Documentation
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Overview ¶
Package buffer implements a bounded, drop-oldest ring of pending UploadRequests for the mAPI-ng client's fail-open uploader (docs/context.md).
A slow or down collector must never block the host: flushed windows are pushed into a fixed-capacity Ring, and the uploader goroutine drains the oldest pending request with retry/backoff. When the ring is full, the oldest request is evicted (drop-oldest) so the newest data always has room — losing stale windows is preferable to losing the freshest ones. The count of summaries in each evicted request is reported later via the envelope's dropped_summaries field so the loss is visible rather than silent.
Concurrency ¶
The Ring is single-goroutine-owned: only the uploader goroutine touches it (Push from the flush path runs on that same goroutine, Peek/PopOldest from the drain path likewise). It therefore carries no internal locking. Callers MUST NOT share a Ring across goroutines.
Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Ring ¶
type Ring struct {
// contains filtered or unexported fields
}
Ring is a fixed-capacity, drop-oldest ring buffer of *UploadRequest. It is not safe for concurrent use; it is owned by a single goroutine (see package doc). The zero value is not usable; construct one with New.
func New ¶
New returns an empty Ring with the given capacity. A capacity below 1 is clamped to 1 so the ring can always hold at least the freshest request.
func (*Ring) Peek ¶
func (r *Ring) Peek() *mapingv1.UploadRequest
Peek returns the oldest element without removing it, or nil if the ring is empty.
func (*Ring) PopOldest ¶
func (r *Ring) PopOldest() *mapingv1.UploadRequest
PopOldest removes and returns the oldest element, or nil if the ring is empty. The vacated slot is niled out so the backing array never pins a removed request.
func (*Ring) Push ¶
func (r *Ring) Push(req *mapingv1.UploadRequest) *mapingv1.UploadRequest
Push appends req as the newest element. If the ring is full it evicts and returns the oldest element (drop-oldest) so the caller can account for its dropped summaries; otherwise it returns nil. The evicted slot is niled out so the backing array never pins a dropped request (no memory leak).
Source Files