pglogrepl

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 Go to latest Published: Mar 7, 2024 License: MIT Imports: 12 Imported by: 91

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pglogrepl

pglogrepl is a Go package for PostgreSQL logical replication.

pglogrepl uses package github.com/jackc/pgx/v5/pgconn as its underlying PostgreSQL connection.

Proper use of this package requires understanding the underlying PostgreSQL concepts. See https://www.postgresql.org/docs/current/protocol-replication.html.

Example

In example/pglogrepl_demo, there is an example demo program that connects to a database and logs all messages sent over logical replication. In example/pgphysrepl_demo, there is an example demo program that connects to a database and logs all messages sent over physical replication.

Testing

Testing requires a user with replication permission, a database to replicate, access allowed in pg_hba.conf, and logical replication enabled in postgresql.conf.

Create a database:

create database pglogrepl;

Create a user:

create user pglogrepl with replication password 'secret';

If you're using PostgreSQL 15 or newer grant access to the public schema, just for these tests:

grant all on schema public to pglogrepl;

Add a replication line to your pg_hba.conf:

host replication pglogrepl 127.0.0.1/32 md5

Change the following settings in your postgresql.conf:

wal_level=logical
max_wal_senders=5
max_replication_slots=5

To run the tests set PGLOGREPL_TEST_CONN_STRING environment variable with a replication connection string (URL or DSN).

Since the base backup would request postgres to create a backup tar and stream it, this test cn be disabled with

PGLOGREPL_SKIP_BASE_BACKUP=true

Example:

PGLOGREPL_TEST_CONN_STRING=postgres://pglogrepl:secret@127.0.0.1/pglogrepl?replication=database go test

Documentation

Overview

Package pglogrepl implements PostgreSQL logical replication client functionality.

pglogrepl uses package github.com/jackc/pgconn as its underlying PostgreSQL connection. Use pgconn to establish a connection to PostgreSQL and then use the pglogrepl functions on that connection.

Proper use of this package requires understanding the underlying PostgreSQL concepts. See https://www.postgresql.org/docs/current/protocol-replication.html.

Index

Constants

View Source 
const (
	TupleDataTypeNull   = uint8('n')
	TupleDataTypeToast  = uint8('u')
	TupleDataTypeText   = uint8('t')
	TupleDataTypeBinary = uint8('b')
)

List of types of data in a tuple.

View Source 
const (
	UpdateMessageTupleTypeNone = uint8(0)
	UpdateMessageTupleTypeKey  = uint8('K')
	UpdateMessageTupleTypeOld  = uint8('O')
	UpdateMessageTupleTypeNew  = uint8('N')
)

List of types of UpdateMessage tuples.

View Source 
const (
	DeleteMessageTupleTypeKey = uint8('K')
	DeleteMessageTupleTypeOld = uint8('O')
)

List of types of DeleteMessage tuples.

View Source 
const (
	TruncateOptionCascade = uint8(1) << iota
	TruncateOptionRestartIdentity
)

List of truncate options.

View Source 
const (
	XLogDataByteID                = 'w'
	PrimaryKeepaliveMessageByteID = 'k'
	StandbyStatusUpdateByteID     = 'r'
)

Variables

This section is empty.

Functions

func DropReplicationSlot 

func DropReplicationSlot(ctx context.Context, conn *pgconn.PgConn, slotName string, options DropReplicationSlotOptions) error

DropReplicationSlot drops a logical replication slot.

func NextTableSpace 

func NextTableSpace(ctx context.Context, conn *pgconn.PgConn) (err error)

NextTableSpace consumes some msgs so we are at start of CopyData

func SendStandbyStatusUpdate 

func SendStandbyStatusUpdate(_ context.Context, conn *pgconn.PgConn, ssu StandbyStatusUpdate) error

SendStandbyStatusUpdate sends a StandbyStatusUpdate to the PostgreSQL server.

The only required field in ssu is WALWritePosition. If WALFlushPosition is 0 then WALWritePosition will be assigned to it. If WALApplyPosition is 0 then WALWritePosition will be assigned to it. If ClientTime is the zero value then the current time will be assigned to it.

func StartReplication 

func StartReplication(ctx context.Context, conn *pgconn.PgConn, slotName string, startLSN LSN, options StartReplicationOptions) error

StartReplication begins the replication process by executing the START_REPLICATION command.

