greenplumn nvarchar2 源码
greenplumn nvarchar2 代码
文件路径:/gpcontrib/orafce/nvarchar2.c
/*----------------------------------------------------------------------------
*
* nvarchar2.c
* NVARCHAR2 type for PostgreSQL.
*
*----------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/hash.h"
#include "libpq/pqformat.h"
#include "nodes/nodeFuncs.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "mb/pg_wchar.h"
#include "fmgr.h"
#include "orafce.h"
#include "builtins.h"
PG_FUNCTION_INFO_V1(nvarchar2in);
PG_FUNCTION_INFO_V1(nvarchar2out);
PG_FUNCTION_INFO_V1(nvarchar2);
PG_FUNCTION_INFO_V1(nvarchar2recv);
/*
* nvarchar2_input -- common guts of nvarchar2in and nvarchar2recv
*
* s is the input text of length len (may not be null-terminated)
* atttypmod is the typmod value to apply
*
* If the input string is too long, raise an error
*
* Uses the C string to text conversion function, which is only appropriate
* if VarChar and text are equivalent types.
*/
static VarChar *
nvarchar2_input(const char *s, size_t len, int32 atttypmod)
{
VarChar *result; /* input data */
size_t maxlen;
maxlen = atttypmod - VARHDRSZ;
/*
* Perform the typmod check; error out if value too long for NVARCHAR2
*/
if (atttypmod >= (int32) VARHDRSZ && len > maxlen)
{
/* Verify that input length is within typmod limit.
*
* NOTE: blankspace is not truncated
*/
size_t mbmaxlen = pg_mbstrlen(s);
if (mbmaxlen > maxlen)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input value length is %zd; too long for type nvarchar2(%zd)", mbmaxlen , maxlen)));
}
result = (VarChar *) cstring_to_text_with_len(s, size2int(len));
return result;
}
/*
* Converts a C string to NVARCHAR2 internal representation. atttypmod
* is the declared length of the type plus VARHDRSZ.
*/
Datum
nvarchar2in(PG_FUNCTION_ARGS)
{
char *s = PG_GETARG_CSTRING(0);
#ifdef NOT_USED
Oid typelem = PG_GETARG_OID(1);
#endif
int32 atttypmod = PG_GETARG_INT32(2);
VarChar *result;
result = nvarchar2_input(s, strlen(s), atttypmod);
PG_RETURN_VARCHAR_P(result);
}
/*
* converts a NVARCHAR2 value to a C string.
*
* Uses the text to C string conversion function, which is only appropriate
* if VarChar and text are equivalent types.
*/
Datum
nvarchar2out(PG_FUNCTION_ARGS)
{
Datum txt = PG_GETARG_DATUM(0);
PG_RETURN_CSTRING(TextDatumGetCString(txt));
}
/*
* converts external binary format to nvarchar
*/
Datum
nvarchar2recv(PG_FUNCTION_ARGS)
{
StringInfo buf = (StringInfo) PG_GETARG_POINTER(0);
#ifdef NOT_USED
Oid typelem = PG_GETARG_OID(1);
#endif
int32 atttypmod = PG_GETARG_INT32(2); /* typmod of the receiving column */
VarChar *result;
char *str; /* received data */
int nbytes; /* length in bytes of recived data */
str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
result = nvarchar2_input(str, nbytes, atttypmod);
pfree(str);
PG_RETURN_VARCHAR_P(result);
}
/*
* nvarchar2send -- convert nvarchar2 to binary value
*
* just use varcharsend()
*/
/*
* nvarchar2_transform()
* Flatten calls to varchar's length coercion function that set the new maximum
* length >= the previous maximum length. We can ignore the isExplicit
* argument, since that only affects truncation cases.
*
* just use varchar_transform()
*/
/*
* Converts a NVARCHAR2 type to the specified size.
*
* maxlen is the typmod, ie, declared length plus VARHDRSZ bytes.
* isExplicit is true if this is for an explicit cast to nvarchar2(N).
*
* Truncation rules: for an explicit cast, silently truncate to the given
* length; for an implicit cast, raise error if length limit is exceeded
*/
Datum
nvarchar2(PG_FUNCTION_ARGS)
{
VarChar *source = PG_GETARG_VARCHAR_PP(0);
int32 typmod = PG_GETARG_INT32(1);
bool isExplicit = PG_GETARG_BOOL(2);
int32 len,
maxlen;
int maxmblen;
char *s_data;
len = VARSIZE_ANY_EXHDR(source);
s_data = VARDATA_ANY(source);
maxlen = typmod - VARHDRSZ;
/* No work if typmod is invalid or supplied data fits it already */
if (maxlen < 0 || len <= maxlen)
PG_RETURN_VARCHAR_P(source);
/* only reach here if string is too long... */
/* truncate multibyte string preserving multibyte boundary */
maxmblen = pg_mbcharcliplen(s_data, len, maxlen);
/* error out if value too long unless it's an explicit cast */
if (!isExplicit)
{
/* if there is still data beyond maxmblen, error out
*
* Remember - no blankspace truncation on implicit cast
*/
if (len > maxmblen)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input value too long for type nvarchar2(%d)", maxlen)));
}
PG_RETURN_VARCHAR_P((VarChar *) cstring_to_text_with_len(s_data, size2int(maxmblen)));
}
/*
* nvarchar2typmodin -- type modifier input function
*
* just use varchartypmodin()
*/
/*
* nvarchar2typmodout -- type modifier output function
*
* just use varchartypmodout()
*/
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