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Module Netmcore_hashtbl

module Netmcore_hashtbl: sig .. end
Shared hashtables


This is a shared memory version of Hashtbl. Note that the degree of parallelization is quite restricted - practically all operations need to be serialized (with the exception of the "ro" variants).
type ('a, 'b, 'h) t 
The type of hash tables from type 'a to type 'b and a header of type 'h
type ('a, 'b, 'h) t_descr 
The marshallable descriptor of a shared hash table
val create : Netmcore.res_id -> 'h -> ('a, 'b, 'h) t
Hashtbl.create pool h creates a new, empty hash table in pool with a header h.
val clear : ('a, 'b, 'h) t -> unit
Empty a hash table.
val add : ('a, 'b, 'h) t -> 'a -> 'b -> unit
add tbl x y adds a binding of x to y in table tbl. Previous bindings for x are not removed, but simply hidden. That is, after performing Netmcore_hashtbl.remove tbl x, the previous binding for x, if any, is restored. (Same behavior as with association lists.)
val find_ro : ('a, 'b, 'h) t -> 'a -> 'b
find_ro tbl x returns the current binding of x in tbl, or raises Not_found if no such binding exists. If it is possible that the table is being modified at the same time, this function can crash. (Suffix "_ro" = for "read-only" hashtables.)
val find_p : ('a, 'b, 'h) t -> 'a -> ('b -> 'r) -> 'r
find_p tbl x f looks up the current binding of x in tbl, and calls f with this binding as argument. During the execution of f the binding is pinned and cannot be garbage-collected. Raises Not_found if there is no such binding.
val find_c : ('a, 'b, 'h) t -> 'a -> 'b
Like find but returns a copy of the binding in normal RAM
val find_all_ro : ('a, 'b, 'h) t -> 'a -> 'b list
Hashtbl.find_all tbl x returns the list of all data associated with x in tbl. The current binding is returned first, then the previous bindings, in reverse order of introduction in the table. If it is possible that the table is being modified at the same time, this function can crash. (Suffix "_ro" = for "read-only" hashtables.)
val find_all_p : ('a, 'b, 'h) t -> 'a -> ('b list -> 'r) -> 'r
Version of find_all with pinned result
val find_all_c : ('a, 'b, 'h) t -> 'a -> 'b list
Version of find_all with copied result
val mem_ro : ('a, 'b, 'h) t -> 'a -> bool
Hashtbl.mem tbl x checks if x is bound in tbl. If it is possible that the table is being modified at the same time, this function can crash. (Suffix "_ro" = for "read-only" hashtables.)
val mem : ('a, 'b, 'h) t -> 'a -> bool
Safe version of mem_ro in the presence of parallel modifications. It is a bit slower, though.
val remove : ('a, 'b, 'h) t -> 'a -> unit
Hashtbl.remove tbl x removes the current binding of x in tbl, restoring the previous binding if it exists. It does nothing if x is not bound in tbl.
val replace : ('a, 'b, 'h) t -> 'a -> 'b -> unit
Hashtbl.replace tbl x y replaces the current binding of x in tbl by a binding of x to y. If x is unbound in tbl, a binding of x to y is added to tbl. This is functionally equivalent to Hashtbl.remove tbl x followed by Hashtbl.add tbl x y.
val iter : ('a -> 'b -> unit) -> ('a, 'b, 'h) t -> unit
Hashtbl.iter f tbl applies f to all bindings in table tbl. f receives the key as first argument, and the associated value as second argument. Each binding is presented exactly once to f. The order in which the bindings are passed to f is unspecified. However, if the table contains several bindings for the same key, they are passed to f in reverse order of introduction, that is, the most recent binding is passed first.

The table cannot be modified while iter is running. Any attempt will result in a deadlock.

val length : ('a, 'b, 'h) t -> int
Hashtbl.length tbl returns the number of bindings in tbl. Multiple bindings are counted multiply, so Hashtbl.length gives the number of times Hashtbl.iter calls its first argument.
val header : ('a, 'b, 'h) t -> 'h
Returns the header
val heap : ('a, 'b, 'h) t -> Obj.t Netmcore_heap.heap
Returns the heap backing this data structure
val descr_of_hashtbl : ('a, 'b, 'h) t -> ('a, 'b, 'h) t_descr
Returns the descriptor
val hashtbl_of_descr : Netmcore.res_id ->
('a, 'b, 'h) t_descr -> ('a, 'b, 'h) t
Look up the hash table for this descriptor
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