Mavryk_raw_protocol_alpha.Mempool_validation
This module implements a mempool structure meant to be used by a shell and bakers in order to incrementally accumulate commutative operations which could then be safely used to bake a new block. These mempool components guarantee a set of properties useful for these purposes:
Mempools do not depend on local data and therefore are serializable. This is useful when a node needs to send a mempool to another (remote-)process (e.g. the baker).
type conflict_handler =
existing_operation:
(Mavryk_protocol_environment_alpha.Operation_hash.t
* Alpha_context.packed_operation) ->
new_operation:
(Mavryk_protocol_environment_alpha.Operation_hash.t
* Alpha_context.packed_operation) ->
[ `Keep | `Replace ]
Type of the function that may be provided in order to resolve a potential conflict when adding an operation to an existing mempool or when merging two mempools. This handler may be defined as a simple order relation over operations (e.g. prioritize the most profitable operations) or an arbitrary one (e.g. prioritize operations where the source is a specific manager).
Returning `Keep
will leave the mempool unchanged and retain the existing_operation
while returning `Replace
will remove existing_operation
and add new_operation
instead.
type add_result =
| Added
Added
means that an operation was successfully added to the mempool without any conflict.
| Replaced of {
}
Replaced {removed}
means that an operation was successfully added but there was a conflict with the removed
operation which was removed from the mempool.
| Unchanged
Unchanged
means that there was a conflict with an existing operation which was considered better by the conflict_handler
, therefore the new operation is discarded and the mempool remains unchanged.
Return type when adding an operation to the mempool
type operation_conflict = Validate_errors.operation_conflict =
| Operation_conflict of {
existing : Mavryk_protocol_environment_alpha.Operation_hash.t;
new_operation : Mavryk_protocol_environment_alpha.Operation_hash.t;
}
type add_error =
| Validation_error of Mavryk_protocol_environment_alpha.Error_monad.error
Mavryk_protocol_environment_alpha.Error_monad.trace
Validation_error _
means that the operation is invalid.
| Add_conflict of operation_conflict
Add_conflict _
means that an operation conflicts with an existing one. This error will only be obtained when no conflict_handler
was provided. Moreover, Validation_error _
takes precedence over Add_conflict _
which implies that we have the implicit invariant that the operation would be valid if there was no conflict. Therefore, if add_operation
would have to be called again, it would be redondant to check the operation's signature.
Error type returned when adding an operation to the mempool fails.
type merge_error =
| Incompatible_mempool
Incompatible_mempool _
means that the two mempools are not built ontop of the same head and therefore cannot be considered.
| Merge_conflict of operation_conflict
Merge_conflict _
arises when two mempools contain conflicting operations and no conflict_handler
was provided.
Error type returned when the merge of two mempools fails.
val encoding : t Mavryk_protocol_environment_alpha.Data_encoding.t
Mempool encoding
val init :
Alpha_context.context ->
Mavryk_protocol_environment_alpha.Chain_id.t ->
predecessor_level:Alpha_context.Level.t ->
predecessor_round:Alpha_context.Round.t ->
predecessor_hash:Mavryk_protocol_environment_alpha.Block_hash.t ->
validation_info * t
Initialize a static validation_info
and mempool
, required to validate and add operations, and an incremental and serializable mempool
.
val add_operation :
?check_signature:bool ->
?conflict_handler:conflict_handler ->
validation_info ->
t ->
(Mavryk_protocol_environment_alpha.Operation_hash.t
* Alpha_context.packed_operation) ->
(t * add_result, add_error)
Mavryk_protocol_environment_alpha.Pervasives.result
Mavryk_protocol_environment_alpha.Lwt.t
Adds an operation to a mempool
if and only if it is valid and does not conflict with previously added operations.
This function checks the validity of an operation (see Validate.check_operation
) and tries to add it to the mempool.
If an error occurs during the validation, the result will be a Validation_error <err>
. If a conflict with a previous operation exists, the result will be an Add_conflict
(see Validate.check_operation_conflict
). Important: no Add_conflict
will be raised if a conflict_handler
is provided (see add_result
).
If no error is raised the operation is potentially added to the mempool
depending on the add_result
value.
val remove_operation :
t ->
Mavryk_protocol_environment_alpha.Operation_hash.t ->
t
remove_operation mempool oph
removes the operation oph
from the mempool
. The mempool
remains unchanged when oph
is not present in the mempool
val merge :
?conflict_handler:conflict_handler ->
t ->
t ->
(t, merge_error) Mavryk_protocol_environment_alpha.Pervasives.result
merge ?conflict_handler existing_mempool new_mempool
merges new_mempool
into existing_mempool
.
Mempools may only be merged if they are compatible: i.e. both have been initialised with the same predecessor block. Otherwise, the Incompatible_mempool
error is returned.
Conflicts between operations from the two mempools can occur. Similarly as add_operation
, a Merge_conflict
error may be raised when no conflict_handler
is provided.
existing_operation
in conflict_handler ~existing_operation ~new_operation
references operations present in existing_mempool
while new_operation
will reference operations present in new_mempool
.
val operations :
t ->
Alpha_context.packed_operation
Mavryk_protocol_environment_alpha.Operation_hash.Map.t
operations mempool
returns the map of operations present in mempool
.