Reindent some comments
Most (older) comments in md.c and smgr.c are indented with a leading tab on all lines, which isn't the current style and makes updating the comments a bit annoying. This reindents all these lines with a single space, as is the normal style. This issue exists in various shapes throughout the code but it's pretty consistent here, and since there is a patch pending to refresh some of the comments in these files, it seems sensible to clean this up here separately. Discussion: https://www.postgresql.org/message-id/flat/22fed8ba-01c3-2008-a256-4ea912d68fab%40enterprisedb.com
This commit is contained in:
Peter Eisentraut
parent
e7bff46e50
commit
0b8ace8d77
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@ -42,41 +42,41 @@
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#include "utils/memutils.h"
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/*
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* The magnetic disk storage manager keeps track of open file
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* descriptors in its own descriptor pool. This is done to make it
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* easier to support relations that are larger than the operating
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* system's file size limit (often 2GBytes). In order to do that,
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* we break relations up into "segment" files that are each shorter than
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* the OS file size limit. The segment size is set by the RELSEG_SIZE
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* configuration constant in pg_config.h.
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* The magnetic disk storage manager keeps track of open file
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* descriptors in its own descriptor pool. This is done to make it
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* easier to support relations that are larger than the operating
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* system's file size limit (often 2GBytes). In order to do that,
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* we break relations up into "segment" files that are each shorter than
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* the OS file size limit. The segment size is set by the RELSEG_SIZE
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* configuration constant in pg_config.h.
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*
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* On disk, a relation must consist of consecutively numbered segment
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* files in the pattern
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* -- Zero or more full segments of exactly RELSEG_SIZE blocks each
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* -- Exactly one partial segment of size 0 <= size < RELSEG_SIZE blocks
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* -- Optionally, any number of inactive segments of size 0 blocks.
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* The full and partial segments are collectively the "active" segments.
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* Inactive segments are those that once contained data but are currently
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* not needed because of an mdtruncate() operation. The reason for leaving
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* them present at size zero, rather than unlinking them, is that other
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* backends and/or the checkpointer might be holding open file references to
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* such segments. If the relation expands again after mdtruncate(), such
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* that a deactivated segment becomes active again, it is important that
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* such file references still be valid --- else data might get written
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* out to an unlinked old copy of a segment file that will eventually
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* disappear.
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* On disk, a relation must consist of consecutively numbered segment
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* files in the pattern
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* -- Zero or more full segments of exactly RELSEG_SIZE blocks each
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* -- Exactly one partial segment of size 0 <= size < RELSEG_SIZE blocks
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* -- Optionally, any number of inactive segments of size 0 blocks.
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* The full and partial segments are collectively the "active" segments.
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* Inactive segments are those that once contained data but are currently
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* not needed because of an mdtruncate() operation. The reason for leaving
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* them present at size zero, rather than unlinking them, is that other
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* backends and/or the checkpointer might be holding open file references to
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* such segments. If the relation expands again after mdtruncate(), such
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* that a deactivated segment becomes active again, it is important that
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* such file references still be valid --- else data might get written
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* out to an unlinked old copy of a segment file that will eventually
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* disappear.
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*
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* File descriptors are stored in the per-fork md_seg_fds arrays inside
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* SMgrRelation. The length of these arrays is stored in md_num_open_segs.
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* Note that a fork's md_num_open_segs having a specific value does not
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* necessarily mean the relation doesn't have additional segments; we may
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* just not have opened the next segment yet. (We could not have "all
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* segments are in the array" as an invariant anyway, since another backend
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* could extend the relation while we aren't looking.) We do not have
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* entries for inactive segments, however; as soon as we find a partial
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* segment, we assume that any subsequent segments are inactive.
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* File descriptors are stored in the per-fork md_seg_fds arrays inside
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* SMgrRelation. The length of these arrays is stored in md_num_open_segs.
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* Note that a fork's md_num_open_segs having a specific value does not
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* necessarily mean the relation doesn't have additional segments; we may
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* just not have opened the next segment yet. (We could not have "all
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* segments are in the array" as an invariant anyway, since another backend
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* could extend the relation while we aren't looking.) We do not have
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* entries for inactive segments, however; as soon as we find a partial
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* segment, we assume that any subsequent segments are inactive.
