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authorMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
committerMatthew Heon <matthew.heon@gmail.com>2017-11-01 11:24:59 -0400
commita031b83a09a8628435317a03f199cdc18b78262f (patch)
treebc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/docker/distribution/blobs.go
parent2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff)
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Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/docker/distribution/blobs.go')
-rw-r--r--vendor/github.com/docker/distribution/blobs.go257
1 files changed, 257 insertions, 0 deletions
diff --git a/vendor/github.com/docker/distribution/blobs.go b/vendor/github.com/docker/distribution/blobs.go
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+package distribution
+
+import (
+ "errors"
+ "fmt"
+ "io"
+ "net/http"
+ "time"
+
+ "github.com/docker/distribution/context"
+ "github.com/docker/distribution/reference"
+ "github.com/opencontainers/go-digest"
+)
+
+var (
+ // ErrBlobExists returned when blob already exists
+ ErrBlobExists = errors.New("blob exists")
+
+ // ErrBlobDigestUnsupported when blob digest is an unsupported version.
+ ErrBlobDigestUnsupported = errors.New("unsupported blob digest")
+
+ // ErrBlobUnknown when blob is not found.
+ ErrBlobUnknown = errors.New("unknown blob")
+
+ // ErrBlobUploadUnknown returned when upload is not found.
+ ErrBlobUploadUnknown = errors.New("blob upload unknown")
+
+ // ErrBlobInvalidLength returned when the blob has an expected length on
+ // commit, meaning mismatched with the descriptor or an invalid value.
+ ErrBlobInvalidLength = errors.New("blob invalid length")
+)
+
+// ErrBlobInvalidDigest returned when digest check fails.
+type ErrBlobInvalidDigest struct {
+ Digest digest.Digest
+ Reason error
+}
+
+func (err ErrBlobInvalidDigest) Error() string {
+ return fmt.Sprintf("invalid digest for referenced layer: %v, %v",
+ err.Digest, err.Reason)
+}
+
+// ErrBlobMounted returned when a blob is mounted from another repository
+// instead of initiating an upload session.
+type ErrBlobMounted struct {
+ From reference.Canonical
+ Descriptor Descriptor
+}
+
+func (err ErrBlobMounted) Error() string {
+ return fmt.Sprintf("blob mounted from: %v to: %v",
+ err.From, err.Descriptor)
+}
+
+// Descriptor describes targeted content. Used in conjunction with a blob
+// store, a descriptor can be used to fetch, store and target any kind of
+// blob. The struct also describes the wire protocol format. Fields should
+// only be added but never changed.
+type Descriptor struct {
+ // MediaType describe the type of the content. All text based formats are
+ // encoded as utf-8.
+ MediaType string `json:"mediaType,omitempty"`
+
+ // Size in bytes of content.
+ Size int64 `json:"size,omitempty"`
+
+ // Digest uniquely identifies the content. A byte stream can be verified
+ // against against this digest.
+ Digest digest.Digest `json:"digest,omitempty"`
+
+ // URLs contains the source URLs of this content.
+ URLs []string `json:"urls,omitempty"`
+
+ // NOTE: Before adding a field here, please ensure that all
+ // other options have been exhausted. Much of the type relationships
+ // depend on the simplicity of this type.
+}
+
+// Descriptor returns the descriptor, to make it satisfy the Describable
+// interface. Note that implementations of Describable are generally objects
+// which can be described, not simply descriptors; this exception is in place
+// to make it more convenient to pass actual descriptors to functions that
+// expect Describable objects.
+func (d Descriptor) Descriptor() Descriptor {
+ return d
+}
+
+// BlobStatter makes blob descriptors available by digest. The service may
+// provide a descriptor of a different digest if the provided digest is not
+// canonical.
+type BlobStatter interface {
+ // Stat provides metadata about a blob identified by the digest. If the
+ // blob is unknown to the describer, ErrBlobUnknown will be returned.
+ Stat(ctx context.Context, dgst digest.Digest) (Descriptor, error)
+}
+
+// BlobDeleter enables deleting blobs from storage.
+type BlobDeleter interface {
+ Delete(ctx context.Context, dgst digest.Digest) error
+}
+
+// BlobEnumerator enables iterating over blobs from storage
+type BlobEnumerator interface {
+ Enumerate(ctx context.Context, ingester func(dgst digest.Digest) error) error
+}
+
+// BlobDescriptorService manages metadata about a blob by digest. Most
+// implementations will not expose such an interface explicitly. Such mappings
+// should be maintained by interacting with the BlobIngester. Hence, this is
+// left off of BlobService and BlobStore.
+type BlobDescriptorService interface {
+ BlobStatter
+
+ // SetDescriptor assigns the descriptor to the digest. The provided digest and
+ // the digest in the descriptor must map to identical content but they may
+ // differ on their algorithm. The descriptor must have the canonical
+ // digest of the content and the digest algorithm must match the
+ // annotators canonical algorithm.
+ //
+ // Such a facility can be used to map blobs between digest domains, with
+ // the restriction that the algorithm of the descriptor must match the
+ // canonical algorithm (ie sha256) of the annotator.
