container.wit

// a Container is a collection of objects
interface container {
  use wasi:io/streams@0.2.2.{
    input-stream,
    output-stream,
  };

  use types.{
    container-metadata,
    error,
    incoming-value,
    object-metadata,
    object-name,
    outgoing-value,
  };

  // this defines the `container` resource
  resource container {
    // returns container name
    name: func() -> result<string, error>;

    // returns container metadata
    info: func() -> result<container-metadata, error>;

    // retrieves an object or portion of an object, as a resource.
    // Start and end offsets are inclusive.
    // Once a data-blob resource has been created, the underlying bytes are held by the blobstore service for the lifetime
    // of the data-blob resource, even if the object they came from is later deleted.
    get-data: func(name: object-name, start: u64, end: u64) -> result<incoming-value, error>;

    // creates or replaces an object with the data blob.
    write-data: func(name: object-name, data: borrow<outgoing-value>) -> result<_, error>;

    // returns list of objects in the container. Order is undefined.
    list-objects: func() -> result<stream-object-names, error>;

    // deletes object.
    // does not return error if object did not exist.
    delete-object: func(name: object-name) -> result<_, error>;

    // deletes multiple objects in the container
    delete-objects: func(names: list<object-name>) -> result<_, error>;

    // returns true if the object exists in this container
    has-object: func(name: object-name) -> result<bool, error>;

    // returns metadata for the object
    object-info: func(name: object-name) -> result<object-metadata, error>;

    // removes all objects within the container, leaving the container empty.
    clear: func() -> result<_, error>;
  }

  // this defines the `stream-object-names` resource which is a representation of stream<object-name>
  resource stream-object-names {
    // reads the next number of objects from the stream
    //
    // This function returns the list of objects read, and a boolean indicating if the end of the stream was reached.
    read-stream-object-names: func(len: u64) -> result<tuple<list<object-name>, bool>, error>;

    // skip the next number of objects in the stream
    //
    // This function returns the number of objects skipped, and a boolean indicating if the end of the stream was reached.
    skip-stream-object-names: func(num: u64) -> result<tuple<u64, bool>, error>;
  }
}