Functor to create a MirageOS' KV_RW store from a Git repository.
module G : Irmin_git.Ginclude Mirage_kv.RWThere is a trade-off between durability and performance. If you want performance, use the batch operation with a chain of sets and removes. They will be applied on the underlying storage layer all at once. Otherwise set and remove will cause a flush in the underlying storage layer every time, which could degrade performance.
include Mirage_kv.ROThe type for errors.
val pp_error : error Fmt.tpp_error is the pretty-printer for errors.
Disconnect from the key-value store. While this might take some time to complete, it can never result in an error.
type key = Mirage_kv.Key.tThe type for keys.
exists t k is Some `Value if k is bound to a value in t, Some `Dictionary if k is a prefix of a valid key in t and None if no key with that prefix exists in t.
exists answers two questions: does the key exist and is it referring to a value or a dictionary.
An error occurs when the underlying storage layer fails.
get t k is the value bound to k in t.
The result is Error (`Value_expected k) if k refers to a dictionary in t.
list t k is the list of entries and their types in the dictionary referenced by k in t.
The result is Error (`Dictionary_expected k) if k refers to a value in t.
last_modified t k is the last time the value bound to k in t has been modified.
The modification time (d, ps) is a span for the signed POSIX picosecond span d * 86_400e12 + ps. d is a signed number of POSIX days and ps a number of picoseconds in the range [0;86_399_999_999_999_999L].
When the value bound to k is a dictionary, the modification time is the latest modification of all entries in that dictionary. This behaviour is only one level deep and not recursive.
The type for write errors.
val pp_write_error : write_error Fmt.tThe pretty-printer for pp_write_error.
val set : t -> key -> string -> (unit, write_error) Stdlib.result Lwt.tset t k v replaces the binding k -> v in t.
Durability is guaranteed unless set is run inside an enclosing batch operation, where durability will be guaranteed at the end of the batch.
val remove : t -> key -> (unit, write_error) Stdlib.result Lwt.tremove t k removes any binding of k in t. If k was bound to a dictionary, the full dictionary will be removed.
Durability is guaranteed unless remove is run inside an enclosing batch operation, where durability will be guaranteed at the end of the batch.
batch t f run f in batch. Ensure the durability of operations.
Since a batch is applied at once, the readings inside a batch will return the state before the entire batch. Concurrent operations will not affect other ones executed during the batch.
Batch applications can fail to apply if other operations are happening concurrently. In case of failure, f will run again with the most recent version of t. The result is Error `Too_many_retries if f is run for more then retries attemps (default is 13).
val connect :
?depth:int ->
?branch:string ->
?root:key ->
?ctx:Mimic.ctx ->
?headers:(string * string) list ->
?author:(unit -> string) ->
?msg:([ `Set of key | `Remove of key | `Batch ] -> string) ->
G.t ->
string ->
t Lwt.tconnect ?depth ?branch ?path ?author ?msg g c uri clones the given uri into g repository, using the given branch, depth and '/'-separated sub-path. By default, branch is master, depth is 1 and path is empty, ie. reads will be relative to the root of the repository. author, msg and c are used to create new commit info values on every update. By defaut author is fun () -> "irmin" <irmin@mirage.io> and msg returns basic information about the kind of operations performed.