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Recommend wrappers of PG_DETOAST_DATUM_PACKED().

When commit 3e23b68dac introduced
single-byte varlena headers, its fmgr.h changes presented
PG_GETARG_TEXT_PP() and PG_GETARG_TEXT_P() as equals.  Its postgres.h
changes presented PG_DETOAST_DATUM_PACKED() and VARDATA_ANY() as the
exceptional case.  Now, instead, firmly recommend PG_GETARG_TEXT_PP()
over PG_GETARG_TEXT_P(); likewise for other ...PP() macros.  This shaves
cycles and invites consistency of style.
This commit is contained in:
Noah Misch
2017-03-12 19:35:33 -04:00
parent 944a026b4e
commit 9d7726c2ba
6 changed files with 74 additions and 57 deletions

View File

@ -66,21 +66,24 @@ PG_FUNCTION_INFO_V1(copytext);
Datum
copytext(PG_FUNCTION_ARGS)
{
text *t = PG_GETARG_TEXT_P(0);
text *t = PG_GETARG_TEXT_PP(0);
/*
* VARSIZE is the total size of the struct in bytes.
* VARSIZE_ANY_EXHDR is the size of the struct in bytes, minus the
* VARHDRSZ or VARHDRSZ_SHORT of its header. Construct the copy with a
* full-length header.
*/
text *new_t = (text *) palloc(VARSIZE(t));
text *new_t = (text *) palloc(VARSIZE_ANY_EXHDR(t) + VARHDRSZ);
SET_VARSIZE(new_t, VARSIZE(t));
SET_VARSIZE(new_t, VARSIZE_ANY_EXHDR(t) + VARHDRSZ);
/*
* VARDATA is a pointer to the data region of the struct.
* VARDATA is a pointer to the data region of the new struct. The source
* could be a short datum, so retrieve its data through VARDATA_ANY.
*/
memcpy((void *) VARDATA(new_t), /* destination */
(void *) VARDATA(t), /* source */
VARSIZE(t) - VARHDRSZ); /* how many bytes */
(void *) VARDATA_ANY(t), /* source */
VARSIZE_ANY_EXHDR(t)); /* how many bytes */
PG_RETURN_TEXT_P(new_t);
}
@ -89,16 +92,16 @@ PG_FUNCTION_INFO_V1(concat_text);
Datum
concat_text(PG_FUNCTION_ARGS)
{
text *arg1 = PG_GETARG_TEXT_P(0);
text *arg2 = PG_GETARG_TEXT_P(1);
int32 arg1_size = VARSIZE(arg1) - VARHDRSZ;
int32 arg2_size = VARSIZE(arg2) - VARHDRSZ;
text *arg1 = PG_GETARG_TEXT_PP(0);
text *arg2 = PG_GETARG_TEXT_PP(1);
int32 arg1_size = VARSIZE_ANY_EXHDR(arg1);
int32 arg2_size = VARSIZE_ANY_EXHDR(arg2);
int32 new_text_size = arg1_size + arg2_size + VARHDRSZ;
text *new_text = (text *) palloc(new_text_size);
SET_VARSIZE(new_text, new_text_size);
memcpy(VARDATA(new_text), VARDATA(arg1), arg1_size);
memcpy(VARDATA(new_text) + arg1_size, VARDATA(arg2), arg2_size);
memcpy(VARDATA(new_text), VARDATA_ANY(arg1), arg1_size);
memcpy(VARDATA(new_text) + arg1_size, VARDATA_ANY(arg2), arg2_size);
PG_RETURN_TEXT_P(new_text);
}