Source file store_intf.ml
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open! Import
open Store_properties
module type S_generic_key = sig
(** {1 Irmin stores}
Irmin stores are tree-like read-write stores with extended capabilities.
They allow an application (or a collection of applications) to work with
multiple local states, which can be forked and merged programmatically,
without having to rely on a global state. In a way very similar to version
control systems, Irmin local states are called {i branches}.
There are two kinds of store in Irmin: the ones based on {{!of_branch}
persistent} named branches and the ones based {{!of_commit} temporary}
detached heads. These exist relative to a local, larger (and shared)
store, and have some (shared) contents. This is exactly the same as usual
version control systems, that the informed user can see as an implicit
purely functional data-structure. *)
module Schema : Schema.S
type repo
(** The type for Irmin repositories. *)
type t
(** The type for Irmin stores. *)
type step = Schema.Path.step [@@deriving irmin]
(** The type for {!type-key} steps. *)
type path = Schema.Path.t [@@deriving irmin]
(** The type for store keys. A key is a sequence of {!step}s. *)
type metadata = Schema.Metadata.t [@@deriving irmin]
(** The type for store metadata. *)
type contents = Schema.Contents.t [@@deriving irmin]
(** The type for store contents. *)
type node [@@deriving irmin]
(** The type for store nodes. *)
type tree [@@deriving irmin]
(** The type for store trees. *)
type hash = Schema.Hash.t [@@deriving irmin]
(** The type for object hashes. *)
type commit
(** Type for [`Commit] identifiers. Similar to Git's commit SHA1s. *)
val commit_t : repo -> commit Type.t
(** [commit_t r] is the value type for {!commit}. *)
type branch = Schema.Branch.t [@@deriving irmin]
(** Type for persistent branch names. Branches usually share a common global
namespace and it's the user's responsibility to avoid name clashes. *)
type slice [@@deriving irmin]
(** Type for store slices. *)
type info = Schema.Info.t [@@deriving irmin]
(** The type for commit info. *)
type lca_error = [ `Max_depth_reached | `Too_many_lcas ] [@@deriving irmin]
(** The type for errors associated with functions computing least common
ancestors *)
type ff_error = [ `No_change | `Rejected | lca_error ] [@@deriving irmin]
(** The type for errors for {!Head.fast_forward}. *)
module Info : sig
include Info.S with type t = info
(** @inline *)
end
type contents_key [@@deriving irmin]
type node_key [@@deriving irmin]
type commit_key [@@deriving irmin]
(** Repositories. *)
module Repo : sig
(** {1 Repositories}
A repository contains a set of branches. *)
type t = repo
(** The type of repository handles. *)
val v : Conf.t -> t Lwt.t
(** [v config] connects to a repository in a backend-specific manner. *)
val config : t -> Conf.t
(** [config repo] is the configuration used to create [repo] *)
include Closeable with type _ t := t
(** @inline *)
val heads : t -> commit list Lwt.t
(** [heads] is {!Head.list}. *)
val branches : t -> branch list Lwt.t
(** [branches] is {!Branch.list}. *)
val export :
?full:bool ->
?depth:int ->
?min:commit list ->
?max:[ `Head | `Max of commit list ] ->
t ->
slice Lwt.t
(** [export t ~full ~depth ~min ~max] exports the store slice between [min]
and [max], using at most [depth] history depth (starting from the max).
If [max] is `Head (also the default value), use the current [heads]. If
[min] is not specified, use an unbound past (but can still be limited by
[depth]).
[depth] is used to limit the depth of the commit history. [None] here
means no limitation.
If [full] is set (default is true), the full graph, including the
commits, nodes and contents, is exported, otherwise it is the commit
history graph only. *)
val import : t -> slice -> (unit, [ `Msg of string ]) result Lwt.t
(** [import t s] imports the contents of the slice [s] in [t]. Does not
modify branches. *)
type elt =
[ `Commit of commit_key
| `Node of node_key
| `Contents of contents_key
| `Branch of branch ]
[@@deriving irmin]
(** The type for elements iterated over by {!iter}. *)
val default_pred_commit : t -> commit_key -> elt list Lwt.t
val default_pred_node : t -> node_key -> elt list Lwt.t
val default_pred_contents : t -> contents_key -> elt list Lwt.t
val iter :
?cache_size:int ->
min:elt list ->
max:elt list ->
?edge:(elt -> elt -> unit Lwt.t) ->
?branch:(branch -> unit Lwt.t) ->
?commit:(commit_key -> unit Lwt.t) ->
?node:(node_key -> unit Lwt.t) ->
?contents:(contents_key -> unit Lwt.t) ->
?skip_branch:(branch -> bool Lwt.t) ->
?skip_commit:(commit_key -> bool Lwt.t) ->
?skip_node:(node_key -> bool Lwt.t) ->
?skip_contents:(contents_key -> bool Lwt.t) ->
?pred_branch:(t -> branch -> elt list Lwt.t) ->
?pred_commit:(t -> commit_key -> elt list Lwt.t) ->
?pred_node:(t -> node_key -> elt list Lwt.t) ->
?pred_contents:(t -> contents_key -> elt list Lwt.t) ->
?rev:bool ->
t ->
unit Lwt.t
(** [iter t] iterates in topological order over the closure graph of [t]. If
[rev] is set (by default it is) the traversal is done in reverse order.
