mirror of
https://github.com/postgres/postgres.git
synced 2025-11-10 17:42:29 +03:00
Postgres95 1.01 Distribution - Virgin Sources
This commit is contained in:
Marc G. Fournier
663
src/backend/access/transam/transsup.c
Normal file
663
src/backend/access/transam/transsup.c
Normal file
@@ -0,0 +1,663 @@
|
||||
/*-------------------------------------------------------------------------
|
||||
*
|
||||
* transsup.c--
|
||||
* postgres transaction access method support code
|
||||
*
|
||||
* Copyright (c) 1994, Regents of the University of California
|
||||
*
|
||||
*
|
||||
* IDENTIFICATION
|
||||
* $Header: /cvsroot/pgsql/src/backend/access/transam/Attic/transsup.c,v 1.1.1.1 1996/07/09 06:21:13 scrappy Exp $
|
||||
*
|
||||
* NOTES
|
||||
* This file contains support functions for the high
|
||||
* level access method interface routines found in transam.c
|
||||
*
|
||||
*-------------------------------------------------------------------------
|
||||
*/
|
||||
#include "postgres.h"
|
||||
|
||||
#include "machine.h" /* in port/ directory (needed for BLCKSZ) */
|
||||
|
||||
#include "storage/buf.h"
|
||||
#include "storage/bufmgr.h"
|
||||
|
||||
#include "utils/rel.h"
|
||||
#include "utils/elog.h"
|
||||
#include "utils/memutils.h"
|
||||
#include "utils/nabstime.h"
|
||||
|
||||
#include "catalog/heap.h"
|
||||
#include "access/transam.h" /* where the declarations go */
|
||||
#include "access/xact.h" /* where the declarations go */
|
||||
|
||||
#include "storage/smgr.h"
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* general support routines
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
|
||||
/* --------------------------------
|
||||
* AmiTransactionOverride
|
||||
*
|
||||
* This function is used to manipulate the bootstrap flag.
|
||||
* --------------------------------
|
||||
*/
|
||||
void
|
||||
AmiTransactionOverride(bool flag)
|
||||
{
|
||||
AMI_OVERRIDE = flag;
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransComputeBlockNumber
|
||||
* --------------------------------
|
||||
*/
|
||||
void
|
||||
TransComputeBlockNumber(Relation relation, /* relation to test */
|
||||
TransactionId transactionId, /* transaction id to test */
|
||||
BlockNumber *blockNumberOutP)
|
||||
{
|
||||
long itemsPerBlock;
|
||||
|
||||
/* ----------------
|
||||
* we calculate the block number of our transaction
|
||||
* by dividing the transaction id by the number of
|
||||
* transaction things per block.
|
||||
* ----------------
|
||||
*/
|
||||
if (relation == LogRelation)
|
||||
itemsPerBlock = TP_NumXidStatusPerBlock;
|
||||
else if (relation == TimeRelation)
|
||||
itemsPerBlock = TP_NumTimePerBlock;
|
||||
else
|
||||
elog(WARN, "TransComputeBlockNumber: unknown relation");
|
||||
|
||||
/* ----------------
|
||||
* warning! if the transaction id's get too large
|
||||
* then a BlockNumber may not be large enough to hold the results
|
||||
* of our division.
|
||||
*
|
||||
* XXX this will all vanish soon when we implement an improved
|
||||
* transaction id schema -cim 3/23/90
|
||||
*
|
||||
* This has vanished now that xid's are 4 bytes (no longer 5).
|
||||
* -mer 5/24/92
|
||||
* ----------------
|
||||
*/
|
||||
(*blockNumberOutP) = transactionId / itemsPerBlock;
|
||||
}
|
||||
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* trans block support routines
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockGetLastTransactionIdStatus
|
||||
*
|
||||
* This returns the status and transaction id of the last
|
||||
* transaction information recorded on the given TransBlock.
|
||||
* --------------------------------
|
||||
*/
|
||||
|
||||
XidStatus
|
||||
TransBlockGetLastTransactionIdStatus(Block tblock,
|
||||
TransactionId baseXid,
|
||||
TransactionId *returnXidP)
|
||||
{
|
||||
Index index;
|
||||
Index maxIndex;
|
||||
bits8 bit1;
|
||||
bits8 bit2;
|
||||
BitIndex offset;
|
||||
XidStatus xstatus;
|
||||
|
||||
/* ----------------
|
||||
* sanity check
|
||||
* ----------------
|
||||
*/
|
||||
Assert((tblock != NULL));
|
||||
|
||||
/* ----------------
|
||||
* search downward from the top of the block data, looking
|
||||
* for the first Non-in progress transaction status. Since we
|
||||
* are scanning backward, this will be last recorded transaction
|
||||
* status on the block.
