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heapam.h previously was included in a number of widely used headers (e.g. execnodes.h, indirectly in executor.h, ...). That's problematic on its own, as heapam.h contains a lot of low-level details that don't need to be exposed that widely, but becomes more problematic with the upcoming introduction of pluggable table storage - it seems inappropriate for heapam.h to be included that widely afterwards. heapam.h was largely only included in other headers to get the HeapScanDesc typedef (which was defined in heapam.h, even though HeapScanDescData is defined in relscan.h). The better solution here seems to be to just use the underlying struct (forward declared where necessary). Similar for BulkInsertState. Another problem was that LockTupleMode was used in executor.h - parts of the file tried to cope without heapam.h, but due to the fact that it indirectly included it, several subsequent violations of that goal were not not noticed. We could just reuse the approach of declaring parameters as int, but it seems nicer to move LockTupleMode to lockoptions.h - that's not a perfect location, but also doesn't seem bad. As a number of files relied on implicitly included heapam.h, a significant number of files grew an explicit include. It's quite probably that a few external projects will need to do the same. Author: Andres Freund Reviewed-By: Alvaro Herrera Discussion: https://postgr.es/m/20190114000701.y4ttcb74jpskkcfb@alap3.anarazel.de
61 lines
1.8 KiB
C
61 lines
1.8 KiB
C
/*-------------------------------------------------------------------------
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*
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* lockoptions.h
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* Common header for some locking-related declarations.
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*
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*
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* Copyright (c) 2014-2019, PostgreSQL Global Development Group
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*
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* src/include/nodes/lockoptions.h
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*
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*-------------------------------------------------------------------------
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*/
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#ifndef LOCKOPTIONS_H
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#define LOCKOPTIONS_H
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/*
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* This enum represents the different strengths of FOR UPDATE/SHARE clauses.
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* The ordering here is important, because the highest numerical value takes
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* precedence when a RTE is specified multiple ways. See applyLockingClause.
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*/
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typedef enum LockClauseStrength
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{
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LCS_NONE, /* no such clause - only used in PlanRowMark */
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LCS_FORKEYSHARE, /* FOR KEY SHARE */
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LCS_FORSHARE, /* FOR SHARE */
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LCS_FORNOKEYUPDATE, /* FOR NO KEY UPDATE */
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LCS_FORUPDATE /* FOR UPDATE */
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} LockClauseStrength;
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/*
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* This enum controls how to deal with rows being locked by FOR UPDATE/SHARE
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* clauses (i.e., it represents the NOWAIT and SKIP LOCKED options).
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* The ordering here is important, because the highest numerical value takes
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* precedence when a RTE is specified multiple ways. See applyLockingClause.
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*/
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typedef enum LockWaitPolicy
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{
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/* Wait for the lock to become available (default behavior) */
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LockWaitBlock,
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/* Skip rows that can't be locked (SKIP LOCKED) */
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LockWaitSkip,
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/* Raise an error if a row cannot be locked (NOWAIT) */
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LockWaitError
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} LockWaitPolicy;
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/*
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* Possible lock modes for a tuple.
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*/
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typedef enum LockTupleMode
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{
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/* SELECT FOR KEY SHARE */
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LockTupleKeyShare,
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/* SELECT FOR SHARE */
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LockTupleShare,
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/* SELECT FOR NO KEY UPDATE, and UPDATEs that don't modify key columns */
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LockTupleNoKeyExclusive,
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/* SELECT FOR UPDATE, UPDATEs that modify key columns, and DELETE */
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LockTupleExclusive
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} LockTupleMode;
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#endif /* LOCKOPTIONS_H */
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