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postgresql/src/include/storage/fsm_internals.h

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Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
/*-------------------------------------------------------------------------
*
Fix inconsistencies and typos in the tree This is numbered take 7, and addresses a set of issues around: - Fixes for typos and incorrect reference names. - Removal of unneeded comments. - Removal of unreferenced functions and structures. - Fixes regarding variable name consistency. Author: Alexander Lakhin Discussion: https://postgr.es/m/10bfd4ac-3e7c-40ab-2b2e-355ed15495e8@gmail.com
2019-07-16 06:23:53 +02:00
* fsm_internals.h
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
* internal functions for free space map
*
*
Update copyright for 2019 Backpatch-through: certain files through 9.4
2019-01-02 18:44:25 +01:00
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
* Portions Copyright (c) 1994, Regents of the University of California
*
Remove cvs keywords from all files.
2010-09-20 22:08:53 +02:00
* src/include/storage/fsm_internals.h
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
*
*-------------------------------------------------------------------------
*/
#ifndef FSM_INTERNALS_H
#define FSM_INTERNALS_H
#include "storage/buf.h"
#include "storage/bufpage.h"
/*
* Structure of a FSM page. See src/backend/storage/freespace/README for
* details.
*/
typedef struct
{
/*
8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list provided by Andrew.
2009-06-11 16:49:15 +02:00
* fsm_search_avail() tries to spread the load of multiple backends by
* returning different pages to different backends in a round-robin
* fashion. fp_next_slot points to the next slot to be returned (assuming
* there's enough space on it for the request). It's defined as an int,
* because it's updated without an exclusive lock. uint16 would be more
* appropriate, but int is more likely to be atomically
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
* fetchable/storable.
*/
8.4 pgindent run, with new combined Linux/FreeBSD/MinGW typedef list provided by Andrew.
2009-06-11 16:49:15 +02:00
int fp_next_slot;
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
/*
* fp_nodes contains the binary tree, stored in array. The first
* NonLeafNodesPerPage elements are upper nodes, and the following
* LeafNodesPerPage elements are leaf nodes. Unused nodes are zero.
*/
Use FLEXIBLE_ARRAY_MEMBER in a bunch more places. Replace some bogus "x[1]" declarations with "x[FLEXIBLE_ARRAY_MEMBER]". Aside from being more self-documenting, this should help prevent bogus warnings from static code analyzers and perhaps compiler misoptimizations. This patch is just a down payment on eliminating the whole problem, but it gets rid of a lot of easy-to-fix cases. Note that the main problem with doing this is that one must no longer rely on computing sizeof(the containing struct), since the result would be compiler-dependent. Instead use offsetof(struct, lastfield). Autoconf also warns against spelling that offsetof(struct, lastfield[0]). Michael Paquier, review and additional fixes by me.
2015-02-20 06:11:42 +01:00
uint8 fp_nodes[FLEXIBLE_ARRAY_MEMBER];
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
} FSMPageData;
typedef FSMPageData *FSMPage;
/*
* Number of non-leaf and leaf nodes, and nodes in total, on an FSM page.
* These definitions are internal to fsmpage.c.
*/
#define NodesPerPage (BLCKSZ - MAXALIGN(SizeOfPageHeaderData) - \
offsetof(FSMPageData, fp_nodes))
#define NonLeafNodesPerPage (BLCKSZ / 2 - 1)
#define LeafNodesPerPage (NodesPerPage - NonLeafNodesPerPage)
/*
* Number of FSM "slots" on a FSM page. This is what should be used
* outside fsmpage.c.
*/
#define SlotsPerFSMPage LeafNodesPerPage
/* Prototypes for functions in fsmpage.c */
Phase 2 pgindent run for v12. Switch to 2.1 version of pg_bsd_indent. This formats multiline function declarations "correctly", that is with additional lines of parameter declarations indented to match where the first line's left parenthesis is. Discussion: https://postgr.es/m/CAEepm=0P3FeTXRcU5B2W3jv3PgRVZ-kGUXLGfd42FFhUROO3ug@mail.gmail.com
2019-05-22 19:04:48 +02:00
extern int fsm_search_avail(Buffer buf, uint8 min_cat, bool advancenext,
bool exclusive_lock_held);
Rewrite the FSM. Instead of relying on a fixed-size shared memory segment, the free space information is stored in a dedicated FSM relation fork, with each relation (except for hash indexes; they don't use FSM). This eliminates the max_fsm_relations and max_fsm_pages GUC options; remove any trace of them from the backend, initdb, and documentation. Rewrite contrib/pg_freespacemap to match the new FSM implementation. Also introduce a new variant of the get_raw_page(regclass, int4, int4) function in contrib/pageinspect that let's you to return pages from any relation fork, and a new fsm_page_contents() function to inspect the new FSM pages.
2008-09-30 12:52:14 +02:00
extern uint8 fsm_get_avail(Page page, int slot);
extern uint8 fsm_get_max_avail(Page page);
extern bool fsm_set_avail(Page page, int slot, uint8 value);
extern bool fsm_truncate_avail(Page page, int nslots);
extern bool fsm_rebuild_page(Page page);
Phase 2 of pgindent updates. Change pg_bsd_indent to follow upstream rules for placement of comments to the right of code, and remove pgindent hack that caused comments following #endif to not obey the general rule. Commit e3860ffa4dd0dad0dd9eea4be9cc1412373a8c89 wasn't actually using the published version of pg_bsd_indent, but a hacked-up version that tried to minimize the amount of movement of comments to the right of code. The situation of interest is where such a comment has to be moved to the right of its default placement at column 33 because there's code there. BSD indent has always moved right in units of tab stops in such cases --- but in the previous incarnation, indent was working in 8-space tab stops, while now it knows we use 4-space tabs. So the net result is that in about half the cases, such comments are placed one tab stop left of before. This is better all around: it leaves more room on the line for comment text, and it means that in such cases the comment uniformly starts at the next 4-space tab stop after the code, rather than sometimes one and sometimes two tabs after. Also, ensure that comments following #endif are indented the same as comments following other preprocessor commands such as #else. That inconsistency turns out to have been self-inflicted damage from a poorly-thought-through post-indent "fixup" in pgindent. This patch is much less interesting than the first round of indent changes, but also bulkier, so I thought it best to separate the effects. Discussion: https://postgr.es/m/E1dAmxK-0006EE-1r@gemulon.postgresql.org Discussion: https://postgr.es/m/30527.1495162840@sss.pgh.pa.us
2017-06-21 21:18:54 +02:00
#endif /* FSM_INTERNALS_H */
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