Cache normalized turns/calls to ~/.cache/codeburn/session-cache.json so
the CLI skips re-parsing unchanged JSONL files on subsequent runs.
File reconciliation uses dev+ino+mtime+size fingerprinting; cost,
classification, and summaries are recomputed at query time. Atomic
writes via temp+fsync+rename, deep structural validation on load,
per-provider env fingerprinting, and best-effort save so cache failures
never break the CLI. ~6x speedup on warm cache.
Three-layer fix for V8 heap exhaustion when parsing heavy session data:
1. Buffer-based readSessionLines (fs-utils.ts): Replace readline with raw
Buffer streaming using Buffer.indexOf(0x0a). Eliminates ConsString trees
that caused OOM when regex-flattening 100MB+ lines. Two-state machine
(ACCUMULATING/SCANNING) skips old lines at ~2KB cost instead of 200MB.
2. Large-line streaming parser (parser.ts): Hand-written JSON scanner for
lines >32KB extracts only cost/token/tool fields without JSON.parse,
avoiding full object graph allocation. Dual string/Buffer paths.
3. Dashboard memory management (dashboard.tsx): Disable auto-refresh for
heavy periods (30d/month/all), clear old dataset before reload via
nextTick to allow GC, prevent overlapping reloads with mutex, lazy
optimize scanning on keypress instead of useEffect.
Also fixes three race conditions in dashboard reload deduplication:
- Early return after nextTick bypassing finally block (permanent mutex lock)
- A->B->A period switching dropping final reload (stale pending)
- Stale pendingReloadRef not cleared when in-flight matches request
- Remove bidirectional fuzzy match in getModelCosts that could return
wrong pricing when a short canonical name prefix-matched a longer key
- Use explicit undefined check in parseLiteLLMEntry so free models with
zero cost are not silently dropped from the LiteLLM pricing database
- Destroy read stream in finally block of readSessionLines to prevent
file descriptor leaks when the generator is abandoned early
- Extend CSV injection escaping to cover tab and carriage-return prefixes
- Add optional chaining fallback for empty periods in exportCsv/exportJson
- Add regression tests for all fixes (models, export, fs-utils)
