PApp-SQL/SQL.xs

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

/* import some stuff from DBIXS.h and DBI.xs */
#define DBIXS_VERSION 93
#define DBI_MAGIC '~'

#define DBISTATE_PERLNAME "DBI::_dbistate"
#define DBISTATE_ADDRSV   (perl_get_sv (DBISTATE_PERLNAME, 0x05))
#define DBIS_PUBLISHED_LVALUE (*(INT2PTR(dbistate_t**, &SvIVX(DBISTATE_ADDRSV))))

static SV *sql_varchar, *sql_integer, *sql_double;
static SV *tmp_iv;

struct dbistate_st {
#define DBISTATE_VERSION  94    /* Must change whenever dbistate_t does */
    /* this must be the first member in structure                       */
    void (*check_version) _((const char *name,
                int dbis_cv, int dbis_cs, int need_dbixs_cv,
                int drc_s, int dbc_s, int stc_s, int fdc_s));

    /* version and size are used to check for DBI/DBD version mis-match */
    U16 version;        /* version of this structure                    */
    U16 size;
    U16 xs_version;     /* version of the overall DBIXS / DBD interface */
    U16 spare_pad;
};
typedef struct dbistate_st dbistate_t;

#define DBIcf_ACTIVE      0x000004      /* needs finish/disconnect before clear */

typedef U32 imp_sth;

/* not strictly part of the API... */
static imp_sth *
sth_get_imp (SV *sth)
{
  MAGIC *mg = mg_find (SvRV (sth), PERL_MAGIC_tied);
  sth = mg->mg_obj;
  mg = mg_find (SvRV (sth), DBI_MAGIC);
  return (imp_sth *)SvPVX (mg->mg_obj);
}

#define DBI_STH_ACTIVE(imp) (*(imp) & DBIcf_ACTIVE)

/* end of import section */

#if (PERL_VERSION < 5) || ((PERL_VERSION == 5) && (PERL_SUBVERSION <= 6))
# define get_sv      perl_get_sv
# define call_method perl_call_method
# define call_sv     perl_call_sv
#endif

#if (PERL_VERSION > 5) || ((PERL_VERSION == 5) && (PERL_SUBVERSION >= 6))
# define CAN_UTF8 1
#endif

#define MAX_CACHED_STATEMENT_SIZE 2048

static SV *
sql_upgrade_utf8 (SV *sv)
{
#if CAN_UTF8
  if (SvPOKp (sv))
    sv_utf8_upgrade (sv);
#endif
  return sv;
}

static SV *
mortalcopy_and_maybe_force_utf8(int utf8, SV *sv)
{
  sv = sv_mortalcopy (sv);
#if CAN_UTF8
  if (utf8 && SvPOKp (sv))
    SvUTF8_on (sv);
#endif
  return sv;
}

#define maybe_upgrade_utf8(utf8,sv) ((utf8) ? sql_upgrade_utf8 (sv) : (sv))

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

typedef struct mc_node
{
  struct mc_node *next;
  HV *stash;
  U32 gen;

  /* DBH */
  SV *prepare;

  /* STH */
  SV *execute;
  SV *bind_param;
  SV *bind_columns;
  SV *fetchrow_arrayref;
  SV *fetchall_arrayref;
  SV *finish;
} mc_node;

static mc_node *first;

static mc_node *
mc_find (HV *stash)
{
  mc_node *mc;
  U32 gen = PL_sub_generation;

#ifdef HvMROMETA
  gen += HvMROMETA (stash)->cache_gen;
#endif

  for (mc = first; mc; mc = mc->next)
    if (mc->stash == stash && mc->gen == gen)
      return mc;

  if (!mc)
    {
      Newz (0, mc, 1, mc_node);
      mc->stash = stash;

      mc->next = first;
      first = mc;
    }
  else
    {
      mc->execute           =
      mc->bind_param        =
      mc->bind_columns      =
      mc->fetchrow_arrayref =
      mc->fetchall_arrayref =
      mc->finish            = 0;
    }

  mc->gen = gen;

  return mc;
}

static void
mc_cache (mc_node *mc, SV **method, const char *name)
{
  *method = (SV *)gv_fetchmethod_autoload (mc->stash, name, 0);

  if (!method)
    croak ("%s: method not found in stash, pelase report.", name);
}

#define mc_cache(mc, method) mc_cache ((mc), &((mc)->method), # method)

typedef struct lru_node
{
  struct lru_node *next;
  struct lru_node *prev;

  U32 hash;
  SV *dbh;
  SV *sql;

