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Diffstat (limited to 'src/include/access/multixact.h')
| -rw-r--r-- | src/include/access/multixact.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h new file mode 100644 index 0000000..6d72900 --- /dev/null +++ b/src/include/access/multixact.h @@ -0,0 +1,160 @@ +/* + * multixact.h + * + * PostgreSQL multi-transaction-log manager + * + * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group + * Portions Copyright (c) 1994, Regents of the University of California + * + * src/include/access/multixact.h + */ +#ifndef MULTIXACT_H +#define MULTIXACT_H + +#include "access/xlogreader.h" +#include "lib/stringinfo.h" + + +/* + * The first two MultiXactId values are reserved to store the truncation Xid + * and epoch of the first segment, so we start assigning multixact values from + * 2. + */ +#define InvalidMultiXactId ((MultiXactId) 0) +#define FirstMultiXactId ((MultiXactId) 1) +#define MaxMultiXactId ((MultiXactId) 0xFFFFFFFF) + +#define MultiXactIdIsValid(multi) ((multi) != InvalidMultiXactId) + +#define MaxMultiXactOffset ((MultiXactOffset) 0xFFFFFFFF) + +/* Number of SLRU buffers to use for multixact */ +#define NUM_MULTIXACTOFFSET_BUFFERS 8 +#define NUM_MULTIXACTMEMBER_BUFFERS 16 + +/* + * Possible multixact lock modes ("status"). The first four modes are for + * tuple locks (FOR KEY SHARE, FOR SHARE, FOR NO KEY UPDATE, FOR UPDATE); the + * next two are used for update and delete modes. + */ +typedef enum +{ + MultiXactStatusForKeyShare = 0x00, + MultiXactStatusForShare = 0x01, + MultiXactStatusForNoKeyUpdate = 0x02, + MultiXactStatusForUpdate = 0x03, + /* an update that doesn't touch "key" columns */ + MultiXactStatusNoKeyUpdate = 0x04, + /* other updates, and delete */ + MultiXactStatusUpdate = 0x05 +} MultiXactStatus; + +#define MaxMultiXactStatus MultiXactStatusUpdate + +/* does a status value correspond to a tuple update? */ +#define ISUPDATE_from_mxstatus(status) \ + ((status) > MultiXactStatusForUpdate) + + +typedef struct MultiXactMember +{ + TransactionId xid; + MultiXactStatus status; +} MultiXactMember; + + +/* ---------------- + * multixact-related XLOG entries + * ---------------- + */ + +#define XLOG_MULTIXACT_ZERO_OFF_PAGE 0x00 +#define XLOG_MULTIXACT_ZERO_MEM_PAGE 0x10 +#define XLOG_MULTIXACT_CREATE_ID 0x20 +#define XLOG_MULTIXACT_TRUNCATE_ID 0x30 + +typedef struct xl_multixact_create +{ + MultiXactId mid; /* new MultiXact's ID */ + MultiXactOffset moff; /* its starting offset in members file */ + int32 nmembers; /* number of member XIDs */ + MultiXactMember members[FLEXIBLE_ARRAY_MEMBER]; +} xl_multixact_create; + +#define SizeOfMultiXactCreate (offsetof(xl_multixact_create, members)) + +typedef struct xl_multixact_truncate +{ + Oid oldestMultiDB; + + /* to-be-truncated range of multixact offsets */ + MultiXactId startTruncOff; /* just for completeness' sake */ + MultiXactId endTruncOff; + + /* to-be-truncated range of multixact members */ + MultiXactOffset startTruncMemb; + MultiXactOffset endTruncMemb; +} xl_multixact_truncate; + +#define SizeOfMultiXactTruncate (sizeof(xl_multixact_truncate)) + + +extern MultiXactId MultiXactIdCreate(TransactionId xid1, + MultiXactStatus status1, TransactionId xid2, + MultiXactStatus status2); +extern MultiXactId MultiXactIdExpand(MultiXactId multi, TransactionId xid, + MultiXactStatus status); +extern MultiXactId MultiXactIdCreateFromMembers(int nmembers, + MultiXactMember *members); + +extern MultiXactId ReadNextMultiXactId(void); +extern bool MultiXactIdIsRunning(MultiXactId multi, bool isLockOnly); +extern void MultiXactIdSetOldestMember(void); +extern int GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **xids, + bool allow_old, bool isLockOnly); +extern bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2); +extern bool MultiXactIdPrecedesOrEquals(MultiXactId multi1, + MultiXactId multi2); + +extern void AtEOXact_MultiXact(void); +extern void AtPrepare_MultiXact(void); +extern void PostPrepare_MultiXact(TransactionId xid); + +extern Size MultiXactShmemSize(void); +extern void MultiXactShmemInit(void); +extern void BootStrapMultiXact(void); +extern void StartupMultiXact(void); +extern void TrimMultiXact(void); +extern void ShutdownMultiXact(void); +extern void SetMultiXactIdLimit(MultiXactId oldest_datminmxid, + Oid oldest_datoid, + bool is_startup); +extern void MultiXactGetCheckptMulti(bool is_shutdown, + MultiXactId *nextMulti, + MultiXactOffset *nextMultiOffset, + MultiXactId *oldestMulti, + Oid *oldestMultiDB); +extern void CheckPointMultiXact(void); +extern MultiXactId GetOldestMultiXactId(void); +extern void TruncateMultiXact(MultiXactId oldestMulti, Oid oldestMultiDB); +extern void MultiXactSetNextMXact(MultiXactId nextMulti, + MultiXactOffset nextMultiOffset); +extern void MultiXactAdvanceNextMXact(MultiXactId minMulti, + MultiXactOffset minMultiOffset); +extern void MultiXactAdvanceOldest(MultiXactId oldestMulti, Oid oldestMultiDB); +extern int MultiXactMemberFreezeThreshold(void); + +extern void multixact_twophase_recover(TransactionId xid, uint16 info, + void *recdata, uint32 len); +extern void multixact_twophase_postcommit(TransactionId xid, uint16 info, + void *recdata, uint32 len); +extern void multixact_twophase_postabort(TransactionId xid, uint16 info, + void *recdata, uint32 len); + +extern void multixact_redo(XLogReaderState *record); +extern void multixact_desc(StringInfo buf, XLogReaderState *record); +extern const char *multixact_identify(uint8 info); +extern char *mxid_to_string(MultiXactId multi, int nmembers, + MultiXactMember *members); + +#endif /* MULTIXACT_H */ |