diff options
Diffstat (limited to 'src/backend/storage/smgr/smgr.c')
| -rw-r--r-- | src/backend/storage/smgr/smgr.c | 170 |
1 files changed, 85 insertions, 85 deletions
diff --git a/src/backend/storage/smgr/smgr.c b/src/backend/storage/smgr/smgr.c index 70d0d570b1a..8a11090944a 100644 --- a/src/backend/storage/smgr/smgr.c +++ b/src/backend/storage/smgr/smgr.c @@ -104,8 +104,8 @@ static void smgrshutdown(int code, Datum arg); /* - * smgrinit(), smgrshutdown() -- Initialize or shut down storage - * managers. + * smgrinit(), smgrshutdown() -- Initialize or shut down storage + * managers. * * Note: smgrinit is called during backend startup (normal or standalone * case), *not* during postmaster start. Therefore, any resources created @@ -142,9 +142,9 @@ smgrshutdown(int code, Datum arg) } /* - * smgropen() -- Return an SMgrRelation object, creating it if need be. + * smgropen() -- Return an SMgrRelation object, creating it if need be. * - * This does not attempt to actually open the underlying file. + * This does not attempt to actually open the underlying file. */ SMgrRelation smgropen(RelFileLocator rlocator, BackendId backend) @@ -245,7 +245,7 @@ smgrclearowner(SMgrRelation *owner, SMgrRelation reln) } /* - * smgrexists() -- Does the underlying file for a fork exist? + * smgrexists() -- Does the underlying file for a fork exist? */ bool smgrexists(SMgrRelation reln, ForkNumber forknum) @@ -254,7 +254,7 @@ smgrexists(SMgrRelation reln, ForkNumber forknum) } /* - * smgrclose() -- Close and delete an SMgrRelation object. + * smgrclose() -- Close and delete an SMgrRelation object. */ void smgrclose(SMgrRelation reln) @@ -284,9 +284,9 @@ smgrclose(SMgrRelation reln) } /* - * smgrrelease() -- Release all resources used by this object. + * smgrrelease() -- Release all resources used by this object. * - * The object remains valid. + * The object remains valid. */ void smgrrelease(SMgrRelation reln) @@ -299,9 +299,9 @@ smgrrelease(SMgrRelation reln) } /* - * smgrreleaseall() -- Release resources used by all objects. + * smgrreleaseall() -- Release resources used by all objects. * - * This is called for PROCSIGNAL_BARRIER_SMGRRELEASE. + * This is called for PROCSIGNAL_BARRIER_SMGRRELEASE. */ void smgrreleaseall(void) @@ -320,7 +320,7 @@ smgrreleaseall(void) } /* - * smgrcloseall() -- Close all existing SMgrRelation objects. + * smgrcloseall() -- Close all existing SMgrRelation objects. */ void smgrcloseall(void) @@ -339,8 +339,8 @@ smgrcloseall(void) } /* - * smgrcloserellocator() -- Close SMgrRelation object for given RelFileLocator, - * if one exists. + * smgrcloserellocator() -- Close SMgrRelation object for given RelFileLocator, + * if one exists. * * This has the same effects as smgrclose(smgropen(rlocator)), but it avoids * uselessly creating a hashtable entry only to drop it again when no @@ -363,11 +363,11 @@ smgrcloserellocator(RelFileLocatorBackend rlocator) } /* - * smgrcreate() -- Create a new relation. + * smgrcreate() -- Create a new relation. * - * Given an already-created (but presumably unused) SMgrRelation, - * cause the underlying disk file or other storage for the fork - * to be created. + * Given an already-created (but presumably unused) SMgrRelation, + * cause the underlying disk file or other storage for the fork + * to be created. */ void smgrcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo) @@ -376,13 +376,13 @@ smgrcreate(SMgrRelation reln, ForkNumber forknum, bool isRedo) } /* - * smgrdosyncall() -- Immediately sync all forks of all given relations + * smgrdosyncall() -- Immediately sync all forks of all given relations * - * All forks of all given relations are synced out to the store. + * All forks of all given relations are synced out to the store. * - * This is equivalent to FlushRelationBuffers() for each smgr relation, - * then calling smgrimmedsync() for all forks of each relation, but it's - * significantly quicker so should be preferred when possible. + * This is equivalent to FlushRelationBuffers() for each smgr relation, + * then calling smgrimmedsync() for all forks of each relation, but it's + * significantly quicker so should be preferred when possible. */ void smgrdosyncall(SMgrRelation *rels, int nrels) @@ -411,14 +411,14 @@ smgrdosyncall(SMgrRelation *rels, int nrels) } /* - * smgrdounlinkall() -- Immediately unlink all forks of all given relations + * smgrdounlinkall() -- Immediately unlink all forks of all given relations * - * All forks of all given relations are removed from the store. This - * should not be used during transactional operations, since it can't be - * undone. + * All forks of all given relations are removed from the store. This + * should not be used during transactional operations, since it can't be + * undone. * - * If isRedo is true, it is okay for the underlying file(s) to be gone - * already. + * If isRedo is true, it is okay for the underlying file(s) to be gone + * already. */ void smgrdounlinkall(SMgrRelation *rels, int nrels, bool isRedo) @@ -485,13 +485,13 @@ smgrdounlinkall(SMgrRelation *rels, int nrels, bool isRedo) /* - * smgrextend() -- Add a new block to a file. + * smgrextend() -- Add a new block to a file. * - * 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. + * 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. - * - * 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.) - * - * 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. + * smgrimmedsync() -- Force the specified relation to stable storage. + * + * 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.) + * + * 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. */ void smgrimmedsync(SMgrRelation reln, ForkNumber forknum) |