  SV *sth;
  imp_sth *sth_imp;

  mc_node *mc;
} 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) */
static U32
lru_hash (SV *dbh, SV *sql)
{
  STRLEN i, l;
  char *b = SvPV (sql, l);
  U32 hash = 2166136261U;

  hash = (hash ^ (U32)dbh) * 16777619U;
  hash = (hash ^        l) * 16777619U;

  for (i = 7; i < l; i += i >> 2)
    hash = (hash ^  b [i]) * 16777619U;

  return hash;
}

/* fetch and "use" */
static lru_node *
lru_fetch (SV *dbh, SV *sql)
{
  lru_node *n;
  U32 hash;

  dbh = SvRV (dbh);
  hash = lru_hash (dbh, sql);

  n = &lru_list;
  do {
    n = n->next;

    if (!n->hash)
      return 0;
  } while (n->hash != hash
           || DBI_STH_ACTIVE (n->sth_imp)
           || !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;
}

static void
lru_trim (void)
{
  while (lru_size > lru_maxsize)
    {
      /* nuke at the end */
      lru_node *n = lru_list.prev;

      n = lru_list.prev;

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

      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, mc_node *mc)
{
  lru_node *n;
  U32 hash;

  if (!lru_maxsize)
    return;
  
  dbh = SvRV (dbh);
  hash = lru_hash (dbh, sql);

  lru_size++;
  lru_trim ();

  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->sth_imp = sth_get_imp (sth);
  n->mc      = mc;

  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;
      lru_trim ();
    }
}

static GV *sql_exec;
static GV *DBH;

#define newconstpv(str) newSVpvn ((str), sizeof (str))

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

PROTOTYPES: DISABLE

BOOT:
{
   struct dbistate_st *dbis = DBIS_PUBLISHED_LVALUE;

   /* this is actually wrong, we should call the check member, apparently */
   assert (dbis->version == DBISTATE_VERSION);
   assert (dbis->xs_version == DBIXS_VERSION);

   tmp_iv = newSViv (0);

   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 (100);
}

void
boot2 (SV *t_str, SV *t_int, SV *t_dbl)
        CODE:
        sql_varchar = newSVsv (t_str);
        sql_integer = newSVsv (t_int);
        sql_double  = newSVsv (t_dbl);

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

void
sql_exec(...)
        ALIAS:
                sql_uexec     = 1
                sql_fetch     = 2
                sql_ufetch    = 3
                sql_fetchall  = 4
                sql_ufetchall = 5
                sql_exists    = 6
                sql_uexists   = 7
        PPCODE:
{
        if (items == 0)
          croak ("Usage: sql_exec [database-handle,] [bind-var-refs,... ] \"sql-statement\", [arguments, ...]");
        else
          {
            int i;
            int arg = 0;
            int bind_first, bind_last;
            int count;
            lru_node *lru;
            SV *dbh = ST(0);
            SV *sth;
            SV *sql;
            SV *execute;
            mc_node *mc;
            STRLEN dc, dd; /* dummy */
            I32 orig_stack = SP - PL_stack_base;

            /* save our arguments against destruction through function calls */
            SP += items;
            
            /* first check wether we should use an explicit db handle */
            if (!is_dbh (dbh))
              {
                /* the next line doesn't work - check why later maybe */
                /* dbh = get_sv ("DBH", FALSE);
                if (!is_dbh (dbh))
                  {*/
                    dbh = GvSV (DBH);
                    if (!is_dbh (dbh))
                      croak ("sql_exec: no $DBH argument and no fallback in $PApp::SQL::DBH");
                      /*croak ("sql_exec: no $DBH found in current package or in PApp::SQL::");
                  }*/
              }
            else
              arg++; /* we consumed one argument */

            /* be more Coro-friendly by keeping a copy, so different threads */
            /* can replace their global handles */
            dbh = sv_2mortal (newSVsv (dbh));

            /* 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 & ~1) == 6)
              {
                SV *neu = sv_2mortal (newSVpv ("select count(*) > 0 from ", 0));
                sv_catsv (neu, sql);
                sv_catpv (neu, " limit 1");
                sql = neu;
                ix -= 4; /* sql_fetch */
              }

            /* now prepare all parameters, by unmagicalising them and upgrading them */
            for (i = arg; i < items; ++i)
              {
                SV *sv = ST (i);

                /* we sv_mortalcopy magical values since DBI seems to have a memory
                 * leak when magical values are passed into execute().
                 */
                if (SvMAGICAL (sv))
                  ST (i) = sv = sv_mortalcopy (sv);

                if ((ix & 1) && SvPOKp (sv) && !SvUTF8 (sv))
                  {
                    ST (i) = sv = sv_mortalcopy (sv);
                    sv_utf8_upgrade (sv);
                  }
              }

