src/database/engine/cache.h
// SPDX-License-Identifier: GPL-3.0-or-later
#ifndef DBENGINE_CACHE_H
#define DBENGINE_CACHE_H
#include "datafile.h"
#include "../rrd.h"
// CACHE COMPILE TIME CONFIGURATION
// #define PGC_COUNT_POINTS_COLLECTED 1
typedef struct pgc PGC;
typedef struct pgc_page PGC_PAGE;
#define PGC_NAME_MAX 23
typedef enum __attribute__ ((__packed__)) {
PGC_OPTIONS_NONE = 0,
PGC_OPTIONS_EVICT_PAGES_INLINE = (1 << 0),
PGC_OPTIONS_FLUSH_PAGES_INLINE = (1 << 1),
PGC_OPTIONS_AUTOSCALE = (1 << 2),
} PGC_OPTIONS;
#define PGC_OPTIONS_DEFAULT (PGC_OPTIONS_EVICT_PAGES_INLINE | PGC_OPTIONS_FLUSH_PAGES_INLINE | PGC_OPTIONS_AUTOSCALE)
typedef struct pgc_entry {
Word_t section; // the section this belongs to
Word_t metric_id; // the metric this belongs to
time_t start_time_s; // the start time of the page
time_t end_time_s; // the end time of the page
size_t size; // the size in bytes of the allocation, outside the cache
void *data; // a pointer to data outside the cache
uint32_t update_every_s; // the update every of the page
bool hot; // true if this entry is currently being collected
uint8_t *custom_data;
} PGC_ENTRY;
#define PGC_CACHE_LINE_PADDING(x) uint8_t padding##x[64]
struct pgc_queue_statistics {
size_t entries;
size_t size;
PGC_CACHE_LINE_PADDING(1);
size_t max_entries;
size_t max_size;
PGC_CACHE_LINE_PADDING(2);
size_t added_entries;
size_t added_size;
PGC_CACHE_LINE_PADDING(3);
size_t removed_entries;
size_t removed_size;
PGC_CACHE_LINE_PADDING(4);
};
struct pgc_statistics {
size_t wanted_cache_size;
size_t current_cache_size;
PGC_CACHE_LINE_PADDING(1);
size_t added_entries;
size_t added_size;
PGC_CACHE_LINE_PADDING(2);
size_t removed_entries;
size_t removed_size;
PGC_CACHE_LINE_PADDING(3);
size_t entries; // all the entries (includes clean, dirty, hot)
size_t size; // all the entries (includes clean, dirty, hot)
size_t evicting_entries;
size_t evicting_size;
size_t flushing_entries;
size_t flushing_size;
size_t hot2dirty_entries;
size_t hot2dirty_size;
PGC_CACHE_LINE_PADDING(4);
size_t acquires;
PGC_CACHE_LINE_PADDING(4a);
size_t releases;
PGC_CACHE_LINE_PADDING(4b);
size_t acquires_for_deletion;
PGC_CACHE_LINE_PADDING(4c);
size_t referenced_entries; // all the entries currently referenced
size_t referenced_size; // all the entries currently referenced
PGC_CACHE_LINE_PADDING(5);
size_t searches_exact;
size_t searches_exact_hits;
size_t searches_exact_misses;
PGC_CACHE_LINE_PADDING(6);
size_t searches_closest;
size_t searches_closest_hits;
size_t searches_closest_misses;
PGC_CACHE_LINE_PADDING(7);
size_t flushes_completed;
size_t flushes_completed_size;
size_t flushes_cancelled;
size_t flushes_cancelled_size;
#ifdef PGC_COUNT_POINTS_COLLECTED
PGC_CACHE_LINE_PADDING(8);
size_t points_collected;
#endif
PGC_CACHE_LINE_PADDING(9);
size_t insert_spins;
size_t evict_spins;
size_t release_spins;
size_t acquire_spins;
size_t delete_spins;
size_t flush_spins;
PGC_CACHE_LINE_PADDING(10);
size_t workers_search;
size_t workers_add;
size_t workers_evict;
size_t workers_flush;
size_t workers_jv2_flush;
size_t workers_hot2dirty;
size_t evict_skipped;
size_t hot_empty_pages_evicted_immediately;
size_t hot_empty_pages_evicted_later;
PGC_CACHE_LINE_PADDING(11);
// events
size_t events_cache_under_severe_pressure;
size_t events_cache_needs_space_aggressively;
size_t events_flush_critical;
PGC_CACHE_LINE_PADDING(12);
struct {
PGC_CACHE_LINE_PADDING(0);
struct pgc_queue_statistics hot;
PGC_CACHE_LINE_PADDING(1);
struct pgc_queue_statistics dirty;
PGC_CACHE_LINE_PADDING(2);
struct pgc_queue_statistics clean;
PGC_CACHE_LINE_PADDING(3);
} queues;
};
typedef void (*free_clean_page_callback)(PGC *cache, PGC_ENTRY entry);
