.......... [DEV-2135] refactored dbcache part 1

9 files changed, 313 insertions, 181 deletions

diff --git a/include/preproc.h b/include/preproc.h
index 662110dbcb6..4db4fc1901a 100644
--- a/include/preproc.h
+++ b/include/preproc.h
@@ -21,7 +21,7 @@
 #define ZABBIX_PREPROC_H
 
 #include "module.h"
-#include "dbcache.h"
+#include "zbxcacheconfig.h"
 
 /* preprocessing step execution result */
 typedef struct
diff --git a/include/dbcache.h b/include/zbxcacheconfig.h
index a99d998c39d..59be3a38d8b 100644
--- a/include/dbcache.h
+++ b/include/zbxcacheconfig.h
@@ -1,9 +1,8 @@
 /*
-** Zabbix
 ** Copyright (C) 2001-2022 Zabbix SIA
 **
 ** This program is free software; you can redistribute it and/or modify
-** it under the terms of the GNU General Public License as published by
+* it under the terms of the GNU General Public License as published by
 ** the Free Software Foundation; either version 2 of the License, or
 ** (at your option) any later version.
 **
@@ -17,19 +16,15 @@
 ** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 **/
 
-#ifndef ZABBIX_DBCACHE_H
-#define ZABBIX_DBCACHE_H
+#ifndef ZABBIX_CACHECONFIG_H
+#define ZABBIX_CACHECONFIG_H
 
 #include "zbxdbhigh.h"
 #include "zbxcomms.h"
-#include "zbxshmem.h"
 #include "zbxeval.h"
 #include "zbxavailability.h"
 #include "zbxversion.h"
 
-#define ZBX_SYNC_DONE		0
-#define	ZBX_SYNC_MORE		1
-
 #define	ZBX_NO_POLLER			255
 #define	ZBX_POLLER_TYPE_NORMAL		0
 #define	ZBX_POLLER_TYPE_UNREACHABLE	1
@@ -60,10 +55,6 @@ zbx_session_type_t;
 
 #define ZBX_SNMPTRAP_LOGGING_ENABLED	1
 
-#define ZBX_IPC_SERVICE_CONFIG		"config"
-#define ZBX_IPC_CONFIG_RELOAD_REQUEST	1
-#define ZBX_IPC_CONFIG_RELOAD_RESPONSE	2
-
 #define ZBX_AGENT_ZABBIX	(INTERFACE_TYPE_AGENT - 1)
 #define ZBX_AGENT_SNMP		(INTERFACE_TYPE_SNMP - 1)
 #define ZBX_AGENT_IPMI		(INTERFACE_TYPE_IPMI - 1)
@@ -74,9 +65,6 @@ zbx_session_type_t;
 extern int	CONFIG_TIMEOUT;
 
 extern zbx_uint64_t	CONFIG_CONF_CACHE_SIZE;
-extern zbx_uint64_t	CONFIG_HISTORY_CACHE_SIZE;
-extern zbx_uint64_t	CONFIG_HISTORY_INDEX_CACHE_SIZE;
-extern zbx_uint64_t	CONFIG_TRENDS_CACHE_SIZE;
 
 extern int	CONFIG_POLLER_FORKS;
 extern int	CONFIG_UNREACHABLE_POLLER_FORKS;
@@ -283,14 +271,6 @@ typedef struct _DC_TRIGGER
 }
 DC_TRIGGER;
 
-/* needed to collect and pass data about items that are involved in generating problem events */
-typedef struct
-{
-	zbx_uint64_t		triggerid;
-	zbx_vector_uint64_t	itemids;
-}
-zbx_trigger_items_t;
-
 typedef struct
 {
 	zbx_uint64_t			hostid;
@@ -327,20 +307,6 @@ typedef struct
 }
 DC_PROXY;
 
-typedef struct
-{
-	zbx_uint64_t	autoreg_hostid;
-	zbx_uint64_t	hostid;
-	char		*host;
-	char		*ip;
-	char		*dns;
-	char		*host_metadata;
-	int		now;
-	unsigned short	port;
-	unsigned short	flag;
-	unsigned int	connection_type;
-}
-zbx_autoreg_host_t;
 
