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Code review for DOMAIN patch.

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This commit is contained in:
Tom Lane
2002-03-20 19:45:13 +00:00
parent 251282d4b7
commit 337b22cb47
37 changed files with 869 additions and 850 deletions
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278
src/backend/parser/parse_coerce.c
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@ -8,25 +8,31 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_coerce.c,v 2.67 2002/03/19 02:18:20 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_coerce.c,v 2.68 2002/03/20 19:44:22 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "catalog/pg_proc.h"
#include "nodes/makefuncs.h"
#include "optimizer/clauses.h"
#include "parser/parse_coerce.h"
#include "parser/parse_expr.h"
#include "parser/parse_func.h"
#include "parser/parse_type.h"
#include "utils/builtins.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
Oid DemoteType(Oid inType);
Oid PromoteTypeToNext(Oid inType);
static Oid PreferredType(CATEGORY category, Oid type);
static Node *build_func_call(Oid funcid, Oid rettype, List *args);
static Oid find_coercion_function(Oid targetTypeId, Oid inputTypeId,
Oid secondArgType);
/* coerce_type()
@ -87,32 +93,28 @@ coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
result = (Node *) newcon;
}
else if (IS_BINARY_COMPATIBLE(inputTypeId, targetTypeId))
else if (IsBinaryCompatible(inputTypeId, targetTypeId))
{
/*
* We don't really need to do a conversion, but we do need to
* attach a RelabelType node so that the expression will be seen
* to have the intended type when inspected by higher-level code.
*/
RelabelType *relabel = makeNode(RelabelType);
relabel->arg = node;
relabel->resulttype = targetTypeId;
/*
*
* XXX could we label result with exprTypmod(node) instead of
* default -1 typmod, to save a possible length-coercion later?
* Would work if both types have same interpretation of typmod,
* which is likely but not certain.
*/
relabel->resulttypmod = -1;
result = (Node *) relabel;
result = (Node *) makeRelabelType(node, targetTypeId, -1);
}
else if (typeInheritsFrom(inputTypeId, targetTypeId))
{
/* Input class type is a subclass of target, so nothing to do */
result = node;
/*
* Input class type is a subclass of target, so nothing to do
* --- except relabel the type. This is binary compatibility
* for complex types.
*/
result = (Node *) makeRelabelType(node, targetTypeId, -1);
}
else
{
@ -121,21 +123,24 @@ coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
* (caller should have determined that there is one), and generate
* an expression tree representing run-time application of the
* conversion function.
*
* For domains, we use the coercion function for the base type.
*/
FuncCall *n = makeNode(FuncCall);
Oid baseTypeId = getBaseType(targetTypeId);
Oid funcId;
n->funcname = typeidTypeName(targetTypeId);
n->args = makeList1(node);
n->agg_star = false;
n->agg_distinct = false;
funcId = find_coercion_function(baseTypeId,
getBaseType(inputTypeId),
InvalidOid);
if (!OidIsValid(funcId))
elog(ERROR, "coerce_type: no conversion function from %s to %s",
format_type_be(inputTypeId), format_type_be(targetTypeId));
result = transformExpr(pstate, (Node *) n, EXPR_COLUMN_FIRST);
result = build_func_call(funcId, baseTypeId, makeList1(node));
/* safety check that we got the right thing */
if (exprType(result) != targetTypeId)
elog(ERROR, "coerce_type: conversion function %s produced %s",
typeidTypeName(targetTypeId),
typeidTypeName(exprType(result)));
/* if domain, relabel with domain type ID */
if (targetTypeId != baseTypeId)
result = (Node *) makeRelabelType(result, targetTypeId, -1);
/*
* If the input is a constant, apply the type conversion function
@ -152,7 +157,8 @@ coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
* nodes that mustn't be collapsed. (It'd be a lot cleaner to
* make a separate node type for that purpose...)
*/
if (IsA(node, Const) &&!((Const *) node)->constisnull)
if (IsA(node, Const) &&
!((Const *) node)->constisnull)
result = eval_const_expressions(result);
}
@ -169,23 +175,18 @@ coerce_type(ParseState *pstate, Node *node, Oid inputTypeId,
*
* Notes:
* This uses the same mechanism as the CAST() SQL construct in gram.y.
* We should also check the function return type on candidate conversion
* routines just to be safe but we do not do that yet...
