1 files changed, 94 insertions, 0 deletions
diff --git a/database/engine/metric.h b/database/engine/metric.h
new file mode 100644
index 00000000..dbb94930
--- /dev/null
+++ b/database/engine/metric.h
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#ifndef DBENGINE_METRIC_H
+#define DBENGINE_METRIC_H
+
+#include "../rrd.h"
+
+#define MRG_CACHE_LINE_PADDING(x) uint8_t padding##x[64]
+
+typedef struct metric METRIC;
+typedef struct mrg MRG;
+
+typedef struct mrg_entry {
+    uuid_t *uuid;
+    Word_t section;
+    time_t first_time_s;
+    time_t last_time_s;
+    uint32_t latest_update_every_s;
+} MRG_ENTRY;
+
+struct mrg_statistics {
+    // --- non-atomic --- under a write lock
+
+    size_t entries;
+    size_t size;    // total memory used, with indexing
+
+    size_t additions;
+    size_t additions_duplicate;
+
+    size_t deletions;
+    size_t delete_having_retention_or_referenced;
+    size_t delete_misses;
+
+    MRG_CACHE_LINE_PADDING(0);
+
+    // --- atomic --- multiple readers / writers
+
+    size_t entries_referenced;
+
+    MRG_CACHE_LINE_PADDING(2);
+    size_t current_references;
+
+    MRG_CACHE_LINE_PADDING(3);
+    size_t search_hits;
+    size_t search_misses;
+
+    MRG_CACHE_LINE_PADDING(4);
+    size_t writers;
+    size_t writers_conflicts;
+};
+
+MRG *mrg_create(ssize_t partitions);
+void mrg_destroy(MRG *mrg);
+
+METRIC *mrg_metric_dup(MRG *mrg, METRIC *metric);
+bool mrg_metric_release(MRG *mrg, METRIC *metric);
+
+METRIC *mrg_metric_add_and_acquire(MRG *mrg, MRG_ENTRY entry, bool *ret);
+METRIC *mrg_metric_get_and_acquire(MRG *mrg, uuid_t *uuid, Word_t section);
+bool mrg_metric_release_and_delete(MRG *mrg, METRIC *metric);
+
+Word_t mrg_metric_id(MRG *mrg, METRIC *metric);
+uuid_t *mrg_metric_uuid(MRG *mrg, METRIC *metric);
+Word_t mrg_metric_section(MRG *mrg, METRIC *metric);
+
+bool mrg_metric_set_first_time_s(MRG *mrg, METRIC *metric, time_t first_time_s);
+bool mrg_metric_set_first_time_s_if_bigger(MRG *mrg, METRIC *metric, time_t first_time_s);
+time_t mrg_metric_get_first_time_s(MRG *mrg, METRIC *metric);
+
+bool mrg_metric_set_clean_latest_time_s(MRG *mrg, METRIC *metric, time_t latest_time_s);
+bool mrg_metric_set_hot_latest_time_s(MRG *mrg, METRIC *metric, time_t latest_time_s);
+time_t mrg_metric_get_latest_time_s(MRG *mrg, METRIC *metric);
+
+bool mrg_metric_set_update_every(MRG *mrg, METRIC *metric, time_t update_every_s);
+bool mrg_metric_set_update_every_s_if_zero(MRG *mrg, METRIC *metric, time_t update_every_s);
+time_t mrg_metric_get_update_every_s(MRG *mrg, METRIC *metric);
+
+void mrg_metric_expand_retention(MRG *mrg, METRIC *metric, time_t first_time_s, time_t last_time_s, time_t update_every_s);
+void mrg_metric_get_retention(MRG *mrg, METRIC *metric, time_t *first_time_s, time_t *last_time_s, time_t *update_every_s);
+bool mrg_metric_zero_disk_retention(MRG *mrg __maybe_unused, METRIC *metric);
+
+bool mrg_metric_set_writer(MRG *mrg, METRIC *metric);
+bool mrg_metric_clear_writer(MRG *mrg, METRIC *metric);
+
+void mrg_get_statistics(MRG *mrg, struct mrg_statistics *s);
+size_t mrg_aral_structures(void);
+size_t mrg_aral_overhead(void);
+
+
+void mrg_update_metric_retention_and_granularity_by_uuid(
+        MRG *mrg, Word_t section, uuid_t *uuid,
+        time_t first_time_s, time_t last_time_s,
+        time_t update_every_s, time_t now_s);
+
+#endif // DBENGINE_METRIC_H