            /* check cache for existing statement handle */
            lru = SvCUR (sql) <= MAX_CACHED_STATEMENT_SIZE
                  ? lru_fetch (dbh, sql)
                  : 0;
            if (!lru)
              {
                mc = mc_find (SvSTASH (SvRV (dbh)));

                if (!mc->prepare)
                  mc_cache (mc, prepare);

                PUSHMARK (SP);
                EXTEND (SP, 2);
                PUSHs (dbh);
                PUSHs (sql);
                PUTBACK;
                count = call_sv (mc->prepare, G_SCALAR);
                SPAGAIN;

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

                sth = POPs;

                if (!SvROK (sth))
                  croak ("sql_exec: buggy DBD driver, prepare returned non-reference for '%s': %s",
                         SvPV (sql, dc),
                         SvPV (get_sv ("DBI::errstr", TRUE), dd));

                mc = mc_find (SvSTASH (SvRV (sth)));

                if (!mc->bind_param)
                  {
                    mc_cache (mc, bind_param);
                    mc_cache (mc, execute);
                    mc_cache (mc, finish);
                  }

                if (SvCUR (sql) <= MAX_CACHED_STATEMENT_SIZE)
                  lru_store (dbh, sql, sth, mc);

                /* on first execution we unfortunately need to use bind_param
                 * to mark any numeric parameters as such.
                 */
                SvIV_set (tmp_iv, 0);

                while (items > arg)
                  {
                    SV *sv = ST (arg);
                    /* we sv_mortalcopy magical values since DBI seems to have a memory
                     * leak when magical values are passed into execute().
                     */

                    PUSHMARK (SP);
                    EXTEND (SP, 4);
                    PUSHs (sth);
                    SvIVX (tmp_iv)++;
                    PUSHs (tmp_iv);
                    PUSHs (sv);

                    PUSHs (
                       SvPOKp (sv) ? sql_varchar
                     : SvNOKp (sv) ? sql_double
                     : SvIOKp (sv) ? sql_integer
                     :               sql_varchar
                    );

                    PUTBACK;
                    call_sv (mc->bind_param, G_VOID);
                    SPAGAIN;

                    arg++;
                  }

                /* now use execute without any arguments */
                PUSHMARK (SP);
                EXTEND (SP, 1);
                PUSHs (sth);
              }
            else
              {
                sth = sv_2mortal (SvREFCNT_inc (lru->sth));
                mc  = lru->mc;

                /* we have previously executed this statement, so we
                 * use the cached types and use execute with arguments.
                 */

                PUSHMARK (SP);
                EXTEND (SP, items - arg + 1);
                PUSHs (sth);
                while (items > arg)
                  {
                    SV *sv = ST (arg);
                    PUSHs (sv);
                    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_sv (mc->execute, G_SCALAR);
            SPAGAIN;

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

            execute = POPs;

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

            sv_setsv (GvSV (sql_exec), execute);

            if (bind_first != bind_last)
              {
                PUSHMARK (SP);
                EXTEND (SP, bind_last - bind_first + 2);
                PUSHs (sth);
                do {
#if CAN_UTF8
                  if (ix & 1)
                     SvUTF8_on (SvRV(ST(bind_first)));
#endif
                  PUSHs (ST(bind_first));
                  bind_first++;
                } while (bind_first != bind_last);

                PUTBACK;

                if (!mc->bind_columns)
                  mc_cache (mc, bind_columns);

                count = call_sv (mc->bind_columns, G_SCALAR);

                SPAGAIN;

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

                if (!SvOK (TOPs))
                  croak ("sql_exec: bind_columns() didn't return a true ('%s'): %s",
                         SvPV (sql, dc),
                         SvPV (get_sv ("DBI::errstr", TRUE), dd));

                POPs;
              }

            if ((ix & ~1) == 2)
              { /* sql_fetch */
                SV *row;

                PUSHMARK (SP);
                XPUSHs (sth);
                PUTBACK;

                if (!mc->fetchrow_arrayref)
                  mc_cache (mc, fetchrow_arrayref);

                count = call_sv (mc->fetchrow_arrayref, G_SCALAR);
                SPAGAIN;

                if (count != 1)
                  abort ();

                row = POPs;

                SP = PL_stack_base + orig_stack;

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

                    switch (GIMME_V)
                      {
                        case G_VOID:
                          /* no thing */
                          break;
                        case G_SCALAR:
                          /* the first element */
                          XPUSHs (mortalcopy_and_maybe_force_utf8 (ix & 1, *av_fetch ((AV *)SvRV (row), 0, 1)));
                          count = 1;
                          break;
                        case G_ARRAY:
                          av = (AV *)SvRV (row);
                          count = AvFILL (av) + 1;
                          EXTEND (SP, count);
                          for (arg = 0; arg < count; arg++)
                            PUSHs (mortalcopy_and_maybe_force_utf8 (ix & 1, AvARRAY (av)[arg]));