* - thomas 1998-03-31
*/
bool
can_coerce_type(int nargs, Oid *input_typeids, Oid *func_typeids)
{
int i;
HeapTuple ftup;
Form_pg_proc pform;
Oid oid_array[FUNC_MAX_ARGS];
/* run through argument list... */
for (i = 0; i < nargs; i++)
{
Oid inputTypeId = input_typeids[i];
Oid targetTypeId = func_typeids[i];
Oid funcId;
/* no problem if same type */
if (inputTypeId == targetTypeId)
@ -195,7 +196,7 @@ can_coerce_type(int nargs, Oid *input_typeids, Oid *func_typeids)
* one of the known-good transparent conversions? then drop
* through...
*/
if (IS_BINARY_COMPATIBLE(inputTypeId, targetTypeId))
if (IsBinaryCompatible(inputTypeId, targetTypeId))
continue;
/* don't know what to do for the output type? then quit... */
@ -232,25 +233,14 @@ can_coerce_type(int nargs, Oid *input_typeids, Oid *func_typeids)
* Else, try for explicit conversion using functions: look for a
* single-argument function named with the target type name and
* accepting the source type.
*
* If either type is a domain, use its base type instead.
*/
MemSet(oid_array, 0, FUNC_MAX_ARGS * sizeof(Oid));
oid_array[0] = inputTypeId;
ftup = SearchSysCache(PROCNAME,
PointerGetDatum(typeidTypeName(targetTypeId)),
Int32GetDatum(1),
PointerGetDatum(oid_array),
0);
if (!HeapTupleIsValid(ftup))
funcId = find_coercion_function(getBaseType(targetTypeId),
getBaseType(inputTypeId),
InvalidOid);
if (!OidIsValid(funcId))
return false;
/* Make sure the function's result type is as expected, too */
pform = (Form_pg_proc) GETSTRUCT(ftup);
if (pform->prorettype != targetTypeId)
{
ReleaseSysCache(ftup);
return false;
}
ReleaseSysCache(ftup);
}
return true;
@ -277,8 +267,8 @@ Node *
coerce_type_typmod(ParseState *pstate, Node *node,
Oid targetTypeId, int32 atttypmod)
{
char *funcname;
Oid oid_array[FUNC_MAX_ARGS];
Oid baseTypeId;
Oid funcId;
/*
* A negative typmod is assumed to mean that no coercion is wanted.
@ -286,30 +276,28 @@ coerce_type_typmod(ParseState *pstate, Node *node,
if (atttypmod < 0 || atttypmod == exprTypmod(node))
return node;
funcname = typeidTypeName(targetTypeId);
MemSet(oid_array, 0, FUNC_MAX_ARGS * sizeof(Oid));
oid_array[0] = targetTypeId;
oid_array[1] = INT4OID;
/* If given type is a domain, use base type instead */
baseTypeId = getBaseType(targetTypeId);
/* attempt to find with arguments exactly as specified... */
if (SearchSysCacheExists(PROCNAME,
PointerGetDatum(funcname),
Int32GetDatum(2),
PointerGetDatum(oid_array),
0))
funcId = find_coercion_function(baseTypeId, baseTypeId, INT4OID);
if (OidIsValid(funcId))
{
A_Const *cons = makeNode(A_Const);
FuncCall *func = makeNode(FuncCall);
Const *cons;
cons->val.type = T_Integer;
cons->val.val.ival = atttypmod;
cons = makeConst(INT4OID,
sizeof(int32),
Int32GetDatum(atttypmod),
false,
true,
false,
false);
func->funcname = funcname;
func->args = makeList2(node, cons);
func->agg_star = false;
func->agg_distinct = false;
node = build_func_call(funcId, baseTypeId, makeList2(node, cons));
node = transformExpr(pstate, (Node *) func, EXPR_COLUMN_FIRST);
/* relabel if it's domain case */
if (targetTypeId != baseTypeId)
node = (Node *) makeRelabelType(node, targetTypeId, atttypmod);
}
return node;
@ -532,6 +520,64 @@ TypeCategory(Oid inType)
} /* TypeCategory() */
/* IsBinaryCompatible()
* Check if two types are binary-compatible.
*
* This notion allows us to cheat and directly exchange values without
* going through the trouble of calling a conversion function.
*
* XXX This should be moved to system catalog lookups
* to allow for better type extensibility.
*/
/*
* This macro describes hard-coded knowledge of binary compatibility
* for built-in types.