+ SetDescriptor(ctx context.Context, dgst digest.Digest, desc Descriptor) error
+
+ // Clear enables descriptors to be unlinked
+ Clear(ctx context.Context, dgst digest.Digest) error
+}
+
+// BlobDescriptorServiceFactory creates middleware for BlobDescriptorService.
+type BlobDescriptorServiceFactory interface {
+ BlobAccessController(svc BlobDescriptorService) BlobDescriptorService
+}
+
+// ReadSeekCloser is the primary reader type for blob data, combining
+// io.ReadSeeker with io.Closer.
+type ReadSeekCloser interface {
+ io.ReadSeeker
+ io.Closer
+}
+
+// BlobProvider describes operations for getting blob data.
+type BlobProvider interface {
+ // Get returns the entire blob identified by digest along with the descriptor.
+ Get(ctx context.Context, dgst digest.Digest) ([]byte, error)
+
+ // Open provides a ReadSeekCloser to the blob identified by the provided
+ // descriptor. If the blob is not known to the service, an error will be
+ // returned.
+ Open(ctx context.Context, dgst digest.Digest) (ReadSeekCloser, error)
+}
+
+// BlobServer can serve blobs via http.
+type BlobServer interface {
+ // ServeBlob attempts to serve the blob, identified by dgst, via http. The
+ // service may decide to redirect the client elsewhere or serve the data
+ // directly.
+ //
+ // This handler only issues successful responses, such as 2xx or 3xx,
+ // meaning it serves data or issues a redirect. If the blob is not
+ // available, an error will be returned and the caller may still issue a
+ // response.
+ //
+ // The implementation may serve the same blob from a different digest
+ // domain. The appropriate headers will be set for the blob, unless they
+ // have already been set by the caller.
+ ServeBlob(ctx context.Context, w http.ResponseWriter, r *http.Request, dgst digest.Digest) error
+}
+
+// BlobIngester ingests blob data.
+type BlobIngester interface {
+ // Put inserts the content p into the blob service, returning a descriptor
+ // or an error.
+ Put(ctx context.Context, mediaType string, p []byte) (Descriptor, error)
+
+ // Create allocates a new blob writer to add a blob to this service. The
+ // returned handle can be written to and later resumed using an opaque
+ // identifier. With this approach, one can Close and Resume a BlobWriter
+ // multiple times until the BlobWriter is committed or cancelled.
+ Create(ctx context.Context, options ...BlobCreateOption) (BlobWriter, error)
+
+ // Resume attempts to resume a write to a blob, identified by an id.
+ Resume(ctx context.Context, id string) (BlobWriter, error)
+}
+
+// BlobCreateOption is a general extensible function argument for blob creation
+// methods. A BlobIngester may choose to honor any or none of the given
+// BlobCreateOptions, which can be specific to the implementation of the
+// BlobIngester receiving them.
+// TODO (brianbland): unify this with ManifestServiceOption in the future
+type BlobCreateOption interface {
+ Apply(interface{}) error
+}
+
+// CreateOptions is a collection of blob creation modifiers relevant to general
+// blob storage intended to be configured by the BlobCreateOption.Apply method.
+type CreateOptions struct {
+ Mount struct {
+ ShouldMount bool
+ From reference.Canonical
+ // Stat allows to pass precalculated descriptor to link and return.
+ // Blob access check will be skipped if set.
+ Stat *Descriptor
+ }
+}
+
+// BlobWriter provides a handle for inserting data into a blob store.
+// Instances should be obtained from BlobWriteService.Writer and
+// BlobWriteService.Resume. If supported by the store, a writer can be
+// recovered with the id.
+type BlobWriter interface {
+ io.WriteCloser
+ io.ReaderFrom
+
+ // Size returns the number of bytes written to this blob.
+ Size() int64
+
+ // ID returns the identifier for this writer. The ID can be used with the
+ // Blob service to later resume the write.
+ ID() string
+
+ // StartedAt returns the time this blob write was started.
+ StartedAt() time.Time
+
+ // Commit completes the blob writer process. The content is verified
+ // against the provided provisional descriptor, which may result in an
+ // error. Depending on the implementation, written data may be validated
+ // against the provisional descriptor fields. If MediaType is not present,
+ // the implementation may reject the commit or assign "application/octet-
+ // stream" to the blob. The returned descriptor may have a different
+ // digest depending on the blob store, referred to as the canonical
+ // descriptor.
+ Commit(ctx context.Context, provisional Descriptor) (canonical Descriptor, err error)
+
+ // Cancel ends the blob write without storing any data and frees any
+ // associated resources. Any data written thus far will be lost. Cancel
+ // implementations should allow multiple calls even after a commit that
+ // result in a no-op. This allows use of Cancel in a defer statement,
+ // increasing the assurance that it is correctly called.
+ Cancel(ctx context.Context) error
+}
+
+// BlobService combines the operations to access, read and write blobs. This
+// can be used to describe remote blob services.
+type BlobService interface {
+ BlobStatter
+ BlobProvider
+ BlobIngester
+}
+
+// BlobStore represent the entire suite of blob related operations. Such an
+// implementation can access, read, write, delete and serve blobs.
+type BlobStore interface {
+ BlobService
+ BlobServer
+ BlobDeleter
+}