|
||||
* ----------------
|
||||
*/
|
||||
maxIndex = TP_NumXidStatusPerBlock;
|
||||
for (index = maxIndex-1; index>=0; index--) {
|
||||
offset = BitIndexOf(index);
|
||||
bit1 = ((bits8) BitArrayBitIsSet((BitArray) tblock, offset++)) << 1;
|
||||
bit2 = (bits8) BitArrayBitIsSet((BitArray) tblock, offset);
|
||||
|
||||
xstatus = (bit1 | bit2) ;
|
||||
|
||||
/* ----------------
|
||||
* here we have the status of some transaction, so test
|
||||
* if the status is recorded as "in progress". If so, then
|
||||
* we save the transaction id in the place specified by the caller.
|
||||
* ----------------
|
||||
*/
|
||||
if (xstatus != XID_INPROGRESS) {
|
||||
if (returnXidP != NULL) {
|
||||
TransactionIdStore(baseXid, returnXidP);
|
||||
TransactionIdAdd(returnXidP, index);
|
||||
}
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/* ----------------
|
||||
* if we get here and index is 0 it means we couldn't find
|
||||
* a non-inprogress transaction on the block. For now we just
|
||||
* return this info to the user. They can check if the return
|
||||
* status is "in progress" to know this condition has arisen.
|
||||
* ----------------
|
||||
*/
|
||||
if (index == 0) {
|
||||
if (returnXidP != NULL)
|
||||
TransactionIdStore(baseXid, returnXidP);
|
||||
}
|
||||
|
||||
/* ----------------
|
||||
* return the status to the user
|
||||
* ----------------
|
||||
*/
|
||||
return xstatus;
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockGetXidStatus
|
||||
*
|
||||
* This returns the status of the desired transaction
|
||||
* --------------------------------
|
||||
*/
|
||||
|
||||
XidStatus
|
||||
TransBlockGetXidStatus(Block tblock,
|
||||
TransactionId transactionId)
|
||||
{
|
||||
Index index;
|
||||
bits8 bit1;
|
||||
bits8 bit2;
|
||||
BitIndex offset;
|
||||
|
||||
/* ----------------
|
||||
* sanity check
|
||||
* ----------------
|
||||
*/
|
||||
if (tblock == NULL) {
|
||||
return XID_INVALID;
|
||||
}
|
||||
|
||||
/* ----------------
|
||||
* calculate the index into the transaction data where
|
||||
* our transaction status is located
|
||||
*
|
||||
* XXX this will be replaced soon when we move to the
|
||||
* new transaction id scheme -cim 3/23/90
|
||||
*
|
||||
* The old system has now been replaced. -mer 5/24/92
|
||||
* ----------------
|
||||
*/
|
||||
index = transactionId % TP_NumXidStatusPerBlock;
|
||||
|
||||
/* ----------------
|
||||
* get the data at the specified index
|
||||
* ----------------
|
||||
*/
|
||||
offset = BitIndexOf(index);
|
||||
bit1 = ((bits8) BitArrayBitIsSet((BitArray) tblock, offset++)) << 1;
|
||||
bit2 = (bits8) BitArrayBitIsSet((BitArray) tblock, offset);
|
||||
|
||||
/* ----------------
|
||||
* return the transaction status to the caller
|
||||
* ----------------
|
||||
*/
|
||||
return (XidStatus)
|
||||
(bit1 | bit2);
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockSetXidStatus
|
||||
*
|
||||
* This sets the status of the desired transaction
|
||||
* --------------------------------
|
||||
*/
|
||||
void
|
||||
TransBlockSetXidStatus(Block tblock,
|
||||
TransactionId transactionId,
|
||||
XidStatus xstatus)
|
||||
{
|
||||
Index index;
|
||||
BitIndex offset;
|
||||
|
||||
/* ----------------
|
||||
* sanity check
|
||||
* ----------------
|
||||
*/
|
||||
if (tblock == NULL)
|
||||
return;
|
||||
|
||||
/* ----------------
|
||||
* calculate the index into the transaction data where
|
||||
* we sould store our transaction status.
