Documentation
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Overview ¶
Package spool shares one in-flight HTTP response between concurrent requests, which stream it while it is still being produced.
Index ¶
Constants ¶
This section is empty.
Variables ¶
ErrNotShared reports that a response cannot be served from the spool. Nothing has been written to the client, so the caller must serve the request itself.
var ErrUncommitted = errors.New("spool fill returned without committing its cache write")
ErrUncommitted reports a fill that stored a cache write and returned without calling Writer.Commit, which would otherwise lose the entry silently.
Functions ¶
This section is empty.
Types ¶
type Config ¶
type Config struct {
Dir string `hcl:"dir,optional" help:"Directory for spool files." default:"${CACHEW_STATE}/spools"`
FillTimeout time.Duration `hcl:"fill-timeout,optional" help:"Maximum duration of a single shared fill. 0 disables the limit." default:"30m"`
ErrorWindow time.Duration `` /* 165-byte string literal not displayed */
}
Config configures the spool Registry.
type FillFunc ¶
FillFunc produces the shared response into w. ctx keeps the starting request's values but not its cancellation; it ends at Registry.Close or FillTimeout.
type Group ¶
type Group struct {
// contains filtered or unexported fields
}
Group coalesces fills by key.
type Registry ¶
type Registry struct {
// contains filtered or unexported fields
}
Registry owns every in-flight fill in the process. Fills run detached from the requests that started them, so Close is the only way to cancel them.
func New ¶
New creates a Registry and removes stale spool files; ctx's cancellation is ignored, use Close. onReleaseError receives cleanup failures from any goroutine and must not call the Registry.
type Result ¶
type Result struct {
// Filled is true when this request started the fill.
Filled bool
// Status is the status code written to the client, or 0 if none was.
Status int
// Wait is how long the request waited for the response headers.
Wait time.Duration
// Bytes is the number of body bytes written to the client.
Bytes int64
}
Result describes how Serve answered a request.
type Retention ¶
type Retention int
Retention controls whether a Group keeps a successful response after its fill ends.
const ( // ReleaseCompleted drops a successful response when its fill ends, for // callers that cache it so later requests hit the cache instead. ReleaseCompleted Retention = iota // RetainCompleted keeps successful responses until the Group is closed, for // callers with nowhere else to serve them from. RetainCompleted )
type Writer ¶
type Writer struct {
// contains filtered or unexported fields
}
Writer receives a fill's response so existing forwarding code can write into it. It must only be used by the fill it was passed to.
func (*Writer) Commit ¶
Commit stores the body in the cache and returns any cache failure, including an abandoned write. Call it after the last Write; it is a no-op without Store.
func (*Writer) Flush ¶
func (w *Writer) Flush()
Flush is a no-op: readers see each Write as soon as it returns.
func (*Writer) Store ¶
Store takes ownership of cw, committing it if the fill succeeds. It must follow a 2xx WriteHeader and precede the first Write.
func (*Writer) Write ¶
Write appends p to the response. A cache failure fails the response only when readers follow the cache write; otherwise the cache write is abandoned.
func (*Writer) WriteHeader ¶
WriteHeader publishes status and a snapshot of the headers to readers. Informational statuses are not forwarded.
Source Files