(** Core types for Lithos *)

(** Phantom type for read-only transactions *)
type ro

(** Phantom type for read-write transactions *)
type rw

type page_id = int64

type metadata =
  { version : int
  ; page_size : int
  ; root_bucket : page_id option
  }

type txn_state =
  | Active
  | Committed
  | Rolled_back

(** Key type - represented as bytes for efficient binary key handling *)
type key = bytes

(** Value type - opaque Bigarray slice for zero-copy access to mmap'd data.

    Values are only valid during the lifetime of the transaction that created them.
    If you need a value to outlive the transaction, copy it with {!bytes_of_value}. *)
type value = (char, Bigarray.int8_unsigned_elt, Bigarray.c_layout) Bigarray.Array1.t

val key_of_string : string -> key
val string_of_key : key -> string

val value_of_string : string -> value
val string_of_value : value -> string

val value_of_bytes : bytes -> value
val bytes_of_value : value -> bytes