void
165	sql_exec(...)
166	ALIAS:
167	sql_fetch = 1
168	sql_fetchall = 2
169	sql_exists = 4
170	PPCODE:
171	{
172	if (items == 0)
173	croak ("Usage: sql_exec [database-handle,] [bind-var-refs,... ] \"sql-statement\", [arguments, ...]");
174	else
175	{
176	int arg = 0;
177	int bind_first, bind_last;
178	int count;
179	SV *dbh = ST(0);
180	SV *sth;
181	SV *sql;
182	SV *execute;
183
184	/* save our arguments against destruction through function calls */
185	SP += items;
186
187	/* first check wether we should use an explicit db handle */
188	if (!is_dbh (dbh))
189	{
190	dbh = get_sv ("DBH", FALSE);
191	if (!is_dbh (dbh))
192	{
193	dbh = GvSV(DBH);
194	if (!is_dbh (dbh))
195	croak ("sql_exec: no $DBH found in current package or in PApp::SQL::");
196	}
197	}
198	else
199	arg++; /* we consumed one argument */
200
201	/* count the remaining references (for bind_columns) */
202	bind_first = arg;
203	while (items > arg && SvROK (ST(arg)))
204	arg++;
205
206	bind_last = arg;
207
208	/* consume the sql-statement itself */
209	if (items <= arg)
210	croak ("sql_exec: required argument \"sql-statement\" missing");
211
212	if (!SvPOK (ST(arg)))
213	croak ("sql_exec: sql-statement must be a string");
214
215	sql = ST(arg); arg++;
216
217	if (ix == 4)
218	{
219	SV neu = sv_2mortal (newSVpv ("select count() > 0 from ", 0));
220	sv_catsv (neu, sql);
221	sv_catpv (neu, " limit 1");
222	sql = neu;
223	ix = 1; /* sql_fetch */
224	}
225
226	/* check cache for existing statement handle (NYI) */
227	sth = lru_fetch (dbh, sql);
228	if (!sth)
229	{
230	PUSHMARK (SP);
231	EXTEND (SP, 2);
232	PUSHs (dbh);
233	PUSHs (sql);
234	PUTBACK;
235	count = call_method ("prepare", G_SCALAR);
236	SPAGAIN;
237
238	if (count != 1)
239	croak ("sql_exec: unable to prepare() statement '%s': %s",
240	SvPV_nolen (sql),
241	SvPV_nolen (get_sv ("DBI::errstr", TRUE)));
242
243	sth = POPs;
244
245	lru_store (dbh, sql, sth);
246	}
247
248	PUSHMARK (SP);
249	EXTEND (SP, items - arg + 1);
250	PUSHs (sth);
251	while (items > arg)
252	{
253	PUSHs (ST(arg));
254	arg++;
255	}
256
257	PUTBACK;
258	/* { static GV *execute;
259	if (!execute) execute = gv_fetchmethod_autoload(SvSTASH(SvRV(sth)), "execute", 0);
260	count = call_sv(GvCV(execute), G_SCALAR);
261	}*/
262	count = call_method ("execute", G_SCALAR);
263	SPAGAIN;
264
265	if (count != 1)
266	croak ("sql_exec: execute() didn't return any value ('%s'): %s",
267	SvPV_nolen (sql),
268	SvPV_nolen (get_sv ("DBI::errstr", TRUE)));
269
270	execute = POPs;
271
272	if (!SvTRUE (execute))
273	croak ("sql_exec: unable to execute statement '%s' (%s)",
274	SvPV_nolen (sql),
275	SvPV_nolen (get_sv ("DBI::errstr", TRUE)));
276
277	sv_setsv (GvSV(sql_exec), execute);
278
279	if (bind_first != bind_last)
280	{
281	PUSHMARK (SP);
282	EXTEND (SP, bind_last - bind_first + 2);
283	PUSHs (sth);
284	do {
285	PUSHs (ST(bind_first));
286	bind_first++;
287	} while (bind_first != bind_last);
288
289	PUTBACK;
290	count = call_method ("bind_columns", G_SCALAR);
291	SPAGAIN;
292
293	if (count != 1)
294	croak ("sql_exec: bind_columns() didn't return any value ('%s'): %s",
295	SvPV_nolen (sql),
296	SvPV_nolen (get_sv ("DBI::errstr", TRUE)));
297
298	if (!SvOK (POPs))
299	croak ("sql_exec: bind_columns() didn't return a true ('%s'): %s",
300	SvPV_nolen (sql),
301	SvPV_nolen (get_sv ("DBI::errstr", TRUE)));
302	}
303
304	/* free our arguments from the stack */
305	SP -= items;
306
307	if (ix == 1)
308	{ /* sql_fetch */
309	SV *row;
310
311	PUSHMARK (SP);
312	XPUSHs (sth);
313	PUTBACK;
314	count = call_method ("fetchrow_arrayref", G_SCALAR);
315	SPAGAIN;
316
317	if (count != 1)
318	abort ();
319
320	row = POPs;
321
322	if (SvROK (row))
323	{
324	AV *av;
325
326	switch (GIMME_V)
327	{
328	case G_VOID:
329	/* no thing */
330	break;
331	case G_SCALAR:
332	/* the first element */
333	XPUSHs (av_fetch ((AV )SvRV (row), 0, 1));
334	break;
335	case G_ARRAY:
336	av = (AV *)SvRV (row);
337	count = AvFILL (av) + 1;
338	EXTEND (SP, count);
339	for (arg = 0; arg < count; arg++)
340	PUSHs (AvARRAY (av)[arg]);
341
342	break;
343	default:
344	abort ();
345	}
346	}
347	}
348	else if (ix == 2)
349	{ /* sql_fetchall */
350	SV *rows;
351
352	PUSHMARK (SP);
353	XPUSHs (sth);
354	PUTBACK;
355	count = call_method ("fetchall_arrayref", G_SCALAR);
356	SPAGAIN;
357
358	if (count != 1)
359	abort ();
360
361	rows = POPs;
362
363	if (SvROK (rows))
364	{
365	AV av = (AV )SvRV (rows);
366	count = AvFILL (av) + 1;
367
368	if (count)
369	{
370	int columns = AvFILL ((AV )SvRV (AvARRAY(av)[0])) + 1; / columns? */
371
372	EXTEND (SP, count);
373	if (columns == 1)
374	for (arg = 0; arg < count; arg++)
375	PUSHs (AvARRAY ((AV *)SvRV (AvARRAY (av)[arg]))[0]);
376	else
377	for (arg = 0; arg < count; arg++)
378	PUSHs (AvARRAY (av)[arg]);
379	}
380	}
381	}
382	else
383	XPUSHs (sth);
384
385	if (ix \|\| GIMME_V == G_VOID)
386	{
387	PUSHMARK (SP);
388	XPUSHs (sth);
389	PUTBACK;
390	(void) call_method ("finish", G_DISCARD);
391	SPAGAIN;
392	}
393	}
394	}
395
396
397