Types

type BaseBackupOptions 

type BaseBackupOptions struct {
	// Request information required to generate a progress report, but might as such have a negative impact on the performance.
	Progress bool
	// Sets the label of the backup. If none is specified, a backup label of 'wal-g' will be used.
	Label string
	// Request a fast checkpoint.
	Fast bool
	// Include the necessary WAL segments in the backup. This will include all the files between start and stop backup in the pg_wal directory of the base directory tar file.
	WAL bool
	// By default, the backup will wait until the last required WAL segment has been archived, or emit a warning if log archiving is not enabled.
	// Specifying NOWAIT disables both the waiting and the warning, leaving the client responsible for ensuring the required log is available.
	NoWait bool
	// Limit (throttle) the maximum amount of data transferred from server to client per unit of time (kb/s).
	MaxRate int32
	// Include information about symbolic links present in the directory pg_tblspc in a file named tablespace_map.
	TablespaceMap bool
	// Disable checksums being verified during a base backup.
	// Note that NoVerifyChecksums=true is only supported since PG11
	NoVerifyChecksums bool
}

type BaseBackupResult 

type BaseBackupResult struct {
	LSN         LSN
	TimelineID  int32
	Tablespaces []BaseBackupTablespace
}

BaseBackupResult will hold the return values of the BaseBackup command

func FinishBaseBackup 

func FinishBaseBackup(ctx context.Context, conn *pgconn.PgConn) (result BaseBackupResult, err error)

FinishBaseBackup wraps up a backup after copying all results from the BASE_BACKUP command.

func StartBaseBackup 

func StartBaseBackup(ctx context.Context, conn *pgconn.PgConn, options BaseBackupOptions) (result BaseBackupResult, err error)

StartBaseBackup begins the process for copying a basebackup by executing the BASE_BACKUP command.

type BaseBackupTablespace 

type BaseBackupTablespace struct {
	OID      int32
	Location string
	Size     int8
}

BaseBackupTablespace represents a tablespace in the backup

type BeginMessage 

type BeginMessage struct {

	//FinalLSN is the final LSN of the transaction.
	FinalLSN LSN
	// CommitTime is the commit timestamp of the transaction.
	CommitTime time.Time
	// Xid of the transaction.
	Xid uint32
	// contains filtered or unexported fields
}

BeginMessage is a begin message.

func (*BeginMessage) Decode 

func (m *BeginMessage) Decode(src []byte) error

Decode decodes the message from src.

func (*BeginMessage) SetType 

func (m *BeginMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*BeginMessage) Type 

func (m *BeginMessage) Type() MessageType

Type returns message type.

type CommitMessage 

type CommitMessage struct {

	// Flags currently unused (must be 0).
	Flags uint8
	// CommitLSN is the LSN of the commit.
	CommitLSN LSN
	// TransactionEndLSN is the end LSN of the transaction.
	TransactionEndLSN LSN
	// CommitTime is the commit timestamp of the transaction
	CommitTime time.Time
	// contains filtered or unexported fields
}

CommitMessage is a commit message.

func (*CommitMessage) Decode 

func (m *CommitMessage) Decode(src []byte) error

Decode decodes the message from src.

func (*CommitMessage) SetType 

func (m *CommitMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*CommitMessage) Type 

func (m *CommitMessage) Type() MessageType

Type returns message type.

type CopyDoneResult 

type CopyDoneResult struct {
	Timeline int32
	LSN      LSN
}

CopyDoneResult is the parsed result as returned by the server after the client sends a CopyDone to the server to confirm ending the copy-both mode.

func SendStandbyCopyDone 

func SendStandbyCopyDone(_ context.Context, conn *pgconn.PgConn) (cdr *CopyDoneResult, err error)

SendStandbyCopyDone sends a StandbyCopyDone to the PostgreSQL server to confirm ending the copy-both mode.