|
||||
*
|
||||
* XXX this will be replaced soon when we move to the
|
||||
* new transaction id scheme -cim 3/23/90
|
||||
*
|
||||
* The new scheme is here -mer 5/24/92
|
||||
* ----------------
|
||||
*/
|
||||
index = transactionId % TP_NumXidStatusPerBlock;
|
||||
|
||||
offset = BitIndexOf(index);
|
||||
|
||||
/* ----------------
|
||||
* store the transaction value at the specified offset
|
||||
* ----------------
|
||||
*/
|
||||
switch(xstatus) {
|
||||
case XID_COMMIT: /* set 10 */
|
||||
BitArraySetBit((BitArray) tblock, offset);
|
||||
BitArrayClearBit((BitArray) tblock, offset + 1);
|
||||
break;
|
||||
case XID_ABORT: /* set 01 */
|
||||
BitArrayClearBit((BitArray) tblock, offset);
|
||||
BitArraySetBit((BitArray) tblock, offset + 1);
|
||||
break;
|
||||
case XID_INPROGRESS: /* set 00 */
|
||||
BitArrayClearBit((BitArray) tblock, offset);
|
||||
BitArrayClearBit((BitArray) tblock, offset + 1);
|
||||
break;
|
||||
default:
|
||||
elog(NOTICE,
|
||||
"TransBlockSetXidStatus: invalid status: %d (ignored)",
|
||||
xstatus);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockGetCommitTime
|
||||
*
|
||||
* This returns the transaction commit time for the
|
||||
* specified transaction id in the trans block.
|
||||
* --------------------------------
|
||||
*/
|
||||
AbsoluteTime
|
||||
TransBlockGetCommitTime(Block tblock,
|
||||
TransactionId transactionId)
|
||||
{
|
||||
Index index;
|
||||
AbsoluteTime *timeArray;
|
||||
|
||||
/* ----------------
|
||||
* sanity check
|
||||
* ----------------
|
||||
*/
|
||||
if (tblock == NULL)
|
||||
return INVALID_ABSTIME;
|
||||
|
||||
/* ----------------
|
||||
* calculate the index into the transaction data where
|
||||
* our transaction commit time is located
|
||||
*
|
||||
* XXX this will be replaced soon when we move to the
|
||||
* new transaction id scheme -cim 3/23/90
|
||||
*
|
||||
* The new scheme is here. -mer 5/24/92
|
||||
* ----------------
|
||||
*/
|
||||
index = transactionId % TP_NumTimePerBlock;
|
||||
|
||||
/* ----------------
|
||||
* return the commit time to the caller
|
||||
* ----------------
|
||||
*/
|
||||
timeArray = (AbsoluteTime *) tblock;
|
||||
return (AbsoluteTime)
|
||||
timeArray[ index ];
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockSetCommitTime
|
||||
*
|
||||
* This sets the commit time of the specified transaction
|
||||
* --------------------------------
|
||||
*/
|
||||
void
|
||||
TransBlockSetCommitTime(Block tblock,
|
||||
TransactionId transactionId,
|
||||
AbsoluteTime commitTime)
|
||||
{
|
||||
Index index;
|
||||
AbsoluteTime *timeArray;
|
||||
|
||||
/* ----------------
|
||||
* sanity check
|
||||
* ----------------
|
||||
*/
|
||||
if (tblock == NULL)
|
||||
return;
|
||||
|
||||
|
||||
/* ----------------
|
||||
* calculate the index into the transaction data where
|
||||
* we sould store our transaction status.
|
||||
*
|
||||
* XXX this will be replaced soon when we move to the
|
||||
* new transaction id scheme -cim 3/23/90
|
||||
*
|
||||
* The new scheme is here. -mer 5/24/92
|
||||
* ----------------
|
||||
*/
|
||||
index = transactionId % TP_NumTimePerBlock;
|
||||
|
||||
/* ----------------
|
||||
* store the transaction commit time at the specified index
|
||||
* ----------------
|
||||
*/
|
||||
timeArray = (AbsoluteTime *) tblock;
|
||||
timeArray[ index ] = commitTime;
|
||||
}
|
||||
|
||||
/* ----------------------------------------------------------------
|
||||
* transam i/o support routines
|
||||
* ----------------------------------------------------------------
|
||||
*/
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockNumberGetXidStatus
|
||||
* --------------------------------
|
||||
*/
|
||||
XidStatus
|
||||
TransBlockNumberGetXidStatus(Relation relation,
|
||||
BlockNumber blockNumber,
|
||||
TransactionId xid,
|
||||
bool *failP)
|
||||
{
|
||||
Buffer buffer; /* buffer associated with block */
|
||||
Block block; /* block containing xstatus */
|
||||
XidStatus xstatus; /* recorded status of xid */
|
||||
bool localfail; /* bool used if failP = NULL */
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY place a read lock on the log relation
|
||||
* That someday is today 5 Aug 1991 -mer
|
||||
* ----------------
|
||||
*/
|
||||
RelationSetLockForRead(relation);
|
||||
|
||||
/* ----------------
|
||||
* get the page containing the transaction information
|
||||
* ----------------
|
||||
*/
|
||||
buffer = ReadBuffer(relation, blockNumber);
|
||||
block = BufferGetBlock(buffer);
|
||||
|
||||
/* ----------------
|
||||
* get the status from the block. note, for now we always
|
||||
* return false in failP.