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*
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* The entire MdfdVec array is palloc'd in the MdCxt memory context.
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* The entire MdfdVec array is palloc'd in the MdCxt memory context.
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*/
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typedef struct _MdfdVec
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@ -154,7 +154,7 @@ _mdfd_open_flags(void)
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}
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/*
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* mdinit() -- Initialize private state for magnetic disk storage manager.
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* mdinit() -- Initialize private state for magnetic disk storage manager.
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*/
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void
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mdinit(void)
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@ -165,7 +165,7 @@ mdinit(void)
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}
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/*
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* mdexists() -- Does the physical file exist?
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* mdexists() -- Does the physical file exist?
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*
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* Note: this will return true for lingering files, with pending deletions
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*/
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@ -184,7 +184,7 @@ mdexists(SMgrRelation reln, ForkNumber forknum)
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}
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/*
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* mdcreate() -- Create a new relation on magnetic disk.
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* mdcreate() -- Create a new relation on magnetic disk.
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*
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* If isRedo is true, it's okay for the relation to exist already.
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*/
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@ -242,7 +242,7 @@ mdcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo)
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}
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/*
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* mdunlink() -- Unlink a relation.
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* mdunlink() -- Unlink a relation.
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*
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* Note that we're passed a RelFileLocatorBackend --- by the time this is called,
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* there won't be an SMgrRelation hashtable entry anymore.
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@ -447,13 +447,13 @@ mdunlinkfork(RelFileLocatorBackend rlocator, ForkNumber forknum, bool isRedo)
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}
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/*
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* mdextend() -- Add a block to the specified relation.
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* mdextend() -- Add a block to the specified relation.
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*
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* The semantics are nearly the same as mdwrite(): write at the
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* specified position. However, this is to be used for the case of
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* extending a relation (i.e., blocknum is at or beyond the current
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* EOF). Note that we assume writing a block beyond current EOF
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* causes intervening file space to become filled with zeroes.
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* The semantics are nearly the same as mdwrite(): write at the
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* specified position. However, this is to be used for the case of
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* extending a relation (i.e., blocknum is at or beyond the current
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* EOF). Note that we assume writing a block beyond current EOF
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* causes intervening file space to become filled with zeroes.
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*/
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void
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mdextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
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@ -515,10 +515,10 @@ mdextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
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}
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/*
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* mdzeroextend() -- Add new zeroed out blocks to the specified relation.
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* mdzeroextend() -- Add new zeroed out blocks to the specified relation.
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*
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* Similar to mdextend(), except the relation can be extended by multiple
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* blocks at once and the added blocks will be filled with zeroes.
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* Similar to mdextend(), except the relation can be extended by multiple
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* blocks at once and the added blocks will be filled with zeroes.
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*/
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void
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mdzeroextend(SMgrRelation reln, ForkNumber forknum,
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@ -623,7 +623,7 @@ mdzeroextend(SMgrRelation reln, ForkNumber forknum,
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}
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/*
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* mdopenfork() -- Open one fork of the specified relation.
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* mdopenfork() -- Open one fork of the specified relation.
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*
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* Note we only open the first segment, when there are multiple segments.
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*
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@ -673,7 +673,7 @@ mdopenfork(SMgrRelation reln, ForkNumber forknum, int behavior)
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}
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/*
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* mdopen() -- Initialize newly-opened relation.
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* mdopen() -- Initialize newly-opened relation.
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*/
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void
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mdopen(SMgrRelation reln)
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@ -684,7 +684,7 @@ mdopen(SMgrRelation reln)
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}
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/*
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* mdclose() -- Close the specified relation, if it isn't closed already.
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* mdclose() -- Close the specified relation, if it isn't closed already.
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*/
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void
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mdclose(SMgrRelation reln, ForkNumber forknum)
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@ -707,7 +707,7 @@ mdclose(SMgrRelation reln, ForkNumber forknum)
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}
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/*
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* mdprefetch() -- Initiate asynchronous read of the specified block of a relation
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* mdprefetch() -- Initiate asynchronous read of the specified block of a relation
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*/
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bool
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mdprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum)
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@ -791,7 +791,7 @@ mdwriteback(SMgrRelation reln, ForkNumber forknum,
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}
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/*
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* mdread() -- Read the specified block from a relation.
