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Postgres FD Implementation
Commit dfc7e7b7 authored by Neil Conway's avatar Neil Conway
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Code cleanup, mostly in the smgr: 

     - Update comment in IsReservedName() to the present day

     - Improve some variable & function names in commands/vacuum.c. I
       was planning to rewrite this to avoid lappend(), but since I
       still intend to do the list rewrite, there's no need for that.

     - Update some smgr comments which seemed to imply that we still
       forced all dirty pages to disk at commit-time.

     - Replace some #ifdef DIAGNOSTIC code with assertions.

     - Make the distinction between OS-level file descriptors and
       virtual file descriptors a little clearer in a few comments

     - Other minor comment improvements in the smgr code
parent 030f8e73
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Showing with 73 additions and 98 deletions
src/backend/catalog/catalog.c
View file @ dfc7e7b7
......@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.50 2003/11/29 19:51:42 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/catalog/catalog.c,v 1.51 2004/01/06 18:07:31 neilc Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -165,8 +165,9 @@ IsToastNamespace(Oid namespaceId)
* IsReservedName
* True iff name starts with the pg_ prefix.
*
* For some classes of objects, the prefix pg_ is reserved
* for system objects only.
* For some classes of objects, the prefix pg_ is reserved for
* system objects only. As of 7.3, this is now only true for
* schema names.
*/
bool
IsReservedName(const char *name)
......
src/backend/commands/analyze.c
View file @ dfc7e7b7
......@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.65 2003/11/29 19:51:47 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.66 2004/01/06 18:07:31 neilc Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -204,8 +204,9 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt)
}
/*
* Check that it's a plain table; we used to do this in getrels() but
* seems safer to check after we've locked the relation.
* Check that it's a plain table; we used to do this in
* get_rel_oids() but seems safer to check after we've locked the
* relation.
*/
if (onerel->rd_rel->relkind != RELKIND_RELATION)
{
......
src/backend/commands/vacuum.c
View file @ dfc7e7b7
......@@ -13,7 +13,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.269 2003/11/29 19:51:47 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/commands/vacuum.c,v 1.270 2004/01/06 18:07:31 neilc Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -108,7 +108,7 @@ static TransactionId FreezeLimit;
/* non-export function prototypes */
static List *getrels(const RangeVar *vacrel, const char *stmttype);
static List *get_rel_oids(const RangeVar *vacrel, const char *stmttype);
static void vac_update_dbstats(Oid dbid,
TransactionId vacuumXID,
TransactionId frozenXID);
......@@ -161,7 +161,7 @@ vacuum(VacuumStmt *vacstmt)
TransactionId initialOldestXmin = InvalidTransactionId;
TransactionId initialFreezeLimit = InvalidTransactionId;
bool all_rels;
List *vrl,
List *relations,
*cur;
if (vacstmt->verbose)
......@@ -216,7 +216,7 @@ vacuum(VacuumStmt *vacstmt)
all_rels = (vacstmt->relation == NULL);
/* Build list of relations to process (note this lives in vac_context) */
vrl = getrels(vacstmt->relation, stmttype);
relations = get_rel_oids(vacstmt->relation, stmttype);
/*
* Formerly, there was code here to prevent more than one VACUUM from
......@@ -282,7 +282,7 @@ vacuum(VacuumStmt *vacstmt)
/*
* Loop to process each selected relation.
*/
foreach(cur, vrl)
foreach(cur, relations)
{
Oid relid = lfirsto(cur);
......@@ -383,21 +383,21 @@ vacuum(VacuumStmt *vacstmt)
* per-relation transactions.
*/
static List *
getrels(const RangeVar *vacrel, const char *stmttype)
get_rel_oids(const RangeVar *vacrel, const char *stmttype)
{
List *vrl = NIL;
List *oid_list = NIL;
MemoryContext oldcontext;
if (vacrel)
{
/* Process specific relation */
/* Process a specific relation */
Oid relid;
relid = RangeVarGetRelid(vacrel, false);
/* Make a relation list entry for this guy */
oldcontext = MemoryContextSwitchTo(vac_context);
vrl = lappendo(vrl, relid);
oid_list = lappendo(oid_list, relid);
MemoryContextSwitchTo(oldcontext);
}
else
......@@ -421,7 +421,7 @@ getrels(const RangeVar *vacrel, const char *stmttype)
{
/* Make a relation list entry for this guy */
oldcontext = MemoryContextSwitchTo(vac_context);
vrl = lappendo(vrl, HeapTupleGetOid(tuple));
oid_list = lappendo(oid_list, HeapTupleGetOid(tuple));
MemoryContextSwitchTo(oldcontext);
}
......@@ -429,7 +429,7 @@ getrels(const RangeVar *vacrel, const char *stmttype)
heap_close(pgclass, AccessShareLock);
}
return vrl;
return oid_list;
}
/*
......@@ -818,8 +818,9 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
}
/*
* Check that it's a plain table; we used to do this in getrels() but
* seems safer to check after we've locked the relation.
