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Name	Size	Permission
attnum.h	1.52 KB	-rw-r--r--
clog.h	1.47 KB	-rw-r--r--
genam.h	7.3 KB	-rw-r--r--
gin.h	1.63 KB	-rw-r--r--
gin_private.h	22.87 KB	-rw-r--r--
gist.h	6.65 KB	-rw-r--r--
gist_private.h	19.09 KB	-rw-r--r--
gistscan.h	718 B	-rw-r--r--
hash.h	12.87 KB	-rw-r--r--
heapam.h	6.25 KB	-rw-r--r--
hio.h	1.25 KB	-rw-r--r--
htup.h	32.13 KB	-rw-r--r--
itup.h	4.3 KB	-rw-r--r--
multixact.h	2.83 KB	-rw-r--r--
nbtree.h	27.43 KB	-rw-r--r--
printtup.h	1.03 KB	-rw-r--r--
reloptions.h	8.61 KB	-rw-r--r--
relscan.h	4.07 KB	-rw-r--r--
rewriteheap.h	1016 B	-rw-r--r--
rmgr.h	804 B	-rw-r--r--
sdir.h	1.43 KB	-rw-r--r--
skey.h	6.87 KB	-rw-r--r--
slru.h	5.16 KB	-rw-r--r--
spgist.h	6.24 KB	-rw-r--r--
spgist_private.h	22.11 KB	-rw-r--r--
subtrans.h	973 B	-rw-r--r--
sysattr.h	891 B	-rw-r--r--
transam.h	6.02 KB	-rw-r--r--
tupconvert.h	1.26 KB	-rw-r--r--
tupdesc.h	4.25 KB	-rw-r--r--
tupmacs.h	7.16 KB	-rw-r--r--
tuptoaster.h	5.52 KB	-rw-r--r--
twophase.h	1.75 KB	-rw-r--r--
twophase_rmgr.h	1.24 KB	-rw-r--r--
valid.h	1.4 KB	-rw-r--r--
visibilitymap.h	1.15 KB	-rw-r--r--
xact.h	8.44 KB	-rw-r--r--
xlog.h	12.43 KB	-rw-r--r--
xlog_internal.h	9.34 KB	-rw-r--r--
xlogdefs.h	4.49 KB	-rw-r--r--
xlogutils.h	956 B	-rw-r--r--

Code Editor : tuptoaster.h

/*-------------------------------------------------------------------------
 *
 * tuptoaster.h
 *	  POSTGRES definitions for external and compressed storage
 *	  of variable size attributes.
 *
 * Copyright (c) 2000-2012, PostgreSQL Global Development Group
 *
 * src/include/access/tuptoaster.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef TUPTOASTER_H
#define TUPTOASTER_H

#include "access/htup.h"
#include "utils/relcache.h"

/*
 * This enables de-toasting of index entries.  Needed until VACUUM is
 * smart enough to rebuild indexes from scratch.
 */
#define TOAST_INDEX_HACK

/*
 * Find the maximum size of a tuple if there are to be N tuples per page.
 */
#define MaximumBytesPerTuple(tuplesPerPage) \
	MAXALIGN_DOWN((BLCKSZ - \
				   MAXALIGN(SizeOfPageHeaderData + (tuplesPerPage) * sizeof(ItemIdData))) \
				  / (tuplesPerPage))

/*
 * These symbols control toaster activation.  If a tuple is larger than
 * TOAST_TUPLE_THRESHOLD, we will try to toast it down to no more than
 * TOAST_TUPLE_TARGET bytes through compressing compressible fields and
 * moving EXTENDED and EXTERNAL data out-of-line.
 *
 * The numbers need not be the same, though they currently are.  It doesn't
 * make sense for TARGET to exceed THRESHOLD, but it could be useful to make
 * it be smaller.
 *
 * Currently we choose both values to match the largest tuple size for which
 * TOAST_TUPLES_PER_PAGE tuples can fit on a heap page.
 *
 * XXX while these can be modified without initdb, some thought needs to be
 * given to needs_toast_table() in toasting.c before unleashing random
 * changes.  Also see LOBLKSIZE in large_object.h, which can *not* be
 * changed without initdb.
 */
#define TOAST_TUPLES_PER_PAGE	4

#define TOAST_TUPLE_THRESHOLD	MaximumBytesPerTuple(TOAST_TUPLES_PER_PAGE)