|
||||
* ----------------
|
||||
*/
|
||||
if (failP == NULL)
|
||||
failP = &localfail;
|
||||
(*failP) = false;
|
||||
|
||||
xstatus = TransBlockGetXidStatus(block, xid);
|
||||
|
||||
/* ----------------
|
||||
* release the buffer and return the status
|
||||
* ----------------
|
||||
*/
|
||||
ReleaseBuffer(buffer);
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY release our lock on the log relation
|
||||
* ----------------
|
||||
*/
|
||||
RelationUnsetLockForRead(relation);
|
||||
|
||||
return
|
||||
xstatus;
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockNumberSetXidStatus
|
||||
* --------------------------------
|
||||
*/
|
||||
void
|
||||
TransBlockNumberSetXidStatus(Relation relation,
|
||||
BlockNumber blockNumber,
|
||||
TransactionId xid,
|
||||
XidStatus xstatus,
|
||||
bool *failP)
|
||||
{
|
||||
Buffer buffer; /* buffer associated with block */
|
||||
Block block; /* block containing xstatus */
|
||||
bool localfail; /* bool used if failP = NULL */
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY gain exclusive access to the log relation
|
||||
*
|
||||
* That someday is today 5 Aug 1991 -mer
|
||||
* ----------------
|
||||
*/
|
||||
RelationSetLockForWrite(relation);
|
||||
|
||||
/* ----------------
|
||||
* get the block containing the transaction status
|
||||
* ----------------
|
||||
*/
|
||||
buffer = ReadBuffer(relation, blockNumber);
|
||||
block = BufferGetBlock(buffer);
|
||||
|
||||
/* ----------------
|
||||
* attempt to update the status of the transaction on the block.
|
||||
* if we are successful, write the block. otherwise release the buffer.
|
||||
* note, for now we always return false in failP.
|
||||
* ----------------
|
||||
*/
|
||||
if (failP == NULL)
|
||||
failP = &localfail;
|
||||
(*failP) = false;
|
||||
|
||||
TransBlockSetXidStatus(block, xid, xstatus);
|
||||
|
||||
if ((*failP) == false)
|
||||
WriteBuffer(buffer);
|
||||
else
|
||||
ReleaseBuffer(buffer);
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY release our lock on the log relation
|
||||
* ----------------
|
||||
*/
|
||||
RelationUnsetLockForWrite(relation);
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockNumberGetCommitTime
|
||||
* --------------------------------
|
||||
*/
|
||||
AbsoluteTime
|
||||
TransBlockNumberGetCommitTime(Relation relation,
|
||||
BlockNumber blockNumber,
|
||||
TransactionId xid,
|
||||
bool *failP)
|
||||
{
|
||||
Buffer buffer; /* buffer associated with block */
|
||||
Block block; /* block containing commit time */
|
||||
bool localfail; /* bool used if failP = NULL */
|
||||
AbsoluteTime xtime; /* commit time */
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY place a read lock on the time relation
|
||||
*
|
||||
* That someday is today 5 Aug. 1991 -mer
|
||||
* ----------------
|
||||
*/
|
||||
RelationSetLockForRead(relation);
|
||||
|
||||
/* ----------------
|
||||
* get the block containing the transaction information
|
||||
* ----------------
|
||||
*/
|
||||
buffer = ReadBuffer(relation, blockNumber);
|
||||
block = BufferGetBlock(buffer);
|
||||
|
||||
/* ----------------
|
||||
* get the commit time from the block
|
||||
* note, for now we always return false in failP.
