1 /*-------------------------------------------------------------------------
4 * routines to support manipulation of the pg_conversion relation
6 * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
11 * $PostgreSQL: pgsql/src/backend/catalog/pg_conversion.c,v 1.23 2005/05/27 00:57:49 neilc Exp $
13 *-------------------------------------------------------------------------
17 #include "access/heapam.h"
18 #include "catalog/dependency.h"
19 #include "catalog/indexing.h"
20 #include "catalog/pg_conversion.h"
21 #include "catalog/pg_proc.h"
22 #include "catalog/namespace.h"
23 #include "utils/builtins.h"
24 #include "utils/lsyscache.h"
25 #include "utils/syscache.h"
26 #include "utils/catcache.h"
27 #include "mb/pg_wchar.h"
28 #include "utils/fmgroids.h"
29 #include "utils/acl.h"
30 #include "miscadmin.h"
35 * Add a new tuple to pg_conversion.
38 ConversionCreate(const char *conname, Oid connamespace,
40 int32 conforencoding, int32 contoencoding,
41 Oid conproc, bool def)
47 char nulls[Natts_pg_conversion];
48 Datum values[Natts_pg_conversion];
56 elog(ERROR, "no conversion name supplied");
58 /* make sure there is no existing conversion of same name */
59 if (SearchSysCacheExists(CONNAMENSP,
60 PointerGetDatum(conname),
61 ObjectIdGetDatum(connamespace),
64 (errcode(ERRCODE_DUPLICATE_OBJECT),
65 errmsg("conversion \"%s\" already exists", conname)));
70 * make sure there is no existing default <for encoding><to
71 * encoding> pair in this name space
73 if (FindDefaultConversion(connamespace,
77 (errcode(ERRCODE_DUPLICATE_OBJECT),
78 errmsg("default conversion for %s to %s already exists",
79 pg_encoding_to_char(conforencoding),
80 pg_encoding_to_char(contoencoding))));
83 /* open pg_conversion */
84 rel = heap_open(ConversionRelationId, RowExclusiveLock);
85 tupDesc = rel->rd_att;
87 /* initialize nulls and values */
88 for (i = 0; i < Natts_pg_conversion; i++)
91 values[i] = (Datum) NULL;
95 namestrcpy(&cname, conname);
96 values[Anum_pg_conversion_conname - 1] = NameGetDatum(&cname);
97 values[Anum_pg_conversion_connamespace - 1] = ObjectIdGetDatum(connamespace);
98 values[Anum_pg_conversion_conowner - 1] = Int32GetDatum(conowner);
99 values[Anum_pg_conversion_conforencoding - 1] = Int32GetDatum(conforencoding);
100 values[Anum_pg_conversion_contoencoding - 1] = Int32GetDatum(contoencoding);
101 values[Anum_pg_conversion_conproc - 1] = ObjectIdGetDatum(conproc);
102 values[Anum_pg_conversion_condefault - 1] = BoolGetDatum(def);
104 tup = heap_formtuple(tupDesc, values, nulls);
106 /* insert a new tuple */
107 oid = simple_heap_insert(rel, tup);
108 Assert(OidIsValid(oid));
110 /* update the index if any */
111 CatalogUpdateIndexes(rel, tup);
113 myself.classId = ConversionRelationId;
114 myself.objectId = HeapTupleGetOid(tup);
115 myself.objectSubId = 0;
117 /* create dependency on conversion procedure */
118 referenced.classId = ProcedureRelationId;
119 referenced.objectId = conproc;
120 referenced.objectSubId = 0;
121 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
124 heap_close(rel, RowExclusiveLock);
132 * Drop a conversion after doing permission checks.
