sdk/fidl/fuchsia.sys2/decls/offer_decl.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library fuchsia.sys2;

/// Declares a capability offered by a component to one of its children, which may
/// have been offered by the component's containing realm, the component itself,
/// or one of its other children.
xunion OfferDecl {
    OfferServiceDecl service;
    OfferDirectoryDecl directory;
};

/// Declares a service offered by a component to one of its children, which may
/// have been offered by the component's containing realm, the component itself,
/// or one of its other children.
table OfferServiceDecl {
    /// The provider of the capability relative to the component itself.
    1: OfferSource source;

    /// Path identifying the service being offered.
    2: string:MAX_PATH_LENGTH source_path;

    /// The list of children to which the capability should be offered.
    3: vector<OfferTarget> targets;
};

/// Declares a directory offered by a component to one of its children, which may
/// have been offered by the component's containing realm, the component itself,
/// or one of its other children.
table OfferDirectoryDecl {
    /// Path identifying the directory being offered.
    1: string:MAX_PATH_LENGTH source_path;

    /// The provider of the capability relative to the component itself.
    2: OfferSource source;

    /// The list of children to which the capability should be offered.
    3: vector<OfferTarget> targets;
};


/// Declares a storage capability offered by a component to one of its children,
/// such as meta storage offered by the component's containing realm or cache
/// storage offered by the component itself.
table StorageOfferDecl {
    /// The type of storage being offered.
    1: StorageType storage_type;

    /// The source of the storage capability.
    2: StorageOfferSource source;

    /// The list of children to which the capability should be offered.
    3: vector<StorageOfferTarget> targets;
};

/// The type of storage offered by this component.
enum StorageType {
    /// General data storage.
    DATA = 1;

    /// Cache storage that may be deleted at any time by the system.
    CACHE = 2;

    /// Meta storage that will be used by component manager to provide
    /// additional functionality for the component.
    META = 3;
};

/// The source of an offered storage capability, which may be either the realm
/// or the name of a storage section on the component itself.
xunion StorageOfferSource {
    RealmRef realm;
    StorageRef storage_section;
};

/// Describes a target for the offering of a storage capability.
table StorageOfferTarget {
    /// The name of the child component to which this storage capability is
    /// being offered.
    1: string:MAX_CHILD_NAME_LENGTH child_name;
};

/// Identifies a source component of an OfferDecl.
// TODO: Split OfferSource by capability type.
xunion OfferSource {
  RealmRef realm;
  SelfRef myself;
  ChildRef child;
};

/// Describes a target for a capability offering.
// TODO: Split OfferTarget by capability type.
table OfferTarget {
    /// The path under which the capability is being offered.
    ///
    /// Must be an absolute path starting with /.
    1: string:MAX_PATH_LENGTH target_path;

    /// Reference to the destination.
    2: OfferDest dest;
};

/// References the destination of an OfferTarget.
xunion OfferDest {
    ChildRef child;
    CollectionRef collection;
};