                          break;
                        default:
                          abort ();
                      }
                 }
              }
            else if ((ix & ~1) == 4)
              { /* sql_fetchall */
                SV *rows;

                PUSHMARK (SP);
                XPUSHs (sth);
                PUTBACK;

                if (!mc->fetchall_arrayref)
                  mc_cache (mc, fetchall_arrayref);

                count = call_sv (mc->fetchall_arrayref, G_SCALAR);
                SPAGAIN;

                if (count != 1)
                  abort ();

                rows = POPs;

                SP = PL_stack_base + orig_stack;

                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 (mortalcopy_and_maybe_force_utf8 (ix & 1, AvARRAY ((AV *)SvRV (AvARRAY (av)[arg]))[0]));
                        else
                          for (arg = 0; arg < count; arg++)
                            PUSHs (mortalcopy_and_maybe_force_utf8 (ix & 1, AvARRAY (av)[arg]));
                      }
                 }
              }
            else
              {
                SP = PL_stack_base + orig_stack;
                XPUSHs (sth);
              }

            if (ix > 1 || GIMME_V == G_VOID)
              {
                orig_stack = SP - PL_stack_base;

                PUSHMARK (SP);
                XPUSHs (sth);
                PUTBACK;

                if (!mc->finish)
                  mc_cache (mc, finish);

                call_sv (mc->finish, G_DISCARD);
                SPAGAIN;

