Bound leak-check history to prevent unbounded memory growth

README.md

@@ -13,7 +13,7 @@ ESPMemoryMonitor is a tiny C++17 helper that wraps ESP-IDF heap/stack inspection
 - Per-region thresholds with hysteresis; `onThreshold` fires on enter/exit of warn/critical bands so alerts do not spam as memory bounces.
 - Optional extras: per-task stack high-water (via `uxTaskGetSystemState`), min-ever-free, and IDF failed-allocation callbacks (`heap_caps_register_failed_alloc_callback`).
 - Scope-based deltas and tag budgets: wrap a code path in `beginScope()` to measure DRAM/PSRAM consumed (or released), attribute it to a tag, and fire `onScope`/`onTagThreshold` callbacks when soft budgets are crossed.
-- Leak suspicion helpers: mark checkpoints for steady-state phases; the monitor compares averages and flags downward free-memory drift or rising fragmentation via `onLeakCheck`.
+- Leak suspicion helpers: mark checkpoints for steady-state phases; the monitor compares averages and flags downward free-memory drift or rising fragmentation via `onLeakCheck`, with bounded checkpoint/result retention.
 - Derived insights: windowed min/avg/max, slope-based bytes/second, and time-to-warn/critical estimates per region.
 - Task visibility: stack state transitions (`Safe/Warn/Critical`), optional new/vanished task detection, and per-task thresholds.
 - Export/panic helpers: convert snapshots to ArduinoJson for telemetry and install a shutdown/panic hook that captures a final snapshot before abort/restart.
@@ -172,6 +172,7 @@ serializeJson(doc, Serial);
 | `enableTaskTracking` | `false` | Emit stack-state transitions and task create/destroy events (requires `enablePerTaskStacks`). |
 | `defaultTaskStackBytes` / `stackWarnFraction` / `stackCriticalFraction` | `4096` / `0.25` / `0.10` | Default stack headroom thresholds when per-task overrides are absent. |
 | `leakNoiseBytes` | `1024` | Ignore free-byte changes smaller than this when flagging leak drift between checkpoints. |
+| `maxLeakChecksInHistory` | `16` | Ring-buffer depth for leak checkpoint timestamps/results (minimum effective value is 1). |
 | `usePSRAMBuffers` | `false` | Best-effort PSRAM preference for monitor-owned dynamic containers and internal storage models (history/scope/tag/task/leak internals plus transient threshold, scope/tag, window, and task-tracking scratch buffers); automatically falls back to normal heap when PSRAM is unavailable. |
 
 `MemorySnapshot` holds `timestampUs` plus vectors of `RegionStats` (free bytes, low-water, largest block, fragmentation, slope/time estimates, window stats) and optional `TaskStackUsage` entries (task name, priority, state, free high-water bytes).

src/esp_memory_monitor/memory_monitor.cpp

@@ -940,8 +940,8 @@ void ESPMemoryMonitor::resetOwnedContainers() {
         std::hash<TaskHandle_t>{},
         std::equal_to<TaskHandle_t>{},
         MemoryMonitorAllocator<std::pair<const TaskHandle_t, InternalTaskStackUsage>>(_usePSRAMBuffers));
-    _leakHistory = MemoryMonitorVector<InternalLeakCheckResult>(MemoryMonitorAllocator<InternalLeakCheckResult>(_usePSRAMBuffers));
-    _leakCheckpoints = MemoryMonitorVector<uint64_t>(MemoryMonitorAllocator<uint64_t>(_usePSRAMBuffers));
+    _leakHistory = MemoryMonitorDeque<InternalLeakCheckResult>(MemoryMonitorAllocator<InternalLeakCheckResult>(_usePSRAMBuffers));
+    _leakCheckpoints = MemoryMonitorDeque<uint64_t>(MemoryMonitorAllocator<uint64_t>(_usePSRAMBuffers));
 }
 
 ESPMemoryMonitor::InternalLeakCheckResult ESPMemoryMonitor::buildLeakCheckLocked(const std::string& label) {
@@ -950,9 +950,13 @@ ESPMemoryMonitor::InternalLeakCheckResult ESPMemoryMonitor::buildLeakCheckLocked
         return result;
     }
 
+    const size_t leakHistoryLimit = std::max<size_t>(1, _config.maxLeakChecksInHistory);
     const uint64_t latestTs = _history.back().timestampUs;
     const uint64_t startTs = _leakCheckpoints.empty() ? _history.front().timestampUs : _leakCheckpoints.back();
     _leakCheckpoints.push_back(latestTs);
+    while (_leakCheckpoints.size() > leakHistoryLimit) {
+        _leakCheckpoints.pop_front();
+    }
 
     auto computeAverages = [&](uint64_t from, uint64_t to) {
         struct RegionAvg {
@@ -1004,6 +1008,9 @@ ESPMemoryMonitor::InternalLeakCheckResult ESPMemoryMonitor::buildLeakCheckLocked
             result.deltas.push_back(delta);
         }
         _leakHistory.push_back(result);
+        while (_leakHistory.size() > leakHistoryLimit) {
+            _leakHistory.pop_front();
+        }
         return result;
     }
 
@@ -1039,6 +1046,9 @@ ESPMemoryMonitor::InternalLeakCheckResult ESPMemoryMonitor::buildLeakCheckLocked
     }
 
     _leakHistory.push_back(result);
+    while (_leakHistory.size() > leakHistoryLimit) {
+        _leakHistory.pop_front();
+    }
     return result;
 }
 

src/esp_memory_monitor/memory_monitor.h

@@ -79,6 +79,7 @@ struct MemoryMonitorConfig {
     float stackWarnFraction = 0.25f;
     float stackCriticalFraction = 0.10f;
     size_t leakNoiseBytes = 1024;
+    size_t maxLeakChecksInHistory = 16;
     bool usePSRAMBuffers = false;
 };
 
@@ -415,8 +416,8 @@ class ESPMemoryMonitor {
     MemoryMonitorVector<TagBudget> _tagBudgets;
     MemoryMonitorUnorderedMap<MemoryMonitorString, TaskStackThreshold> _taskThresholds;
     MemoryMonitorUnorderedMap<TaskHandle_t, InternalTaskStackUsage> _knownTasks;
-    MemoryMonitorVector<InternalLeakCheckResult> _leakHistory;
-    MemoryMonitorVector<uint64_t> _leakCheckpoints;
+    MemoryMonitorDeque<InternalLeakCheckResult> _leakHistory;
+    MemoryMonitorDeque<uint64_t> _leakCheckpoints;
     bool _panicHookInstalled = false;
 };