Module Picos_htblSource

Lock-free hash table.

Example:

  # let t : (int, string) Picos_htbl.t =
      Picos_htbl.create ~hashed_type:(module Int) ()
  val t : (int, string) Picos_htbl.t = <abstr>

  # Picos_htbl.try_add t 42 "The answer"
  - : bool = true

  # Picos_htbl.try_add t 101 "Basics"
  - : bool = true

  # Picos_htbl.find_exn t 42
  - : string = "The answer"

  # Picos_htbl.try_add t 101 "The basics"
  - : bool = false

  # Picos_htbl.remove_all t |> List.of_seq
  - : (int * string) list = [(101, "Basics"); (42, "The answer")]

🏎️ Single key reads with this hash table are actually wait-free rather than just lock-free. Internal resizing automatically uses all the threads that are trying to write to the hash table.

Sourcetype (!'k, !'v) t

Represents a lock-free hash table mapping keys of type 'k to values of type 'v.

Sourcetype 'k hashed_type = (module Hashtbl.HashedType with type t = 'k)

First-class module type abbreviation.

Sourceval create : ?hashed_type:'k hashed_type -> unit -> ('k, 'v) t

create ~hashed_type:(module Key) () creates a new empty lock-free hash table.

The optional hashed_type argument can be used to specify the equal and hash operations on keys. Slow polymorphic equality (=) and slow polymorphic seeded_hash (Random.bits ()) is used by default.

Sourceval find_exn : ('k, 'v) t -> 'k -> 'v

find_exn htbl key returns the current binding of key in the hash table htbl or raises Not_found if no such binding exists.

Sourceval mem : ('k, 'v) t -> 'k -> bool

mem htbl key determines whether the hash table htbl has a binding for the key.

Sourceval try_add : ('k, 'v) t -> 'k -> 'v -> bool

try_add htbl key value tries to add a new binding of key to value to the hash table htbl. Returns true on success and false in case the hash table already contained a binding for key.

Sourceval try_remove : ('k, 'v) t -> 'k -> bool

try_remove htbl key tries to remove a binding of key from the hash table htbl. Returns true on success and false in case the hash table did not contain a binding for key.

Sourceval remove_exn : ('k, 'v) t -> 'k -> 'v

remove_exn htbl key tries to remove a binding of key from the hash table htbl and return it or raise Not_found if no such binding exists.

Sourceval remove_all : ('k, 'v) t -> ('k * 'v) Seq.t

remove_all htbl takes a snapshot of the bindings in the hash table, removes the bindings from the hash table, and returns the snapshot as an association sequence.

🐌 This is a linear time operation.

Sourceval to_seq : ('k, 'v) t -> ('k * 'v) Seq.t

to_seq htbl takes a snapshot of the bindings in the hash table and returns them as an association sequence.

🐌 This is a linear time operation.