Module `Node.Val`Source

Val provides base functions for node values.

Node values

Sourcetype t = value

The type for node values.

Sourceval t : t Irmin.Type.t

Sourcetype metadata = Metadata.t

The type for node metadata.

Sourceval metadata_t : metadata Irmin.Type.t

Sourcetype hash = key

The type for keys.

Sourceval hash_t : hash Irmin.Type.t

Sourcetype step = Path.step

The type for steps between nodes.

Sourceval step_t : step Irmin.Type.t

Sourcetype value = [

| `Node of hash
| `Contents of hash * metadata

]

The type for either (node) keys or (contents) keys combined with their metadata.

Sourceval value_t : value Irmin.Type.t

Sourceval of_list : (step * value) list -> t

of_list l is the node n such that list n = l.

Source

val list : 
  ?offset:int ->
  ?length:int ->
  ?cache:bool ->
  t ->
  (step * value) list

list t is the contents of t. offset and length are used to paginate results.

caching

cache regulates the caching behaviour regarding the node's internal data which may be lazily loaded from the backend, depending on the node implementation.

cache defaults to true which may greatly reduce the IOs and the runtime but may also increase the memory consumption.

cache = false doesn't replace a call to clear, it only prevents the storing of new data, it doesn't discard the existing one.

Sourceval of_seq : (unit -> (step * value) Seq.node) -> t

of_seq s is the node n such that seq n = s.

Source

val seq : 
  ?offset:int ->
  ?length:int ->
  ?cache:bool ->
  t ->
  unit ->
  (step * value) Seq.node

seq t is the contents of t. offset and length are used to paginate results.

See caching for an explanation of the cache parameter

Sourceval empty : t

empty is the empty node.

Sourceval is_empty : t -> bool

is_empty t is true iff t is empty.

Sourceval length : t -> int

length t is the number of entries in t.

Sourceval hash_exn : ?force:bool -> t -> hash

hash_exn t is the hash of t.

Another way of computing it is Hash.Typed(Hash)(Node).hash t which computes the pre-hash of t before hashing it using Hash. hash_exn might be faster because the it may be optimised (e.g. it may use caching).

hash_exn t is hash_exn ~force:true t which is not expected to raise an exception. hash_exn ~force:false t will raise Not_found if the hash requires IOs to be computed.

Sourceval clear : t -> unit

Cleanup internal caches.

Sourceval find : ?cache:bool -> t -> step -> value option

find t s is the value associated with s in t.

A node can point to user-defined contents. The edge between the node and the contents is labeled by a step.

See caching for an explanation of the cache parameter

Sourceval add : t -> step -> value -> t

add t s v is the node where find t v is Some s but is similar to t otherwise.

Sourceval remove : t -> step -> t

remove t s is the node where find t s is None but is similar to t otherwise.

Sourceval default : metadata

default is the default metadata value.

Proofs

Sourcetype proof = [

| `Blinded of hash
| `Values of (step * value) list
| `Inode of int * (int * proof) list

]

The type for proof trees.

Sourceval proof_t : proof Irmin.Type.t

Sourceval to_proof : t -> proof

Sourceval of_proof : depth:int -> proof -> t option

Sourceexception Dangling_hash of {

context : string;
hash : hash;

}

type head := [

| `Node of (step * value) list
| `Inode of int * (int * hash) list

]

Sourceval head : t -> head

Recursive Nodes

Some Node implementations (like irmin-pack's inodes) can represent a node as a set of nodes. One operation on such "high-level" node corresponds to a sequence of recursive calls to the underlying "lower-level" nodes. Note: theses effects are not in the Lwt monad on purpose (so Tree.hash and Tree.equal are not in the Lwt monad as well).

type effect := expected_depth:int -> hash -> t option

The type for read effects.

Sourceval with_handler : (effect -> effect) -> t -> t

with_handler f replace the current effect handler h by f h. f h will be called for all the recursive read effects that are required by recursive operations on nodes. .

Install

Dune Dependency

Authors

Maintainers

Sources

doc/irmin.mem/Irmin_mem/Make/Private/Node/Val/index.html

Module `Node.Val`Source

Node values

Proofs

Recursive Nodes

package irmin

Install

Dune Dependency

Authors

Maintainers

Sources

doc/irmin.mem/Irmin_mem/Make/Private/Node/Val/index.html

Module Node.ValSource

Node values

Proofs

Recursive Nodes

Module `Node.Val`Source