type CreateReplicationSlotOptions 

type CreateReplicationSlotOptions struct {
	Temporary      bool
	SnapshotAction string
	Mode           ReplicationMode
}

type CreateReplicationSlotResult 

type CreateReplicationSlotResult struct {
	SlotName        string
	ConsistentPoint string
	SnapshotName    string
	OutputPlugin    string
}

CreateReplicationSlotResult is the parsed results the CREATE_REPLICATION_SLOT command.

func CreateReplicationSlot 

func CreateReplicationSlot(
	ctx context.Context,
	conn *pgconn.PgConn,
	slotName string,
	outputPlugin string,
	options CreateReplicationSlotOptions,
) (CreateReplicationSlotResult, error)

CreateReplicationSlot creates a logical replication slot.

func ParseCreateReplicationSlot 

func ParseCreateReplicationSlot(mrr *pgconn.MultiResultReader) (CreateReplicationSlotResult, error)

ParseCreateReplicationSlot parses the result of the CREATE_REPLICATION_SLOT command.

type DeleteMessage 

type DeleteMessage struct {
	RelationID uint32
	// OldTupleType
	//   Byte1('K'):
	//     Identifies the following TupleData submessage as a key.
	//     This field is present if the table in which the delete has happened uses an index
	//     as REPLICA IDENTITY.
	//
	//   Byte1('O')
	//     Identifies the following TupleData message as an old tuple.
	//     This field is present if the table in which the delete has happened has
	//     REPLICA IDENTITY set to FULL.
	//
	// The Delete message may contain either a 'K' message part or an 'O' message part,
	// but never both of them.
	OldTupleType uint8
	OldTuple     *TupleData
	// contains filtered or unexported fields
}

DeleteMessage is a delete message.

func (*DeleteMessage) Decode 

func (m *DeleteMessage) Decode(src []byte) (err error)

Decode decodes a message from src.

func (*DeleteMessage) SetType 

func (m *DeleteMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*DeleteMessage) Type 

func (m *DeleteMessage) Type() MessageType

Type returns message type.

type DeleteMessageV2 

type DeleteMessageV2 struct {
	DeleteMessage
	InStreamMessageV2WithXid
}

DeleteMessageV2 is a delete message.

func (*DeleteMessageV2) DecodeV2 

func (m *DeleteMessageV2) DecodeV2(src []byte, inStream bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*DeleteMessageV2) SetType 

func (m *DeleteMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*DeleteMessageV2) Type 

func (m *DeleteMessageV2) Type() MessageType

Type returns message type.

type DropReplicationSlotOptions 

type DropReplicationSlotOptions struct {
	Wait bool
}

type IdentifySystemResult 

type IdentifySystemResult struct {
	SystemID string
	Timeline int32
	XLogPos  LSN
	DBName   string
}

IdentifySystemResult is the parsed result of the IDENTIFY_SYSTEM command.

func IdentifySystem 

func IdentifySystem(ctx context.Context, conn *pgconn.PgConn) (IdentifySystemResult, error)

IdentifySystem executes the IDENTIFY_SYSTEM command.

func ParseIdentifySystem 

func ParseIdentifySystem(mrr *pgconn.MultiResultReader) (IdentifySystemResult, error)

ParseIdentifySystem parses the result of the IDENTIFY_SYSTEM command.

type InStreamMessageV2WithXid 

type InStreamMessageV2WithXid struct {
	// Xid of the transaction (only present for streamed transactions).
	Xid uint32
}

InStreamMessageV2WithXid is a V2 protocol message

type InsertMessage 

type InsertMessage struct {

	// RelationID is the ID of the relation corresponding to the ID in the relation message.
	RelationID uint32
	Tuple      *TupleData
	// contains filtered or unexported fields
}

InsertMessage is a insert message

func (*InsertMessage) Decode 

func (m *InsertMessage) Decode(src []byte) error

Decode decodes to message from src.

func (*InsertMessage) SetType 

func (m *InsertMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*InsertMessage) Type 

func (m *InsertMessage) Type() MessageType

Type returns message type.

type InsertMessageV2 

type InsertMessageV2 struct {
	InsertMessage
	InStreamMessageV2WithXid
}

InsertMessageV2 is an insert message.

