Generic TTL cache with Eio
ocaml-linkedin: apply dune fmt
Pure formatting changes from `dune fmt`: doc comment placement moves
from above the binding to below it for `type`s, multi-line `match`
expressions collapse onto one line where they fit, and infix operator
applications pick up spaces (`Soup.($?)` -> `Soup.( $? )`). No
semantic changes.
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README.md
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README.md
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## Installation
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Install with opam:
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```sh
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$ opam install cache
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```
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opam install cache
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If opam cannot find the package, it may not yet be released in the public
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`opam-repository`. Add the overlay repository, then install it:
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```sh
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$ opam repo add samoht https://tangled.org/gazagnaire.org/opam-overlay.git
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$ opam update
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$ opam install cache
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```
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## Usage
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### String-keyed cache (pre-instantiated)
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```ocaml
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let cache = Cache.String.create ~clock:(Eio.Stdenv.clock env) () in
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Cache.String.set cache "user:42" user_data;
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match Cache.String.get cache "user:42" with
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| Some data -> (* use cached data *)
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| None -> (* expired or missing *)
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let lookup env =
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let cache = Cache.String.create ~clock:(Eio.Stdenv.clock env) () in
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Cache.String.set cache "user:42" "Alice";
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match Cache.String.get cache "user:42" with
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| Some data -> ()
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| None -> ()
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```
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### Compute-if-absent pattern
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```ocaml
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(* Returns cached value or computes and caches it *)
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let data = Cache.String.get_or_compute cache "user:42" (fun () ->
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fetch_from_database 42)
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let data cache =
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Cache.String.get_or_compute cache "user:42" (fun () -> "Alice")
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```
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### Custom key type
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```ocaml
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module IntCache = Cache.Make (struct
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type t = int
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let equal = Int.equal
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let hash = Hashtbl.hash
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end)
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let cache = IntCache.create ~clock ~base_ttl:300.0 ~jitter:0.1 ()
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let cache clock = IntCache.create ~clock ~base_ttl:300.0 ~jitter:0.1 ()
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```
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## API
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