Buffers

Quick Reference#

Each buffer is a FIFO queue: once it is over its capacity the oldest record is evicted, silently.

Capacity#

Every buffer holds 500 records by default, except frame performance, which holds 3600 (about a minute at 60fps).

CrumbsStore.setCapacity(2000); // every buffer but frame perf
CrumbsStore.setCapacity(5000, kind: CrumbsKind.logs); // one buffer
CrumbsStore.setCapacity(7200, kind: CrumbsKind.framePerf);

CrumbsKind names the buffers: http, logs, exceptions, models, caches, events, gates, dumps, queries, framePerf.

• A cap for one kind wins over the shared cap, whichever was set last. The shared call leaves a kind cap alone.
• A cap below the buffer's current length trims on the next record, not retroactively.
• A cap of zero or less keeps nothing.
• CrumbsStore.resetForTesting() (tests only) empties the buffers, restores both default caps, clears the per-kind caps and unregisters CrumbsRedaction.redactor.

Monotonic timestamps#

LogRecordEntry and EventRecord carry atUs, stamped at construction from FlutterTimeline.now and serialised in toJson, so a log line orders against an event whatever the wall clock did. time stays the wall-clock field for display. atUs is also the cursor that ext.crumbs.console and ext.crumbs.events page on (see Cursor and filters).

Reading with limit and minLevel#

CrumbsStore.recentX(limit:) returns the newest limit records, oldest first; without limit it returns the whole buffer.

• A zero or negative limit returns an empty list.
• recentLogs(minLevel:) keeps records at or above the named package:logging level (FINEST, FINER, FINE, CONFIG, INFO, WARNING, SEVERE, SHOUT, any case). A name that is not a level matches nothing and returns an empty list, so a typo never reads as a clean log.

Related Documentation#

• Cursor and filters: since, type, logger and cursor on the read extensions.
• Redaction: what the store masks before a record enters its buffer.
• File sink: a timeline on disk that outlives the in-memory buffers.