func (*InsertMessageV2) DecodeV2 

func (m *InsertMessageV2) DecodeV2(src []byte, inStream bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*InsertMessageV2) SetType 

func (m *InsertMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*InsertMessageV2) Type 

func (m *InsertMessageV2) Type() MessageType

Type returns message type.

type LSN 

type LSN uint64

LSN is a PostgreSQL Log Sequence Number. See https://www.postgresql.org/docs/current/datatype-pg-lsn.html.

func IsErrEndTimeline 

func IsErrEndTimeline(err error) (int64, LSN, bool)

func ParseLSN 

func ParseLSN(s string) (LSN, error)

ParseLSN parses the given XXX/XXX text format LSN used by PostgreSQL.

func (*LSN) Scan 

func (lsn *LSN) Scan(src interface{}) error

Scan implements the Scanner interface.

func (LSN) String 

func (lsn LSN) String() string

String formats the LSN value into the XXX/XXX format which is the text format used by PostgreSQL.

func (LSN) Value 

func (lsn LSN) Value() (driver.Value, error)

Value implements the Valuer interface.

type LogicalDecodingMessage 

type LogicalDecodingMessage struct {
	LSN           LSN
	Transactional bool
	Prefix        string
	Content       []byte
	// contains filtered or unexported fields
}

LogicalDecodingMessage is a logical decoding message.

func (*LogicalDecodingMessage) Decode 

func (m *LogicalDecodingMessage) Decode(src []byte) (err error)

Decode decodes a message from src.

func (*LogicalDecodingMessage) SetType 

func (m *LogicalDecodingMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*LogicalDecodingMessage) Type 

func (m *LogicalDecodingMessage) Type() MessageType

Type returns message type.

type LogicalDecodingMessageV2 

type LogicalDecodingMessageV2 struct {
	LogicalDecodingMessage
	InStreamMessageV2WithXid
}

LogicalDecodingMessageV2 is a logical decoding message.

func (*LogicalDecodingMessageV2) DecodeV2 

func (m *LogicalDecodingMessageV2) DecodeV2(src []byte, inStream bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*LogicalDecodingMessageV2) SetType 

func (m *LogicalDecodingMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*LogicalDecodingMessageV2) Type 

func (m *LogicalDecodingMessageV2) Type() MessageType

Type returns message type.

type Message 

type Message interface {
	Type() MessageType
}

Message is a message received from server.

func Parse 

func Parse(data []byte) (m Message, err error)

Parse parse a logical replication message.

func ParseV2 

func ParseV2(data []byte, inStream bool) (m Message, err error)

ParseV2 parse a logical replication message from protocol version #2 it accepts a slice of bytes read from PG and inStream parameter inStream must be true when StreamStartMessageV2 has been read it must be false after StreamStopMessageV2 has been read

type MessageDecoder 

type MessageDecoder interface {
	Decode([]byte) error
}

MessageDecoder decodes message into struct.

type MessageDecoderV2 

type MessageDecoderV2 interface {
	MessageDecoder
	DecodeV2(src []byte, inStream bool) error
}

MessageDecoderV2 decodes message from V2 protocol into struct.

type MessageType 

type MessageType uint8

MessageType indicates the type of a logical replication message. 

const (
	MessageTypeBegin        MessageType = 'B'
	MessageTypeMessage      MessageType = 'M'
	MessageTypeCommit       MessageType = 'C'
	MessageTypeOrigin       MessageType = 'O'
	MessageTypeRelation     MessageType = 'R'
	MessageTypeType         MessageType = 'Y'
	MessageTypeInsert       MessageType = 'I'
	MessageTypeUpdate       MessageType = 'U'
	MessageTypeDelete       MessageType = 'D'
	MessageTypeTruncate     MessageType = 'T'
	MessageTypeStreamStart  MessageType = 'S'
	MessageTypeStreamStop   MessageType = 'E'
	MessageTypeStreamCommit MessageType = 'c'
	MessageTypeStreamAbort  MessageType = 'A'
)

List of types of logical replication messages.

func (MessageType) String 

func (t MessageType) String() string

type OriginMessage 

type OriginMessage struct {

	// CommitLSN is the LSN of the commit on the origin server.
	CommitLSN LSN
	Name      string
	// contains filtered or unexported fields
}