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* mdread() -- Read the specified block from a relation.
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*/
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void
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mdread(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
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@ -856,11 +856,11 @@ mdread(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
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}
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/*
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* mdwrite() -- Write the supplied block at the appropriate location.
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* mdwrite() -- Write the supplied block at the appropriate location.
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*
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* This is to be used only for updating already-existing blocks of a
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* relation (ie, those before the current EOF). To extend a relation,
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* use mdextend().
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* This is to be used only for updating already-existing blocks of a
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* relation (ie, those before the current EOF). To extend a relation,
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* use mdextend().
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*/
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void
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mdwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
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@ -924,12 +924,12 @@ mdwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
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}
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/*
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* mdnblocks() -- Get the number of blocks stored in a relation.
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* mdnblocks() -- Get the number of blocks stored in a relation.
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*
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* Important side effect: all active segments of the relation are opened
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* and added to the md_seg_fds array. If this routine has not been
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* called, then only segments up to the last one actually touched
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* are present in the array.
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* Important side effect: all active segments of the relation are opened
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* and added to the md_seg_fds array. If this routine has not been
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* called, then only segments up to the last one actually touched
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* are present in the array.
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*/
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BlockNumber
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mdnblocks(SMgrRelation reln, ForkNumber forknum)
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@ -986,7 +986,7 @@ mdnblocks(SMgrRelation reln, ForkNumber forknum)
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}
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/*
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* mdtruncate() -- Truncate relation to specified number of blocks.
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* mdtruncate() -- Truncate relation to specified number of blocks.
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*/
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void
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mdtruncate(SMgrRelation reln, ForkNumber forknum, BlockNumber nblocks)
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@ -1080,7 +1080,7 @@ mdtruncate(SMgrRelation reln, ForkNumber forknum, BlockNumber nblocks)
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}
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/*
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* mdimmedsync() -- Immediately sync a relation to stable storage.
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* mdimmedsync() -- Immediately sync a relation to stable storage.
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*
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* Note that only writes already issued are synced; this routine knows
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* nothing of dirty buffers that may exist inside the buffer manager. We
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@ -1275,7 +1275,7 @@ DropRelationFiles(RelFileLocator *delrels, int ndelrels, bool isRedo)
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/*
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* _fdvec_resize() -- Resize the fork's open segments array
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* _fdvec_resize() -- Resize the fork's open segments array
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*/
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static void
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_fdvec_resize(SMgrRelation reln,
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@ -1376,8 +1376,8 @@ _mdfd_openseg(SMgrRelation reln, ForkNumber forknum, BlockNumber segno,
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}
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/*
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* _mdfd_getseg() -- Find the segment of the relation holding the
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* specified block.
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* _mdfd_getseg() -- Find the segment of the relation holding the
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* specified block.
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*
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* If the segment doesn't exist, we ereport, return NULL, or create the
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* segment, according to "behavior". Note: skipFsync is only used in the
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@ -104,8 +104,8 @@ static void smgrshutdown(int code, Datum arg);
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/*
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* smgrinit(), smgrshutdown() -- Initialize or shut down storage
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* managers.
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* smgrinit(), smgrshutdown() -- Initialize or shut down storage
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* managers.
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*
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* Note: smgrinit is called during backend startup (normal or standalone
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* case), *not* during postmaster start. Therefore, any resources created
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@ -142,9 +142,9 @@ smgrshutdown(int code, Datum arg)
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}
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/*
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* smgropen() -- Return an SMgrRelation object, creating it if need be.
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* smgropen() -- Return an SMgrRelation object, creating it if need be.
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*
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* This does not attempt to actually open the underlying file.
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* This does not attempt to actually open the underlying file.
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*/
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SMgrRelation
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smgropen(RelFileLocator rlocator, BackendId backend)
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@ -245,7 +245,7 @@ smgrclearowner(SMgrRelation *owner, SMgrRelation reln)
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}
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/*
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* smgrexists() -- Does the underlying file for a fork exist?
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* smgrexists() -- Does the underlying file for a fork exist?
