9956: Remove obsolete TODO comment.

[arvados.git] / services / keepstore / volume.go

diff --git a/services/keepstore/volume.go b/services/keepstore/volume.go
index 8ae6660fd477fa90365a019c837a121a08cc9595..6e01e75b879b339232603d38f93cb040ecc6d86c 100644 (file)
--- a/services/keepstore/volume.go
+++ b/services/keepstore/volume.go
@@ -10,6 +10,15 @@ import (
 // for example, a single mounted disk, a RAID array, an Amazon S3 volume,
 // etc.
 type Volume interface {
+       // Volume type as specified in config file. Examples: "S3",
+       // "Directory".
+       Type() string
+
+       // Do whatever private setup tasks and configuration checks
+       // are needed. Return non-nil if the volume is unusable (e.g.,
+       // invalid config).
+       Start() error
+
        // Get a block: copy the block data into buf, and return the
        // number of bytes copied.
        //
@@ -150,7 +159,7 @@ type Volume interface {
        // loc is as described in Get.
        //
        // If the timestamp for the given locator is newer than
-       // blobSignatureTTL, Trash must not trash the data.
+       // BlobSignatureTTL, Trash must not trash the data.
        //
        // If a Trash operation overlaps with any Touch or Put
        // operations on the same locator, the implementation must
@@ -171,7 +180,7 @@ type Volume interface {
        // reliably or fail outright.
        //
        // Corollary: A successful Touch or Put guarantees a block
-       // will not be trashed for at least blobSignatureTTL
+       // will not be trashed for at least BlobSignatureTTL
        // seconds.
        Trash(loc string) error
 
@@ -204,11 +213,18 @@ type Volume interface {
        // responses to PUT requests.
        Replication() int
 
-       // EmptyTrash looks for trashed blocks that exceeded trashLifetime
+       // EmptyTrash looks for trashed blocks that exceeded TrashLifetime
        // and deletes them from the volume.
        EmptyTrash()
 }
 
+// A VolumeWithExamples provides example configs to display in the
+// -help message.
+type VolumeWithExamples interface {
+       Volume
+       Examples() []Volume
+}
+
 // A VolumeManager tells callers which volumes can read, which volumes
 // can write, and on which volume the next write should be attempted.
 type VolumeManager interface {