OriginMessage is an origin message.

func (*OriginMessage) Decode 

func (m *OriginMessage) Decode(src []byte) error

Decode decodes to message from src.

func (*OriginMessage) SetType 

func (m *OriginMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*OriginMessage) Type 

func (m *OriginMessage) Type() MessageType

Type returns message type.

type PrimaryKeepaliveMessage 

type PrimaryKeepaliveMessage struct {
	ServerWALEnd   LSN
	ServerTime     time.Time
	ReplyRequested bool
}

func ParsePrimaryKeepaliveMessage 

func ParsePrimaryKeepaliveMessage(buf []byte) (PrimaryKeepaliveMessage, error)

ParsePrimaryKeepaliveMessage parses a Primary keepalive message from the server.

type RelationMessage 

type RelationMessage struct {
	RelationID      uint32
	Namespace       string
	RelationName    string
	ReplicaIdentity uint8
	ColumnNum       uint16
	Columns         []*RelationMessageColumn
	// contains filtered or unexported fields
}

RelationMessage is a relation message.

func (*RelationMessage) Decode 

func (m *RelationMessage) Decode(src []byte) error

Decode decodes to message from src.

func (*RelationMessage) SetType 

func (m *RelationMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*RelationMessage) Type 

func (m *RelationMessage) Type() MessageType

Type returns message type.

type RelationMessageColumn 

type RelationMessageColumn struct {
	// Flags for the column. Currently, it can be either 0 for no flags or 1 which marks the column as part of the key.
	Flags uint8

	Name string

	// DataType is the ID of the column's data type.
	DataType uint32

	// TypeModifier is type modifier of the column (atttypmod).
	TypeModifier int32
}

RelationMessageColumn is one column in a RelationMessage.

type RelationMessageV2 

type RelationMessageV2 struct {
	RelationMessage
	InStreamMessageV2WithXid
}

RelationMessageV2 is a relation message.

func (*RelationMessageV2) DecodeV2 

func (m *RelationMessageV2) DecodeV2(src []byte, inStream bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*RelationMessageV2) SetType 

func (m *RelationMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*RelationMessageV2) Type 

func (m *RelationMessageV2) Type() MessageType

Type returns message type.

type ReplicationMode 

type ReplicationMode int
const (
	LogicalReplication ReplicationMode = iota
	PhysicalReplication
)

func (ReplicationMode) String 

func (mode ReplicationMode) String() string

String formats the mode into a postgres valid string

type StandbyStatusUpdate 

type StandbyStatusUpdate struct {
	WALWritePosition LSN       // The WAL position that's been locally written
	WALFlushPosition LSN       // The WAL position that's been locally flushed
	WALApplyPosition LSN       // The WAL position that's been locally applied
	ClientTime       time.Time // Client system clock time
	ReplyRequested   bool      // Request server to reply immediately.
}

StandbyStatusUpdate is a message sent from the client that acknowledges receipt of WAL records.

type StartReplicationOptions 

type StartReplicationOptions struct {
	Timeline   int32 // 0 means current server timeline
	Mode       ReplicationMode
	PluginArgs []string
}

type StreamAbortMessageV2 

type StreamAbortMessageV2 struct {
	Xid uint32
	// Xid of the subtransaction (will be same as xid of the transaction for top-level transactions).
	SubXid uint32
	// contains filtered or unexported fields
}

StreamAbortMessageV2 is a stream abort message.

func (*StreamAbortMessageV2) Decode 

func (m *StreamAbortMessageV2) Decode(_ []byte) error

Decode parse src into message struct. The src must contain the complete message starts after the first message type byte.

func (*StreamAbortMessageV2) DecodeV2 

func (m *StreamAbortMessageV2) DecodeV2(src []byte, _ bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*StreamAbortMessageV2) SetType 

func (m *StreamAbortMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*StreamAbortMessageV2) Type 

func (m *StreamAbortMessageV2) Type() MessageType

Type returns message type.

type StreamCommitMessageV2 

type StreamCommitMessageV2 struct {
	Xid               uint32
	Flags             uint8 // currently unused
	CommitLSN         LSN
	TransactionEndLSN LSN
	CommitTime        time.Time
	// contains filtered or unexported fields
}

