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Diffstat (limited to 'database/engine/pagecache.h')
| -rw-r--r-- | database/engine/pagecache.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/database/engine/pagecache.h b/database/engine/pagecache.h new file mode 100644 index 00000000..d1e29aaa --- /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 */
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