[skip_branch], [skip_commit], [skip_node] and [skip_contents] allow the
traversal to be stopped when the corresponding objects are traversed. By
default no objects are skipped.
The [branch], [commit], [node] and [contents] functions are called
whenever the corresponding objects are traversed. By default these
functions do nothing. These functions are not called on skipped objects.
[pred_branch], [pred_commit], [pred_node] and [pred_contents] implicitly
define the graph underlying the traversal. By default they exactly match
the underlying Merkle graph of the repository [t]. These functions can
be used to traverse a slightly modified version of that graph, for
instance by modifying [pred_contents] to implicitly link structured
contents with other objects in the graph.
The traversed objects are all included between [min] (included) and
[max] (included), following the Merkle graph order. Moreover, the [min]
boundary is extended as follows:
- contents and node objects in [min] stop the traversal; their
predecessors are not traversed.
- commit objects in [min] stop the traversal for their commit
predecessors, but their sub-node are still traversed. This allows
users to define an inclusive range of commit to iterate over.
- branch objects in [min] implicitly add to [min] the commit they are
pointing to; this allow users to define the iteration between two
branches.
[cache_size] is the size of the LRU used to store traversed objects. If
an entry is evicted from the LRU, it can be traversed multiple times by
{!Repo.iter}. When [cache_size] is [None] (the default), no entries is
ever evicted from the cache; hence every object is only traversed once,
at the cost of having to store all the traversed objects in memory. *)
val breadth_first_traversal :
?cache_size:int ->
max:elt list ->
?branch:(branch -> unit Lwt.t) ->
?commit:(commit_key -> unit Lwt.t) ->
?node:(node_key -> unit Lwt.t) ->
?contents:(contents_key -> unit Lwt.t) ->
?pred_branch:(t -> branch -> elt list Lwt.t) ->
?pred_commit:(t -> commit_key -> elt list Lwt.t) ->
?pred_node:(t -> node_key -> elt list Lwt.t) ->
?pred_contents:(t -> contents_key -> elt list Lwt.t) ->
t ->
unit Lwt.t
end
val empty : repo -> t Lwt.t
(** [empty repo] is a temporary, empty store. Becomes a normal temporary store
after the first update. *)
val main : repo -> t Lwt.t
(** [main r] is a persistent store based on [r]'s main branch. This operation
is cheap, can be repeated multiple times. *)
val of_branch : repo -> branch -> t Lwt.t
(** [of_branch r name] is a persistent store based on the branch [name].
Similar to {!main}, but use [name] instead of {!Irmin.Branch.S.main}. *)
val of_commit : commit -> t Lwt.t
(** [of_commit c] is a temporary store, based on the commit [c].
Temporary stores do not have stable names: instead they can be addressed
using the hash of the current commit. Temporary stores are similar to
Git's detached heads. In a temporary store, all the operations are
performed relative to the current head and update operations can modify
the current head: the current stores's head will automatically become the
new head obtained after performing the update. *)
val repo : t -> repo
(** [repo t] is the repository containing [t]. *)
val tree : t -> tree Lwt.t
(** [tree t] is [t]'s current tree. Contents is not allowed at the root of the
tree. *)
module Status : sig
type t = [ `Empty | `Branch of branch | `Commit of commit ]
(** The type for store status. *)
val t : repo -> t Type.t
(** [t] is the value type for {!type-t}. *)
val pp : t Fmt.t
(** [pp] is the pretty-printer for store status. *)
end
val status : t -> Status.t
(** [status t] is [t]'s status. It can either be a branch, a commit or empty. *)
(** Managing the store's heads. *)
module Head : sig
val list : repo -> commit list Lwt.t
(** [list t] is the list of all the heads in local store. Similar to
[git rev-list --all]. *)
val find : t -> commit option Lwt.t
(** [find t] is the current head of the store [t]. This works for both
persistent and temporary branches. In the case of a persistent branch,
this involves getting the the head associated with the branch, so this
may block. In the case of a temporary store, it simply returns the
current head. Returns [None] if the store has no contents. Similar to
[git rev-parse HEAD]. *)
val get : t -> commit Lwt.t
(** Same as {!find} but raise [Invalid_argument] if the store does not have
any contents. *)
val set : t -> commit -> unit Lwt.t
(** [set t h] updates [t]'s contents with the contents of the commit [h].
