🡠 irmin-pack

Irmin backend which stores values in a pack file
Module type
Class type
Library irmin-pack.unix
include Irmin_pack.Indexable.S with type key := hash Irmin_pack.Pack_key.t with type hash := hash with type 'a t = 'a t
include Irmin.Indexable.S with type key := hash Irmin_pack.Pack_key.t with type hash := hash with type 'a t = 'a t

Read-only stores

Read-only stores are store where it is only possible to read existing values.

type 'a t = 'a t

The type for stores. The 'a phantom type carries information about the store mutability.

type value

The type for raw values.

mem t k is true iff k is present in t.

find t k is Some v if k is associated to v in t and None is k is not present in t.

val close : 'a t -> unit Lwt.t

close t frees up all the resources associated with t. Any operations run on a closed handle will raise Closed.

val index : [> Irmin.Perms.read ] t -> hash -> hash Irmin_pack.Pack_key.t option Lwt.t

Indexing maps the hash of a value to a corresponding key of that value in the store. For stores that are addressed by hashes directly, this is typically fun _t h -> Lwt.return (Key.of_hash h); for stores with more complex addressing schemes, index may attempt a lookup operation in the store.

In general, indexing is best-effort and reveals no information about the membership of the value in the store. In particular:

  • index t hash = Some key doesn't guarantee mem t key: the value with hash hash may still be absent from the store;
  • index t hash = None doesn't guarantee that there is no key such that mem t key and Key.to_hash key = hash: the value may still be present in the store under a key that is not indexed.
val batch : Irmin.Perms.read t -> ( [ Irmin.Perms.read | Irmin.Perms.write ] t -> 'a Lwt.t ) -> 'a Lwt.t

batch t f applies the writes in f in a separate batch. The exact guarantees depend on the implementation.

module Key : Irmin.Key.S with type t = hash Irmin_pack.Pack_key.t and type hash = hash

Overwrite add to work with a read-only database handler.

val unsafe_add : 'a t -> hash -> value -> hash Irmin_pack.Pack_key.t Lwt.t

Overwrite unsafe_add to work with a read-only database handler.

val index_direct : _ t -> hash -> hash Irmin_pack.Pack_key.t option
val unsafe_append : ensure_unique:bool -> overcommit:bool -> 'a t -> hash -> value -> hash Irmin_pack.Pack_key.t
val unsafe_mem : 'a t -> hash Irmin_pack.Pack_key.t -> bool
val unsafe_find : check_integrity:bool -> 'a t -> hash Irmin_pack.Pack_key.t -> value option
type file_manager = file_manager
type dict = dict
val integrity_check : offset:Optint.Int63.t -> length:int -> hash -> _ t -> ( unit, [ `Wrong_hash | `Absent_value ] ) result
module Entry_prefix : sig ... end
val read_and_decode_entry_prefix : off:Optint.Int63.t -> file_manager -> Entry_prefix.t

Read the entry prefix at offset off.

val index_direct_with_kind : 'a t -> hash -> (hash Irmin_pack.Pack_key.t * Irmin_pack.Pack_value.Kind.t) option

Returns the key and the kind of an object indexed by hash.