*/
#define IS_BINARY_COMPATIBLE(a,b) \
(((a) == BPCHAROID && (b) == TEXTOID) \
|| ((a) == BPCHAROID && (b) == VARCHAROID) \
|| ((a) == VARCHAROID && (b) == TEXTOID) \
|| ((a) == VARCHAROID && (b) == BPCHAROID) \
|| ((a) == TEXTOID && (b) == BPCHAROID) \
|| ((a) == TEXTOID && (b) == VARCHAROID) \
|| ((a) == OIDOID && (b) == INT4OID) \
|| ((a) == OIDOID && (b) == REGPROCOID) \
|| ((a) == INT4OID && (b) == OIDOID) \
|| ((a) == INT4OID && (b) == REGPROCOID) \
|| ((a) == REGPROCOID && (b) == OIDOID) \
|| ((a) == REGPROCOID && (b) == INT4OID) \
|| ((a) == ABSTIMEOID && (b) == INT4OID) \
|| ((a) == INT4OID && (b) == ABSTIMEOID) \
|| ((a) == RELTIMEOID && (b) == INT4OID) \
|| ((a) == INT4OID && (b) == RELTIMEOID) \
|| ((a) == INETOID && (b) == CIDROID) \
|| ((a) == CIDROID && (b) == INETOID) \
|| ((a) == BITOID && (b) == VARBITOID) \
|| ((a) == VARBITOID && (b) == BITOID))
bool
IsBinaryCompatible(Oid type1, Oid type2)
{
if (type1 == type2)
return true;
if (IS_BINARY_COMPATIBLE(type1, type2))
return true;
/*
* Perhaps the types are domains; if so, look at their base types
*/
if (OidIsValid(type1))
type1 = getBaseType(type1);
if (OidIsValid(type2))
type2 = getBaseType(type2);
if (type1 == type2)
return true;
if (IS_BINARY_COMPATIBLE(type1, type2))
return true;
return false;
}
/* IsPreferredType()
* Check if this type is a preferred type.
* XXX This should be moved to system catalog lookups
@ -606,31 +652,81 @@ PreferredType(CATEGORY category, Oid type)
return result;
} /* PreferredType() */
/*
* find_coercion_function
* Look for a coercion function between two types.
*
* A coercion function must be named after (the internal name of) its
* result type, and must accept exactly the specified input type.
*
* This routine is also used to look for length-coercion functions, which
* are similar but accept a second argument. secondArgType is the type
* of the second argument (normally INT4OID), or InvalidOid if we are
* looking for a regular coercion function.
*
* If a function is found, return its pg_proc OID; else return InvalidOid.
*/
static Oid
find_coercion_function(Oid targetTypeId, Oid inputTypeId, Oid secondArgType)
{
char *funcname;
Oid oid_array[FUNC_MAX_ARGS];
int nargs;
HeapTuple ftup;
Form_pg_proc pform;
Oid funcid;
funcname = typeidTypeName(targetTypeId);
MemSet(oid_array, 0, FUNC_MAX_ARGS * sizeof(Oid));
oid_array[0] = inputTypeId;
if (OidIsValid(secondArgType))
{
oid_array[1] = secondArgType;
nargs = 2;
}
else
nargs = 1;
ftup = SearchSysCache(PROCNAME,
PointerGetDatum(funcname),
Int32GetDatum(nargs),
PointerGetDatum(oid_array),
0);
if (!HeapTupleIsValid(ftup))
return InvalidOid;
/* Make sure the function's result type is as expected, too */
pform = (Form_pg_proc) GETSTRUCT(ftup);
if (pform->prorettype != targetTypeId)
{
ReleaseSysCache(ftup);
return InvalidOid;
}
funcid = ftup->t_data->t_oid;
ReleaseSysCache(ftup);
return funcid;
}
/*
* If the targetTypeId is a domain, we really want to coerce
* the tuple to the domain type -- not the domain itself
* Build an expression tree representing a function call.
*
* The argument expressions must have been transformed already.
*/
Oid
getBaseType(Oid inType)
static Node *
build_func_call(Oid funcid, Oid rettype, List *args)
{
HeapTuple tup;
Form_pg_type typTup;
Func *funcnode;
Expr *expr;
tup = SearchSysCache(TYPEOID,
ObjectIdGetDatum(inType),
0, 0, 0);
funcnode = makeNode(Func);
funcnode->funcid = funcid;
funcnode->functype = rettype;
funcnode->func_fcache = NULL;
typTup = ((Form_pg_type) GETSTRUCT(tup));
expr = makeNode(Expr);
expr->typeOid = rettype;
expr->opType = FUNC_EXPR;
expr->oper = (Node *) funcnode;
expr->args = args;
/*
* Assume that typbasetype exists and is a base type, where inType
* was a domain
*/
if (typTup->typtype == 'd')
inType = typTup->typbasetype;
ReleaseSysCache(tup);
return inType;
return (Node *) expr;
}