Can cause data loss as it discards the current contents. Similar to
[git reset --hard <hash>]. *)
val fast_forward :
t -> ?max_depth:int -> ?n:int -> commit -> (unit, ff_error) result Lwt.t
(** [fast_forward t h] is similar to {!set} but the [t]'s head is updated to
[h] only if [h] is stricly in the future of [t]'s current head.
[max_depth] or [n] are used to limit the search space of the lowest
common ancestors (see {!lcas}).
The result is:
- [Ok ()] if the operation is succesfull;
- [Error `No_change] if [h] is already [t]'s head;
- [Error `Rejected] if [h] is not in the strict future of [t]'s head.
- [Error e] if the history exploration has been cut before getting
useful results. In that case. the operation can be retried using
different parameters of [n] and [max_depth] to get better results. *)
val test_and_set :
t -> test:commit option -> set:commit option -> bool Lwt.t
(** Same as {!set} but check that the value is [test] before updating to
[set]. Use {!set} or {!val-merge} instead if possible. *)
val merge :
into:t ->
info:Info.f ->
?max_depth:int ->
?n:int ->
commit ->
(unit, Merge.conflict) result Lwt.t
(** [merge ~into:t ?max_head ?n commit] merges the contents of the commit
associated to [commit] into [t]. [max_depth] is the maximal depth used
for getting the lowest common ancestor. [n] is the maximum number of
lowest common ancestors. If present, [max_depth] or [n] are used to
limit the search space of the lowest common ancestors (see {!lcas}). *)
end
module Hash : Hash.S with type t = hash
(** Object hashes. *)
(** [Commit] defines immutable objects to describe store updates. *)
module Commit : sig
type t = commit
(** The type for store commits. *)
val t : repo -> t Type.t
(** [t] is the value type for {!type-t}. *)
val pp_hash : t Fmt.t
(** [pp] is the pretty-printer for commit. Display only the hash. *)
val v :
?clear:bool ->
repo ->
info:info ->
parents:commit_key list ->
tree ->
commit Lwt.t
(** [v r i ~parents:p t] is the commit [c] such that:
- [info c = i]
- [parents c = p]
- [tree c = t]
When [clear] is set (the default), the tree cache is emptied upon the
function's completion, mirroring the effect of invoking {!Tree.clear}. *)
val tree : commit -> tree
(** [tree c] is [c]'s root tree. *)
val parents : commit -> commit_key list
(** [parents c] are [c]'s parents. *)
val info : commit -> info
(** [info c] is [c]'s info. *)
val hash : commit -> hash
(** [hash c] is [c]'s hash. *)
(** {1 Import/Export} *)
val key : commit -> commit_key
(** [key c] is [c]'s key. *)
val of_key : repo -> commit_key -> commit option Lwt.t
(** [of_key r k] is the the commit object in [r] with key [k], or [None] if
no such commit object exists. *)
val of_hash : repo -> hash -> commit option Lwt.t
(** [of_hash r h] is the commit object in [r] with hash [h], or [None] if no
such commit object is indexed in [r].
{b Note:} in stores for which {!commit_key} = {!type-hash}, this
function has identical behaviour to {!of_key}. *)
end
(** [Contents] provides base functions for the store's contents. *)
module Contents : sig
include Contents.S with type t = contents
(** {1 Import/Export} *)
val hash : contents -> hash
(** [hash c] it [c]'s hash. *)
val of_key : repo -> contents_key -> contents option Lwt.t
(** [of_key r k] is the contents object in [r] with key [k], or [None] if no
such contents object exists. *)
val of_hash : repo -> hash -> contents option Lwt.t
(** [of_hash r h] is the contents object in [r] with hash [h], or [None] if
no such contents object is indexed in [r].