StreamCommitMessageV2 is a stream commit message.

func (*StreamCommitMessageV2) Decode 

func (m *StreamCommitMessageV2) Decode(_ []byte) error

Decode parse src into message struct. The src must contain the complete message starts after the first message type byte.

func (*StreamCommitMessageV2) DecodeV2 

func (m *StreamCommitMessageV2) DecodeV2(src []byte, _ bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*StreamCommitMessageV2) SetType 

func (m *StreamCommitMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*StreamCommitMessageV2) Type 

func (m *StreamCommitMessageV2) Type() MessageType

Type returns message type.

type StreamStartMessageV2 

type StreamStartMessageV2 struct {
	Xid uint32
	// A value of 1 indicates this is the first stream segment for this XID, 0 for any other stream segment
	FirstSegment uint8
	// contains filtered or unexported fields
}

StreamStartMessageV2 is a stream start message.

func (*StreamStartMessageV2) Decode 

func (m *StreamStartMessageV2) Decode(_ []byte) error

Decode parse src into message struct. The src must contain the complete message starts after the first message type byte.

func (*StreamStartMessageV2) DecodeV2 

func (m *StreamStartMessageV2) DecodeV2(src []byte, _ bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*StreamStartMessageV2) SetType 

func (m *StreamStartMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*StreamStartMessageV2) Type 

func (m *StreamStartMessageV2) Type() MessageType

Type returns message type.

type StreamStopMessageV2 

type StreamStopMessageV2 struct {
	// contains filtered or unexported fields
}

StreamStopMessageV2 is a stream stop message.

func (*StreamStopMessageV2) Decode 

func (m *StreamStopMessageV2) Decode(_ []byte) error

Decode parse src into message struct. The src must contain the complete message starts after the first message type byte.

func (*StreamStopMessageV2) DecodeV2 

func (m *StreamStopMessageV2) DecodeV2(_ []byte, _ bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*StreamStopMessageV2) SetType 

func (m *StreamStopMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*StreamStopMessageV2) Type 

func (m *StreamStopMessageV2) Type() MessageType

Type returns message type.

type TimelineHistoryResult 

type TimelineHistoryResult struct {
	FileName string
	Content  []byte
}

TimelineHistoryResult is the parsed result of the TIMELINE_HISTORY command.

func ParseTimelineHistory 

func ParseTimelineHistory(mrr *pgconn.MultiResultReader) (TimelineHistoryResult, error)

ParseTimelineHistory parses the result of the TIMELINE_HISTORY command.

func TimelineHistory 

func TimelineHistory(ctx context.Context, conn *pgconn.PgConn, timeline int32) (TimelineHistoryResult, error)

TimelineHistory executes the TIMELINE_HISTORY command.

type TruncateMessage 

type TruncateMessage struct {
	RelationNum uint32
	Option      uint8
	RelationIDs []uint32
	// contains filtered or unexported fields
}

TruncateMessage is a truncate message.

func (*TruncateMessage) Decode 

func (m *TruncateMessage) Decode(src []byte) (err error)

Decode decodes to message from src.

func (*TruncateMessage) SetType 

func (m *TruncateMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*TruncateMessage) Type 

func (m *TruncateMessage) Type() MessageType

Type returns message type.

type TruncateMessageV2 

type TruncateMessageV2 struct {
	TruncateMessage
	InStreamMessageV2WithXid
}

TruncateMessageV2 is a truncate message.

func (*TruncateMessageV2) DecodeV2 

func (m *TruncateMessageV2) DecodeV2(src []byte, inStream bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*TruncateMessageV2) SetType 

func (m *TruncateMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*TruncateMessageV2) Type 

func (m *TruncateMessageV2) Type() MessageType

Type returns message type.

type TupleData 

type TupleData struct {
	ColumnNum uint16
	Columns   []*TupleDataColumn
	// contains filtered or unexported fields
}

TupleData contains row change information.

func (*TupleData) Decode 

func (m *TupleData) Decode(src []byte) (int, error)

Decode decodes to message from src.

