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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) 1996-2019, 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 "access/tableam.h"
21 #include "catalog/catalog.h"
22 #include "catalog/dependency.h"
23 #include "catalog/indexing.h"
24 #include "catalog/objectaccess.h"
25 #include "catalog/pg_conversion.h"
26 #include "catalog/pg_namespace.h"
27 #include "catalog/pg_proc.h"
28 #include "mb/pg_wchar.h"
29 #include "utils/builtins.h"
30 #include "utils/catcache.h"
31 #include "utils/fmgroids.h"
32 #include "utils/rel.h"
33 #include "utils/syscache.h"
34 
35 /*
36  * ConversionCreate
37  *
38  * Add a new tuple to pg_conversion.
39  */
41 ConversionCreate(const char *conname, Oid connamespace,
42  Oid conowner,
43  int32 conforencoding, int32 contoencoding,
44  Oid conproc, bool def)
45 {
46  int i;
47  Relation rel;
48  TupleDesc tupDesc;
49  HeapTuple tup;
50  Oid oid;
51  bool nulls[Natts_pg_conversion];
52  Datum values[Natts_pg_conversion];
54  ObjectAddress myself,
55  referenced;
56 
57  /* sanity checks */
58  if (!conname)
59  elog(ERROR, "no conversion name supplied");
60 
61  /* make sure there is no existing conversion of same name */
63  PointerGetDatum(conname),
64  ObjectIdGetDatum(connamespace)))
65  ereport(ERROR,
67  errmsg("conversion \"%s\" already exists", conname)));
68 
69  if (def)
70  {
71  /*
72  * make sure there is no existing default <for encoding><to encoding>
73  * pair in this name space
74  */
75  if (FindDefaultConversion(connamespace,
76  conforencoding,
77  contoencoding))
78  ereport(ERROR,
80  errmsg("default conversion for %s to %s already exists",
81  pg_encoding_to_char(conforencoding),
82  pg_encoding_to_char(contoencoding))));
83  }
84 
85  /* open pg_conversion */
86  rel = table_open(ConversionRelationId, RowExclusiveLock);
87  tupDesc = rel->rd_att;
88 
89  /* initialize nulls and values */
90  for (i = 0; i < Natts_pg_conversion; i++)
91  {
92  nulls[i] = false;
93  values[i] = (Datum) NULL;
94  }
95 
96  /* form a tuple */
97  namestrcpy(&cname, conname);
99  Anum_pg_conversion_oid);
100  values[Anum_pg_conversion_oid - 1] = ObjectIdGetDatum(oid);
101  values[Anum_pg_conversion_conname - 1] = NameGetDatum(&cname);
102  values[Anum_pg_conversion_connamespace - 1] = ObjectIdGetDatum(connamespace);
103  values[Anum_pg_conversion_conowner - 1] = ObjectIdGetDatum(conowner);
104  values[Anum_pg_conversion_conforencoding - 1] = Int32GetDatum(conforencoding);
105  values[Anum_pg_conversion_contoencoding - 1] = Int32GetDatum(contoencoding);
106  values[Anum_pg_conversion_conproc - 1] = ObjectIdGetDatum(conproc);
107  values[Anum_pg_conversion_condefault - 1] = BoolGetDatum(def);
108 
109  tup = heap_form_tuple(tupDesc, values, nulls);
110 
111  /* insert a new tuple */
112  CatalogTupleInsert(rel, tup);
113 
114  myself.classId = ConversionRelationId;
115  myself.objectId = oid;
116  myself.objectSubId = 0;
117 
118  /* create dependency on conversion procedure */
119  referenced.classId = ProcedureRelationId;
120  referenced.objectId = conproc;
121  referenced.objectSubId = 0;
122  recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
123 
124  /* create dependency on namespace */
125  referenced.classId = NamespaceRelationId;
126  referenced.objectId = connamespace;
127  referenced.objectSubId = 0;
128  recordDependencyOn(&myself, &referenced, DEPENDENCY_NORMAL);
129 
130  /* create dependency on owner */
131  recordDependencyOnOwner(ConversionRelationId, oid, conowner);
132 
133  /* dependency on extension */
134  recordDependencyOnCurrentExtension(&myself, false);
135 
136  /* Post creation hook for new conversion */
137  InvokeObjectPostCreateHook(ConversionRelationId, oid, 0);
138 
139  heap_freetuple(tup);
141 
142  return myself;
143 }
144 
145 /*
146  * RemoveConversionById
147  *
148  * Remove a tuple from pg_conversion by Oid. This function is solely
149  * called inside catalog/dependency.c
150  */
151 void
152 RemoveConversionById(Oid conversionOid)
153 {
154  Relation rel;
155  HeapTuple tuple;
156  TableScanDesc scan;
157  ScanKeyData scanKeyData;
158 
159  ScanKeyInit(&scanKeyData,
160  Anum_pg_conversion_oid,
161  BTEqualStrategyNumber, F_OIDEQ,
162  ObjectIdGetDatum(conversionOid));
163 
164  /* open pg_conversion */
165  rel = table_open(ConversionRelationId, RowExclusiveLock);
166 
167  scan = table_beginscan_catalog(rel, 1, &scanKeyData);
168 
169  /* search for the target tuple */
171  CatalogTupleDelete(rel, &tuple->t_self);
172  else
173  elog(ERROR, "could not find tuple for conversion %u", conversionOid);
174  table_endscan(scan);
176 }
177 
178 /*
179  * FindDefaultConversion
180  *
181  * Find "default" conversion proc by for_encoding and to_encoding in the
182  * given namespace.
