1 /*-------------------------------------------------------------------------
4 * routines to support manipulation of the pg_conversion relation
6 * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
7 * Portions Copyright (c) 1994, Regents of the University of California
11 * $Header: /cvsroot/pgsql/src/backend/catalog/pg_conversion.c,v 1.14 2003/08/04 00:43:16 momjian Exp $
13 *-------------------------------------------------------------------------
17 #include "access/heapam.h"
18 #include "catalog/catname.h"
19 #include "catalog/dependency.h"
20 #include "catalog/indexing.h"
21 #include "catalog/pg_class.h"
22 #include "catalog/pg_conversion.h"
23 #include "catalog/namespace.h"
24 #include "utils/builtins.h"
25 #include "utils/lsyscache.h"
26 #include "utils/syscache.h"
27 #include "utils/catcache.h"
28 #include "mb/pg_wchar.h"
29 #include "utils/fmgroids.h"
30 #include "utils/acl.h"
31 #include "miscadmin.h"
36 * Add a new tuple to pg_conversion.
39 ConversionCreate(const char *conname, Oid connamespace,
41 int32 conforencoding, int32 contoencoding,
42 Oid conproc, bool def)
48 char nulls[Natts_pg_conversion];
49 Datum values[Natts_pg_conversion];
57 elog(ERROR, "no conversion name supplied");
59 /* make sure there is no existing conversion of same name */
60 if (SearchSysCacheExists(CONNAMENSP,
61 PointerGetDatum(conname),
62 ObjectIdGetDatum(connamespace),
65 (errcode(ERRCODE_DUPLICATE_OBJECT),
66 errmsg("conversion \"%s\" already exists", conname)));
71 * make sure there is no existing default <for encoding><to
72 * encoding> pair in this name space
74 if (FindDefaultConversion(connamespace,
78 (errcode(ERRCODE_DUPLICATE_OBJECT),
79 errmsg("default conversion for %s to %s already exists",
80 pg_encoding_to_char(conforencoding),
81 pg_encoding_to_char(contoencoding))));
84 /* open pg_conversion */
85 rel = heap_openr(ConversionRelationName, RowExclusiveLock);
86 tupDesc = rel->rd_att;
88 /* initialize nulls and values */
89 for (i = 0; i < Natts_pg_conversion; i++)
92 values[i] = (Datum) NULL;
96 namestrcpy(&cname, conname);
97 values[Anum_pg_conversion_conname - 1] = NameGetDatum(&cname);
98 values[Anum_pg_conversion_connamespace - 1] = ObjectIdGetDatum(connamespace);
99 values[Anum_pg_conversion_conowner - 1] = Int32GetDatum(conowner);
100 values[Anum_pg_conversion_conforencoding - 1] = Int32GetDatum(conforencoding);
101 values[Anum_pg_conversion_contoencoding - 1] = Int32GetDatum(contoencoding);
102 values[Anum_pg_conversion_conproc - 1] = ObjectIdGetDatum(conproc);
103 values[Anum_pg_conversion_condefault - 1] = BoolGetDatum(def);
105 tup = heap_formtuple(tupDesc, values, nulls);
107 /* insert a new tuple */
108 oid = simple_heap_insert(rel, tup);
109 Assert(OidIsValid(oid));
111 /* update the index if any */
112 CatalogUpdateIndexes(rel, tup);
114 myself.classId = RelationGetRelid(rel);
115 myself.objectId = HeapTupleGetOid(tup);
116 myself.objectSubId = 0;
118 /* create dependency on conversion procedure */
119 referenced.classId = RelOid_pg_proc;
120 referenced.objectId = conproc;
121 referenced.objectSubId = 0;
122 recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
125 heap_close(rel, RowExclusiveLock);
133 * Drop a conversion after doing permission checks.