func (*TupleData) SetType 

func (m *TupleData) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*TupleData) Type 

func (m *TupleData) Type() MessageType

Type returns message type.

type TupleDataColumn 

type TupleDataColumn struct {
	// DataType indicates how the data is stored.
	//	 Byte1('n') Identifies the data as NULL value.
	//	 Or
	//	 Byte1('u') Identifies unchanged TOASTed value (the actual value is not sent).
	//	 Or
	//	 Byte1('t') Identifies the data as text formatted value.
	//	 Or
	//	 Byte1('b') Identifies the data as binary value.
	DataType uint8
	Length   uint32
	// Data is th value of the column, in text format. (A future release might support additional formats.) n is the above length.
	Data []byte
}

TupleDataColumn is a column in a TupleData.

func (*TupleDataColumn) Int64 

func (c *TupleDataColumn) Int64() (int64, error)

Int64 parse column data as an int64 integer.

type TypeMessage 

type TypeMessage struct {
	DataType  uint32
	Namespace string
	Name      string
	// contains filtered or unexported fields
}

TypeMessage is a type message.

func (*TypeMessage) Decode 

func (m *TypeMessage) Decode(src []byte) error

Decode decodes to message from src.

func (*TypeMessage) SetType 

func (m *TypeMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*TypeMessage) Type 

func (m *TypeMessage) Type() MessageType

Type returns message type.

type TypeMessageV2 

type TypeMessageV2 struct {
	TypeMessage
	InStreamMessageV2WithXid
}

TypeMessageV2 is a type message.

func (*TypeMessageV2) DecodeV2 

func (m *TypeMessageV2) DecodeV2(src []byte, inStream bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*TypeMessageV2) SetType 

func (m *TypeMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*TypeMessageV2) Type 

func (m *TypeMessageV2) Type() MessageType

Type returns message type.

type UpdateMessage 

type UpdateMessage struct {
	RelationID uint32

	// OldTupleType
	//   Byte1('K'):
	//     Identifies the following TupleData submessage as a key.
	//     This field is optional and is only present if the update changed data
	//     in any of the column(s) that are part of the REPLICA IDENTITY index.
	//
	//   Byte1('O'):
	//     Identifies the following TupleData submessage as an old tuple.
	//     This field is optional and is only present if table in which the update happened
	//     has REPLICA IDENTITY set to FULL.
	//
	//   The Update message may contain either a 'K' message part or an 'O' message part
	//   or neither of them, but never both of them.
	OldTupleType uint8
	OldTuple     *TupleData

	// NewTuple is the contents of a new tuple.
	//   Byte1('N'): Identifies the following TupleData message as a new tuple.
	NewTuple *TupleData
	// contains filtered or unexported fields
}

UpdateMessage is a update message.

func (*UpdateMessage) Decode 

func (m *UpdateMessage) Decode(src []byte) (err error)

Decode decodes to message from src.

func (*UpdateMessage) SetType 

func (m *UpdateMessage) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*UpdateMessage) Type 

func (m *UpdateMessage) Type() MessageType

Type returns message type.

type UpdateMessageV2 

type UpdateMessageV2 struct {
	UpdateMessage
	InStreamMessageV2WithXid
}

UpdateMessageV2 is an update message.

func (*UpdateMessageV2) DecodeV2 

func (m *UpdateMessageV2) DecodeV2(src []byte, inStream bool) (err error)

DecodeV2 decodes to message from V2 src.

func (*UpdateMessageV2) SetType 

func (m *UpdateMessageV2) SetType(t MessageType)

SetType sets message type. This method is added to help writing test code in application. The message type is still defined by message data.

func (*UpdateMessageV2) Type 

func (m *UpdateMessageV2) Type() MessageType

Type returns message type.

type XLogData 

type XLogData struct {
	WALStart     LSN
	ServerWALEnd LSN
	ServerTime   time.Time
	WALData      []byte
}

func ParseXLogData 

func ParseXLogData(buf []byte) (XLogData, error)

ParseXLogData parses a XLogData message from the server.

Source Files

View all Source files

Directories

Path Synopsis
example
pglogrepl_demo
pgphysrepl_demo

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