filesystems

type ContextFS ¶ added in v0.9.0

type ContextFS interface {
	FS

	PutContext(ctx context.Context, fileName, folder string) error
	GetContext(ctx context.Context, destination string, items ...string) error
	ListContext(ctx context.Context, prefix string) ([]Listing, error)

	// DeleteContext removes the named items. Passing none deletes everything,
	// which is what FS.Delete does for callers that relied on it.
	DeleteContext(ctx context.Context, items []string) error
}

ContextFS is FS with cancellation, deadlines and trace propagation.

The four methods on FS take no context, so every implementation ends up calling context.Background() internally. That means an upload whose HTTP handler has already gone away keeps running -- for S3, billable transfer for a response nobody will read -- a Get of a large object cannot be bounded, and anything the otel module traces stops at the filesystem boundary because the span context cannot reach it.

This is a second interface rather than a change to FS, because changing FS would break every implementation written against it to deliver a benefit callers can opt into instead. Implementations satisfy both; FS's methods are thin wrappers passing context.Background().

DeleteContext also corrects two things FS.Delete gets wrong and cannot fix without breaking callers:

• It returns an error rather than a bool. After the aws-sdk-go-v2 migration there are three distinct failure modes -- the list failed, the batch call failed, or the response reported per-key errors -- and false discards which one happened.
• It honours its items argument. FS.Delete ignores it and empties the whole bucket, inherited from the v1 implementation and preserved deliberately so an SDK migration would not quietly change semantics. A new method is the right place to stop carrying that forward.

type FS ¶

type FS interface {
	Put(fileName, folder string) error
	Get(destination string, items ...string) error
	List(prefix string) ([]Listing, error)
	Delete(items []string) bool
}

FS is an interface that defines the methods that a filesystem must implement

type Listing ¶

type Listing struct {
	Etag         string
	LastModified time.Time
	Key          string
	Size         float64
	IsDir        bool
}

Listing is a struct that represents a file or directory in a filesystem