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Commit 050710b

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Michael Meskes
committed
Add bytea datatype to ECPG.
So far ECPG programs had to treat binary data for bytea column as 'char' type. But this meant converting from/to escaped format with PQunescapeBytea/ PQescapeBytea() and therefore forcing users to add unnecessary code and cost for the conversion in runtime. By adding a dedicated datatype for bytea most of this special handling is no longer needed. Author: Matsumura-san ("Matsumura, Ryo" <matsumura.ryo@jp.fujitsu.com>) Discussion: https://postgr.es/m/flat/03040DFF97E6E54E88D3BFEE5F5480F737A141F9@G01JPEXMBYT04
1 parent 3fdc374 commit 050710b

18 files changed

+983
-49
lines changed

‎doc/src/sgml/ecpg.sgml

Lines changed: 32 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -917,7 +917,7 @@ do
917917

918918
<row>
919919
<entry><type>character(<replaceable>n</replaceable>)</type>, <type>varchar(<replaceable>n</replaceable>)</type>, <type>text</type></entry>
920-
<entry><type>char[<replaceable>n</replaceable>+1]</type>, <type>VARCHAR[<replaceable>n</replaceable>+1]</type><footnote><para>declared in <filename>ecpglib.h</filename></para></footnote></entry>
920+
<entry><type>char[<replaceable>n</replaceable>+1]</type>, <type>VARCHAR[<replaceable>n</replaceable>+1]</type></entry>
921921
</row>
922922

923923
<row>
@@ -947,7 +947,7 @@ do
947947

948948
<row>
949949
<entry><type>bytea</type></entry>
950-
<entry><type>char *</type></entry>
950+
<entry><type>char *</type>, <type>bytea[<replaceable>n</replaceable>]</type></entry>
951951
</row>
952952
</tbody>
953953
</tgroup>
@@ -1204,6 +1204,36 @@ EXEC SQL END DECLARE SECTION;
12041204
</programlisting>
12051205
</para>
12061206
</sect4>
1207+
1208+
<sect4>
1209+
<title id="ecpg-type-bytea">bytea</title>
1210+
1211+
<para>
1212+
The handling of the <type>bytea</type> type is also similar to
1213+
the <type>VARCHAR</type>. The definition on an array of type
1214+
<type>bytea</type> is converted into a named struct for every
1215+
variable. A declaration like:
1216+
<programlisting>
1217+
bytea var[180];
1218+
</programlisting>
1219+
is converted into:
1220+
<programlisting>
1221+
struct bytea_var { int len; char arr[180]; } var;
1222+
</programlisting>
1223+
The member <structfield>arr</structfield> hosts binary format
1224+
data. It also can handle even <literal>'\0'</literal> as part of
1225+
data unlike <type>VARCHAR</type>.
1226+
The data is converted from/to hex format and sent/received by
1227+
ecpglib.
1228+
</para>
1229+
1230+
<note>
1231+
<para>
1232+
<type>bytea</type> variable can be used only when
1233+
<xref linkend="guc-bytea-output"/> is set to <literal>hex</literal>.
1234+
</para>
1235+
</note>
1236+
</sect4>
12071237
</sect3>
12081238

12091239
<sect3 id="ecpg-variables-nonprimitive-c">

‎src/interfaces/ecpg/ecpglib/data.c

Lines changed: 129 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -122,6 +122,86 @@ check_special_value(char *ptr, double *retval, char **endptr)
122122
return false;
123123
}
124124

125+
/* imported from src/backend/utils/adt/encode.c */
126+
127+
unsigned
128+
ecpg_hex_enc_len(unsigned srclen)
129+
{
130+
return srclen << 1;
131+
}
132+
133+
unsigned
134+
ecpg_hex_dec_len(unsigned srclen)
135+
{
136+
return srclen >> 1;
137+
}
138+
139+
static inline char
140+
get_hex(char c)
141+
{
142+
static const int8 hexlookup[128] = {
143+
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
144+
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
145+
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
146+
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1,
147+
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
148+
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
149+
-1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
150+
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
151+
};
152+
int res = -1;
153+
154+
if (c > 0 && c < 127)
155+
res = hexlookup[(unsigned char) c];
156+
157+
return (char) res;
158+
}
159+
160+
static unsigned
161+
hex_decode(const char *src, unsigned len, char *dst)
162+
{
163+
const char *s,
164+
*srcend;
165+
char v1,
166+
v2,
167+
*p;
168+
169+
srcend = src + len;
170+
s = src;
171+
p = dst;
172+
while (s < srcend)
173+
{
174+
if (*s == ' ' || *s == '\n' || *s == '\t' || *s == '\r')
175+
{
176+
s++;
177+
continue;
178+
}
179+
v1 = get_hex(*s++) << 4;
180+
if (s >= srcend)
181+
return -1;
182+
183+
v2 = get_hex(*s++);
184+
*p++ = v1 | v2;
185+
}
186+
187+
return p - dst;
188+
}
189+
190+
unsigned
191+
ecpg_hex_encode(const char *src, unsigned len, char *dst)
192+
{
193+
static const char hextbl[] = "0123456789abcdef";
194+
const char *end = src + len;
195+
196+
while (src < end)
197+
{
198+
*dst++ = hextbl[(*src >> 4) & 0xF];
199+
*dst++ = hextbl[*src & 0xF];
200+
src++;
201+
}
202+
return len * 2;
203+
}
204+
125205
bool
126206
ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
127207
enum ECPGttype type, enum ECPGttype ind_type,
@@ -447,6 +527,55 @@ ecpg_get_data(const PGresult *results, int act_tuple, int act_field, int lineno,
447527
return false;
448528
break;
449529