                SP = PL_stack_base + orig_stack;
              }
          }
}


Revision:	1.27
Committed:	Thu Sep 20 09:00:44 2012 UTC (11 years, 8 months ago) by root
Branch:	MAIN
Changes since 1.26:	+2 -3 lines
Log Message:	* empty log message *
#	Content
1	#include "EXTERN.h"
2	#include "perl.h"
3	#include "XSUB.h"
4
5	/* import some stuff from DBIXS.h and DBI.xs */
6	#define DBIXS_VERSION 93
7	#define DBI_MAGIC '~'
8
9	#define DBISTATE_PERLNAME "DBI::_dbistate"
10	#define DBISTATE_ADDRSV (perl_get_sv (DBISTATE_PERLNAME, 0x05))
11	#define DBIS_PUBLISHED_LVALUE ((INT2PTR(dbistate_t*, &SvIVX(DBISTATE_ADDRSV))))
12
13	static SV sql_varchar, sql_integer, *sql_double;
14	static SV *tmp_iv;
15
16	struct dbistate_st {
17	#define DBISTATE_VERSION 94 /* Must change whenever dbistate_t does */
18	/* this must be the first member in structure */
19	void (check_version) _((const char name,
20	int dbis_cv, int dbis_cs, int need_dbixs_cv,
21	int drc_s, int dbc_s, int stc_s, int fdc_s));
22
23	/* version and size are used to check for DBI/DBD version mis-match */
24	U16 version; /* version of this structure */
25	U16 size;
26	U16 xs_version; /* version of the overall DBIXS / DBD interface */
27	U16 spare_pad;
28	};
29	typedef struct dbistate_st dbistate_t;
30
31	#define DBIcf_ACTIVE 0x000004 /* needs finish/disconnect before clear */
32
33	typedef U32 imp_sth;
34
35	/* not strictly part of the API... */
36	static imp_sth *
37	sth_get_imp (SV *sth)
38	{
39	MAGIC *mg = mg_find (SvRV (sth), PERL_MAGIC_tied);
40	sth = mg->mg_obj;
41	mg = mg_find (SvRV (sth), DBI_MAGIC);
42	return (imp_sth *)SvPVX (mg->mg_obj);
43	}
44
45	#define DBI_STH_ACTIVE(imp) (*(imp) & DBIcf_ACTIVE)
46
47	/* end of import section */
48
49	#if (PERL_VERSION < 5) \|\| ((PERL_VERSION == 5) && (PERL_SUBVERSION <= 6))
50	# define get_sv perl_get_sv
51	# define call_method perl_call_method
52	# define call_sv perl_call_sv
53	#endif
54
55	#if (PERL_VERSION > 5) \|\| ((PERL_VERSION == 5) && (PERL_SUBVERSION >= 6))
56	# define CAN_UTF8 1
57	#endif
58
59	#define MAX_CACHED_STATEMENT_SIZE 2048
60
61	static SV *
62	sql_upgrade_utf8 (SV *sv)
63	{
64	#if CAN_UTF8
65	if (SvPOKp (sv))
66	sv_utf8_upgrade (sv);
67	#endif
68	return sv;
69	}
70
71	static SV *
72	mortalcopy_and_maybe_force_utf8(int utf8, SV *sv)
73	{
74	sv = sv_mortalcopy (sv);
75	#if CAN_UTF8
76	if (utf8 && SvPOKp (sv))
77	SvUTF8_on (sv);
78	#endif
79	return sv;
80	}
81
82	#define maybe_upgrade_utf8(utf8,sv) ((utf8) ? sql_upgrade_utf8 (sv) : (sv))
83
84	#define is_dbh(sv) ((sv) && sv_isobject (sv) && sv_derived_from ((sv), "DBI::db"))
85
86	typedef struct mc_node
87	{
88	struct mc_node *next;
89	HV *stash;
90	U32 gen;
91
92	/* DBH */
93	SV *prepare;
94
95	/* STH */
96	SV *execute;
97	SV *bind_param;
98	SV *bind_columns;
99	SV *fetchrow_arrayref;
100	SV *fetchall_arrayref;
101	SV *finish;
102	} mc_node;
103
104	static mc_node *first;
105
106	static mc_node *
107	mc_find (HV *stash)
108	{
109	mc_node *mc;
110	U32 gen = PL_sub_generation;
111
112	#ifdef HvMROMETA
113	gen += HvMROMETA (stash)->cache_gen;
114	#endif
115
116	for (mc = first; mc; mc = mc->next)
117	if (mc->stash == stash && mc->gen == gen)
118	return mc;
119
120	if (!mc)
121	{
122	Newz (0, mc, 1, mc_node);
123	mc->stash = stash;
124
125	mc->next = first;
126	first = mc;
127	}
128	else
129	{
130	mc->execute =
131	mc->bind_param =
132	mc->bind_columns =
133	mc->fetchrow_arrayref =
134	mc->fetchall_arrayref =
135	mc->finish = 0;
136	}
137
138	mc->gen = gen;
139
140	return mc;
141	}
142
143	static void
144	mc_cache (mc_node mc, SV method, const char name)
145	{
146	method = (SV )gv_fetchmethod_autoload (mc->stash, name, 0);
147
148	if (!method)
149	croak ("%s: method not found in stash, pelase report.", name);
150	}
151
152	#define mc_cache(mc, method) mc_cache ((mc), &((mc)->method), # method)
153
154	typedef struct lru_node
155	{
156	struct lru_node *next;
157	struct lru_node *prev;
158
159	U32 hash;
