Merging upstream version 1.15.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 132 insertions, 0 deletions

diff --git a/database/engine/pagecache.h b/database/engine/pagecache.h
new file mode 100644
index 000000000..d1e29aaab
--- /dev/null
+++ b/database/engine/pagecache.h
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_PAGECACHE_H
+#define NETDATA_PAGECACHE_H
+
+#include "rrdengine.h"
+
+/* Forward declerations */
+struct rrdengine_instance;
+struct extent_info;
+
+#define INVALID_TIME (0)
+
+/* Page flags */
+#define RRD_PAGE_DIRTY          (1LU << 0)
+#define RRD_PAGE_LOCKED         (1LU << 1)
+#define RRD_PAGE_READ_PENDING   (1LU << 2)
+#define RRD_PAGE_WRITE_PENDING  (1LU << 3)
+#define RRD_PAGE_POPULATED      (1LU << 4)
+
+struct rrdeng_page_cache_descr {
+    void *page;
+    uint32_t page_length;
+    usec_t start_time;
+    usec_t end_time;
+    uuid_t *id; /* never changes */
+    struct extent_info *extent;
+    unsigned long flags;
+    void *private;
+    struct rrdeng_page_cache_descr *prev;
+    struct rrdeng_page_cache_descr *next;
+
+    /* TODO: move waiter logic to concurrency table */
+    unsigned refcnt;
+    uv_mutex_t mutex; /* always take it after the page cache lock or after the commit lock */
+    uv_cond_t cond;
+    unsigned waiters;
+    struct rrdeng_collect_handle *handle; /* API user */
+};
+
+#define PAGE_CACHE_MAX_PRELOAD_PAGES    (256)
+
+/* maps time ranges to pages */
+struct pg_cache_page_index {
+    uuid_t id;
+    /*
+     * care: JudyL_array indices are converted from useconds to seconds to fit in one word in 32-bit architectures
+     * TODO: examine if we want to support better granularity than seconds
+     */
+    Pvoid_t JudyL_array;
+    uv_rwlock_t lock;
+
+    /*
+     * Only one effective writer, data deletion workqueue.
+     * It's also written during the DB loading phase.
+     */
+    usec_t oldest_time;
+
+    /*
+     * Only one effective writer, data collection thread.
+     * It's also written by the data deletion workqueue when data collection is disabled for this metric.
+     */
+    usec_t latest_time;
+};
+
+/* maps UUIDs to page indices */
+struct pg_cache_metrics_index {
+    uv_rwlock_t lock;
+    Pvoid_t JudyHS_array;
+};
+
+/* gathers dirty pages to be written on disk */
+struct pg_cache_commited_page_index {
+    uv_rwlock_t lock;
+
+    Pvoid_t JudyL_array;
+
+    /*
+     * Dirty page correlation ID is a hint. Dirty pages that are correlated should have
+     * a small correlation ID difference. Dirty pages in memory should never have the
+     * same ID at the same time for correctness.
+     */
+    Word_t latest_corr_id;
+
+    unsigned nr_commited_pages;
+};
+
+/* gathers populated pages to be evicted */
+struct pg_cache_replaceQ {
+    uv_rwlock_t lock; /* LRU lock */
+
+    struct rrdeng_page_cache_descr *head; /* LRU */
+    struct rrdeng_page_cache_descr *tail; /* MRU */
+};
+
+struct page_cache { /* TODO: add statistics */
+    uv_rwlock_t pg_cache_rwlock; /* page cache lock */
+
+    struct pg_cache_metrics_index metrics_index;
+    struct pg_cache_commited_page_index commited_page_index;
+    struct pg_cache_replaceQ replaceQ;
+
+    unsigned page_descriptors;
+    unsigned populated_pages;
+};
+
+extern void pg_cache_wake_up_waiters_unsafe(struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_wait_event_unsafe(struct rrdeng_page_cache_descr *descr);
+extern unsigned long pg_cache_wait_event(struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_replaceQ_insert(struct rrdengine_instance *ctx,
+                                     struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_replaceQ_delete(struct rrdengine_instance *ctx,
+                                     struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_replaceQ_set_hot(struct rrdengine_instance *ctx,
+                                      struct rrdeng_page_cache_descr *descr);
+extern struct rrdeng_page_cache_descr *pg_cache_create_descr(void);
+extern void pg_cache_put_unsafe(struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_put(struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_insert(struct rrdengine_instance *ctx, struct pg_cache_page_index *index,
+                            struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_punch_hole(struct rrdengine_instance *ctx, struct rrdeng_page_cache_descr *descr);
+extern struct pg_cache_page_index *
+        pg_cache_preload(struct rrdengine_instance *ctx, uuid_t *id, usec_t start_time, usec_t end_time);
+extern struct rrdeng_page_cache_descr *
+        pg_cache_lookup(struct rrdengine_instance *ctx, struct pg_cache_page_index *index, uuid_t *id,
+                        usec_t point_in_time);
+extern struct pg_cache_page_index *create_page_index(uuid_t *id);
+extern void init_page_cache(struct rrdengine_instance *ctx);
+extern void pg_cache_add_new_metric_time(struct pg_cache_page_index *page_index, struct rrdeng_page_cache_descr *descr);
+extern void pg_cache_update_metric_times(struct pg_cache_page_index *page_index);
+
+#endif /* NETDATA_PAGECACHE_H */
\ No newline at end of file