typedef void (*save_dirty_page_callback)(PGC *cache, PGC_ENTRY *entries_array, PGC_PAGE **pages_array, size_t entries);
typedef void (*save_dirty_init_callback)(PGC *cache, Word_t section);
// create a cache
PGC *pgc_create(const char *name,
size_t clean_size_bytes, free_clean_page_callback pgc_free_clean_cb,
size_t max_dirty_pages_per_flush, save_dirty_init_callback pgc_save_init_cb, save_dirty_page_callback pgc_save_dirty_cb,
size_t max_pages_per_inline_eviction, size_t max_inline_evictors,
size_t max_skip_pages_per_inline_eviction,
size_t max_flushes_inline,
PGC_OPTIONS options, size_t partitions, size_t additional_bytes_per_page);
// destroy the cache
void pgc_destroy(PGC *cache);
#define PGC_SECTION_ALL ((Word_t)0)
void pgc_flush_all_hot_and_dirty_pages(PGC *cache, Word_t section);
// add a page to the cache and return a pointer to it
PGC_PAGE *pgc_page_add_and_acquire(PGC *cache, PGC_ENTRY entry, bool *added);
// get another reference counter on an already referenced page
PGC_PAGE *pgc_page_dup(PGC *cache, PGC_PAGE *page);
// release a page (all pointers to it are now invalid)
void pgc_page_release(PGC *cache, PGC_PAGE *page);
// mark a hot page dirty, and release it
void pgc_page_hot_to_dirty_and_release(PGC *cache, PGC_PAGE *page, bool never_flush);
// find a page from the cache
typedef enum {
PGC_SEARCH_EXACT,
PGC_SEARCH_CLOSEST,
PGC_SEARCH_FIRST,
PGC_SEARCH_NEXT,
PGC_SEARCH_LAST,
PGC_SEARCH_PREV,
} PGC_SEARCH;
PGC_PAGE *pgc_page_get_and_acquire(PGC *cache, Word_t section, Word_t metric_id, time_t start_time_s, PGC_SEARCH method);
// get information from an acquired page
Word_t pgc_page_section(PGC_PAGE *page);
Word_t pgc_page_metric(PGC_PAGE *page);
time_t pgc_page_start_time_s(PGC_PAGE *page);
time_t pgc_page_end_time_s(PGC_PAGE *page);
uint32_t pgc_page_update_every_s(PGC_PAGE *page);
uint32_t pgc_page_fix_update_every(PGC_PAGE *page, uint32_t update_every_s);
time_t pgc_page_fix_end_time_s(PGC_PAGE *page, time_t end_time_s);
void *pgc_page_data(PGC_PAGE *page);
void *pgc_page_custom_data(PGC *cache, PGC_PAGE *page);
size_t pgc_page_data_size(PGC *cache, PGC_PAGE *page);
bool pgc_is_page_hot(PGC_PAGE *page);
bool pgc_is_page_dirty(PGC_PAGE *page);
bool pgc_is_page_clean(PGC_PAGE *page);
void pgc_reset_hot_max(PGC *cache);
size_t pgc_get_current_cache_size(PGC *cache);
size_t pgc_get_wanted_cache_size(PGC *cache);
// resetting the end time of a hot page
void pgc_page_hot_set_end_time_s(PGC *cache, PGC_PAGE *page, time_t end_time_s);
bool pgc_page_to_clean_evict_or_release(PGC *cache, PGC_PAGE *page);
typedef void (*migrate_to_v2_callback)(Word_t section, unsigned datafile_fileno, uint8_t type, Pvoid_t JudyL_metrics, Pvoid_t JudyL_extents_pos, size_t count_of_unique_extents, size_t count_of_unique_metrics, size_t count_of_unique_pages, void *data);
void pgc_open_cache_to_journal_v2(PGC *cache, Word_t section, unsigned datafile_fileno, uint8_t type, migrate_to_v2_callback cb, void *data);
void pgc_open_evict_clean_pages_of_datafile(PGC *cache, struct rrdengine_datafile *datafile);
size_t pgc_count_clean_pages_having_data_ptr(PGC *cache, Word_t section, void *ptr);
size_t pgc_count_hot_pages_having_data_ptr(PGC *cache, Word_t section, void *ptr);
typedef size_t (*dynamic_target_cache_size_callback)(void);
void pgc_set_dynamic_target_cache_size_callback(PGC *cache, dynamic_target_cache_size_callback callback);
// return true when there is more work to do
bool pgc_evict_pages(PGC *cache, size_t max_skip, size_t max_evict);
bool pgc_flush_pages(PGC *cache, size_t max_flushes);
struct pgc_statistics pgc_get_statistics(PGC *cache);
size_t pgc_hot_and_dirty_entries(PGC *cache);
struct aral_statistics *pgc_aral_statistics(void);
size_t pgc_aral_structures(void);
size_t pgc_aral_overhead(void);
#endif // DBENGINE_CACHE_H