160	SV *dbh;
161	SV *sql;
162
163	SV *sth;
164	imp_sth *sth_imp;
165
166	mc_node *mc;
167	} lru_node;
168
169	static lru_node lru_list;
170	static int lru_size;
171	static int lru_maxsize;
172
173	#define lru_init() lru_list.next = &lru_list; lru_list.prev = &lru_list /* other fields are zero */
174
175	/* this is primitive, yet effective */
176	/* the returned value must never be zero (or bad things will happen) */
177	static U32
178	lru_hash (SV dbh, SV sql)
179	{
180	STRLEN i, l;
181	char *b = SvPV (sql, l);
182	U32 hash = 2166136261U;
183
184	hash = (hash ^ (U32)dbh) * 16777619U;
185	hash = (hash ^ l) * 16777619U;
186
187	for (i = 7; i < l; i += i >> 2)
188	hash = (hash ^ b [i]) * 16777619U;
189
190	return hash;
191	}
192
193	/* fetch and "use" */
194	static lru_node *
195	lru_fetch (SV dbh, SV sql)
196	{
197	lru_node *n;
198	U32 hash;
199
200	dbh = SvRV (dbh);
201	hash = lru_hash (dbh, sql);
202
203	n = &lru_list;
204	do {
205	n = n->next;
206
207	if (!n->hash)
208	return 0;
209	} while (n->hash != hash
210	\|\| DBI_STH_ACTIVE (n->sth_imp)
211	\|\| !sv_eq (n->sql, sql)
212	\|\| n->dbh != dbh);
213
214	/* found, so return to the start of the list */
215	n->prev->next = n->next;
216	n->next->prev = n->prev;
217
218	n->next = lru_list.next;
219	n->prev = &lru_list;
220	lru_list.next->prev = n;
221	lru_list.next = n;
222
223	return n;
224	}
225
226	static void
227	lru_trim (void)
228	{
229	while (lru_size > lru_maxsize)
230	{
231	/* nuke at the end */
232	lru_node *n = lru_list.prev;
233
234	n = lru_list.prev;
235
236	lru_list.prev = n->prev;
237	n->prev->next = &lru_list;
238
239	SvREFCNT_dec (n->dbh);
240	SvREFCNT_dec (n->sql);
241	SvREFCNT_dec (n->sth);
242	Safefree (n);
243
244	lru_size--;
245	}
246	}
247
248	/* store a not-yet existing entry(!) */
249	static void
250	lru_store (SV dbh, SV sql, SV sth, mc_node mc)
251	{
252	lru_node *n;
253	U32 hash;
254
255	if (!lru_maxsize)
256	return;
257
258	dbh = SvRV (dbh);
259	hash = lru_hash (dbh, sql);
260
261	lru_size++;
262	lru_trim ();
263
264	New (0, n, 1, lru_node);
265
266	n->hash = hash;
267	n->dbh = dbh; SvREFCNT_inc (dbh); /* note: this is the dbi hash itself, not the reference */
268	n->sql = newSVsv (sql);
269	n->sth = sth; SvREFCNT_inc (sth);
270	n->sth_imp = sth_get_imp (sth);
271	n->mc = mc;
272
273	n->next = lru_list.next;
274	n->prev = &lru_list;
275	lru_list.next->prev = n;
276	lru_list.next = n;
277	}
278
279	static void
280	lru_cachesize (int size)
281	{
282	if (size >= 0)
283	{
284	lru_maxsize = size;
285	lru_trim ();
286	}
287	}
288
289	static GV *sql_exec;
290	static GV *DBH;
291
292	#define newconstpv(str) newSVpvn ((str), sizeof (str))
293
294	MODULE = PApp::SQL PACKAGE = PApp::SQL
295
296	PROTOTYPES: DISABLE
297
298	BOOT:
299	{
300	struct dbistate_st *dbis = DBIS_PUBLISHED_LVALUE;
301
302	/* this is actually wrong, we should call the check member, apparently */
303	assert (dbis->version == DBISTATE_VERSION);
304	assert (dbis->xs_version == DBIXS_VERSION);
305
306	tmp_iv = newSViv (0);
307
308	sql_exec = gv_fetchpv ("PApp::SQL::sql_exec", TRUE, SVt_PV);
309	DBH = gv_fetchpv ("PApp::SQL::DBH" , TRUE, SVt_PV);
310
311	/* apache might BOOT: twice :( */
312	if (lru_size)
313	lru_cachesize (0);
314
315	lru_init ();
316	lru_cachesize (100);
317	}
318
319	void
320	boot2 (SV t_str, SV t_int, SV *t_dbl)
321	CODE:
322	sql_varchar = newSVsv (t_str);
323	sql_integer = newSVsv (t_int);
324	sql_double = newSVsv (t_dbl);
325
326	int
327	cachesize(size = -1)
328	int size
329	CODE:
330	RETVAL = lru_maxsize;
331	lru_cachesize (size);
332	OUTPUT:
333	RETVAL
334
335	void
336	sql_exec(...)
337	ALIAS:
338	sql_uexec = 1
339	sql_fetch = 2
340	sql_ufetch = 3
341	sql_fetchall = 4
342	sql_ufetchall = 5
343	sql_exists = 6
344	sql_uexists = 7
345	PPCODE:
346	{
347	if (items == 0)
348	croak ("Usage: sql_exec [database-handle,] [bind-var-refs,... ] \"sql-statement\", [arguments, ...]");
349	else
350	{
351	int i;
352	int arg = 0;