#define TOAST_TUPLE_TARGET		TOAST_TUPLE_THRESHOLD

/*
 * The code will also consider moving MAIN data out-of-line, but only as a
 * last resort if the previous steps haven't reached the target tuple size.
 * In this phase we use a different target size, currently equal to the
 * largest tuple that will fit on a heap page.  This is reasonable since
 * the user has told us to keep the data in-line if at all possible.
 */
#define TOAST_TUPLES_PER_PAGE_MAIN	1

#define TOAST_TUPLE_TARGET_MAIN MaximumBytesPerTuple(TOAST_TUPLES_PER_PAGE_MAIN)

/*
 * If an index value is larger than TOAST_INDEX_TARGET, we will try to
 * compress it (we can't move it out-of-line, however).  Note that this
 * number is per-datum, not per-tuple, for simplicity in index_form_tuple().
 */
#define TOAST_INDEX_TARGET		(MaxHeapTupleSize / 16)

/*
 * When we store an oversize datum externally, we divide it into chunks
 * containing at most TOAST_MAX_CHUNK_SIZE data bytes.  This number *must*
 * be small enough that the completed toast-table tuple (including the
 * ID and sequence fields and all overhead) will fit on a page.
 * The coding here sets the size on the theory that we want to fit
 * EXTERN_TUPLES_PER_PAGE tuples of maximum size onto a page.
 *
 * NB: Changing TOAST_MAX_CHUNK_SIZE requires an initdb.
 */
#define EXTERN_TUPLES_PER_PAGE	4		/* tweak only this */

#define EXTERN_TUPLE_MAX_SIZE	MaximumBytesPerTuple(EXTERN_TUPLES_PER_PAGE)

#define TOAST_MAX_CHUNK_SIZE	\
	(EXTERN_TUPLE_MAX_SIZE -							\
	 MAXALIGN(offsetof(HeapTupleHeaderData, t_bits)) -	\
	 sizeof(Oid) -										\
	 sizeof(int32) -									\
	 VARHDRSZ)

/* ----------
 * toast_insert_or_update -
 *
 *	Called by heap_insert() and heap_update().
 * ----------
 */
extern HeapTuple toast_insert_or_update(Relation rel,
					   HeapTuple newtup, HeapTuple oldtup,
					   int options);

/* ----------
 * toast_delete -
 *
 *	Called by heap_delete().
 * ----------
 */
extern void toast_delete(Relation rel, HeapTuple oldtup);

/* ----------
 * heap_tuple_fetch_attr() -
 *
 *		Fetches an external stored attribute from the toast
 *		relation. Does NOT decompress it, if stored external
 *		in compressed format.
 * ----------
 */
extern struct varlena *heap_tuple_fetch_attr(struct varlena * attr);

/* ----------
 * heap_tuple_untoast_attr() -
 *
 *		Fully detoasts one attribute, fetching and/or decompressing
 *		it as needed.
 * ----------
 */
extern struct varlena *heap_tuple_untoast_attr(struct varlena * attr);

/* ----------
 * heap_tuple_untoast_attr_slice() -
 *
 *		Fetches only the specified portion of an attribute.
 *		(Handles all cases for attribute storage)
 * ----------
 */
extern struct varlena *heap_tuple_untoast_attr_slice(struct varlena * attr,
							  int32 sliceoffset,
							  int32 slicelength);

/* ----------
 * toast_flatten_tuple -
 *
 *	"Flatten" a tuple to contain no out-of-line toasted fields.
 *	(This does not eliminate compressed or short-header datums.)
 * ----------
 */
extern HeapTuple toast_flatten_tuple(HeapTuple tup, TupleDesc tupleDesc);

/* ----------
 * toast_flatten_tuple_to_datum -
 *
 *	"Flatten" a tuple containing out-of-line toasted fields into a Datum.
 * ----------
 */
extern Datum toast_flatten_tuple_to_datum(HeapTupleHeader tup,
							 uint32 tup_len,
							 TupleDesc tupleDesc);

/* ----------
 * toast_compress_datum -
 *
 *	Create a compressed version of a varlena datum, if possible
 * ----------
 */
extern Datum toast_compress_datum(Datum value);

/* ----------
 * toast_raw_datum_size -
 *
 *	Return the raw (detoasted) size of a varlena datum
 * ----------
 */
extern Size toast_raw_datum_size(Datum value);

/* ----------
 * toast_datum_size -
 *
 *	Return the storage size of a varlena datum
 * ----------
 */
extern Size toast_datum_size(Datum value);

#endif   /* TUPTOASTER_H */

${this.title}

Code Editor : tuptoaster.h