Mavkit_crawler.Layer_1
This module allow to follow the layer 1 chain by subscribing to the head monitoring RPC offered by the Mavryk node, reconnecting, etc.
type Mavryk_base.TzPervasives.error +=
| Cannot_find_predecessor of Mavryk_base.TzPervasives.Block_hash.t
| Http_connection_error of Cohttp.Code.status_code * string
val start :
name:string ->
reconnection_delay:float ->
?protocols:Mavryk_base.TzPervasives.Protocol_hash.t list ->
Mavryk_client_base.Client_context.full ->
t Lwt.t
start ~name ~reconnection_delay ?protocols cctxt
connects to a Mavryk node and starts monitoring new heads. One can iterate on the heads by calling iter_heads
on its result. reconnection_delay
gives an initial delay for the reconnection which is used in an exponential backoff. The name
is used to differentiate events. If protocols
is provided, only heads of these protocols will be monitored.
val create :
name:string ->
reconnection_delay:float ->
?protocols:Mavryk_base.TzPervasives.Protocol_hash.t list ->
Mavryk_client_base.Client_context.full ->
t
create ~name ~reconnection_delay ?protocols cctxt
creates a Layer 1 context without connecting to a Mavryk node. Use connect
to connect to start monitoring heads. If protocols
is provided, only heads of these protocols will be monitored.
val shutdown : t -> unit Lwt.t
shutdown t
properly shuts the layer 1 down. This function is to be used on exit.
val iter_heads :
?name:string ->
t ->
((Mavryk_base.TzPervasives.Block_hash.t * Mavryk_base.Block_header.t) ->
unit Mavryk_base.TzPervasives.tzresult Lwt.t) ->
unit Mavryk_base.TzPervasives.tzresult Lwt.t
iter_heads ?name t f
calls f
on all new heads appearing in the layer 1 chain. In case of a disconnection with the layer 1 node, it reconnects automatically. If f
returns an error (other than a disconnection), iter_heads
terminates and returns the error. A name
can be provided to differentiate iterations on the same connection.
val wait_first :
t ->
(Mavryk_base.TzPervasives.Block_hash.t * Mavryk_base.Block_header.t) Lwt.t
wait_first t
waits for the first head to appear in the stream and returns it.
val get_latest_head :
t ->
(Mavryk_base.TzPervasives.Block_hash.t * Mavryk_base.Block_header.t) option
get_latest_head t
returns the latest L1 head if at least one was seen by t
. The head is the one sent by the heads monitoring RPC of the L1 node, independently of how they were processed by the current process.
val get_predecessor_opt :
?max_read:int ->
t ->
(Mavryk_base.TzPervasives.Block_hash.t * int32) ->
(Mavryk_base.TzPervasives.Block_hash.t * int32) option
Mavryk_base.TzPervasives.tzresult
Lwt.t
get_predecessor_opt ?max_read state head
returns the predecessor of block head
, when head
is not the genesis block. max_read
(by default 8
) is used to cache a number of predecessors (including head
) to avoid some RPC calls when one need to access multiple predecessors.
val get_predecessor :
?max_read:int ->
t ->
(Mavryk_base.TzPervasives.Block_hash.t * int32) ->
(Mavryk_base.TzPervasives.Block_hash.t * int32)
Mavryk_base.TzPervasives.tzresult
Lwt.t
get_predecessor ?max_read state head
returns the predecessor block of head
.
val nth_predecessor :
get_predecessor:('a -> 'a Mavryk_base.TzPervasives.tzresult Lwt.t) ->
int ->
'a ->
('a * 'a Mavryk_base.TzPervasives.trace) Mavryk_base.TzPervasives.tzresult
Lwt.t
nth_predecessor ~get_predecessor n head
returns block, history
where block
is the nth predecessor of head
and history
is the list of blocks between block
(excluded) and head
(included) on the chain. It uses the function get_predecessor
to retrieve the predecessor of one block.
val get_mavryk_reorg_for_new_head :
t ->
?get_old_predecessor:
((Mavryk_base.TzPervasives.Block_hash.t * int32) ->
(Mavryk_base.TzPervasives.Block_hash.t * int32)
Mavryk_base.TzPervasives.tzresult
Lwt.t) ->
[ `Head of Mavryk_base.TzPervasives.Block_hash.t * int32 | `Level of int32 ] ->
(Mavryk_base.TzPervasives.Block_hash.t * int32) ->
(Mavryk_base.TzPervasives.Block_hash.t * int32) Reorg.t
Mavryk_base.TzPervasives.tzresult
Lwt.t
get_mavryk_reorg_for_new_head l1_ctxt ?get_old_predecessor old_head
new_head
returns the reorganization of L1 blocks between old_head
and new_head
. If old_head
is `Level l
, then it returns the reorganization between new_head
and level l
on the same chain. get_old_predecessor
can be provided to use a different function (than by default get_predecessor
) to retrieve the predecessors of the old head. This is necessary when the old head is not in the L1 chain anymore and forgotten by the L1 node.
val client_context_with_timeout :
Mavryk_client_base.Client_context.full ->
float ->
Mavryk_client_base.Client_context.full
client_context_with_timeout ctxt timeout
creates a client context where RPCs will be made with timeout timeout
seconds. Calls that timeout will resolve with an error RPC_timeout
which will trigger a reconnection in iter_heads
.