Documentation ¶
Overview ¶
Package repocpi contains the implementation support for repository backends. It offers three methods to create component version, component and repository objects based on three simple implementation interfaces.
The basic provisioning model is layered:
on layer 1 there is the user facing API defined in package github.com/open-component-model/ocm/pkg/contexts/ocm.
on layer 2 (this package) there is a backend agnostic implementation of standard functionality based on layer 3. This is divided into two parts
a) the view objects provided by the Dup() calls of the layer 1 API. All dups are internally based on a single base object. These objects are called bridge. They act as base object for the views and as abstraction for the implementation objects providing generic implementations potentially based on the implementation functionality. (see bridge design pattern https://refactoring.guru/design-patterns/bridge)
b) the bridge object as base for all dup views is used to implement some common functionality like the view management. The bridge object is closed, when the last view disappears. This bridge object then calls the final storage backend implementation interface.
the storage backend implementations based on the implementation interfaces provided by layer 2.
The implementation interfaces and the functions to create API objects are:
- interface ComponentVersionAccessImpl is used to create an ocm.ComponentVersionAccess object using the function NewComponentVersionAccess.
- interface ComponentAccessImpl is used to create an ocm.ComponentAccess object using the function NewComponentAccess.
- interface RepositoryImpl is used to create an ocm.ComponentAccess object using the function NewRepository.
Component version implementations provide basic access to component versions and their descriptors. They keep a reference to component implementations, which are again based on repository implementations. The task of repository implementations is to provide component objects. Their implementations are responsible to provide component version objects.
Besides this basic implementation interface with separated object for a repository, component and component version, there is support for a simplified implementation interface (StorageBackendImpl). This is a single interface bundling all required functionality to implement the objects for the three concerned elements. With NewStorageBackend it is possible to instantiate a new kind of repository based on this single interface. The required objects for components and component versions are generically provided based on the methods provided by this interface.
Index ¶
- Variables
- func GetComponentVersionImpl[T ComponentVersionAccessImpl](cv cpi.ComponentVersionAccess) (T, error)
- func NewComponentAccess(impl ComponentAccessImpl, kind string, main bool, closer ...io.Closer) (cpi.ComponentAccess, error)
- func NewComponentVersionAccess(name, version string, impl ComponentVersionAccessImpl, ...) (cpi.ComponentVersionAccess, error)
- func NewNoneRefRepositoryView(i RepositoryBridge) cpi.Repository
- func NewRepository(impl RepositoryImpl, kind string, closer ...io.Closer) cpi.Repository
- func NewStorageBackend(kind string, impl StorageBackendImpl) cpi.Repository
- type BlobCache
- type BlobCacheEntry
- type BlobCacheKey
- type BlobContainer
- type ComponentAccessBridge
- type ComponentAccessImpl
- type ComponentAccessInfo
- type ComponentAccessViewManager
- type ComponentVersionAccessBridge
- type ComponentVersionAccessImpl
- type ComponentVersionAccessInfo
- type ComponentVersionAccessViewManager
- type Repository
- type RepositoryBridge
- type RepositoryImpl
- type RepositoryViewManager
- type StorageBackendImpl
Constants ¶
This section is empty.
Variables ¶
var ( ErrClosed = resource.ErrClosed ErrTempVersion = fmt.Errorf("temporary component version cannot be updated") )
Functions ¶
func GetComponentVersionImpl ¶
func GetComponentVersionImpl[T ComponentVersionAccessImpl](cv cpi.ComponentVersionAccess) (T, error)
func NewComponentAccess ¶
func NewComponentAccess(impl ComponentAccessImpl, kind string, main bool, closer ...io.Closer) (cpi.ComponentAccess, error)
func NewComponentVersionAccess ¶
func NewComponentVersionAccess(name, version string, impl ComponentVersionAccessImpl, lazy, persistent, direct bool, closer ...io.Closer) (cpi.ComponentVersionAccess, error)
func NewNoneRefRepositoryView ¶
func NewNoneRefRepositoryView(i RepositoryBridge) cpi.Repository
NewNoneRefRepositoryView provides a repository reflecting the state of the view manager without holding an additional reference.
func NewRepository ¶
func NewRepository(impl RepositoryImpl, kind string, closer ...io.Closer) cpi.Repository
func NewStorageBackend ¶
func NewStorageBackend(kind string, impl StorageBackendImpl) cpi.Repository
NewStorageBackend provides a complete repository view with repository, component and component version objects based on the implementation of the sole interface StorageBackendImpl. No further implementations are required besides a dedicated specification object, the dependent object types are generically provided based on the methods of this interface. The kind parameter is used to denote the kind of repository in ids and log messages.