353	int bind_first, bind_last;
354	int count;
355	lru_node *lru;
356	SV *dbh = ST(0);
357	SV *sth;
358	SV *sql;
359	SV *execute;
360	mc_node *mc;
361	STRLEN dc, dd; /* dummy */
362	I32 orig_stack = SP - PL_stack_base;
363
364	/* save our arguments against destruction through function calls */
365	SP += items;
366
367	/* first check wether we should use an explicit db handle */
368	if (!is_dbh (dbh))
369	{
370	/* the next line doesn't work - check why later maybe */
371	/* dbh = get_sv ("DBH", FALSE);
372	if (!is_dbh (dbh))
373	{*/
374	dbh = GvSV (DBH);
375	if (!is_dbh (dbh))
376	croak ("sql_exec: no $DBH argument and no fallback in $PApp::SQL::DBH");
377	/*croak ("sql_exec: no $DBH found in current package or in PApp::SQL::");
378	}*/
379	}
380	else
381	arg++; /* we consumed one argument */
382
383	/* be more Coro-friendly by keeping a copy, so different threads */
384	/* can replace their global handles */
385	dbh = sv_2mortal (newSVsv (dbh));
386
387	/* count the remaining references (for bind_columns) */
388	bind_first = arg;
389	while (items > arg && SvROK (ST(arg)))
390	arg++;
391
392	bind_last = arg;
393
394	/* consume the sql-statement itself */
395	if (items <= arg)
396	croak ("sql_exec: required argument \"sql-statement\" missing");
397
398	if (!SvPOK (ST(arg)))
399	croak ("sql_exec: sql-statement must be a string");
400
401	sql = ST(arg); arg++;
402
403	if ((ix & ~1) == 6)
404	{
405	SV neu = sv_2mortal (newSVpv ("select count() > 0 from ", 0));
406	sv_catsv (neu, sql);
407	sv_catpv (neu, " limit 1");
408	sql = neu;
409	ix -= 4; /* sql_fetch */
410	}
411
412	/* now prepare all parameters, by unmagicalising them and upgrading them */
413	for (i = arg; i < items; ++i)
414	{
415	SV *sv = ST (i);
416
417	/* we sv_mortalcopy magical values since DBI seems to have a memory
418	* leak when magical values are passed into execute().
419	*/
420	if (SvMAGICAL (sv))
421	ST (i) = sv = sv_mortalcopy (sv);
422
423	if ((ix & 1) && SvPOKp (sv) && !SvUTF8 (sv))
424	{
425	ST (i) = sv = sv_mortalcopy (sv);
426	sv_utf8_upgrade (sv);
427	}
428	}
429
430	/* check cache for existing statement handle */
431	lru = SvCUR (sql) <= MAX_CACHED_STATEMENT_SIZE
432	? lru_fetch (dbh, sql)
433	: 0;
434	if (!lru)
435	{
436	mc = mc_find (SvSTASH (SvRV (dbh)));
437
438	if (!mc->prepare)
439	mc_cache (mc, prepare);
440
441	PUSHMARK (SP);
442	EXTEND (SP, 2);
443	PUSHs (dbh);
444	PUSHs (sql);
445	PUTBACK;
446	count = call_sv (mc->prepare, G_SCALAR);
447	SPAGAIN;
448
449	if (count != 1)
450	croak ("sql_exec: unable to prepare() statement '%s': %s",
451	SvPV (sql, dc),
452	SvPV (get_sv ("DBI::errstr", TRUE), dd));
453
454	sth = POPs;
455
456	if (!SvROK (sth))
457	croak ("sql_exec: buggy DBD driver, prepare returned non-reference for '%s': %s",
458	SvPV (sql, dc),
459	SvPV (get_sv ("DBI::errstr", TRUE), dd));
460
461	mc = mc_find (SvSTASH (SvRV (sth)));
462
463	if (!mc->bind_param)
464	{
465	mc_cache (mc, bind_param);
466	mc_cache (mc, execute);
467	mc_cache (mc, finish);
468	}
469
470	if (SvCUR (sql) <= MAX_CACHED_STATEMENT_SIZE)
471	lru_store (dbh, sql, sth, mc);
472
473	/* on first execution we unfortunately need to use bind_param
474	* to mark any numeric parameters as such.
475	*/
476	SvIV_set (tmp_iv, 0);
477
478	while (items > arg)
479	{
480	SV *sv = ST (arg);
481	/* we sv_mortalcopy magical values since DBI seems to have a memory
482	* leak when magical values are passed into execute().
483	*/
484
485	PUSHMARK (SP);
486	EXTEND (SP, 4);
487	PUSHs (sth);
488	SvIVX (tmp_iv)++;
489	PUSHs (tmp_iv);
490	PUSHs (sv);
491
492	PUSHs (
493	SvPOKp (sv) ? sql_varchar
494	: SvNOKp (sv) ? sql_double
495	: SvIOKp (sv) ? sql_integer
496	: sql_varchar
497	);
498
499	PUTBACK;
500	call_sv (mc->bind_param, G_VOID);
501	SPAGAIN;
502
503	arg++;
504	}
505
506	/* now use execute without any arguments */
507	PUSHMARK (SP);
508	EXTEND (SP, 1);
509	PUSHs (sth);
510	}
511	else
512	{
513	sth = sv_2mortal (SvREFCNT_inc (lru->sth));
