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pg_conversion.c
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1 /*-------------------------------------------------------------------------
2  *
3  * pg_conversion.c
4  * routines to support manipulation of the pg_conversion relation
5  *
6  * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/backend/catalog/pg_conversion.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "postgres.h"
16 
17 #include "access/heapam.h"
18 #include "access/htup_details.h"
19 #include "access/sysattr.h"
20 #include "catalog/dependency.h"
21 #include "catalog/indexing.h"
22 #include "catalog/objectaccess.h"
23 #include "catalog/pg_conversion.h"
24 #include "catalog/pg_namespace.h"
25 #include "catalog/pg_proc.h"
26 #include "mb/pg_wchar.h"
27 #include "utils/builtins.h"
28 #include "utils/catcache.h"
29 #include "utils/fmgroids.h"
30 #include "utils/rel.h"
31 #include "utils/syscache.h"
32 #include "utils/tqual.h"
33 
34 /*
35  * ConversionCreate
36  *
37  * Add a new tuple to pg_conversion.
38  */
40 ConversionCreate(const char *conname, Oid connamespace,
41  Oid conowner,
42  int32 conforencoding, int32 contoencoding,
43  Oid conproc, bool def)
44 {
45  int i;
46  Relation rel;
47  TupleDesc tupDesc;
48  HeapTuple tup;
49  bool nulls[Natts_pg_conversion];
50  Datum values[Natts_pg_conversion];
52  ObjectAddress myself,
53  referenced;
54 
55  /* sanity checks */
56  if (!conname)
57  elog(ERROR, "no conversion name supplied");
58 
59  /* make sure there is no existing conversion of same name */
61  PointerGetDatum(conname),
62  ObjectIdGetDatum(connamespace)))
63  ereport(ERROR,
65  errmsg("conversion \"%s\" already exists", conname)));
66 
67  if (def)
68  {
69  /*
70  * make sure there is no existing default <for encoding><to encoding>
71  * pair in this name space
72  */
73  if (FindDefaultConversion(connamespace,
74  conforencoding,
75  contoencoding))
76  ereport(ERROR,
78  errmsg("default conversion for %s to %s already exists",
79  pg_encoding_to_char(conforencoding),
80  pg_encoding_to_char(contoencoding))));
81  }
82 
83  /* open pg_conversion */
84  rel = heap_open(ConversionRelationId, RowExclusiveLock);
85  tupDesc = rel->rd_att;
86 
87  /* initialize nulls and values */
88  for (i = 0; i < Natts_pg_conversion; i++)
89  {
90  nulls[i] = false;
91  values[i] = (Datum) NULL;
92  }
93 
94  /* form a tuple */
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] = ObjectIdGetDatum(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);
103 
104  tup = heap_form_tuple(tupDesc, values, nulls);
105 
106  /* insert a new tuple */
107  CatalogTupleInsert(rel, tup);
108 
109  myself.classId = ConversionRelationId;
110  myself.objectId = HeapTupleGetOid(tup);
111  myself.objectSubId = 0;
112 
113  /* create dependency on conversion procedure */
114  referenced.classId = ProcedureRelationId;
115  referenced.objectId = conproc;
116  referenced.objectSubId = 0;
117  recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
118 
119  /* create dependency on namespace */
120  referenced.classId = NamespaceRelationId;
121  referenced.objectId = connamespace;
122  referenced.objectSubId = 0;
123  recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
124 
125  /* create dependency on owner */
126  recordDependencyOnOwner(ConversionRelationId, HeapTupleGetOid(tup),
127  conowner);
128 
129  /* dependency on extension */
130  recordDependencyOnCurrentExtension(&myself, false);
131 
132  /* Post creation hook for new conversion */
133  InvokeObjectPostCreateHook(ConversionRelationId, HeapTupleGetOid(tup), 0);
134 
135  heap_freetuple(tup);
137 
138  return myself;
139 }
140 
141 /*
142  * RemoveConversionById
143  *
144  * Remove a tuple from pg_conversion by Oid. This function is solely
145  * called inside catalog/dependency.c
146  */
147 void
148 RemoveConversionById(Oid conversionOid)
149 {
150  Relation rel;
151  HeapTuple tuple;
152  HeapScanDesc scan;
153  ScanKeyData scanKeyData;
154 
155  ScanKeyInit(&scanKeyData,
157  BTEqualStrategyNumber, F_OIDEQ,
158  ObjectIdGetDatum(conversionOid));
159 
160  /* open pg_conversion */
161  rel = heap_open(ConversionRelationId, RowExclusiveLock);
162 
163  scan = heap_beginscan_catalog(rel, 1, &scanKeyData);
164 
165  /* search for the target tuple */
167  CatalogTupleDelete(rel, &tuple->t_self);
168  else
169  elog(ERROR, "could not find tuple for conversion %u", conversionOid);
170  heap_endscan(scan);
172 }
173 
174 /*
175  * FindDefaultConversion
176  *
177  * Find "default" conversion proc by for_encoding and to_encoding in the
178  * given namespace.
