/*----------------------------------------------------------------------------

*

* varchar2.c

* VARCHAR2 type for PostgreSQL.

*

*----------------------------------------------------------------------------

*/

#include "postgres.h"

#include "access/hash.h"

#include "access/tuptoaster.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"

/* prototype declarations */

extern PGDLLEXPORT Datum varchar2in(PG_FUNCTION_ARGS); /* C string to internal

VARCHAR2 representation */

extern PGDLLEXPORT Datum varchar2out(PG_FUNCTION_ARGS); /* VARCHAR2 to C string */

extern PGDLLEXPORT Datum varchar2(PG_FUNCTION_ARGS); /* VARCHAR2 length check */

extern PGDLLEXPORT Datum varchar2typmodin(PG_FUNCTION_ARGS); /* type modifier internal conversion */

extern PGDLLEXPORT Datum varchar2recv(PG_FUNCTION_ARGS); /* external binary format to VARCHAR2 */

PG_FUNCTION_INFO_V1(varchar2in);

PG_FUNCTION_INFO_V1(varchar2out);

PG_FUNCTION_INFO_V1(varchar2);

PG_FUNCTION_INFO_V1(varchar2typmodin);

PG_FUNCTION_INFO_V1(varchar2recv);

/*

* 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)

if (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, len);

return result;

}

/*

* Converts a C string to VARCHAR2 internal representation. atttypmod

* is the declared length of the type plus VARHDRSZ.

*/

PGDLLEXPORT

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.

*/

PGDLLEXPORT

Datum

varchar2out(PG_FUNCTION_ARGS)

{

Datum txt = PG_GETARG_DATUM(0);

PG_RETURN_CSTRING(TextDatumGetCString(txt));

}

/*

* converts external binary format to varchar

*/

PGDLLEXPORT

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()

*/

/*

* 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

*/

PGDLLEXPORT

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()

*/