diff options
Diffstat (limited to 'src/include/storage/large_object.h')
| -rw-r--r-- | src/include/storage/large_object.h | 52 |
1 files changed, 32 insertions, 20 deletions
diff --git a/src/include/storage/large_object.h b/src/include/storage/large_object.h index c480f5b787..6bb0c4fcf2 100644 --- a/src/include/storage/large_object.h +++ b/src/include/storage/large_object.h @@ -8,39 +8,54 @@ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc * Portions Copyright (c) 1994, Regents of the University of California * - * $Id: large_object.h,v 1.17 2000/10/22 05:27:23 momjian Exp $ + * $Id: large_object.h,v 1.18 2000/10/24 01:38:43 tgl Exp $ * *------------------------------------------------------------------------- */ #ifndef LARGE_OBJECT_H #define LARGE_OBJECT_H -#include <sys/types.h> +#include "utils/rel.h" -#include "access/relscan.h" -/* - * This structure will eventually have lots more stuff associated with it. +/*---------- + * Data about a currently-open large object. + * + * id is the logical OID of the large object + * offset is the current seek offset within the LO + * heap_r holds an open-relation reference to pg_largeobject + * index_r holds an open-relation reference to pg_largeobject_loid_pn_index + * + * NOTE: before 7.1, heap_r and index_r held references to the separate + * table and index of a specific large object. Now they all live in one rel. + *---------- */ -typedef struct LargeObjectDesc -{ - Relation heap_r; /* heap relation */ - Relation index_r; /* index relation on seqno attribute */ - IndexScanDesc iscan; /* index scan we're using */ - TupleDesc hdesc; /* heap relation tuple desc */ - TupleDesc idesc; /* index relation tuple desc */ - uint32 lowbyte; /* low byte on the current page */ - uint32 highbyte; /* high byte on the current page */ +typedef struct LargeObjectDesc { + Oid id; uint32 offset; /* current seek pointer */ - ItemPointerData htid; /* tid of current heap tuple */ + int flags; /* locking info, etc */ +/* flag bits: */ #define IFS_RDLOCK (1 << 0) #define IFS_WRLOCK (1 << 1) -#define IFS_ATEOF (1 << 2) - u_long flags; /* locking info, etc */ + Relation heap_r; + Relation index_r; } LargeObjectDesc; + +/* + * Each "page" (tuple) of a large object can hold this much data + * + * Calculation is max tuple size less tuple header, loid field (Oid), + * pageno field (int32), and varlena header of data (int32). Note we + * assume none of the fields will be NULL, hence no need for null bitmap. + */ +#define LOBLKSIZE (MaxTupleSize \ + - MAXALIGN(offsetof(HeapTupleHeaderData, t_bits)) \ + - sizeof(Oid) - sizeof(int32) * 2) + + /* * Function definitions... */ @@ -55,7 +70,4 @@ extern int inv_tell(LargeObjectDesc *obj_desc); extern int inv_read(LargeObjectDesc *obj_desc, char *buf, int nbytes); extern int inv_write(LargeObjectDesc *obj_desc, char *buf, int nbytes); -/* added for buffer leak prevention [ PA ] */ -extern void inv_cleanindex(LargeObjectDesc *obj_desc); - #endif /* LARGE_OBJECT_H */ |