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*/
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bool
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smgrexists(SMgrRelation reln, ForkNumber forknum)
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@ -254,7 +254,7 @@ smgrexists(SMgrRelation reln, ForkNumber forknum)
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}
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/*
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* smgrclose() -- Close and delete an SMgrRelation object.
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* smgrclose() -- Close and delete an SMgrRelation object.
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*/
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void
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smgrclose(SMgrRelation reln)
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@ -284,9 +284,9 @@ smgrclose(SMgrRelation reln)
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}
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/*
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* smgrrelease() -- Release all resources used by this object.
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* smgrrelease() -- Release all resources used by this object.
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*
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* The object remains valid.
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* The object remains valid.
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*/
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void
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smgrrelease(SMgrRelation reln)
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@ -299,9 +299,9 @@ smgrrelease(SMgrRelation reln)
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}
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/*
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* smgrreleaseall() -- Release resources used by all objects.
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* smgrreleaseall() -- Release resources used by all objects.
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*
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* This is called for PROCSIGNAL_BARRIER_SMGRRELEASE.
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* This is called for PROCSIGNAL_BARRIER_SMGRRELEASE.
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*/
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void
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smgrreleaseall(void)
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@ -320,7 +320,7 @@ smgrreleaseall(void)
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}
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/*
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* smgrcloseall() -- Close all existing SMgrRelation objects.
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* smgrcloseall() -- Close all existing SMgrRelation objects.
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*/
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void
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smgrcloseall(void)
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@ -339,8 +339,8 @@ smgrcloseall(void)
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}
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/*
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* smgrcloserellocator() -- Close SMgrRelation object for given RelFileLocator,
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* if one exists.
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* smgrcloserellocator() -- Close SMgrRelation object for given RelFileLocator,
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* if one exists.
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*
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* This has the same effects as smgrclose(smgropen(rlocator)), but it avoids
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* uselessly creating a hashtable entry only to drop it again when no
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@ -363,11 +363,11 @@ smgrcloserellocator(RelFileLocatorBackend rlocator)
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}
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/*
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* smgrcreate() -- Create a new relation.
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* smgrcreate() -- Create a new relation.
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*
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* Given an already-created (but presumably unused) SMgrRelation,
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* cause the underlying disk file or other storage for the fork
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* to be created.
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* Given an already-created (but presumably unused) SMgrRelation,
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* cause the underlying disk file or other storage for the fork
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* to be created.
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*/
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void
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smgrcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo)
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@ -376,13 +376,13 @@ smgrcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo)
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}
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/*
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* smgrdosyncall() -- Immediately sync all forks of all given relations
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* smgrdosyncall() -- Immediately sync all forks of all given relations
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*
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* All forks of all given relations are synced out to the store.
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* All forks of all given relations are synced out to the store.
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*
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* This is equivalent to FlushRelationBuffers() for each smgr relation,
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* then calling smgrimmedsync() for all forks of each relation, but it's
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* significantly quicker so should be preferred when possible.
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* This is equivalent to FlushRelationBuffers() for each smgr relation,
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* then calling smgrimmedsync() for all forks of each relation, but it's
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* significantly quicker so should be preferred when possible.
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*/
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void
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smgrdosyncall(SMgrRelation *rels, int nrels)
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@ -411,14 +411,14 @@ smgrdosyncall(SMgrRelation *rels, int nrels)
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}
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/*
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* smgrdounlinkall() -- Immediately unlink all forks of all given relations
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* smgrdounlinkall() -- Immediately unlink all forks of all given relations
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*
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* All forks of all given relations are removed from the store. This
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* should not be used during transactional operations, since it can't be
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* undone.
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* All forks of all given relations are removed from the store. This
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* should not be used during transactional operations, since it can't be
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* undone.
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*
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* If isRedo is true, it is okay for the underlying file(s) to be gone
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* already.
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* If isRedo is true, it is okay for the underlying file(s) to be gone
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* already.
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*/
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void
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smgrdounlinkall(SMgrRelation *rels, int nrels, bool isRedo)
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@ -485,13 +485,13 @@ smgrdounlinkall(SMgrRelation *rels, int nrels, bool isRedo)
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/*
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* smgrextend() -- Add a new block to a file.
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* smgrextend() -- Add a new block to a file.
