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// 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 */
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