514	mc = lru->mc;
515
516	/* we have previously executed this statement, so we
517	* use the cached types and use execute with arguments.
518	*/
519
520	PUSHMARK (SP);
521	EXTEND (SP, items - arg + 1);
522	PUSHs (sth);
523	while (items > arg)
524	{
525	SV *sv = ST (arg);
526	PUSHs (sv);
527	arg++;
528	}
529	}
530
531	PUTBACK;
532	/* { static GV *execute;
533	if (!execute) execute = gv_fetchmethod_autoload(SvSTASH(SvRV(sth)), "execute", 0);
534	count = call_sv(GvCV(execute), G_SCALAR);
535	}*/
536	count = call_sv (mc->execute, G_SCALAR);
537	SPAGAIN;
538
539	if (count != 1)
540	croak ("sql_exec: execute() didn't return any value ('%s'): %s",
541	SvPV (sql, dc),
542	SvPV (get_sv ("DBI::errstr", TRUE), dd));
543
544	execute = POPs;
545
546	if (!SvTRUE (execute))
547	croak ("sql_exec: unable to execute statement '%s' (%s)",
548	SvPV (sql, dc),
549	SvPV (get_sv ("DBI::errstr", TRUE), dd));
550
551	sv_setsv (GvSV (sql_exec), execute);
552
553	if (bind_first != bind_last)
554	{
555	PUSHMARK (SP);
556	EXTEND (SP, bind_last - bind_first + 2);
557	PUSHs (sth);
558	do {
559	#if CAN_UTF8
560	if (ix & 1)
561	SvUTF8_on (SvRV(ST(bind_first)));
562	#endif
563	PUSHs (ST(bind_first));
564	bind_first++;
565	} while (bind_first != bind_last);
566
567	PUTBACK;
568
569	if (!mc->bind_columns)
570	mc_cache (mc, bind_columns);
571
572	count = call_sv (mc->bind_columns, G_SCALAR);
573
574	SPAGAIN;
575
576	if (count != 1)
577	croak ("sql_exec: bind_columns() didn't return any value ('%s'): %s",
578	SvPV (sql, dc),
579	SvPV (get_sv ("DBI::errstr", TRUE), dd));
580
581	if (!SvOK (TOPs))
582	croak ("sql_exec: bind_columns() didn't return a true ('%s'): %s",
583	SvPV (sql, dc),
584	SvPV (get_sv ("DBI::errstr", TRUE), dd));
585
586	POPs;
587	}
588
589	if ((ix & ~1) == 2)
590	{ /* sql_fetch */
591	SV *row;
592
593	PUSHMARK (SP);
594	XPUSHs (sth);
595	PUTBACK;
596
597	if (!mc->fetchrow_arrayref)
598	mc_cache (mc, fetchrow_arrayref);
599
600	count = call_sv (mc->fetchrow_arrayref, G_SCALAR);
601	SPAGAIN;
602
603	if (count != 1)
604	abort ();
605
606	row = POPs;
607
608	SP = PL_stack_base + orig_stack;
609
610	if (SvROK (row))
611	{
612	AV *av;
613
614	switch (GIMME_V)
615	{
616	case G_VOID:
617	/* no thing */
618	break;
619	case G_SCALAR:
620	/* the first element */
621	XPUSHs (mortalcopy_and_maybe_force_utf8 (ix & 1, av_fetch ((AV )SvRV (row), 0, 1)));
622	count = 1;
623	break;
624	case G_ARRAY:
625	av = (AV *)SvRV (row);
626	count = AvFILL (av) + 1;
627	EXTEND (SP, count);
628	for (arg = 0; arg < count; arg++)
629	PUSHs (mortalcopy_and_maybe_force_utf8 (ix & 1, AvARRAY (av)[arg]));
630
631	break;
632	default:
633	abort ();
634	}
635	}
636	}
637	else if ((ix & ~1) == 4)
638	{ /* sql_fetchall */
639	SV *rows;
640
641	PUSHMARK (SP);
642	XPUSHs (sth);
643	PUTBACK;
644
645	if (!mc->fetchall_arrayref)
646	mc_cache (mc, fetchall_arrayref);
647
648	count = call_sv (mc->fetchall_arrayref, G_SCALAR);
649	SPAGAIN;
650
651	if (count != 1)
652	abort ();
653
654	rows = POPs;
655
656	SP = PL_stack_base + orig_stack;
657
658	if (SvROK (rows))
659	{
660	AV av = (AV )SvRV (rows);
661	count = AvFILL (av) + 1;
662
663	if (count)
664	{
665	int columns = AvFILL ((AV ) SvRV (AvARRAY (av)[0])) + 1; / columns? */
666
667	EXTEND (SP, count);
668	if (columns == 1)
669	for (arg = 0; arg < count; arg++)
670	PUSHs (mortalcopy_and_maybe_force_utf8 (ix & 1, AvARRAY ((AV *)SvRV (AvARRAY (av)[arg]))[0]));
671	else
672	for (arg = 0; arg < count; arg++)
673	PUSHs (mortalcopy_and_maybe_force_utf8 (ix & 1, AvARRAY (av)[arg]));
674	}
675	}
676	}
677	else
678	{
679	SP = PL_stack_base + orig_stack;
680	XPUSHs (sth);
681	}
682
683	if (ix > 1 \|\| GIMME_V == G_VOID)
684	{
685	orig_stack = SP - PL_stack_base;
686
687	PUSHMARK (SP);
688	XPUSHs (sth);
689	PUTBACK;
690
691	if (!mc->finish)
692	mc_cache (mc, finish);
693
694	call_sv (mc->finish, G_DISCARD);
695	SPAGAIN;
696
697	SP = PL_stack_base + orig_stack;
698	}
699	}
700	}
701
702
703