1 files changed, 62 insertions, 0 deletions
diff --git a/database/engine/pagecache.h b/database/engine/pagecache.h
new file mode 100644
index 00000000..dbcbea53
--- /dev/null
+++ b/database/engine/pagecache.h
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_PAGECACHE_H
+#define NETDATA_PAGECACHE_H
+
+#include "rrdengine.h"
+
+extern struct mrg *main_mrg;
+extern struct pgc *main_cache;
+extern struct pgc *open_cache;
+extern struct pgc *extent_cache;
+
+/* Forward declarations */
+struct rrdengine_instance;
+
+#define INVALID_TIME (0)
+#define MAX_PAGE_CACHE_FETCH_RETRIES (3)
+#define PAGE_CACHE_FETCH_WAIT_TIMEOUT (3)
+
+extern struct rrdeng_cache_efficiency_stats rrdeng_cache_efficiency_stats;
+
+struct page_descr_with_data {
+    uuid_t *id;
+    Word_t metric_id;
+    usec_t start_time_ut;
+    usec_t end_time_ut;
+    uint8_t type;
+    uint32_t update_every_s;
+    uint32_t page_length;
+    struct pgd *pgd;
+
+    struct {
+        struct page_descr_with_data *prev;
+        struct page_descr_with_data *next;
+    } link;
+};
+
+#define PAGE_INFO_SCRATCH_SZ (8)
+struct rrdeng_page_info {
+    uint8_t scratch[PAGE_INFO_SCRATCH_SZ]; /* scratch area to be used by page-cache users */
+
+    usec_t start_time_ut;
+    usec_t end_time_ut;
+    uint32_t page_length;
+};
+
+struct pg_alignment {
+    uint32_t refcount;
+};
+
+struct rrdeng_query_handle;
+struct page_details_control;
+
+void rrdeng_prep_wait(struct page_details_control *pdc);
+void rrdeng_prep_query(struct page_details_control *pdc, bool worker);
+void pg_cache_preload(struct rrdeng_query_handle *handle);
+struct pgc_page *pg_cache_lookup_next(struct rrdengine_instance *ctx, struct page_details_control *pdc, time_t now_s, time_t last_update_every_s, size_t *entries);
+void pgc_and_mrg_initialize(void);
+
+void pgc_open_add_hot_page(Word_t section, Word_t metric_id, time_t start_time_s, time_t end_time_s, time_t update_every_s, struct rrdengine_datafile *datafile, uint64_t extent_offset, unsigned extent_size, uint32_t page_length);
+
+#endif /* NETDATA_PAGECACHE_H */