530+
case ECPGt_bytea:
531+
{
532+
struct ECPGgeneric_varchar *variable =
533+
(struct ECPGgeneric_varchar *) (var + offset * act_tuple);
534+
long dst_size,
535+
src_size,
536+
dec_size;
537+
538+
dst_size = ecpg_hex_enc_len(varcharsize);
539+
src_size = size - 2; /* exclude backslash + 'x' */
540+
dec_size = src_size < dst_size ? src_size : dst_size;
541+
variable->len = hex_decode(pval + 2, dec_size, variable->arr);
542+
543+
if (dst_size < src_size)
544+
{
545+
long rcv_size = ecpg_hex_dec_len(size - 2);
546+
547+
/* truncation */
548+
switch (ind_type)
549+
{
550+
case ECPGt_short:
551+
case ECPGt_unsigned_short:
552+
*((short *) (ind + ind_offset * act_tuple)) = rcv_size;
553+
break;
554+
case ECPGt_int:
555+
case ECPGt_unsigned_int:
556+
*((int *) (ind + ind_offset * act_tuple)) = rcv_size;
557+
break;
558+
case ECPGt_long:
559+
case ECPGt_unsigned_long:
560+
*((long *) (ind + ind_offset * act_tuple)) = rcv_size;
561+
break;
562+
#ifdef HAVE_LONG_LONG_INT
563+
case ECPGt_long_long:
564+
case ECPGt_unsigned_long_long:
565+
*((long long int *) (ind + ind_offset * act_tuple)) = rcv_size;
566+
break;
567+
#endif /* HAVE_LONG_LONG_INT */
568+
default:
569+
break;
570+
}
571+
sqlca->sqlwarn[0] = sqlca->sqlwarn[1] = 'W';
572+
}
573+
574+
pval += size;
575+
576+
}
577+
break;
578+
450579
case ECPGt_char:
451580
case ECPGt_unsigned_char:
452581
case ECPGt_string:

‎src/interfaces/ecpg/ecpglib/descriptor.c

Lines changed: 23 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -587,6 +587,28 @@ ECPGset_desc_header(int lineno, const char *desc_name, int count)
587587
return true;
588588
}
589589

590+
static void
591+
set_desc_attr(struct descriptor_item *desc_item, struct variable *var,
592+
char *tobeinserted)
593+
{
594+
if (var->type != ECPGt_bytea)
595+
desc_item->is_binary = false;
596+
597+
else
598+
{
599+
struct ECPGgeneric_varchar *variable =
600+
(struct ECPGgeneric_varchar *) (var->value);
601+
602+
desc_item->is_binary = true;
603+
desc_item->data_len = variable->len;
604+
}
605+
606+
ecpg_free(desc_item->data); /* free() takes care of a
607+
* potential NULL value */
608+
desc_item->data = (char *) tobeinserted;
609+
}
610+
611+
590612
bool
591613
ECPGset_desc(int lineno, const char *desc_name, int index,...)
592614
{
@@ -666,9 +688,7 @@ ECPGset_desc(int lineno, const char *desc_name, int index,...)
666688
return false;
667689
}
668690

669-
ecpg_free(desc_item->data); /* free() takes care of a
670-
* potential NULL value */
671-
desc_item->data = (char *) tobeinserted;
691+
set_desc_attr(desc_item, var, tobeinserted);
672692
tobeinserted = NULL;
673693
break;
674694
}

‎src/interfaces/ecpg/ecpglib/ecpglib_extern.h

Lines changed: 14 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -40,6 +40,13 @@ struct ECPGgeneric_varchar
4040
char arr[FLEXIBLE_ARRAY_MEMBER];
4141
};
4242

43+
/* A generic bytea type. */
44+
struct ECPGgeneric_bytea
45+
{
46+
int len;
47+
char arr[FLEXIBLE_ARRAY_MEMBER];
48+
};
49+
4350
/*
4451
* type information cache
4552
*/
@@ -75,6 +82,8 @@ struct statement
7582
#endif
7683
int nparams;
7784
char **paramvalues;
85+
int *paramlengths;
86+
int *paramformats;
7887
PGresult *results;
7988
};
8089

@@ -133,6 +142,8 @@ struct descriptor_item
133142
int precision;
134143
int scale;
135144
int type;
145+
bool is_binary;
146+
int data_len;
136147
struct descriptor_item *next;
137148
};
138149

@@ -226,6 +237,9 @@ struct sqlda_compat *ecpg_build_compat_sqlda(int, PGresult *, int, enum COMPAT_M
226237
void ecpg_set_compat_sqlda(int, struct sqlda_compat **, const PGresult *, int, enum COMPAT_MODE);
227238
struct sqlda_struct *ecpg_build_native_sqlda(int, PGresult *, int, enum COMPAT_MODE);
228239
void ecpg_set_native_sqlda(int, struct sqlda_struct **, const PGresult *, int, enum COMPAT_MODE);
240+
unsigned ecpg_hex_dec_len(unsigned srclen);
241+
unsigned ecpg_hex_enc_len(unsigned srclen);
242+
unsigned ecpg_hex_encode(const char *src, unsigned len, char *dst);
229243

230244
/* SQLSTATE values generated or processed by ecpglib (intentionally
231245
* not exported -- users should refer to the codes directly) */

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