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Diffstat (limited to 'src/backend/access/transam/transam.c')
| -rw-r--r-- | src/backend/access/transam/transam.c | 318 |
1 files changed, 0 insertions, 318 deletions
diff --git a/src/backend/access/transam/transam.c b/src/backend/access/transam/transam.c deleted file mode 100644 index c4ca0c7071b..00000000000 --- a/src/backend/access/transam/transam.c +++ /dev/null @@ -1,318 +0,0 @@ -/*------------------------------------------------------------------------- - * - * transam.c - * postgres transaction log interface routines - * - * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group - * Portions Copyright (c) 1994, Regents of the University of California - * - * - * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/transam/transam.c,v 1.53 2002/06/20 20:29:25 momjian Exp $ - * - * NOTES - * This file contains the high level access-method interface to the - * transaction system. - * - *------------------------------------------------------------------------- - */ - -#include "postgres.h" - -#include "access/clog.h" -#include "access/transam.h" - - -/* ---------------- - * Flag indicating that we are bootstrapping. - * - * Transaction ID generation is disabled during bootstrap; we just use - * BootstrapTransactionId. Also, the transaction ID status-check routines - * are short-circuited; they claim that BootstrapTransactionId has already - * committed, allowing tuples already inserted to be seen immediately. - * ---------------- - */ -bool AMI_OVERRIDE = false; - - -static bool TransactionLogTest(TransactionId transactionId, XidStatus status); -static void TransactionLogUpdate(TransactionId transactionId, - XidStatus status); - -/* ---------------- - * Single-item cache for results of TransactionLogTest. - * ---------------- - */ -static TransactionId cachedTestXid = InvalidTransactionId; -static XidStatus cachedTestXidStatus; - - -/* ---------------------------------------------------------------- - * postgres log access method interface - * - * TransactionLogTest - * TransactionLogUpdate - * ---------------------------------------------------------------- - */ - -/* -------------------------------- - * TransactionLogTest - * -------------------------------- - */ - -static bool /* true/false: does transaction id have - * specified status? */ -TransactionLogTest(TransactionId transactionId, /* transaction id to test */ - XidStatus status) /* transaction status */ -{ - XidStatus xidstatus; /* recorded status of xid */ - - /* - * Before going to the commit log manager, check our single item cache - * to see if we didn't just check the transaction status a moment ago. - */ - if (TransactionIdEquals(transactionId, cachedTestXid)) - return (status == cachedTestXidStatus); - - /* - * Also, check to see if the transaction ID is a permanent one. - */ - if (!TransactionIdIsNormal(transactionId)) - { - if (TransactionIdEquals(transactionId, BootstrapTransactionId)) - return (status == TRANSACTION_STATUS_COMMITTED); - if (TransactionIdEquals(transactionId, FrozenTransactionId)) - return (status == TRANSACTION_STATUS_COMMITTED); - return (status == TRANSACTION_STATUS_ABORTED); - } - - /* - * Get the status. - */ - xidstatus = TransactionIdGetStatus(transactionId); - - /* - * DO NOT cache status for unfinished transactions! - */ - if (xidstatus != TRANSACTION_STATUS_IN_PROGRESS) - { - TransactionIdStore(transactionId, &cachedTestXid); - cachedTestXidStatus = xidstatus; - } - - return (status == xidstatus); -} - -/* -------------------------------- - * TransactionLogUpdate - * -------------------------------- - */ -static void -TransactionLogUpdate(TransactionId transactionId, /* trans id to update */ - XidStatus status) /* new trans status */ -{ - /* - * update the commit log - */ - TransactionIdSetStatus(transactionId, status); - - /* - * update (invalidate) our single item TransactionLogTest cache. - */ - TransactionIdStore(transactionId, &cachedTestXid); - cachedTestXidStatus = status; -} - -/* -------------------------------- - * AmiTransactionOverride - * - * This function is used to manipulate the bootstrap flag. - * -------------------------------- - */ -void -AmiTransactionOverride(bool flag) -{ - AMI_OVERRIDE = flag; -} - -/* ---------------------------------------------------------------- - * Interface functions - * - * TransactionId DidCommit - * TransactionId DidAbort - * TransactionId IsInProgress - * ======== - * these functions test the transaction status of - * a specified transaction id. - * - * TransactionId Commit - * TransactionId Abort - * ======== - * these functions set the transaction status - * of the specified xid. - * - * ---------------------------------------------------------------- - */ - -/* -------------------------------- - * TransactionId DidCommit - * TransactionId DidAbort - * TransactionId IsInProgress - * -------------------------------- - */ - -/* - * TransactionIdDidCommit - * True iff transaction associated with the identifier did commit. - * - * Note: - * Assumes transaction identifier is valid. - */ -bool /* true if given transaction committed */ -TransactionIdDidCommit(TransactionId transactionId) -{ - if (AMI_OVERRIDE) - { - Assert(transactionId == BootstrapTransactionId); - return true; - } - - return TransactionLogTest(transactionId, TRANSACTION_STATUS_COMMITTED); -} - -/* - * TransactionIdDidAbort - * True iff transaction associated with the identifier did abort. - * - * Note: - * Assumes transaction identifier is valid. - */ -bool /* true if given transaction aborted */ -TransactionIdDidAbort(TransactionId transactionId) -{ - if (AMI_OVERRIDE) - { - Assert(transactionId == BootstrapTransactionId); - return false; - } - - return TransactionLogTest(transactionId, TRANSACTION_STATUS_ABORTED); -} - -/* - * Now this func in shmem.c and gives quality answer by scanning - * PGPROC structures of all running backend. - vadim 11/26/96 - * - * Old comments: - * true if given transaction has neither committed nor aborted - */ -#ifdef NOT_USED -bool -TransactionIdIsInProgress(TransactionId transactionId) -{ - if (AMI_OVERRIDE) - { - Assert(transactionId == BootstrapTransactionId); - return false; - } - - return TransactionLogTest(transactionId, TRANSACTION_STATUS_IN_PROGRESS); -} -#endif /* NOT_USED */ - -/* -------------------------------- - * TransactionId Commit - * TransactionId Abort - * -------------------------------- - */ - -/* - * TransactionIdCommit - * Commits the transaction associated with the identifier. - * - * Note: - * Assumes transaction identifier is valid. - */ -void -TransactionIdCommit(TransactionId transactionId) -{ - TransactionLogUpdate(transactionId, TRANSACTION_STATUS_COMMITTED); -} - -/* - * TransactionIdAbort - * Aborts the transaction associated with the identifier. - * - * Note: - * Assumes transaction identifier is valid. - */ -void -TransactionIdAbort(TransactionId transactionId) -{ - TransactionLogUpdate(transactionId, TRANSACTION_STATUS_ABORTED); -} - - -/* - * TransactionIdPrecedes --- is id1 logically < id2? - */ -bool -TransactionIdPrecedes(TransactionId id1, TransactionId id2) -{ - /* - * If either ID is a permanent XID then we can just do unsigned - * comparison. If both are normal, do a modulo-2^31 comparison. - */ - int32 diff; - - if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2)) - return (id1 < id2); - - diff = (int32) (id1 - id2); - return (diff < 0); -} - -/* - * TransactionIdPrecedesOrEquals --- is id1 logically <= id2? - */ -bool -TransactionIdPrecedesOrEquals(TransactionId id1, TransactionId id2) -{ - int32 diff; - - if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2)) - return (id1 <= id2); - - diff = (int32) (id1 - id2); - return (diff <= 0); -} - -/* - * TransactionIdFollows --- is id1 logically > id2? - */ -bool -TransactionIdFollows(TransactionId id1, TransactionId id2) -{ - int32 diff; - - if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2)) - return (id1 > id2); - - diff = (int32) (id1 - id2); - return (diff > 0); -} - -/* - * TransactionIdFollowsOrEquals --- is id1 logically >= id2? - */ -bool -TransactionIdFollowsOrEquals(TransactionId id1, TransactionId id2) -{ - int32 diff; - - if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2)) - return (id1 >= id2); - - diff = (int32) (id1 - id2); - return (diff >= 0); -} |