{b Note:} in stores for which {!contents_key} = {!type-hash}, this
function has identical behaviour to {!of_key}. *)
end
(** Managing store's trees. *)
module Tree : sig
include
Tree.S
with type t := tree
and type step := step
and type path := path
and type metadata := metadata
and type contents := contents
and type contents_key := contents_key
and type node := node
and type hash := hash
(** {1 Import/Export} *)
type kinded_key =
[ `Contents of contents_key * metadata | `Node of node_key ]
[@@deriving irmin]
(** Keys in the Irmin store are tagged with the type of the value they
reference (either {!contents} or {!node}). In the [contents] case, the
key is paired with corresponding {!metadata}. *)
val key : tree -> kinded_key option
(** [key t] is the key of tree [t] in the underlying repository, if it
exists. Tree objects that exist entirely in memory (such as those built
with {!of_concrete}) have no backend key until they are exported to a
repository, and so will return [None]. *)
val find_key : Repo.t -> tree -> kinded_key option Lwt.t
(** [find_key r t] is the key of a tree object with the same hash as [t] in
[r], if such a key exists and is indexed. *)
val of_key : Repo.t -> kinded_key -> tree option Lwt.t
(** [of_key r h] is the tree object in [r] having [h] as key, or [None] if
no such tree object exists. *)
val shallow : Repo.t -> kinded_key -> tree
(** [shallow r h] is the shallow tree object with the key [h]. No check is
performed to verify if [h] actually exists in [r]. *)
val hash : ?cache:bool -> tree -> hash
(** [hash t] is the hash of tree [t]. *)
type kinded_hash = [ `Contents of hash * metadata | `Node of hash ]
(** Like {!kinded_key}, but with hashes as value references rather than
keys. *)
val kinded_hash : ?cache:bool -> tree -> kinded_hash
(** [kinded_hash t] is [c]'s kinded hash. *)
val of_hash : Repo.t -> kinded_hash -> tree option Lwt.t
(** [of_hash r h] is the tree object in [r] with hash [h], or [None] if no
such tree object is indexed in [r].
{b Note:} in stores for which {!node_key} = {!contents_key} =
{!type-hash}, this function has identical behaviour to {!of_key}. *)
(** {1 Proofs} *)
type ('proof, 'result) producer :=
repo ->
kinded_key ->
(tree -> (tree * 'result) Lwt.t) ->
('proof * 'result) Lwt.t
(** [produce r h f] runs [f] on top of a real store [r], producing a proof
and a result using the initial root hash [h].
The trees produced during [f]'s computation will carry the full history
of reads. This history will be reset when [f] is complete so subtrees
escaping the scope of [f] will not cause memory leaks.
Calling [produce_proof] recursively has an undefined behaviour. *)
type verifier_error =
[ `Proof_mismatch of string
| `Stream_too_long of string
| `Stream_too_short of string ]
[@@deriving irmin]
(** The type for errors associated with functions that verify proofs. *)
type ('proof, 'result) verifier :=
'proof ->
(tree -> (tree * 'result) Lwt.t) ->
(tree * 'result, verifier_error) result Lwt.t
(** [verify p f] runs [f] in checking mode. [f] is a function that takes a
tree as input and returns a new version of the tree and a result. [p] is
a proof, that is a minimal representation of the tree that contains what
[f] should be expecting.
Therefore, contrary to trees found in a storage, the contents of the
trees passed to [f] may not be available. For this reason, looking up a
value at some [path] can now produce three distinct outcomes:
- A value [v] is present in the proof [p] and returned :
[find tree path] is a promise returning [Some v];
- [path] is known to have no value in [tree] : [find tree path] is a
promise returning [None]; and
- [path] is known to have a value in [tree] but [p] does not provide it
because [f] should not need it: [verify] returns an error classifying
[path] as an invalid path (see below).
The same semantics apply to all operations on the tree [t] passed to [f]
and on all operations on the trees built from [f].
The generated tree is the tree after [f] has completed. That tree is
disconnected from the backend. It is possible to run operations on it as
long as they don't require loading shallowed subtrees, otherwise it
would raise [Dangling_hash].
The result is [Error _] if the proof is rejected:
- For tree proofs: when [p.before] is different from the hash of
[p.state];
- For tree and stream proofs: when [p.after] is different from the hash
of [f p.state];
- For tree and stream proofs: when [f p.state] tries to access paths
invalid paths in [p.state];
- For stream proofs: when the proof is not empty once [f] is done. *)
type tree_proof := Proof.tree Proof.t
(** The type for tree proofs.
Guarantee that the given computation performs exactly the same state
operations as the generating computation, *in some order*. *)
val produce_proof : (tree_proof, 'a) producer
(** [produce_proof] is the producer of tree proofs. *)
val verify_proof : (tree_proof, 'a) verifier
(** [verify_proof] is the verifier of tree proofs. *)
val hash_of_proof_state : Proof.tree -> kinded_hash
type stream_proof := Proof.stream Proof.t
(** The type for stream proofs.
Guarantee that the given computation performs exactly the same state
operations as the generating computation, in the exact same order.
