greenplumn varchar2 源码

  • 2022-08-18
  • 浏览 (522)

greenplumn varchar2 代码

文件路径:/gpcontrib/orafce/varchar2.c

/*----------------------------------------------------------------------------
 *
 *     varchar2.c
 *     VARCHAR2 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(varchar2in);
PG_FUNCTION_INFO_V1(varchar2out);
PG_FUNCTION_INFO_V1(varchar2);
PG_FUNCTION_INFO_V1(varchar2recv);
PG_FUNCTION_INFO_V1(orafce_concat2);
PG_FUNCTION_INFO_V1(orafce_varchar_transform);

bool orafce_varchar2_null_safe_concat = false;


/*
 * varchar2_input -- common guts of varchar2in and varchar2recv
 *
 * 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 *
varchar2_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 VARCHAR2
	 */
	if (atttypmod >= (int32) VARHDRSZ && len > maxlen)
		ereport(ERROR,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
					errmsg("input value length is %zd; too long for type varchar2(%zd)", len , maxlen)));

	result = (VarChar *) cstring_to_text_with_len(s, size2int(len));
	return  result;
}

/*
 * Converts a C string to VARCHAR2 internal representation.  atttypmod
 * is the declared length of the type plus VARHDRSZ.
 */
Datum
varchar2in(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 = varchar2_input(s, strlen(s), atttypmod);
	PG_RETURN_VARCHAR_P(result);
}


/*
 * converts a VARCHAR2 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
varchar2out(PG_FUNCTION_ARGS)
{
	Datum   txt = PG_GETARG_DATUM(0);

	PG_RETURN_CSTRING(TextDatumGetCString(txt));
}

/*
 * converts external binary format to varchar
 */
Datum
varchar2recv(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 = varchar2_input(str, nbytes, atttypmod);
	pfree(str);
	PG_RETURN_VARCHAR_P(result);
}


/*
 * varchar2send -- convert varchar2 to binary value
 *
 * just use varcharsend()
 */

/*
 * varchar2_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()
 */

Datum
orafce_varchar_transform(PG_FUNCTION_ARGS)
{
#if PG_VERSION_NUM < 120000

	return varchar_transform(fcinfo);

#else

	return varchar_support(fcinfo);

#endif
}


/*
 * Converts a VARCHAR2 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 varchar2(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
varchar2(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;
	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);

	/* error out if value too long unless it's an explicit cast */
	if (!isExplicit)
	{
		if (len > maxlen)
			ereport(ERROR,
					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
						errmsg("input value length is %d; too long for type varchar2(%d)",len ,maxlen)));
	}

	PG_RETURN_VARCHAR_P((VarChar *) cstring_to_text_with_len(s_data,maxlen));
}


/*
 * varchar2typmodin -- type modifier input function
 *
 * just use varchartypmodin()
 */

/*
 * varchar2typmodout -- type modifier output function
 *
 * just use varchartypmodout()
 */


/*
 * orafce_concat2 - null safe concat
 *
 * returns NULL instead empty string
 */
Datum
orafce_concat2(PG_FUNCTION_ARGS)
{
	text	   *arg1 = NULL,
			   *arg2 = NULL,
			   *result;
	int32		len1 = 0,
				len2 = 0,
				len;
	char	   *ptr;

	if (!PG_ARGISNULL(0))
	{
		arg1 = PG_GETARG_TEXT_PP(0);
		len1 = VARSIZE_ANY_EXHDR(arg1);
	}
	if (!PG_ARGISNULL(1))
	{
		arg2 = PG_GETARG_TEXT_PP(1);
		len2 = VARSIZE_ANY_EXHDR(arg2);
	}

	/* default behave should be compatible with Postgres */
	if (!orafce_varchar2_null_safe_concat)
	{
		if (PG_ARGISNULL(0) || PG_ARGISNULL(1))
			PG_RETURN_NULL();
	}
	else
	{
		if (len1 == 0 && len2 == 0)
			PG_RETURN_NULL();
	}

	/* hard work, we should to concat strings */
	len = len1 + len2 + VARHDRSZ;

	result = (text *) palloc(len);
	SET_VARSIZE(result, len);

	ptr = VARDATA(result);

	if (len1 > 0)
		memcpy(ptr, VARDATA_ANY(arg1), len1);
	if (len2 > 0)
		memcpy(ptr + len1, VARDATA_ANY(arg2), len2);

	PG_RETURN_TEXT_P(result);
}

相关信息

greenplumn 源码目录

相关文章

greenplumn aggregate 源码

greenplumn alert 源码

greenplumn assert 源码

greenplumn assert 源码

greenplumn builtins 源码

greenplumn charlen 源码

greenplumn charpad 源码

greenplumn convert 源码

greenplumn datefce 源码

greenplumn file 源码

0  赞