135 ConversionDrop(Oid conversionOid, DropBehavior behavior)
138 ObjectAddress object;
140 tuple = SearchSysCache(CONOID,
141 ObjectIdGetDatum(conversionOid),
143 if (!HeapTupleIsValid(tuple))
144 elog(ERROR, "cache lookup failed for conversion %u", conversionOid);
147 ((Form_pg_conversion) GETSTRUCT(tuple))->conowner != GetUserId())
148 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CONVERSION,
149 NameStr(((Form_pg_conversion) GETSTRUCT(tuple))->conname));
151 ReleaseSysCache(tuple);
156 object.classId = ConversionRelationId;
157 object.objectId = conversionOid;
158 object.objectSubId = 0;
160 performDeletion(&object, behavior);
164 * RemoveConversionById
166 * Remove a tuple from pg_conversion by Oid. This function is solely
167 * called inside catalog/dependency.c
170 RemoveConversionById(Oid conversionOid)
176 ScanKeyData scanKeyData;
178 ScanKeyInit(&scanKeyData,
179 ObjectIdAttributeNumber,
180 BTEqualStrategyNumber, F_OIDEQ,
181 ObjectIdGetDatum(conversionOid));
183 /* open pg_conversion */
184 rel = heap_open(ConversionRelationId, RowExclusiveLock);
185 tupDesc = rel->rd_att;
187 scan = heap_beginscan(rel, SnapshotNow,
190 /* search for the target tuple */
191 if (HeapTupleIsValid(tuple = heap_getnext(scan, ForwardScanDirection)))
192 simple_heap_delete(rel, &tuple->t_self);
194 elog(ERROR, "could not find tuple for conversion %u", conversionOid);
196 heap_close(rel, RowExclusiveLock);
200 * FindDefaultConversion
202 * Find "default" conversion proc by for_encoding and to_encoding in the
205 * If found, returns the procedure's oid, otherwise InvalidOid. Note that
206 * you get the procedure's OID not the conversion's OID!
209 FindDefaultConversion(Oid name_space, int32 for_encoding, int32 to_encoding)
213 Form_pg_conversion body;
214 Oid proc = InvalidOid;
217 catlist = SearchSysCacheList(CONDEFAULT, 3,
218 ObjectIdGetDatum(name_space),
219 Int32GetDatum(for_encoding),
220 Int32GetDatum(to_encoding),
223 for (i = 0; i < catlist->n_members; i++)
225 tuple = &catlist->members[i]->tuple;
226 body = (Form_pg_conversion) GETSTRUCT(tuple);
227 if (body->condefault)
229 proc = body->conproc;
233 ReleaseSysCacheList(catlist);
240 * Find conversion by namespace and conversion name.
241 * Returns conversion OID.
244 FindConversion(const char *conname, Oid connamespace)
251 /* search pg_conversion by connamespace and conversion name */
252 tuple = SearchSysCache(CONNAMENSP,
253 PointerGetDatum(conname),
254 ObjectIdGetDatum(connamespace),
256 if (!HeapTupleIsValid(tuple))
259 procoid = ((Form_pg_conversion) GETSTRUCT(tuple))->conproc;
260 conoid = HeapTupleGetOid(tuple);
262 ReleaseSysCache(tuple);
264 /* Check we have execute rights for the function */
265 aclresult = pg_proc_aclcheck(procoid, GetUserId(), ACL_EXECUTE);
266 if (aclresult != ACLCHECK_OK)
273 * Execute SQL99's CONVERT function.
275 * CONVERT <left paren> <character value expression>
276 * USING <form-of-use conversion name> <right paren>
278 * TEXT convert_using(TEXT string, TEXT conversion_name)
281 pg_convert_using(PG_FUNCTION_ARGS)
283 text *string = PG_GETARG_TEXT_P(0);
284 text *conv_name = PG_GETARG_TEXT_P(1);
289 Form_pg_conversion body;
291 unsigned char *result;
294 /* Convert input string to null-terminated form */
295 len = VARSIZE(string) - VARHDRSZ;
296 str = palloc(len + 1);
297 memcpy(str, VARDATA(string), len);
300 /* Look up the conversion name */
301 parsed_name = textToQualifiedNameList(conv_name);
302 convoid = FindConversionByName(parsed_name);
303 if (!OidIsValid(convoid))
305 (errcode(ERRCODE_UNDEFINED_OBJECT),
306 errmsg("conversion \"%s\" does not exist",
307 NameListToString(parsed_name))));
309 tuple = SearchSysCache(CONOID,
310 ObjectIdGetDatum(convoid),
312 if (!HeapTupleIsValid(tuple))
313 elog(ERROR, "cache lookup failed for conversion %u", convoid);
314 body = (Form_pg_conversion) GETSTRUCT(tuple);
316 /* Temporary result area should be more than big enough */
317 result = palloc(len * 4 + 1);
319 OidFunctionCall5(body->conproc,
320 Int32GetDatum(body->conforencoding),
321 Int32GetDatum(body->contoencoding),
322 CStringGetDatum(str),
323 CStringGetDatum(result),
326 ReleaseSysCache(tuple);
329 * build text result structure. we cannot use textin() here, since
330 * textin assumes that input string encoding is same as database
333 len = strlen(result) + VARHDRSZ;
334 retval = palloc(len);
335 VARATT_SIZEP(retval) = len;
336 memcpy(VARDATA(retval), result, len - VARHDRSZ);
341 PG_RETURN_TEXT_P(retval);