Types ¶
type BlobCache ¶
type BlobCache interface { // AddBlobFor stores blobs for added blobs not yet accessible // by generated access method until version is finally added. AddBlobFor(acc BlobCacheKey, blob BlobCacheEntry) error // GetBlobFor retrieves the original blob access for // a given access specification. GetBlobFor(acc BlobCacheKey) BlobCacheEntry RemoveBlobFor(acc BlobCacheKey) Clear() error }
func NewBlobCache ¶
func NewBlobCache() BlobCache
type BlobCacheEntry ¶
type BlobCacheEntry = blobaccess.BlobAccess
type BlobCacheKey ¶
type BlobCacheKey = interface{}
type BlobContainer ¶
type BlobContainer interface { GetBlob(name string) (cpi.DataAccess, error) // GetStorageContext creates a storage context for blobs // that is used to feed blob handlers for specific blob storage methods. // If no handler accepts the blob, the AddBlobFor method will // be used to store the blob GetStorageContext() cpi.StorageContext // AddBlob stores a local blob together with the component and // potentially provides a global reference according to the OCI distribution spec // if the blob described an oci artifact. // The resulting access information (global and local) is provided as // an access method specification usable in a component descriptor. // This is the direct technical storage, without caring about any handler. AddBlob(blob cpi.BlobAccess, refName string, global cpi.AccessSpec) (cpi.AccessSpec, error) }
BlobContainer is the interface for an element capable to store blobs.
type ComponentAccessBridge ¶
type ComponentAccessBridge interface { resource.ResourceImplementation[cpi.ComponentAccess] GetContext() cpi.Context IsReadOnly() bool GetName() string IsOwned(access cpi.ComponentVersionAccess) bool ListVersions() ([]string, error) LookupVersion(version string) (cpi.ComponentVersionAccess, error) HasVersion(vers string) (bool, error) NewVersion(version string, overrides ...bool) (cpi.ComponentVersionAccess, error) Close() error AddVersion(cv cpi.ComponentVersionAccess, opts *cpi.AddVersionOptions) (ferr error) }
func GetComponentAccessBridge ¶
func GetComponentAccessBridge(n cpi.ComponentAccess) (ComponentAccessBridge, error)
type ComponentAccessImpl ¶
type ComponentAccessImpl interface { SetBridge(bridge ComponentAccessBridge) GetParentBridge() RepositoryViewManager GetContext() cpi.Context GetName() string IsReadOnly() bool ListVersions() ([]string, error) HasVersion(vers string) (bool, error) LookupVersion(version string) (*ComponentVersionAccessInfo, error) NewVersion(version string, overrides ...bool) (*ComponentVersionAccessInfo, error) io.Closer }
ComponentAccessImpl is the provider implementation interface for component versions.
func GetComponentAccessImplementation ¶
func GetComponentAccessImplementation(n cpi.ComponentAccess) (ComponentAccessImpl, error)
type ComponentAccessInfo ¶
type ComponentAccessInfo struct { Impl ComponentAccessImpl Kind string Main bool }
type ComponentAccessViewManager ¶
type ComponentAccessViewManager = resource.ViewManager[cpi.ComponentAccess] // here you have to use an alias
type ComponentVersionAccessBridge ¶
type ComponentVersionAccessBridge interface { resource.ResourceImplementation[cpi.ComponentVersionAccess] common.VersionedElement io.Closer GetContext() cpi.Context Repository() cpi.Repository GetImplementation() ComponentVersionAccessImpl EnablePersistence() bool DiscardChanges() IsPersistent() bool GetDescriptor() *compdesc.ComponentDescriptor AccessMethod(cpi.AccessSpec, refmgmt.ExtendedAllocatable) (cpi.AccessMethod, error) // GetStorageContext creates a storage context for blobs // that is used to feed blob handlers for specific blob storage methods. // If no handler accepts the blob, the AddBlob method will // be used to store the blob GetStorageContext() cpi.StorageContext // AddBlob stores a local blob together with the component and // potentially provides a global reference. // The resulting access information (global and local) is provided as // an access method specification usable in a component descriptor. // This is the direct technical storage, without caring about any handler. AddBlob(blob cpi.BlobAccess, arttype, refName string, global cpi.AccessSpec, final bool, opts *cpi.BlobUploadOptions) (cpi.AccessSpec, error) IsReadOnly() bool SetReadOnly() // ShouldUpdate checks, whether an update is indicated // by the state of object, considering persistence, lazy, discard // and update mode state ShouldUpdate(final bool) bool // GetBlobCache retieves the blob cache used to store preliminary // blob accesses for freshly generated local access specs not directly // usable until a component version is finally added to the repository. GetBlobCache() BlobCache // UseDirectAccess returns true if composition should be directly // forwarded to the repository backend., UseDirectAccess() bool // Update persists the current state of the component version to the // underlying repository backend. Update(final bool) error }
func GetComponentVersionAccessBridge ¶
func GetComponentVersionAccessBridge(n cpi.ComponentVersionAccess) (ComponentVersionAccessBridge, error)
type ComponentVersionAccessImpl ¶
type ComponentVersionAccessImpl interface { GetContext() cpi.Context SetBridge(bridge ComponentVersionAccessBridge) GetParentBridge() ComponentAccessBridge Repository() cpi.Repository IsReadOnly() bool SetReadOnly() GetDescriptor() *compdesc.ComponentDescriptor SetDescriptor(*compdesc.ComponentDescriptor) error AccessMethod(acc cpi.AccessSpec, cv refmgmt.ExtendedAllocatable) (cpi.AccessMethod, error) BlobContainer io.Closer }
ComponentVersionAccessImpl is the provider implementation interface for component versions.