183  *
184  * If found, returns the procedure's oid, otherwise InvalidOid. Note that
185  * you get the procedure's OID not the conversion's OID!
186  */
187 Oid
188 FindDefaultConversion(Oid name_space, int32 for_encoding, int32 to_encoding)
189 {
190  CatCList *catlist;
191  HeapTuple tuple;
192  Form_pg_conversion body;
193  Oid proc = InvalidOid;
194  int i;
195 
197  ObjectIdGetDatum(name_space),
198  Int32GetDatum(for_encoding),
199  Int32GetDatum(to_encoding));
200 
201  for (i = 0; i < catlist->n_members; i++)
202  {
203  tuple = &catlist->members[i]->tuple;
204  body = (Form_pg_conversion) GETSTRUCT(tuple);
205  if (body->condefault)
206  {
207  proc = body->conproc;
208  break;
209  }
210  }
211  ReleaseSysCacheList(catlist);
212  return proc;
213 }
Oid GetNewOidWithIndex(Relation relation, Oid indexId, AttrNumber oidcolumn)
Definition: catalog.c:322
#define NameGetDatum(X)
Definition: postgres.h:595
int n_members
Definition: catcache.h:176
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:133
#define GETSTRUCT(TUP)
Definition: htup_details.h:655
#define InvokeObjectPostCreateHook(classId, objectId, subId)
Definition: objectaccess.h:145
TableScanDesc table_beginscan_catalog(Relation relation, int nkeys, struct ScanKeyData *key)
Definition: tableam.c:98
#define PointerGetDatum(X)
Definition: postgres.h:556
int errcode(int sqlerrcode)
Definition: elog.c:608
void CatalogTupleDelete(Relation heapRel, ItemPointer tid)
Definition: indexing.c:269
void recordDependencyOn(const ObjectAddress *depender, const ObjectAddress *referenced, DependencyType behavior)
Definition: pg_depend.c:43
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, Datum *values, bool *isnull)
Definition: heaptuple.c:1020
void recordDependencyOnOwner(Oid classId, Oid objectId, Oid owner)
Definition: pg_shdepend.c:164
void heap_freetuple(HeapTuple htup)
Definition: heaptuple.c:1338
unsigned int Oid
Definition: postgres_ext.h:31
int namestrcpy(Name name, const char *str)
Definition: name.c:250
void RemoveConversionById(Oid conversionOid)
signed int int32
Definition: c.h:347
CatCTup * members[FLEXIBLE_ARRAY_MEMBER]
Definition: catcache.h:178
#define ObjectIdGetDatum(X)
Definition: postgres.h:507
#define ERROR
Definition: elog.h:43
ItemPointerData t_self
Definition: htup.h:65
Definition: c.h:604
HeapTuple heap_getnext(TableScanDesc sscan, ScanDirection direction)
Definition: heapam.c:1290
#define RowExclusiveLock
Definition: lockdefs.h:38
#define ereport(elevel, rest)
Definition: elog.h:141
#define ReleaseSysCacheList(x)
Definition: syscache.h:217
ObjectAddress ConversionCreate(const char *conname, Oid connamespace, Oid conowner, int32 conforencoding, int32 contoencoding, Oid conproc, bool def)
Definition: pg_conversion.c:41
uintptr_t Datum
Definition: postgres.h:367
FormData_pg_conversion * Form_pg_conversion
Definition: pg_conversion.h:62
TupleDesc rd_att
Definition: rel.h:84
#define BoolGetDatum(X)
Definition: postgres.h:402
#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:138
#define ConversionOidIndexId
Definition: indexing.h:141
#define SearchSysCacheExists2(cacheId, key1, key2)
Definition: syscache.h:185
static void table_endscan(TableScanDesc scan)
Definition: tableam.h:831
static Datum values[MAXATTR]
Definition: bootstrap.c:167
#define Int32GetDatum(X)
Definition: postgres.h:479
int errmsg(const char *fmt,...)
Definition: elog.c:822
#define SearchSysCacheList3(cacheId, key1, key2, key3)
Definition: syscache.h:214
#define elog(elevel,...)
Definition: elog.h:228
int i
void ScanKeyInit(ScanKey entry, AttrNumber attributeNumber, StrategyNumber strategy, RegProcedure procedure, Datum argument)
Definition: scankey.c:76
HeapTupleData tuple
Definition: catcache.h:121
Oid FindDefaultConversion(Oid name_space, int32 for_encoding, int32 to_encoding)
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:39
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:31
void CatalogTupleInsert(Relation heapRel, HeapTuple tup)
Definition: indexing.c:183
#define BTEqualStrategyNumber
Definition: stratnum.h:31