diff options
Diffstat (limited to 'src/include/replication/walreceiver.h')
| -rw-r--r-- | src/include/replication/walreceiver.h | 136 |
1 files changed, 130 insertions, 6 deletions
diff --git a/src/include/replication/walreceiver.h b/src/include/replication/walreceiver.h index ac1acbb27ec..c75dcebea0c 100644 --- a/src/include/replication/walreceiver.h +++ b/src/include/replication/walreceiver.h @@ -213,39 +213,163 @@ typedef struct WalRcvExecResult TupleDesc tupledesc; } WalRcvExecResult; -/* libpqwalreceiver hooks */ -typedef WalReceiverConn *(*walrcv_connect_fn) (const char *conninfo, bool logical, +/* WAL receiver - libpqwalreceiver hooks */ + +/* + * walrcv_connect_fn + * + * Establish connection to a cluster. 'logical' is true if the + * connection is logical, and false if the connection is physical. + * 'appname' is a name associated to the connection, to use for example + * with fallback_application_name or application_name. Returns the + * details about the connection established, as defined by + * WalReceiverConn for each WAL receiver module. On error, NULL is + * returned with 'err' including the error generated. + */ +typedef WalReceiverConn *(*walrcv_connect_fn) (const char *conninfo, + bool logical, const char *appname, char **err); + +/* + * walrcv_check_conninfo_fn + * + * Parse and validate the connection string given as of 'conninfo'. + */ typedef void (*walrcv_check_conninfo_fn) (const char *conninfo); + +/* + * walrcv_get_conninfo_fn + * + * Returns a user-displayable conninfo string. Note that any + * security-sensitive fields should be obfuscated. + */ typedef char *(*walrcv_get_conninfo_fn) (WalReceiverConn *conn); + +/* + * walrcv_get_senderinfo_fn + * + * Provide information of the WAL sender this WAL receiver is connected + * to, as of 'sender_host' for the host of the sender and 'sender_port' + * for its port. + */ typedef void (*walrcv_get_senderinfo_fn) (WalReceiverConn *conn, char **sender_host, int *sender_port); + +/* + * walrcv_identify_system_fn + * + * Run IDENTIFY_SYSTEM on the cluster connected to and validate the + * identity of the cluster. Returns the system ID of the cluster + * connected to. 'primary_tli' is the timeline ID of the sender. + */ typedef char *(*walrcv_identify_system_fn) (WalReceiverConn *conn, TimeLineID *primary_tli); + +/* + * walrcv_server_version_fn + * + * Returns the version number of the cluster connected to. + */ typedef int (*walrcv_server_version_fn) (WalReceiverConn *conn); + +/* + * walrcv_readtimelinehistoryfile_fn + * + * Fetch from cluster the timeline history file for timeline 'tli'. + * Returns the name of the timeline history file as of 'filename', its + * contents as of 'content' and its 'size'. + */ typedef void (*walrcv_readtimelinehistoryfile_fn) (WalReceiverConn *conn, TimeLineID tli, char **filename, - char **content, int *size); + char **content, + int *size); + +/* + * walrcv_startstreaming_fn + * + * Start streaming WAL data from given streaming options. Returns true + * if the connection has switched successfully to copy-both mode and false + * if the server received the command and executed it successfully, but + * didn't switch to copy-mode. + */ typedef bool (*walrcv_startstreaming_fn) (WalReceiverConn *conn, const WalRcvStreamOptions *options); + +/* + * walrcv_endstreaming_fn + * + * Stop streaming of WAL data. Returns the next timeline ID of the cluster + * connected to in 'next_tli', or 0 if there was no report. + */ typedef void (*walrcv_endstreaming_fn) (WalReceiverConn *conn, TimeLineID *next_tli); -typedef int (*walrcv_receive_fn) (WalReceiverConn *conn, char **buffer, + +/* + * walrcv_receive_fn + * + * Receive a message available from the WAL stream. 'buffer' is a pointer + * to a buffer holding the message received. Returns the length of the data, + * 0 if no data is available yet ('wait_fd' is a socket descriptor which can + * be waited on before a retry), and -1 if the cluster ended the COPY. + */ +typedef int (*walrcv_receive_fn) (WalReceiverConn *conn, + char **buffer, pgsocket *wait_fd); -typedef void (*walrcv_send_fn) (WalReceiverConn *conn, const char *buffer, + +/* + * walrcv_send_fn + * + * Send a message of size 'nbytes' to the WAL stream with 'buffer' as + * contents. + */ +typedef void (*walrcv_send_fn) (WalReceiverConn *conn, + const char *buffer, int nbytes); + +/* + * walrcv_create_slot_fn + * + * Create a new replication slot named 'slotname'. 'temporary' defines + * if the slot is temporary. 'snapshot_action' defines the behavior wanted + * for an exported snapshot (see replication protocol for more details). + * 'lsn' includes the LSN position at which the created slot became + * consistent. Returns the name of the exported snapshot for a logical + * slot, or NULL for a physical slot. + */ typedef char *(*walrcv_create_slot_fn) (WalReceiverConn *conn, - const char *slotname, bool temporary, + const char *slotname, + bool temporary, CRSSnapshotAction snapshot_action, XLogRecPtr *lsn); + +/* + * walrcv_get_backend_pid_fn + * + * Returns the PID of the remote backend process. + */ typedef pid_t (*walrcv_get_backend_pid_fn) (WalReceiverConn *conn); + +/* + * walrcv_exec_fn + * + * Send generic queries (and commands) to the remote cluster. 'nRetTypes' + * is the expected number of returned attributes, and 'retTypes' an array + * including their type OIDs. Returns the status of the execution and + * tuples if any. + */ typedef WalRcvExecResult *(*walrcv_exec_fn) (WalReceiverConn *conn, const char *query, const int nRetTypes, const Oid *retTypes); + +/* + * walrcv_disconnect_fn + * + * Disconnect with the cluster. + */ typedef void (*walrcv_disconnect_fn) (WalReceiverConn *conn); typedef struct WalReceiverFunctionsType |