func GetComponentVersionAccessImplementation ¶
func GetComponentVersionAccessImplementation(n cpi.ComponentVersionAccess) (ComponentVersionAccessImpl, error)
type ComponentVersionAccessInfo ¶
type ComponentVersionAccessInfo struct { Impl ComponentVersionAccessImpl Lazy bool Persistent bool }
type ComponentVersionAccessViewManager ¶
type ComponentVersionAccessViewManager = resource.ViewManager[cpi.ComponentVersionAccess]
type Repository ¶ added in v0.13.0
type Repository = internal.Repository
type RepositoryBridge ¶
type RepositoryBridge interface { resource.ResourceImplementation[cpi.Repository] GetContext() cpi.Context IsReadOnly() bool SetReadOnly() GetSpecification() cpi.RepositorySpec ComponentLister() cpi.ComponentLister ExistsComponentVersion(name string, version string) (bool, error) LookupComponentVersion(name string, version string) (cpi.ComponentVersionAccess, error) LookupComponent(name string) (cpi.ComponentAccess, error) io.Closer }
func GetRepositoryBridge ¶
func GetRepositoryBridge(n cpi.Repository) (RepositoryBridge, error)
type RepositoryImpl ¶
type RepositoryImpl interface { SetBridge(bridge RepositoryBridge) GetContext() cpi.Context IsReadOnly() bool SetReadOnly() GetSpecification() cpi.RepositorySpec ComponentLister() cpi.ComponentLister ExistsComponentVersion(name string, version string) (bool, error) LookupComponent(name string) (*ComponentAccessInfo, error) io.Closer }
func GetRepositoryImplementation ¶
func GetRepositoryImplementation(n cpi.Repository) (RepositoryImpl, error)
type RepositoryViewManager ¶
type RepositoryViewManager = resource.ViewManager[cpi.Repository] // here you have to use an alias
type StorageBackendImpl ¶
type StorageBackendImpl interface { io.Closer GetContext() cpi.Context GetSpecification() cpi.RepositorySpec // IsReadOnly returns readonly mode for repo, // if key is given for the dedicated component version access. IsReadOnly(key ...common.NameVersion) bool // SetReadOnly sets readonly mode for repo, // if key is given for the dedicated component version access. SetReadOnly(key ...common.NameVersion) ComponentLister() cpi.ComponentLister HasComponent(name string) (bool, error) HasComponentVersion(key common.NameVersion) (bool, error) ListVersions(comp string) ([]string, error) HasVersion(vers string) (bool, error) GetDescriptor(key common.NameVersion) (*compdesc.ComponentDescriptor, error) SetDescriptor(key common.NameVersion, descriptor *compdesc.ComponentDescriptor) error AccessMethod(key common.NameVersion, acc cpi.AccessSpec, cv refmgmt.ExtendedAllocatable) (cpi.AccessMethod, error) GetStorageContext(key common.NameVersion) cpi.StorageContext GetBlob(key common.NameVersion, name string) (cpi.DataAccess, error) AddBlob(key common.NameVersion, blob cpi.BlobAccess, refName string, global cpi.AccessSpec) (cpi.AccessSpec, error) }
StorageBackendImpl is an interface which can be implemented to provide a complete repository view with repository, component and component version objects, which are generically implemented based on the methods of this interface.
A repository interface based on this implementation interface can be created using the function NewStorageBackend.