* Check that it's a plain table; we used to do this in
* get_rel_oids() but seems safer to check after we've locked the
* relation.
*/
if (onerel->rd_rel->relkind != expected_relkind)
{
......
src/backend/storage/smgr/md.c
View file @ dfc7e7b7
......@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.99 2003/11/29 19:51:57 pgsql Exp $
* $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.100 2004/01/06 18:07:31 neilc Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -25,18 +25,15 @@
#include "utils/inval.h"
#include "utils/memutils.h"
#undef DIAGNOSTIC
/*
* The magnetic disk storage manager keeps track of open file descriptors
* in its own descriptor pool. This happens for two reasons. First, at
* transaction boundaries, we walk the list of descriptors and flush
* anything that we've dirtied in the current transaction. Second, we want
* to support relations larger than the OS' file size limit (often 2GBytes).
* In order to do that, we break relations up into chunks of < 2GBytes
* and store one chunk in each of several files that represent the relation.
* See the BLCKSZ and RELSEG_SIZE configuration constants in include/pg_config.h.
* The magnetic disk storage manager keeps track of open file
* descriptors in its own descriptor pool. This is done to make it
* easier to support relations that are larger than the operating
* system's file size limit (often 2GBytes). In order to do that, we
* we break relations up into chunks of < 2GBytes and store one chunk
* in each of several files that represent the relation. See the
* BLCKSZ and RELSEG_SIZE configuration constants in
* include/pg_config.h.
*
* The file descriptor stored in the relation cache (see RelationGetFile())
* is actually an index into the Md_fdvec array. -1 indicates not open.
......@@ -67,7 +64,7 @@ static MdfdVec *Md_fdvec = (MdfdVec *) NULL;
static int Md_Free = -1; /* head of freelist of unused fdvec
* entries */
static int CurFd = 0; /* first never-used fdvec index */
static MemoryContext MdCxt; /* context for all my allocations */
static MemoryContext MdCxt; /* context for all md.c allocations */
/* routines declared here */
static void mdclose_fd(int fd);
......@@ -84,11 +81,8 @@ static BlockNumber _mdnblocks(File file, Size blcksz);
/*
* mdinit() -- Initialize private state for magnetic disk storage manager.
*
* We keep a private table of all file descriptors. Whenever we do
* a write to one, we mark it dirty in our table. Whenever we force
* changes to disk, we mark the file descriptor clean. At transaction
* commit, we force changes to disk for all dirty file descriptors.
* This routine allocates and initializes the table.
* We keep a private table of all file descriptors. This routine
* allocates and initializes the table.
*
* Returns SM_SUCCESS or SM_FAIL with errno set as appropriate.
*/
......@@ -247,16 +241,13 @@ mdextend(Relation reln, BlockNumber blocknum, char *buffer)
#ifndef LET_OS_MANAGE_FILESIZE
seekpos = (long) (BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE)));
#ifdef DIAGNOSTIC
if (seekpos >= BLCKSZ * RELSEG_SIZE)
elog(FATAL, "seekpos too big");
#endif
Assert(seekpos < BLCKSZ * RELSEG_SIZE);
#else
seekpos = (long) (BLCKSZ * (blocknum));
#endif
/*
* Note: because caller obtained blocknum by calling mdnblocks, which
* Note: because caller obtained blocknum by calling _mdnblocks, which
* did a seek(SEEK_END), this seek is often redundant and will be
* optimized away by fd.c. It's not redundant, however, if there is a
* partial page at the end of the file. In that case we want to try
......@@ -282,10 +273,7 @@ mdextend(Relation reln, BlockNumber blocknum, char *buffer)
}
#ifndef LET_OS_MANAGE_FILESIZE
#ifdef DIAGNOSTIC
if (_mdnblocks(v->mdfd_vfd, BLCKSZ) > ((BlockNumber) RELSEG_SIZE))
elog(FATAL, "segment too big");
#endif
Assert(_mdnblocks(v->mdfd_vfd, BLCKSZ) <= ((BlockNumber) RELSEG_SIZE));
#endif
return SM_SUCCESS;
......@@ -335,11 +323,7 @@ mdopen(Relation reln)
Md_fdvec[vfd].mdfd_flags = (uint16) 0;
#ifndef LET_OS_MANAGE_FILESIZE
Md_fdvec[vfd].mdfd_chain = (MdfdVec *) NULL;
#ifdef DIAGNOSTIC
if (_mdnblocks(fd, BLCKSZ) > ((BlockNumber) RELSEG_SIZE))
elog(FATAL, "segment too big");
#endif
Assert(_mdnblocks(fd, BLCKSZ) <= ((BlockNumber) RELSEG_SIZE));
#endif
return vfd;
......@@ -348,7 +332,7 @@ mdopen(Relation reln)
/*
* mdclose() -- Close the specified relation, if it isn't closed already.
