package tezos-context

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package tezos-context
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Tezos - Versioned, block indexed (key x value) store

type Tezos_base__TzPervasives.error +=
  1. | Cannot_create_file of string
  2. | Cannot_open_file of string
  3. | Cannot_find_protocol
  4. | Suspicious_file of int

Generic interface

module type S = sig ... end
include S
include Tezos_context_sigs.Context.VIEW with type key = string list and type value = bytes
type t

The type for context views.

type key = string list

The type for context keys.

type value = bytes

The type for context values.

type tree

The type for context trees.

Getters

val mem : t -> key -> bool Lwt.t

mem t k is an Lwt promise that resolves to true iff k is bound to a value in t.

val mem_tree : t -> key -> bool Lwt.t

mem_tree t k is like mem but for trees.

val find : t -> key -> value option Lwt.t

find t k is an Lwt promise that resolves to Some v if k is bound to the value v in t and None otherwise.

val find_tree : t -> key -> tree option Lwt.t

find_tree t k is like find but for trees.

val list : t -> ?offset:int -> ?length:int -> key -> (string * tree) list Lwt.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 add : t -> key -> value -> t Lwt.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.

val add_tree : t -> key -> tree -> t Lwt.t

add_tree is like add but for trees.

val remove : t -> key -> t Lwt.t

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.

Folding

val fold : ?depth:Tezos_context_sigs.Context.depth -> t -> key -> order:[ `Sorted | `Undefined ] -> init:'a -> f:(key -> tree -> 'a -> 'a Lwt.t) -> 'a Lwt.t

fold ?depth t root ~order ~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.

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.

If order is `Sorted (the default), the elements are traversed in lexicographic order of their keys. For large nodes, it is memory-consuming, use `Undefined for a more memory efficient fold.

module Tree : sig ... end
type context = t
type index

A block-indexed (key x value) store directory.

val init : ?patch_context: (context -> (context, Tezos_error_monad.TzCore.error list) result Lwt.t) -> ?readonly:bool -> string -> index Lwt.t

Open or initialize a versioned store at a given path.

val close : index -> unit Lwt.t

Close the index. Does not fail when the context is already closed.

val sync : index -> unit Lwt.t

Sync the context with disk. Only useful for read-only instances. Does not fail when the context is not in read-only mode.

val compute_testchain_chain_id : Tezos_crypto.Block_hash.t -> Tezos_crypto.Chain_id.t
val compute_testchain_genesis : Tezos_crypto.Block_hash.t -> Tezos_crypto.Block_hash.t

merkle_tree t leaf_kind key returns a Merkle proof for key (i.e. whose hashes reach key). If leaf_kind is Block_services.Hole, the value at key is a hash. If leaf_kind is Block_services.Raw_context, the value at key is a Block_services.raw_context. Values higher in the returned tree are hashes of the siblings on the path to reach key.

Accessing and Updating Versions

val exists : index -> Tezos_crypto.Context_hash.t -> bool Lwt.t
val checkout : index -> Tezos_crypto.Context_hash.t -> context option Lwt.t
val hash : time:Tezos_base.Time.Protocol.t -> ?message:string -> t -> Tezos_crypto.Context_hash.t
val commit : time:Tezos_base.Time.Protocol.t -> ?message:string -> context -> Tezos_crypto.Context_hash.t Lwt.t
val set_master : index -> Tezos_crypto.Context_hash.t -> unit Lwt.t

Hash version

Get the hash version used for the context

Set the hash version used for the context. It may recalculate the hashes of the whole context, which can be a long process. Returns an Error if the hash version is unsupported.

Predefined Fields

val remove_test_chain : context -> context Lwt.t
val fork_test_chain : context -> protocol:Tezos_crypto.Protocol_hash.t -> expiration:Tezos_base.Time.Protocol.t -> context Lwt.t
val clear_test_chain : index -> Tezos_crypto.Chain_id.t -> unit Lwt.t
val find_predecessor_block_metadata_hash : context -> Tezos_crypto.Block_metadata_hash.t option Lwt.t
val add_predecessor_block_metadata_hash : context -> Tezos_crypto.Block_metadata_hash.t -> context Lwt.t
val find_predecessor_ops_metadata_hash : context -> Tezos_crypto.Operation_metadata_list_list_hash.t option Lwt.t
val add_predecessor_ops_metadata_hash : context -> Tezos_crypto.Operation_metadata_list_list_hash.t -> context Lwt.t

Context dumping

val restore_context : index -> expected_context_hash:Tezos_crypto.Context_hash.t -> nb_context_elements:int -> fd:Lwt_unix.file_descr -> (unit, Tezos_error_monad.TzCore.error list) result Lwt.t
val check_protocol_commit_consistency : index -> expected_context_hash:Tezos_crypto.Context_hash.t -> given_protocol_hash:Tezos_crypto.Protocol_hash.t -> author:string -> message:string -> timestamp:Tezos_base.Time.Protocol.t -> test_chain_status:Tezos_base.Test_chain_status.t -> predecessor_block_metadata_hash:Tezos_crypto.Block_metadata_hash.t option -> predecessor_ops_metadata_hash: Tezos_crypto.Operation_metadata_list_list_hash.t option -> data_merkle_root:Tezos_crypto.Context_hash.t -> parents_contexts:Tezos_crypto.Context_hash.t list -> bool Lwt.t
module Checks : sig ... end

Offline integrity checking and statistics for contexts.