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*
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* The semantics are nearly the same as smgrwrite(): write at the
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* specified position. However, this is to be used for the case of
|
||||
* extending a relation (i.e., blocknum is at or beyond the current
|
||||
* EOF). Note that we assume writing a block beyond current EOF
|
||||
* causes intervening file space to become filled with zeroes.
|
||||
* The semantics are nearly the same as smgrwrite(): write at the
|
||||
* specified position. However, this is to be used for the case of
|
||||
* extending a relation (i.e., blocknum is at or beyond the current
|
||||
* EOF). Note that we assume writing a block beyond current EOF
|
||||
* causes intervening file space to become filled with zeroes.
|
||||
*/
|
||||
void
|
||||
smgrextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
||||
|
|
@ -512,11 +512,11 @@ smgrextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrzeroextend() -- Add new zeroed out blocks to a file.
|
||||
* smgrzeroextend() -- Add new zeroed out blocks to a file.
|
||||
*
|
||||
* Similar to smgrextend(), except the relation can be extended by
|
||||
* multiple blocks at once and the added blocks will be filled with
|
||||
* zeroes.
|
||||
* Similar to smgrextend(), except the relation can be extended by
|
||||
* multiple blocks at once and the added blocks will be filled with
|
||||
* zeroes.
|
||||
*/
|
||||
void
|
||||
smgrzeroextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
||||
|
|
@ -537,11 +537,11 @@ smgrzeroextend(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrprefetch() -- Initiate asynchronous read of the specified block of a relation.
|
||||
* smgrprefetch() -- Initiate asynchronous read of the specified block of a relation.
|
||||
*
|
||||
* In recovery only, this can return false to indicate that a file
|
||||
* doesn't exist (presumably it has been dropped by a later WAL
|
||||
* record).
|
||||
* In recovery only, this can return false to indicate that a file
|
||||
* doesn't exist (presumably it has been dropped by a later WAL
|
||||
* record).
|
||||
*/
|
||||
bool
|
||||
smgrprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum)
|
||||
|
|
@ -550,12 +550,12 @@ smgrprefetch(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum)
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrread() -- read a particular block from a relation into the supplied
|
||||
* buffer.
|
||||
* smgrread() -- read a particular block from a relation into the supplied
|
||||
* buffer.
|
||||
*
|
||||
* This routine is called from the buffer manager in order to
|
||||
* instantiate pages in the shared buffer cache. All storage managers
|
||||
* return pages in the format that POSTGRES expects.
|
||||
* This routine is called from the buffer manager in order to
|
||||
* instantiate pages in the shared buffer cache. All storage managers
|
||||
* return pages in the format that POSTGRES expects.
|
||||
*/
|
||||
void
|
||||
smgrread(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
||||
|
|
@ -565,19 +565,19 @@ smgrread(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrwrite() -- Write the supplied buffer out.
|
||||
* smgrwrite() -- Write the supplied buffer out.
|
||||
*
|
||||
* This is to be used only for updating already-existing blocks of a
|
||||
* relation (ie, those before the current EOF). To extend a relation,
|
||||
* use smgrextend().
|
||||
* This is to be used only for updating already-existing blocks of a
|
||||
* relation (ie, those before the current EOF). To extend a relation,
|
||||
* use smgrextend().
|
||||
*
|
||||
* This is not a synchronous write -- the block is not necessarily
|
||||
* on disk at return, only dumped out to the kernel. However,
|
||||
* provisions will be made to fsync the write before the next checkpoint.
|
||||
* This is not a synchronous write -- the block is not necessarily
|
||||
* on disk at return, only dumped out to the kernel. However,
|
||||
* provisions will be made to fsync the write before the next checkpoint.
|
||||
*
|
||||
* skipFsync indicates that the caller will make other provisions to
|
||||
* fsync the relation, so we needn't bother. Temporary relations also
|
||||
* do not require fsync.
|
||||
* skipFsync indicates that the caller will make other provisions to
|
||||
* fsync the relation, so we needn't bother. Temporary relations also
|
||||
* do not require fsync.
|
||||
*/
|
||||
void
|
||||
smgrwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
||||
|
|
@ -589,7 +589,7 @@ smgrwrite(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
|||
|
||||
|
||||
/*
|
||||
* smgrwriteback() -- Trigger kernel writeback for the supplied range of
|
||||
* smgrwriteback() -- Trigger kernel writeback for the supplied range of
|
||||
* blocks.
