pg_freespacemap.c File Reference

#include "postgres.h"
#include "access/relation.h"
#include "fmgr.h"
#include "storage/freespace.h"
#include "utils/rel.h"

Include dependency graph for pg_freespacemap.c:

Go to the source code of this file.

Functions
	PG_MODULE_MAGIC_EXT (.name="pg_freespacemap",.version=PG_VERSION)
	PG_FUNCTION_INFO_V1 (pg_freespace)
Datum	pg_freespace (PG_FUNCTION_ARGS)

Function Documentation

pg_freespace()

Datum pg_freespace

(

PG_FUNCTION_ARGS

)

Definition at line 28 of file pg_freespacemap.c.

{
    Oid         relid = PG_GETARG_OID(0);
    int64       blkno = PG_GETARG_INT64(1);
    int16       freespace;
    Relation    rel;
 
    rel = relation_open(relid, AccessShareLock);
 
    if (!RELKIND_HAS_STORAGE(rel->rd_rel->relkind))
        ereport(ERROR,
                (errcode(ERRCODE_WRONG_OBJECT_TYPE),
                 errmsg("relation \"%s\" does not have storage",
                        RelationGetRelationName(rel)),
                 errdetail_relkind_not_supported(rel->rd_rel->relkind)));
 
    if (blkno < 0 || blkno > MaxBlockNumber)
        ereport(ERROR,
                (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
                 errmsg("invalid block number")));
 
    freespace = GetRecordedFreeSpace(rel, blkno);
 
    relation_close(rel, AccessShareLock);
    PG_RETURN_INT16(freespace);
}

References AccessShareLock, ereport, errcode(), errdetail_relkind_not_supported(), errmsg(), ERROR, fb(), GetRecordedFreeSpace(), MaxBlockNumber, PG_GETARG_INT64, PG_GETARG_OID, PG_RETURN_INT16, RelationData::rd_rel, relation_close(), relation_open(), and RelationGetRelationName.

PG_FUNCTION_INFO_V1()

PG_FUNCTION_INFO_V1

(

pg_freespace

)

PG_MODULE_MAGIC_EXT()

PG_MODULE_MAGIC_EXT	(	.	name = "pg_freespacemap",
		.	version = PG_VERSION
	)