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ea1b99a661
With the 'noError' argument, you can try to convert a buffer without knowing the character boundaries beforehand. The functions now need to return the number of input bytes successfully converted. This is is a backwards-incompatible change, if you have created a custom encoding conversion with CREATE CONVERSION. This adds a check to pg_upgrade for that, refusing the upgrade if there are any user-defined encoding conversions. Custom conversions are very rare, there are no commonly used extensions that I know of that uses that feature. No other objects can depend on conversions, so if you do have one, you can fairly easily drop it before upgrading, and recreate it after the upgrade with an updated version. Add regression tests for built-in encoding conversions. This doesn't cover every conversion, but it covers all the internal functions in conv.c that are used to implement the conversions. Reviewed-by: John Naylor Discussion: https://www.postgresql.org/message-id/e7861509-3960-538a-9025-b75a61188e01%40iki.fi
140 lines
4.6 KiB
C
140 lines
4.6 KiB
C
/*-------------------------------------------------------------------------
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*
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* conversioncmds.c
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* conversion creation command support code
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*
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* Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/commands/conversioncmds.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include "access/htup_details.h"
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#include "catalog/dependency.h"
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#include "catalog/indexing.h"
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#include "catalog/pg_conversion.h"
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#include "catalog/pg_type.h"
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#include "commands/alter.h"
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#include "commands/conversioncmds.h"
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#include "mb/pg_wchar.h"
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#include "miscadmin.h"
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#include "parser/parse_func.h"
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#include "utils/acl.h"
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#include "utils/builtins.h"
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#include "utils/lsyscache.h"
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#include "utils/rel.h"
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#include "utils/syscache.h"
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/*
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* CREATE CONVERSION
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*/
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ObjectAddress
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CreateConversionCommand(CreateConversionStmt *stmt)
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{
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Oid namespaceId;
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char *conversion_name;
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AclResult aclresult;
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int from_encoding;
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int to_encoding;
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Oid funcoid;
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const char *from_encoding_name = stmt->for_encoding_name;
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const char *to_encoding_name = stmt->to_encoding_name;
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List *func_name = stmt->func_name;
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static const Oid funcargs[] = {INT4OID, INT4OID, CSTRINGOID, INTERNALOID, INT4OID, BOOLOID};
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char result[1];
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Datum funcresult;
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/* Convert list of names to a name and namespace */
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namespaceId = QualifiedNameGetCreationNamespace(stmt->conversion_name,
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&conversion_name);
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/* Check we have creation rights in target namespace */
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aclresult = pg_namespace_aclcheck(namespaceId, GetUserId(), ACL_CREATE);
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if (aclresult != ACLCHECK_OK)
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aclcheck_error(aclresult, OBJECT_SCHEMA,
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get_namespace_name(namespaceId));
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/* Check the encoding names */
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from_encoding = pg_char_to_encoding(from_encoding_name);
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if (from_encoding < 0)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("source encoding \"%s\" does not exist",
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from_encoding_name)));
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to_encoding = pg_char_to_encoding(to_encoding_name);
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if (to_encoding < 0)
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ereport(ERROR,
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(errcode(ERRCODE_UNDEFINED_OBJECT),
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errmsg("destination encoding \"%s\" does not exist",
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to_encoding_name)));
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/*
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* We consider conversions to or from SQL_ASCII to be meaningless. (If
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* you wish to change this, note that pg_do_encoding_conversion() and its
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* sister functions have hard-wired fast paths for any conversion in which
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* the source or target encoding is SQL_ASCII, so that an encoding
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* conversion function declared for such a case will never be used.)
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*/
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if (from_encoding == PG_SQL_ASCII || to_encoding == PG_SQL_ASCII)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
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errmsg("encoding conversion to or from \"SQL_ASCII\" is not supported")));
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/*
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* Check the existence of the conversion function. Function name could be
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* a qualified name.
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*/
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funcoid = LookupFuncName(func_name, sizeof(funcargs) / sizeof(Oid),
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funcargs, false);
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/* Check it returns int4, else it's probably the wrong function */
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if (get_func_rettype(funcoid) != INT4OID)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
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errmsg("encoding conversion function %s must return type %s",
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NameListToString(func_name), "integer")));
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/* Check we have EXECUTE rights for the function */
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aclresult = pg_proc_aclcheck(funcoid, GetUserId(), ACL_EXECUTE);
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if (aclresult != ACLCHECK_OK)
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aclcheck_error(aclresult, OBJECT_FUNCTION,
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NameListToString(func_name));
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/*
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* Check that the conversion function is suitable for the requested source
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* and target encodings. We do that by calling the function with an empty
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* string; the conversion function should throw an error if it can't
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* perform the requested conversion.
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*/
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funcresult = OidFunctionCall6(funcoid,
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Int32GetDatum(from_encoding),
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Int32GetDatum(to_encoding),
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CStringGetDatum(""),
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CStringGetDatum(result),
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Int32GetDatum(0),
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BoolGetDatum(false));
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/*
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* The function should return 0 for empty input. Might as well check that,
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* too.
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*/
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if (DatumGetInt32(funcresult) != 0)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
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errmsg("encoding conversion function %s returned incorrect result for empty input",
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NameListToString(func_name))));
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/*
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* All seem ok, go ahead (possible failure would be a duplicate conversion
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* name)
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*/
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return ConversionCreate(conversion_name, namespaceId, GetUserId(),
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from_encoding, to_encoding, funcoid, stmt->def);
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}
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