136 ConversionDrop(Oid conversionOid, DropBehavior behavior)
139 ObjectAddress object;
141 tuple = SearchSysCache(CONOID,
142 ObjectIdGetDatum(conversionOid),
144 if (!HeapTupleIsValid(tuple))
145 elog(ERROR, "cache lookup failed for conversion %u", conversionOid);
148 ((Form_pg_conversion) GETSTRUCT(tuple))->conowner != GetUserId())
149 aclcheck_error(ACLCHECK_NOT_OWNER, ACL_KIND_CONVERSION,
150 NameStr(((Form_pg_conversion) GETSTRUCT(tuple))->conname));
152 ReleaseSysCache(tuple);
157 object.classId = get_system_catalog_relid(ConversionRelationName);
158 object.objectId = conversionOid;
159 object.objectSubId = 0;
161 performDeletion(&object, behavior);
165 * RemoveConversionById
167 * Remove a tuple from pg_conversion by Oid. This function is solely
168 * called inside catalog/dependency.c
171 RemoveConversionById(Oid conversionOid)
177 ScanKeyData scanKeyData;
179 ScanKeyEntryInitialize(&scanKeyData,
181 ObjectIdAttributeNumber,
183 ObjectIdGetDatum(conversionOid));
185 /* open pg_conversion */
186 rel = heap_openr(ConversionRelationName, RowExclusiveLock);
187 tupDesc = rel->rd_att;
189 scan = heap_beginscan(rel, SnapshotNow,
192 /* search for the target tuple */
193 if (HeapTupleIsValid(tuple = heap_getnext(scan, ForwardScanDirection)))
194 simple_heap_delete(rel, &tuple->t_self);
196 elog(ERROR, "could not find tuple for conversion %u", conversionOid);
198 heap_close(rel, RowExclusiveLock);
202 * FindDefaultConversion
204 * Find "default" conversion proc by for_encoding and to_encoding in the
207 * If found, returns the procedure's oid, otherwise InvalidOid. Note that
208 * you get the procedure's OID not the conversion's OID!
211 FindDefaultConversion(Oid name_space, int32 for_encoding, int32 to_encoding)
215 Form_pg_conversion body;
216 Oid proc = InvalidOid;
219 catlist = SearchSysCacheList(CONDEFAULT, 3,
220 ObjectIdGetDatum(name_space),
221 Int32GetDatum(for_encoding),
222 Int32GetDatum(to_encoding),
225 for (i = 0; i < catlist->n_members; i++)
227 tuple = &catlist->members[i]->tuple;
228 body = (Form_pg_conversion) GETSTRUCT(tuple);
229 if (body->condefault)
231 proc = body->conproc;
235 ReleaseSysCacheList(catlist);
242 * Find conversion by namespace and conversion name.
243 * Returns conversion OID.
246 FindConversion(const char *conname, Oid connamespace)
253 /* search pg_conversion by connamespace and conversion name */
254 tuple = SearchSysCache(CONNAMENSP,
255 PointerGetDatum(conname),
256 ObjectIdGetDatum(connamespace),
258 if (!HeapTupleIsValid(tuple))
261 procoid = ((Form_pg_conversion) GETSTRUCT(tuple))->conproc;
262 conoid = HeapTupleGetOid(tuple);
264 ReleaseSysCache(tuple);
266 /* Check we have execute rights for the function */
267 aclresult = pg_proc_aclcheck(procoid, GetUserId(), ACL_EXECUTE);
268 if (aclresult != ACLCHECK_OK)
275 * Execute SQL99's CONVERT function.
277 * CONVERT <left paren> <character value expression>
278 * USING <form-of-use conversion name> <right paren>
280 * TEXT convert_using(TEXT string, TEXT conversion_name)
283 pg_convert_using(PG_FUNCTION_ARGS)
285 text *string = PG_GETARG_TEXT_P(0);
286 text *conv_name = PG_GETARG_TEXT_P(1);
291 Form_pg_conversion body;
293 unsigned char *result;
296 /* Convert input string to null-terminated form */
297 len = VARSIZE(string) - VARHDRSZ;
298 str = palloc(len + 1);
299 memcpy(str, VARDATA(string), len);
302 /* Look up the conversion name */
303 parsed_name = textToQualifiedNameList(conv_name, "convert_using");
304 convoid = FindConversionByName(parsed_name);
305 if (!OidIsValid(convoid))
307 (errcode(ERRCODE_UNDEFINED_OBJECT),
308 errmsg("conversion \"%s\" does not exist",
309 NameListToString(parsed_name))));
311 tuple = SearchSysCache(CONOID,
312 ObjectIdGetDatum(convoid),
314 if (!HeapTupleIsValid(tuple))
315 elog(ERROR, "cache lookup failed for conversion %u", convoid);
316 body = (Form_pg_conversion) GETSTRUCT(tuple);
318 /* Temporary result area should be more than big enough */
319 result = palloc(len * 4 + 1);
321 OidFunctionCall5(body->conproc,
322 Int32GetDatum(body->conforencoding),
323 Int32GetDatum(body->contoencoding),
324 CStringGetDatum(str),
325 CStringGetDatum(result),
328 ReleaseSysCache(tuple);
331 * build text result structure. we cannot use textin() here, since
332 * textin assumes that input string encoding is same as database
335 len = strlen(result) + VARHDRSZ;
336 retval = palloc(len);
337 VARATT_SIZEP(retval) = len;
338 memcpy(VARDATA(retval), result, len - VARHDRSZ);
343 PG_RETURN_TEXT_P(retval);