Calling [fold] with [order = `Undefined] during the
production/verification of streamed proofs is undefined. *)
val produce_stream : (stream_proof, 'a) producer
(** [produce_stream] is the producer of stream proofs. *)
val verify_stream : (stream_proof, 'a) verifier
(** [verify_stream] is the verifier of stream proofs. *)
end
(** {1 Reads} *)
val kind : t -> path -> [ `Contents | `Node ] option Lwt.t
(** [kind] is {!Tree.kind} applied to [t]'s root tree. *)
val list : t -> path -> (step * tree) list Lwt.t
(** [list t] is {!Tree.list} applied to [t]'s root tree. *)
val mem : t -> path -> bool Lwt.t
(** [mem t] is {!Tree.mem} applied to [t]'s root tree. *)
val mem_tree : t -> path -> bool Lwt.t
(** [mem_tree t] is {!Tree.mem_tree} applied to [t]'s root tree. *)
val find_all : t -> path -> (contents * metadata) option Lwt.t
(** [find_all t] is {!Tree.find_all} applied to [t]'s root tree. *)
val find : t -> path -> contents option Lwt.t
(** [find t] is {!Tree.find} applied to [t]'s root tree. *)
val get_all : t -> path -> (contents * metadata) Lwt.t
(** [get_all t] is {!Tree.get_all} applied on [t]'s root tree. *)
val get : t -> path -> contents Lwt.t
(** [get t] is {!Tree.get} applied to [t]'s root tree. *)
val find_tree : t -> path -> tree option Lwt.t
(** [find_tree t] is {!Tree.find_tree} applied to [t]'s root tree. *)
val get_tree : t -> path -> tree Lwt.t
(** [get_tree t k] is {!Tree.get_tree} applied to [t]'s root tree. *)
type kinded_key := [ `Contents of contents_key | `Node of node_key ]
val key : t -> path -> kinded_key option Lwt.t
(** [id t k] *)
val hash : t -> path -> hash option Lwt.t
(** [hash t k] *)
(** {1 Updates} *)
type write_error =
[ Merge.conflict | `Too_many_retries of int | `Test_was of tree option ]
[@@deriving irmin]
(** The type for write errors.
- Merge conflict.
- Concurrent transactions are competing to get the current operation
committed and too many attemps have been tried (livelock).
- A "test and set" operation has failed and the current value is [v]
instead of the one we were waiting for. *)
val set :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
contents ->
(unit, write_error) result Lwt.t
(** [set t k ~info v] sets [k] to the value [v] in [t]. Discard any previous
results but ensure that no operation is lost in the history.
This function always uses {!Metadata.default} as metadata. Use {!set_tree}
with `[Contents (c, m)] for different ones.
When [clear] is set (the default), the tree cache is emptied upon the
function's completion, mirroring the effect of invoking {!Tree.clear}.
The result is [Error `Too_many_retries] if the concurrent operations do
not allow the operation to commit to the underlying storage layer
(livelock). *)
val set_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
contents ->
unit Lwt.t
(** [set_exn] is like {!set} but raise [Failure _] instead of using a result
type. *)
val set_tree :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
tree ->
(unit, write_error) result Lwt.t
(** [set_tree] is like {!set} but for trees. *)
val set_tree_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
tree ->
unit Lwt.t
(** [set_tree] is like {!set_exn} but for trees. *)
val remove :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
(unit, write_error) result Lwt.t
(** [remove t ~info k] remove any bindings to [k] in [t].
The result is [Error `Too_many_retries] if the concurrent operations do
not allow the operation to commit to the underlying storage layer
(livelock). *)
val remove_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
unit Lwt.t
(** [remove_exn] is like {!remove} but raise [Failure _] instead of a using
result type. *)
val test_and_set :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
test:contents option ->
set:contents option ->
(unit, write_error) result Lwt.t
(** [test_and_set ~test ~set] is like {!set} but it atomically checks that the
tree is [test] before modifying it to [set].
This function always uses {!Metadata.default} as metadata. Use
{!test_and_set_tree} with `[Contents (c, m)] for different ones.
The result is [Error (`Test t)] if the current tree is [t] instead of
[test].
