CurrentSourceEach operation has a level, giving an estimate of the cost or risk of the operation. When testing a pipeline, it can be useful to set a maximum level, or to require confirmation for more risky operations.
An OCurrent pipeline is made up of primitive operations. A primitive is roughly the content of a single box in the diagram.
include Current_term.S.TERM
with type metadata := Metadata.t
and type 'a primitive := 'a Primitive.tAn 'a t is a term that produces a value of type 'a.
Information about operations hidden behind a bind.
active x is a term indicating that the result is not determined yet.
val state :
?hidden:bool ->
'a t ->
('a, [ `Active of Current_term.Output.active | `Msg of string ]) result tstate t always immediately returns a successful result giving the current state of t.
catch t successfully returns Ok x if t evaluates successfully to x, or successfully returns Error e if t fails with error e. If t is active then catch t will be active too.
of_output x is a returned, failed or active term.
map f x is a term that runs x and then transforms the result using f.
The optional equality function ?eq defaults to physical equality. When f produces an updated result following a change in x, the equality function will be called with the previous and the new value eq b_old b_new: returning true indicates that the change can be ignored and should not propagate further down the pipeline.
map_error f x is a term that runs x and then transforms the error string (if any) using f.
pair a b is the pair containing the results of evaluating a and b (in parallel).
val list_map :
(module Current_term.S.ORDERED with type t = 'a) ->
?collapse_key:string ->
?label:string ->
('a t -> 'b t) ->
'a list t ->
'b list tlist_map (module T) f xs adds f to the end of each input term and collects all the results into a single list.
val list_iter :
(module Current_term.S.ORDERED with type t = 'a) ->
?collapse_key:string ->
?label:string ->
('a t -> unit t) ->
'a list t ->
unit tLike list_map but for the simpler case when the result is unit.
list_seq x evaluates to a list containing the results of evaluating each element in x, once all elements of x have successfully completed.
option_map f x is a term that evaluates to Some (f y) if x evaluates to Some y, or to None otherwise.
Like option_map but for the simpler case when the result is unit.
option_seq None is Current.return None and option_seq (Some x) is Current.map some x. This is useful for handling optional arguments that are currents.
all xs is a term that succeeds if every term in xs succeeds. The labels are used if some terms fail, to indicate which ones are failing.
gate ~on:ctrl x is the same as x, once ctrl succeeds.
Note: gate does not delay x; it only delays whatever you put after the gate. e.g.
let binary = build src in
let tests_ok = test binary in
binary |> gate ~on:tests_ok |> deploycutoff ~eq x is the same as x, but changes to x that are equal according to eq do not propagate further down. It should be used when values of type 'a have a precise definition of equality to avoid triggering redundant work.
collapse ~key ~value ~input t is a term that behaves just like t, but when shown in a diagram it can be expanded or collapsed. When collapsed, it is shown as "input -> +" and the user can expand it to show t instead. The idea is that input is a dependency of t and the "+" represents everything in t after that. key and value are used as the parameters (e.g. in a URL) to control whether this is expanded or not. For example collapse ~key:"repo" ~value:"mirage/mirage-www" ~input:repo (process repo) Note: list_map ~collapse_key provides an easy way to use this.
val collapse_list :
key:string ->
value:string ->
input:_ t ->
'a t list ->
'a t list * unit tcollapse_list ~key ~value ~input t is a term that behaves just like t list, but when shown in a diagram it can be expanded or collapsed.
with_context ctx f is the term f (), where f is evaluated in context ctx. This means that ctx will be treated as an input to all terms created by f in the diagrams.
N.B. these operations create terms that cannot be statically analysed until after they are executed.
bind f x is a term that first runs x to get y and then behaves as the term f y. Static analysis cannot look inside the f function until x is ready, so using bind makes static analysis less useful. You can use the info argument to provide some information here.
primitive ~info f x is a term that evaluates f on each new value of x. This is used to provide the primitive operations, which can then be combined using the other combinators in this module. info is used to label the operation in the diagram.
component name is used to annotate binds, so that the system can show a name for the operations hidden inside the bind's function. name is used as the label for the bind in the generated dot diagrams. For convenience, name can also be a format string.
observe x evaluates the current state of term x. A `Blocked value occurs when the term failed because an upstream dependency errored.
A monitor is an input pipeline stage that can watch for external events.
module Analysis :
Current_term.S.ANALYSIS
with type 'a term := 'a t
and type metadata := Metadata.tDiagram generation, introspection, and statistics.
Variable pipeline inputs.
state_dir name is a directory under which state (build results, logs) can be stored. name identifies the sub-component of OCurrent, each of which gets its own subdirectory.
Like Lwt_switch, but the cleanup functions are called in sequence, not in parallel.
Resource pools, to control how many jobs can use a resource at a time. To use a pool within a job, pass the pool to Job.start or call Job.use_pool.
Jobs with log files. This is mostly an internal interface - use Current_cache instead.
Analysing job logs.