Managing store's trees.
Tree provides immutable, in-memory partial mirror of the store, with lazy reads and delayed writes.
Trees are like staging area in Git: they are immutable temporary non-persistent areas (they disappear if the host crash), held in memory for efficiency, where reads are done lazily and writes are done only when needed on commit: if you modify a key twice, only the last change will be written to the store when you commit.
empty is the empty tree. The empty tree does not have associated backend configuration values, as they can perform in-memory operation, independently of any given backend.
val of_contents : ?metadata :metadata -> contents -> tree of_contents c is the subtree built from the contents c.
of_node n is the subtree built from the node n.
The type for tree elements.
General-purpose constructor for trees.
val kind : tree -> key -> [ `Contents | `Node ] optionLwt .tkind t k is the type of s in t. It could either be a tree node or some file contents. It is None if k is not present in t.
val is_empty : tree -> is_empty t is true iff t is emptykind`Contents are never considered empty.
diff x y is the difference of contents between x and y.
type 'a or_error = ('a , [ `Dangling_hash of hash ] ) Stdlib .result Operations on lazy nodes can fail if the underlying store does not contain the expected hash.
module Contents : sig ... end Operations on lazy tree contents.
val mem : tree -> key -> bool Lwt .t mem t k is true iff k is associated to some contents in t.
find_all t k is Some (b, m) if k is associated to the contents b and metadata m in t and None if k is not present in t.
val length : node -> int Lwt .t find n is the number of entries in n.
find is similar to find_all
Same as find_allInvalid_arg if k is not present in t.
val list :
tree -> ?offset :int -> ?length :int -> key -> (step * tree ) listLwt .tlist t key is the list of files and sub-nodes stored under k in t. The result order is not specified but is stable.
offset and length are used for pagination.
Same as get_all
add t k c is the tree where the key k is bound to the contents c but is similar to t for other bindings.
update t k f is the tree t' that is the same as t for all keys except k, and whose binding for k is determined by f (find t k).
If k refers to an internal node of t, f is called with None to determine the value with which to replace it.
remove t k is the tree where k bindings has been removed but is similar to t for other bindings.
val mem_tree : tree -> key -> bool Lwt .t mem_tree t k is false iff find_tree k = None.
find_tree t k is Some v if k is associated to v in t. It is None if k is not present in t.
get_tree t k is v if k is associated to v in t. Raise Invalid_arg if k is not present in t.
add_tree t k v is the tree where the key k is bound to the non-empty tree v but is similar to t for other bindings.
If v is empty, this is equivalent to remove t k.
update_tree t k f is the tree t' that is the same as t for all subtrees except under k, and whose subtree at k is determined by f (find_tree t k).
f returning either None or Some empty causes the subtree at k to be unbound (i.e. it is equivalent to remove t k).
merge is the 3-way merge function for trees.
General-purpose destructor for trees.
val empty_marks : unit -> marks empty_marks () is an empty collection of marks.
type 'a force = [ | `True | `False of key -> 'a -> 'a Lwt .t | `And_clear ] The type for foldforce parameter. `True forces the fold to read the objects of the lazy nodes and contents. `False f is applying f on every lazy node and content value instead. `And_clear is like `True but also eagerly empties the Tree caches when traversing sub-nodes.
type uniq = [ | `False | `True | `Marks of marks ] The type for folduniq parameters. `False folds over all the nodes. `True does not recurse on nodes already seen. `Marks m uses the collection of marks m to store the cache of keys: the fold will modify m. This can be used for incremental folds.
type 'a node_fn = key -> step list-> 'a -> 'a Lwt .t The type for foldpre and post parameters.
type depth = [ | `Eq of int | `Le of int | `Lt of int | `Ge of int | `Gt of int ] The type for fold depths.
Eq d folds over nodes and contents of depth exactly d.Lt d folds over nodes and contents of depth strictly less than d.Gt d folds over nodes and contents of depth strictly more than d.Le d is Eq d and Lt d. Ge d is Eq d and Gt d.
fold f t acc folds f over t's leafs.
For every node n, ui n is a leaf node, call f path n. Otherwise:
Call pre path n. By default pre is the identity; Recursively call fold on each children, in lexicographic order; Call post path n; By default post is the identity. See forceforce parameters. By default it is `And_clear.
See uniquniq parameters. By default it is `False.
The fold depth is controlled by the depth parameter.
type stats = { nodes : int; leafs : int; skips : int; depth : int; width : int; } val stats : ?force :bool -> tree -> stats Lwt .tstats ~force t are t's statistics. If force is true, this will force the reading of lazy nodes. By default it is false.
The type for concrete trees.
of_concrete c is the subtree equivalent of the concrete tree c.
to_concrete t is the concrete tree equivalent of the subtree t.
val clear : ?depth :int -> tree -> clear ?depth t clears all caches in the tree t for subtrees with a depth higher than depth. If depth is not set, all of the subtrees are cleared.
type counters = { mutable contents_hash : int;mutable contents_find : int;mutable contents_add : int;mutable node_hash : int;mutable node_mem : int;mutable node_add : int;mutable node_find : int;mutable node_val_v : int;mutable node_val_find : int;mutable node_val_list : int;} val dump_counters : unit Fmt .t val reset_counters : unit -> unitval inspect : tree -> [ `Contents | `Node of [ `Map | `Hash | `Value ] hash r c it c's hash in the repository r.
Hashes in the Irmin store are tagged with the type of the value they reference (either contentsnodecontents case, the hash is paired with corresponding metadata
of_hash r h is the the tree object in r having h as hash, or None is no such tree object exists.
shallow r h is the shallow tree object with the hash h. No check is performed to verify if h actually exists in r.