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Library
Module
Module type
Parameter
Class
Class type
Tree provides immutable, in-memory partial mirror of the context, with lazy reads and delayed writes. The trees are Merkle trees that carry the same hash as the part of the context they mirror.
Trees are immutable and non-persistent (they disappear if the host crash), held in memory for efficiency, where reads are done lazily and writes are done only when needed, e.g. on Context.commit. If a key is modified twice, only the last value will be written to disk on commit.
val get :
tree->key->(value,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
get t k is an Lwt promise that resolves to Ok v if k is bound to the value v in t and Storage_ErrorMissing_key otherwise.
val get_tree :
tree->key->(tree,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
val list :
tree->?offset:int ->?length:int ->key->(string * tree) listLwt.t
list t key is the list of files and sub-nodes stored under k in t. The result order is not specified but is stable.
offset and length are used for pagination.
Setters
val init :
tree->key->value->(tree,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
init t k v is an Lwt promise that resolves to Ok c if:
k is unbound in t;
k is bound to v in c;
and c is similar to t otherwise.
It is Storage_errorExisting_key if k is already bound in t.
val init_tree :
tree->key->tree->(tree,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
val update :
tree->key->value->(tree,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
update t k v is an Lwt promise that resolves to Ok c if:
k is bound in t;
k is bound to v in c;
and c is similar to t otherwise.
It is Storage_errorMissing_key if k is not already bound in t.
val update_tree :
tree->key->tree->(tree,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
add t k v is an Lwt promise that resolves to c such that:
k is bound to v in c;
and c is similar to t otherwise.
If k was already bound in t to a value that is physically equal to v, the result of the function is a promise that resolves to t. Otherwise, the previous binding of k in t disappears.
remove t k v is an Lwt promise that resolves to c such that:
k is unbound in c;
and c is similar to t otherwise.
val remove_existing :
tree->key->(tree,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
remove_existing t k v is an Lwt promise that resolves to Ok c if:
k is bound in t to a value;
k is unbound in c;
and c is similar to t otherwise.
val remove_existing_tree :
tree->key->(tree,
Tezos_protocol_environment_012_Psithaca__Environment.Error_monad.errorTezos_protocol_environment_012_Psithaca__Environment.Error_monad.trace)Stdlib.resultLwt.t
remove_existing_tree t k v is an Lwt promise that reolves to Ok c if:
val fold :
?depth:[ `Eq of int| `Le of int| `Lt of int| `Ge of int| `Gt of int ]->tree->key->order:[ `Sorted | `Undefined ]->init:'a->f:(key->tree->'a->'aLwt.t)->'aLwt.t
fold ?depth t root ~init ~f recursively folds over the trees and values of t. The f callbacks are called with a key relative to root. f is never called with an empty key for values; i.e., folding over a value is a no-op.
Elements are traversed in lexical order of keys.
The depth is 0-indexed. If depth is set (by default it is not), then f is only called when the conditions described by the parameter is true:
Eq d folds over nodes and contents of depth exactly d.
Lt d folds over nodes and contents of depth strictly less than d.
Le d folds over nodes and contents of depth less than or equal to d.
Gt d folds over nodes and contents of depth strictly more than d.
Ge d folds over nodes and contents of depth more than or equal to d.