179  *
180  * If found, returns the procedure's oid, otherwise InvalidOid. Note that
181  * you get the procedure's OID not the conversion's OID!
182  */
183 Oid
184 FindDefaultConversion(Oid name_space, int32 for_encoding, int32 to_encoding)
185 {
186  CatCList *catlist;
187  HeapTuple tuple;
188  Form_pg_conversion body;
189  Oid proc = InvalidOid;
190  int i;
191 
193  ObjectIdGetDatum(name_space),
194  Int32GetDatum(for_encoding),
195  Int32GetDatum(to_encoding));
196 
197  for (i = 0; i < catlist->n_members; i++)
198  {
199  tuple = &catlist->members[i]->tuple;
200  body = (Form_pg_conversion) GETSTRUCT(tuple);
201  if (body->condefault)
202  {
203  proc = body->conproc;
204  break;
205  }
206  }
207  ReleaseSysCacheList(catlist);
208  return proc;
209 }
#define NameGetDatum(X)
Definition: postgres.h:578
int n_members
Definition: catcache.h:176
#define GETSTRUCT(TUP)
Definition: htup_details.h:673
void heap_endscan(HeapScanDesc scan)
Definition: heapam.c:1572
#define InvokeObjectPostCreateHook(classId, objectId, subId)
Definition: objectaccess.h:145
#define ObjectIdAttributeNumber
Definition: sysattr.h:22
#define PointerGetDatum(X)
Definition: postgres.h:539
int errcode(int sqlerrcode)
Definition: elog.c:575
void CatalogTupleDelete(Relation heapRel, ItemPointer tid)
Definition: indexing.c:256
void recordDependencyOn(const ObjectAddress *depender, const ObjectAddress *referenced, DependencyType behavior)
Definition: pg_depend.c:44
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull)
Definition: heaptuple.c:1074
#define heap_close(r, l)
Definition: heapam.h:97
void recordDependencyOnOwner(Oid classId, Oid objectId, Oid owner)
Definition: pg_shdepend.c:159
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1773
unsigned int Oid
Definition: postgres_ext.h:31
int namestrcpy(Name name, const char *str)
Definition: name.c:216
void RemoveConversionById(Oid conversionOid)
signed int int32
Definition: c.h:313
CatCTup * members[FLEXIBLE_ARRAY_MEMBER]
Definition: catcache.h:178
#define ObjectIdGetDatum(X)
Definition: postgres.h:490
#define ERROR
Definition: elog.h:43
Oid CatalogTupleInsert(Relation heapRel, HeapTuple tup)
Definition: indexing.c:163
ItemPointerData t_self
Definition: htup.h:65
Definition: c.h:570
#define RowExclusiveLock
Definition: lockdefs.h:38
HeapScanDesc heap_beginscan_catalog(Relation relation, int nkeys, ScanKey key)
Definition: heapam.c:1412
#define ereport(elevel, rest)
Definition: elog.h:122
#define ReleaseSysCacheList(x)
Definition: syscache.h:216
ObjectAddress ConversionCreate(const char *conname, Oid connamespace, Oid conowner, int32 conforencoding, int32 contoencoding, Oid conproc, bool def)
Definition: pg_conversion.c:40
uintptr_t Datum
Definition: postgres.h:365
FormData_pg_conversion * Form_pg_conversion
Definition: pg_conversion.h:56
HeapTuple heap_getnext(HeapScanDesc scan, ScanDirection direction)
Definition: heapam.c:1835
Relation heap_open(Oid relationId, LOCKMODE lockmode)
Definition: heapam.c:1294
TupleDesc rd_att
Definition: rel.h:85
#define BoolGetDatum(X)
Definition: postgres.h:385
#define InvalidOid
Definition: postgres_ext.h:36
const char * pg_encoding_to_char(int encoding)
Definition: encnames.c:607
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
void recordDependencyOnCurrentExtension(const ObjectAddress *object, bool isReplace)
Definition: pg_depend.c:139
#define SearchSysCacheExists2(cacheId, key1, key2)
Definition: syscache.h:184
static Datum values[MAXATTR]
Definition: bootstrap.c:164
#define Int32GetDatum(X)
Definition: postgres.h:462
int errmsg(const char *fmt,...)
Definition: elog.c:797
#define SearchSysCacheList3(cacheId, key1, key2, key3)
Definition: syscache.h:213
int i
void ScanKeyInit(ScanKey entry, AttrNumber attributeNumber, StrategyNumber strategy, RegProcedure procedure, Datum argument)
Definition: scankey.c:76
HeapTupleData tuple
Definition: catcache.h:121
#define elog
Definition: elog.h:219
Oid FindDefaultConversion(Oid name_space, int32 for_encoding, int32 to_encoding)
#define HeapTupleGetOid(tuple)
Definition: htup_details.h:712
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:32
#define BTEqualStrategyNumber
Definition: stratnum.h:31