|
||||
*/
|
||||
void
|
||||
|
|
@ -601,8 +601,8 @@ smgrwriteback(SMgrRelation reln, ForkNumber forknum, BlockNumber blocknum,
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrnblocks() -- Calculate the number of blocks in the
|
||||
* supplied relation.
|
||||
* smgrnblocks() -- Calculate the number of blocks in the
|
||||
* supplied relation.
|
||||
*/
|
||||
BlockNumber
|
||||
smgrnblocks(SMgrRelation reln, ForkNumber forknum)
|
||||
|
|
@ -622,8 +622,8 @@ smgrnblocks(SMgrRelation reln, ForkNumber forknum)
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrnblocks_cached() -- Get the cached number of blocks in the supplied
|
||||
* relation.
|
||||
* smgrnblocks_cached() -- Get the cached number of blocks in the supplied
|
||||
* relation.
|
||||
*
|
||||
* Returns an InvalidBlockNumber when not in recovery and when the relation
|
||||
* fork size is not cached.
|
||||
|
|
@ -642,8 +642,8 @@ smgrnblocks_cached(SMgrRelation reln, ForkNumber forknum)
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrtruncate() -- Truncate the given forks of supplied relation to
|
||||
* each specified numbers of blocks
|
||||
* smgrtruncate() -- Truncate the given forks of supplied relation to
|
||||
* each specified numbers of blocks
|
||||
*
|
||||
* The truncation is done immediately, so this can't be rolled back.
|
||||
*
|
||||
|
|
@ -694,27 +694,27 @@ smgrtruncate(SMgrRelation reln, ForkNumber *forknum, int nforks, BlockNumber *nb
|
|||
}
|
||||
|
||||
/*
|
||||
* smgrimmedsync() -- Force the specified relation to stable storage.
|
||||
* smgrimmedsync() -- Force the specified relation to stable storage.
|
||||
*
|
||||
* Synchronously force all previous writes to the specified relation
|
||||
* down to disk.
|
||||
* Synchronously force all previous writes to the specified relation
|
||||
* down to disk.
|
||||
*
|
||||
* This is useful for building completely new relations (eg, new
|
||||
* indexes). Instead of incrementally WAL-logging the index build
|
||||
* steps, we can just write completed index pages to disk with smgrwrite
|
||||
* or smgrextend, and then fsync the completed index file before
|
||||
* committing the transaction. (This is sufficient for purposes of
|
||||
* crash recovery, since it effectively duplicates forcing a checkpoint
|
||||
* for the completed index. But it is *not* sufficient if one wishes
|
||||
* to use the WAL log for PITR or replication purposes: in that case
|
||||
* we have to make WAL entries as well.)
|
||||
* This is useful for building completely new relations (eg, new
|
||||
* indexes). Instead of incrementally WAL-logging the index build
|
||||
* steps, we can just write completed index pages to disk with smgrwrite
|
||||
* or smgrextend, and then fsync the completed index file before
|
||||
* committing the transaction. (This is sufficient for purposes of
|
||||
* crash recovery, since it effectively duplicates forcing a checkpoint
|
||||
* for the completed index. But it is *not* sufficient if one wishes
|
||||
* to use the WAL log for PITR or replication purposes: in that case
|
||||
* we have to make WAL entries as well.)
|
||||
*
|
||||
* The preceding writes should specify skipFsync = true to avoid
|
||||
* duplicative fsyncs.
|
||||
* The preceding writes should specify skipFsync = true to avoid
|
||||
* duplicative fsyncs.
|
||||
*
|
||||
* Note that you need to do FlushRelationBuffers() first if there is
|
||||
* any possibility that there are dirty buffers for the relation;
|
||||
* otherwise the sync is not very meaningful.
|
||||
* Note that you need to do FlushRelationBuffers() first if there is
|
||||
* any possibility that there are dirty buffers for the relation;
|
||||
* otherwise the sync is not very meaningful.
|
||||
*/
|
||||
void
|
||||
smgrimmedsync(SMgrRelation reln, ForkNumber forknum)
|
||||
|
|
|
|||
Loading…
Reference in New Issue