|
||||
* ----------------
|
||||
*/
|
||||
if (failP == NULL)
|
||||
failP = &localfail;
|
||||
(*failP) = false;
|
||||
|
||||
xtime = TransBlockGetCommitTime(block, xid);
|
||||
|
||||
/* ----------------
|
||||
* release the buffer and return the commit time
|
||||
* ----------------
|
||||
*/
|
||||
ReleaseBuffer(buffer);
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY release our lock on the time relation
|
||||
* ----------------
|
||||
*/
|
||||
RelationUnsetLockForRead(relation);
|
||||
|
||||
if ((*failP) == false)
|
||||
return xtime;
|
||||
else
|
||||
return INVALID_ABSTIME;
|
||||
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransBlockNumberSetCommitTime
|
||||
* --------------------------------
|
||||
*/
|
||||
void
|
||||
TransBlockNumberSetCommitTime(Relation relation,
|
||||
BlockNumber blockNumber,
|
||||
TransactionId xid,
|
||||
AbsoluteTime xtime,
|
||||
bool *failP)
|
||||
{
|
||||
Buffer buffer; /* buffer associated with block */
|
||||
Block block; /* block containing commit time */
|
||||
bool localfail; /* bool used if failP = NULL */
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY gain exclusive access to the time relation
|
||||
*
|
||||
* That someday is today 5 Aug. 1991 -mer
|
||||
* ----------------
|
||||
*/
|
||||
RelationSetLockForWrite(relation);
|
||||
|
||||
/* ----------------
|
||||
* get the block containing our commit time
|
||||
* ----------------
|
||||
*/
|
||||
buffer = ReadBuffer(relation, blockNumber);
|
||||
block = BufferGetBlock(buffer);
|
||||
|
||||
/* ----------------
|
||||
* attempt to update the commit time of the transaction on the block.
|
||||
* if we are successful, write the block. otherwise release the buffer.
|
||||
* note, for now we always return false in failP.
|
||||
* ----------------
|
||||
*/
|
||||
if (failP == NULL)
|
||||
failP = &localfail;
|
||||
(*failP) = false;
|
||||
|
||||
TransBlockSetCommitTime(block, xid, xtime);
|
||||
|
||||
if ((*failP) == false)
|
||||
WriteBuffer(buffer);
|
||||
else
|
||||
ReleaseBuffer(buffer);
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY release our lock on the time relation
|
||||
* ----------------
|
||||
*/
|
||||
RelationUnsetLockForWrite(relation);
|
||||
|
||||
}
|
||||
|
||||
/* --------------------------------
|
||||
* TransGetLastRecordedTransaction
|
||||
* --------------------------------
|
||||
*/
|
||||
void
|
||||
TransGetLastRecordedTransaction(Relation relation,
|
||||
TransactionId xid, /* return: transaction id */
|
||||
bool *failP)
|
||||
{
|
||||
BlockNumber blockNumber; /* block number */
|
||||
Buffer buffer; /* buffer associated with block */
|
||||
Block block; /* block containing xid status */
|
||||
BlockNumber n; /* number of blocks in the relation */
|
||||
TransactionId baseXid;
|
||||
|
||||
(*failP) = false;
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY gain exclusive access to the log relation
|
||||
*
|
||||
* That someday is today 5 Aug. 1991 -mer
|
||||
* It looks to me like we only need to set a read lock here, despite
|
||||
* the above comment about exclusive access. The block is never
|
||||
* actually written into, we only check status bits.
|
||||
* ----------------
|
||||
*/
|
||||
RelationSetLockForRead(relation);
|
||||
|
||||
/* ----------------
|
||||
* we assume the last block of the log contains the last
|
||||
* recorded transaction. If the relation is empty we return
|
||||
* failure to the user.
|
||||
* ----------------
|
||||
*/
|
||||
n = RelationGetNumberOfBlocks(relation);
|
||||
if (n == 0) {
|
||||
(*failP) = true;
|
||||
return;
|
||||
}
|
||||
|
||||
/* ----------------
|
||||
* get the block containing the transaction information
|
||||
* ----------------
|
||||
*/
|
||||
blockNumber = n-1;
|
||||
buffer = ReadBuffer(relation, blockNumber);
|
||||
block = BufferGetBlock(buffer);
|
||||
|
||||
/* ----------------
|
||||
* get the last xid on the block
|
||||
* ----------------
|
||||
*/
|
||||
baseXid = blockNumber * TP_NumXidStatusPerBlock;
|
||||
|
||||
/* XXX ???? xid won't get returned! - AY '94 */
|
||||
(void) TransBlockGetLastTransactionIdStatus(block, baseXid, &xid);
|
||||
|
||||
ReleaseBuffer(buffer);
|
||||
|
||||
/* ----------------
|
||||
* SOMEDAY release our lock on the log relation
|
||||
* ----------------
|
||||
*/
|
||||
RelationUnsetLockForRead(relation);
|
||||
}
|
||||
Reference in New Issue
Block a user