*
* AND FREE fd vector! It may be re-used for other relation!
* AND FREE fd vector! It may be re-used for other relations!
* reln should be flushed from cache after closing !..
*
* Returns SM_SUCCESS or SM_FAIL with errno set as appropriate.
......@@ -418,11 +402,7 @@ mdread(Relation reln, BlockNumber blocknum, char *buffer)
#ifndef LET_OS_MANAGE_FILESIZE
seekpos = (long) (BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE)));
#ifdef DIAGNOSTIC
if (seekpos >= BLCKSZ * RELSEG_SIZE)
elog(FATAL, "seekpos too big");
#endif
Assert(seekpos < BLCKSZ * RELSEG_SIZE);
#else
seekpos = (long) (BLCKSZ * (blocknum));
#endif
......@@ -466,10 +446,7 @@ mdwrite(Relation reln, BlockNumber blocknum, char *buffer)
#ifndef LET_OS_MANAGE_FILESIZE
seekpos = (long) (BLCKSZ * (blocknum % ((BlockNumber) RELSEG_SIZE)));
#ifdef DIAGNOSTIC
if (seekpos >= BLCKSZ * RELSEG_SIZE)
elog(FATAL, "seekpos too big");
#endif
Assert(seekpos < BLCKSZ * RELSEG_SIZE);
#else
seekpos = (long) (BLCKSZ * (blocknum));
#endif
......@@ -505,10 +482,7 @@ mdblindwrt(RelFileNode rnode,
#ifndef LET_OS_MANAGE_FILESIZE
seekpos = (long) (BLCKSZ * (blkno % ((BlockNumber) RELSEG_SIZE)));
#ifdef DIAGNOSTIC
if (seekpos >= BLCKSZ * RELSEG_SIZE)
elog(FATAL, "seekpos too big");
#endif
Assert(seekpos < BLCKSZ * RELSEG_SIZE);
#else
seekpos = (long) (BLCKSZ * (blkno));
#endif
......@@ -722,8 +696,6 @@ mdcommit(void)
/*
* mdabort() -- Abort a transaction.
*
* Changes need not be forced to disk at transaction abort.
*/
int
mdabort(void)
......@@ -748,7 +720,7 @@ mdsync(void)
}
/*
* _fdvec_alloc () -- grab a free (or new) md file descriptor vector.
* _fdvec_alloc() -- Grab a free (or new) md file descriptor vector.
*/
static int
_fdvec_alloc(void)
......@@ -802,7 +774,7 @@ _fdvec_alloc(void)
}
/*
* _fdvec_free () -- free md file descriptor vector.
* _fdvec_free() -- free md file descriptor vector.
*
*/
static
......@@ -853,19 +825,18 @@ _mdfd_openseg(Relation reln, BlockNumber segno, int oflags)
v->mdfd_flags = (uint16) 0;
#ifndef LET_OS_MANAGE_FILESIZE
v->mdfd_chain = (MdfdVec *) NULL;
#ifdef DIAGNOSTIC
if (_mdnblocks(fd, BLCKSZ) > ((BlockNumber) RELSEG_SIZE))
elog(FATAL, "segment too big");
#endif
Assert(_mdnblocks(fd, BLCKSZ) <= ((BlockNumber) RELSEG_SIZE));
#endif
/* all done */
return v;
}
/* Get the fd for the relation, opening it if it's not already open */
/*
* _mdfd_getrelnfd() -- Get the (virtual) fd for the relation,
* opening it if it's not already open
*
*/
static int
_mdfd_getrelnfd(Relation reln)
{
......@@ -882,8 +853,11 @@ _mdfd_getrelnfd(Relation reln)
return fd;
}
/* Find the segment of the relation holding the specified block */
/*
* _mdfd_getseg() -- Find the segment of the relation holding the
* specified block
*
*/
static MdfdVec *
_mdfd_getseg(Relation reln, BlockNumber blkno)
{
......@@ -942,7 +916,6 @@ _mdfd_getseg(Relation reln, BlockNumber blkno)
*
* The return value is the kernel descriptor, or -1 on failure.