The result is [Error `Too_many_retries] if the concurrent operations do
not allow the operation to commit to the underlying storage layer
(livelock). *)
val test_and_set_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
test:contents option ->
set:contents option ->
unit Lwt.t
(** [test_and_set_exn] is like {!test_and_set} but raise [Failure _] instead
of using a result type. *)
val test_and_set_tree :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
test:tree option ->
set:tree option ->
(unit, write_error) result Lwt.t
(** [test_and_set_tree] is like {!test_and_set} but for trees. *)
val test_and_set_tree_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
t ->
path ->
test:tree option ->
set:tree option ->
unit Lwt.t
(** [test_and_set_tree_exn] is like {!test_and_set_exn} but for trees. *)
val test_set_and_get :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:(unit -> info) ->
t ->
path ->
test:contents option ->
set:contents option ->
(commit option, write_error) result Lwt.t
(** [test_set_and_get] is like {!test_and_set} except it also returns the
commit associated with updating the store with the new value if the
[test_and_set] is successful. No commit is returned if there was no update
to the store. *)
val test_set_and_get_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:(unit -> info) ->
t ->
path ->
test:contents option ->
set:contents option ->
commit option Lwt.t
(** [test_set_and_get_exn] is like {!test_set_and_get} but raises [Failure _]
instead. *)
val test_set_and_get_tree :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:(unit -> info) ->
t ->
path ->
test:tree option ->
set:tree option ->
(commit option, write_error) result Lwt.t
(** [test_set_and_get_tree] is like {!test_set_and_get} but for a
{!type-tree} *)
val test_set_and_get_tree_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:(unit -> info) ->
t ->
path ->
test:tree option ->
set:tree option ->
commit option Lwt.t
(** [test_set_and_get_tree_exn] is like {!test_set_and_get_tree} but raises
[Failure _] instead. *)
val merge :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
old:contents option ->
t ->
path ->
contents option ->
(unit, write_error) result Lwt.t
(** [merge ~old] is like {!set} but merge the current tree and the new tree
using [old] as ancestor in case of conflicts.
This function always uses {!Metadata.default} as metadata. Use
{!merge_tree} with `[Contents (c, m)] for different ones.
The result is [Error (`Conflict c)] if the merge failed with the conflict
[c].
The result is [Error `Too_many_retries] if the concurrent operations do
not allow the operation to commit to the underlying storage layer
(livelock). *)
val merge_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
old:contents option ->
t ->
path ->
contents option ->
unit Lwt.t
(** [merge_exn] is like {!val-merge} but raise [Failure _] instead of using a
result type. *)
val merge_tree :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
old:tree option ->
t ->
path ->
tree option ->
(unit, write_error) result Lwt.t
(** [merge_tree] is like {!merge_tree} but for trees. *)
val merge_tree_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
info:Info.f ->
old:tree option ->
t ->
path ->
tree option ->
unit Lwt.t
(** [merge_tree] is like {!merge_tree} but for trees. *)
val with_tree :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
?strategy:[ `Set | `Test_and_set | `Merge ] ->
info:Info.f ->
t ->
path ->
(tree option -> tree option Lwt.t) ->
(unit, write_error) result Lwt.t
(** [with_tree t k ~info f] replaces {i atomically} the subtree [v] under [k]
in the store [t] by the contents of the tree [f v], using the commit info
[info ()].
If [v = f v] and [allow_empty] is unset (default) then, the operation is a
no-op.
If [v != f v] and no other changes happen concurrently, [f v] becomes the
new subtree under [k]. If other changes happen concurrently to that
operations, the semantics depend on the value of [strategy]:
- if [strategy = `Set], use {!set} and discard any concurrent updates to
[k].
- if [strategy = `Test_and_set] (default), use {!test_and_set} and ensure
that no concurrent operations are updating [k].
- if [strategy = `Merge], use {!val-merge} and ensure that concurrent
updates and merged with the values present at the beginning of the
transaction.
{b Note:} Irmin transactions provides
{{:https://en.wikipedia.org/wiki/Snapshot_isolation} snapshot isolation}
guarantees: reads and writes are isolated in every transaction, but only
write conflicts are visible on commit. *)
val with_tree_exn :
?clear:bool ->
?retries:int ->
?allow_empty:bool ->
?parents:commit list ->
?strategy:[ `Set | `Test_and_set | `Merge ] ->
info:Info.f ->
t ->
path ->
(tree option -> tree option Lwt.t) ->
unit Lwt.t
(** [with_tree_exn] is like {!with_tree} but raise [Failure _] instead of
using a return type. *)
(** {1 Clones} *)
val clone : src:t -> dst:branch -> t Lwt.t
(** [clone ~src ~dst] makes [dst] points to [Head.get src]. [dst] is created
if needed. Remove the current contents en [dst] if [src] is {!val-empty}. *)
(** {1 Watches} *)
type watch
(** The type for store watches. *)
val watch : t -> ?init:commit -> (commit Diff.t -> unit Lwt.t) -> watch Lwt.t
(** [watch t f] calls [f] every time the contents of [t]'s head is updated.