*/
static int
_mdfd_blind_getseg(RelFileNode rnode, BlockNumber blkno)
{
......
src/backend/storage/smgr/smgr.c
View file @ dfc7e7b7
......@@ -11,7 +11,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.67 2003/12/12 18:45:09 petere Exp $
* $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.68 2004/01/06 18:07:31 neilc Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -382,7 +382,7 @@ smgrblindwrt(int16 which,
}
/*
* smgrnblocks() -- Calculate the number of POSTGRES blocks in the
* smgrnblocks() -- Calculate the number of blocks in the
* supplied relation.
*
* Returns the number of blocks on success, aborts the current
......@@ -411,8 +411,8 @@ smgrnblocks(int16 which, Relation reln)
}
/*
* smgrtruncate() -- Truncate supplied relation to a specified number
* of blocks
* smgrtruncate() -- Truncate supplied relation to the specified number
* of blocks
*
* Returns the number of blocks on success, aborts the current
* transaction on failure.
......@@ -444,7 +444,7 @@ smgrtruncate(int16 which, Relation reln, BlockNumber nblocks)
}
/*
* smgrDoPendingDeletes() -- take care of relation deletes at end of xact.
* smgrDoPendingDeletes() -- Take care of relation deletes at end of xact.
*/
int
smgrDoPendingDeletes(bool isCommit)
......@@ -494,7 +494,7 @@ smgrDoPendingDeletes(bool isCommit)
* smgrcommit() -- Prepare to commit changes made during the current
* transaction.
*
* This is called before we actually commit.
* This is called before we actually commit.
*/
int
smgrcommit(void)
......@@ -538,7 +538,7 @@ smgrabort(void)
}
/*
* Sync files to disk at checkpoint time.
* smgrsync() -- Sync files to disk at checkpoint time.
*/
int
smgrsync(void)
......
src/include/utils/rel.h
View file @ dfc7e7b7
......@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $PostgreSQL: pgsql/src/include/utils/rel.h,v 1.71 2003/11/29 22:41:16 pgsql Exp $
* $PostgreSQL: pgsql/src/include/utils/rel.h,v 1.72 2004/01/06 18:07:32 neilc Exp $
*
*-------------------------------------------------------------------------
*/
......@@ -104,7 +104,9 @@ typedef struct PgStat_Info
typedef struct RelationData
{
File rd_fd; /* open file descriptor, or -1 if none */
File rd_fd; /* open file descriptor, or -1 if
* none; this is NOT an operating
* system file descriptor */
RelFileNode rd_node; /* file node (physical identifier) */
BlockNumber rd_nblocks; /* number of blocks in rel */
BlockNumber rd_targblock; /* current insertion target block, or
......@@ -220,22 +222,21 @@ typedef Relation *RelationPtr;
/*
* RelationGetRelid
*
* returns the OID of the relation
* Returns the OID of the relation
*/
#define RelationGetRelid(relation) ((relation)->rd_id)
/*
* RelationGetFile
*
* Returns the open file descriptor for the rel
* Returns the open file descriptor for the rel, or -1 if
* none. This is NOT an operating system file descriptor; see md.c
* for more information
*/
#define RelationGetFile(relation) ((relation)->rd_fd)
/*
* RelationGetNumberOfAttributes
*
* Returns the number of attributes.
* Returns the number of attributes in a relation.
*/
#define RelationGetNumberOfAttributes(relation) ((relation)->rd_rel->relnatts)
......@@ -247,8 +248,7 @@ typedef Relation *RelationPtr;
/*
* RelationGetRelationName
*
* Returns the rel's name.
* Returns the rel's name.
*
* Note that the name is only unique within the containing namespace.
*/
......@@ -257,8 +257,7 @@ typedef Relation *RelationPtr;
/*
* RelationGetNamespace
*
* Returns the rel's namespace OID.
* Returns the rel's namespace OID.
*/
#define RelationGetNamespace(relation) \
((relation)->rd_rel->relnamespace)
......
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