{b Note:} even if [f] might skip some head updates, it will never be
called concurrently: all consecutive calls to [f] are done in sequence, so
we ensure that the previous one ended before calling the next one. *)
val watch_key :
t ->
path ->
?init:commit ->
((commit * tree) Diff.t -> unit Lwt.t) ->
watch Lwt.t
(** [watch_key t key f] calls [f] every time the [key]'s value is added,
removed or updated. If the current branch is deleted, no signal is sent to
the watcher. *)
val unwatch : watch -> unit Lwt.t
(** [unwatch w] disable [w]. Return once the [w] is fully disabled. *)
(** {1 Merges and Common Ancestors} *)
type 'a merge =
info:Info.f ->
?max_depth:int ->
?n:int ->
'a ->
(unit, Merge.conflict) result Lwt.t
(** The type for merge functions. *)
val merge_into : into:t -> t merge
(** [merge_into ~into:x ~info:i t] merges [t]'s current branch into [x]'s
current branch using the info [i]. After that operation, the two stores
are still independent. Similar to [git merge <branch>]. *)
val merge_with_branch : t -> branch merge
(** Same as {!val-merge} but with a branch ID. *)
val merge_with_commit : t -> commit merge
(** Same as {!val-merge} but with a commit_id. *)
val lcas :
?max_depth:int -> ?n:int -> t -> t -> (commit list, lca_error) result Lwt.t
(** [lca ?max_depth ?n msg t1 t2] returns the collection of least common
ancestors between the heads of [t1] and [t2] branches.
- [max_depth] is the maximum depth of the exploration (default is
[max_int]). Return [Error `Max_depth_reached] if this depth is exceeded.
- [n] is the maximum expected number of lcas. Stop the exploration as soon
as [n] lcas are found. Return [Error `Too_many_lcas] if more [lcas] are
found. *)
val lcas_with_branch :
t ->
?max_depth:int ->
?n:int ->
branch ->
(commit list, lca_error) result Lwt.t
(** Same as {!lcas} but takes a branch ID as argument. *)
val lcas_with_commit :
t ->
?max_depth:int ->
?n:int ->
commit ->
(commit list, lca_error) result Lwt.t
(** Same as {!lcas} but takes a commmit as argument. *)
(** {1 History} *)
module History : Graph.Sig.P with type V.t = commit
(** An history is a DAG of heads. *)
val history :
?depth:int -> ?min:commit list -> ?max:commit list -> t -> History.t Lwt.t
(** [history ?depth ?min ?max t] is a view of the history of the store [t], of
depth at most [depth], starting from the [t]'s head (or from [max] if the
head is not set) and stopping at [min] if specified. *)
val last_modified : ?depth:int -> ?n:int -> t -> path -> commit list Lwt.t
(** [last_modified ?number c k] is the list of the last [number] commits that
modified [path], in ascending order of date. [depth] is the maximum depth
to be explored in the commit graph, if any. Default value for [number] is
1. *)
(** Manipulate branches. *)
module Branch : sig
(** {1 Branch Store}
Manipulate relations between {{!branch} branches} and {{!commit}
commits}. *)
val mem : repo -> branch -> bool Lwt.t
(** [mem r b] is true iff [b] is present in [r]. *)
val find : repo -> branch -> commit option Lwt.t
(** [find r b] is [Some c] iff [c] is bound to [b] in [t]. It is [None] if
[b] is not present in [t]. *)
val get : repo -> branch -> commit Lwt.t
(** [get t b] is similar to {!find} but raise [Invalid_argument] if [b] is
not present in [t]. *)
val set : repo -> branch -> commit -> unit Lwt.t
(** [set t b c] bounds [c] to [b] in [t]. *)
val remove : repo -> branch -> unit Lwt.t
(** [remove t b] removes [b] from [t]. *)
val list : repo -> branch list Lwt.t
(** [list t] is the list of branches present in [t]. *)
val watch :
repo ->
branch ->
?init:commit ->
(commit Diff.t -> unit Lwt.t) ->
watch Lwt.t
(** [watch t b f] calls [f] on every change in [b]. *)
val watch_all :
repo ->
?init:(branch * commit) list ->
(branch -> commit Diff.t -> unit Lwt.t) ->
watch Lwt.t
(** [watch_all t f] calls [f] on every branch-related change in [t],
including creation/deletion events. *)
include Branch.S with type t = branch
(** Base functions for branches. *)
end
(** [Path] provides base functions for the stores's paths. *)
module Path : Path.S with type t = path and type step = step
module Metadata : Metadata.S with type t = metadata
(** [Metadata] provides base functions for node metadata. *)
(** Backend functions, which might be used by the backends. *)
module Backend :
Backend.S
with module Schema = Schema
with type Slice.t = slice
and type Repo.t = repo
and module Hash = Hash
and module Node.Path = Path
and type Contents.key = contents_key
and type Node.key = node_key
and type Commit.key = commit_key
type Remote.t +=
| E of Backend.Remote.endpoint
(** Extend the [remote] type with [endpoint]. *)
(** {2 Converters to backend types} *)
val of_backend_node : repo -> Backend.Node.value -> node
val to_backend_node : node -> Backend.Node.value Lwt.t
val to_backend_portable_node : node -> Backend.Node_portable.t Lwt.t
val to_backend_commit : commit -> Backend.Commit.value
(** [to_backend_commit c] is the backend commit object associated with the
commit [c]. *)
val of_backend_commit :
repo -> Backend.Commit.Key.t -> Backend.Commit.value -> commit
(** [of_backend_commit r k c] is the commit associated with the backend commit
object [c] that hash key [k] in [r]. *)
val save_contents :
[> write ] Backend.Contents.t -> contents -> contents_key Lwt.t
(** Save a content into the database *)
val save_tree :
?clear:bool ->
repo ->
[> write ] Backend.Contents.t ->
[> read_write ] Backend.Node.t ->
tree ->
kinded_key Lwt.t
(** Save a tree into the database. Does not do any reads.
When [clear] is set (the default), the tree cache is emptied upon the
function's completion, mirroring the effect of invoking {!Tree.clear}. *)
(** {2 Deprecated} *)
val master : repo -> t Lwt.t
[@@ocaml.deprecated "Use `main` instead."]
(** @deprecated Use {!main} instead *)
end
module type S = sig
type hash
(** @inline *)
include
S_generic_key
with type Schema.Hash.t = hash
and type hash := hash
and type contents_key = hash
and type node_key = hash
and type commit_key = hash
end
module S_is_a_generic_keyed (X : S) : S_generic_key = X
module type Maker_generic_key = sig
type endpoint
include Key.Store_spec.S
module Make (Schema : Schema.S) :
S_generic_key
with module Schema = Schema
and type Backend.Remote.endpoint = endpoint
and type contents_key = (Schema.Hash.t, Schema.Contents.t) contents_key
and type node_key = Schema.Hash.t node_key
and type commit_key = Schema.Hash.t commit_key
end
module type Maker =
Maker_generic_key
with type ('h, _) contents_key = 'h
and type 'h node_key = 'h
and type 'h commit_key = 'h
module type Json_tree = functor
(Store : S with type Schema.Contents.t = Contents.json)
-> sig
include Contents.S with type t = Contents.json
val to_concrete_tree : t -> Store.Tree.concrete
val of_concrete_tree : Store.Tree.concrete -> t
val get_tree : Store.tree -> Store.path -> t Lwt.t
(** Extract a [json] value from tree at the given key. *)
val set_tree : Store.tree -> Store.path -> t -> Store.tree Lwt.t
(** Project a [json] value onto a tree at the given key. *)
val get : Store.t -> Store.path -> t Lwt.t
(** Extract a [json] value from a store at the given key. *)
val set :
Store.t -> Store.path -> t -> info:(unit -> Store.info) -> unit Lwt.t
(** Project a [json] value onto a store at the given key. *)
end
module type KV_generic_key =
S_generic_key
with type Schema.Path.step = string
and type Schema.Path.t = string list
and type Schema.Branch.t = string
module type KV =
S
with type Schema.Path.step = string
and type Schema.Path.t = string list
and type Schema.Branch.t = string
module type KV_maker_generic_key = sig
type endpoint
type metadata
type hash
type info
include Key.Store_spec.S
module Make (C : Contents.S) :
KV_generic_key
with module Schema.Contents = C
and type Schema.Metadata.t = metadata
and type Backend.Remote.endpoint = endpoint
and type Schema.Hash.t = hash
and type contents_key = (hash, C.t) contents_key
and type node_key = hash node_key
and type commit_key = hash commit_key
and type Schema.Info.t = info
end
module type KV_maker =
KV_maker_generic_key
with type ('h, _) contents_key = 'h
and type 'h node_key = 'h
and type 'h commit_key = 'h
module type Sigs = sig
module type S = S
module type Maker = Maker
module type Json_tree = Json_tree
module type KV = KV
module type KV_maker = KV_maker
module Generic_key : sig
module type S = S_generic_key
module type KV = KV_generic_key
module type Maker = Maker_generic_key
module type KV_maker = KV_maker_generic_key
end
type Remote.t +=
| Store : (module Generic_key.S with type t = 'a) * 'a -> Remote.t
module Make (B : Backend.S) :
Generic_key.S
with module Schema = B.Schema
and type slice = B.Slice.t
and type repo = B.Repo.t
and type contents_key = B.Contents.key
and type node_key = B.Node.key
and type commit_key = B.Commit.key
and module Backend = B
module Json_tree : Json_tree
(** [Json_tree] is used to project JSON values onto trees. Instead of the
entire object being stored under one key, it is split across several keys
starting at the specified root key. *)
end