 #define ZBX_ACTION_OPCLASS_NONE			0
 #define ZBX_ACTION_OPCLASS_NORMAL		1
@@ -514,48 +480,6 @@ typedef struct
 }
 zbx_correlation_rules_t;
 
-/* value_avg_t structure is used for item average value trend calculations. */
-/*                                                                          */
-/* For double values the average value is calculated on the fly with the    */
-/* following formula: avg = (dbl * count + value) / (count + 1) and stored  */
-/* into dbl member.                                                         */
-/* For uint64 values the item values are summed into ui64 member and the    */
-/* average value is calculated before flushing trends to database:          */
-/* avg = ui64 / count                                                       */
-typedef union
-{
-	double		dbl;
-	zbx_uint128_t	ui64;
-}
-value_avg_t;
-
-typedef struct
-{
-	zbx_uint64_t	itemid;
-	history_value_t	value_min;
-	value_avg_t	value_avg;
-	history_value_t	value_max;
-	int		clock;
-	int		num;
-	int		disable_from;
-	unsigned char	value_type;
-}
-ZBX_DC_TREND;
-
-typedef struct
-{
-	zbx_uint64_t	itemid;
-	history_value_t	value;
-	zbx_uint64_t	lastlogsize;
-	zbx_timespec_t	ts;
-	int		mtime;
-	unsigned char	value_type;
-	unsigned char	flags;		/* see ZBX_DC_FLAG_* */
-	unsigned char	state;
-	int		ttl;		/* time-to-live of the history value */
-}
-ZBX_DC_HISTORY;
-
 /* item queue data */
 typedef struct
 {
@@ -580,13 +504,6 @@ typedef struct
 }
 zbx_proxy_counter_t;
 
-typedef enum
-{
-	ZBX_COUNTER_TYPE_UI64,
-	ZBX_COUNTER_TYPE_DBL
-}
-zbx_counter_type_t;
-
 typedef struct
 {
 	unsigned char	type;
@@ -623,31 +540,6 @@ typedef struct
 }
 zbx_config_cache_info_t;
 
-typedef struct
-{
-	zbx_uint64_t	history_counter;	/* the total number of processed values */
-	zbx_uint64_t	history_float_counter;	/* the number of processed float values */
-	zbx_uint64_t	history_uint_counter;	/* the number of processed uint values */
-	zbx_uint64_t	history_str_counter;	/* the number of processed str values */
-	zbx_uint64_t	history_log_counter;	/* the number of processed log values */
-	zbx_uint64_t	history_text_counter;	/* the number of processed text values */
-	zbx_uint64_t	notsupported_counter;	/* the number of processed not supported items */
-}
-ZBX_DC_STATS;
-
-/* the write cache statistics */
-typedef struct
-{
-	ZBX_DC_STATS	stats;
-	zbx_uint64_t	history_free;
-	zbx_uint64_t	history_total;
-	zbx_uint64_t	index_free;
-	zbx_uint64_t	index_total;
-	zbx_uint64_t	trend_free;
-	zbx_uint64_t	trend_total;
-}
-zbx_wcache_info_t;
-
 int	is_item_processed_by_server(unsigned char type, const char *key);
 int	zbx_is_counted_in_item_queue(unsigned char type, const char *key);
 int	in_maintenance_without_data_collection(unsigned char maintenance_status, unsigned char maintenance_type,
@@ -655,46 +547,10 @@ int	in_maintenance_without_data_collection(unsigned char maintenance_status, uns
 void	dc_add_history(zbx_uint64_t itemid, unsigned char item_value_type, unsigned char item_flags,
 		AGENT_RESULT *result, const zbx_timespec_t *ts, unsigned char state, const char *error);
 void	dc_flush_history(void);
-void	zbx_sync_history_cache(int *values_num, int *triggers_num, int *more);
-void	zbx_log_sync_history_cache_progress(void);
 
 #define ZBX_SYNC_NONE	0
 #define ZBX_SYNC_ALL	1
 
-int	init_database_cache(char **error);
-void	free_database_cache(int);
-
-void	change_proxy_history_count(int change_count);
-void	reset_proxy_history_count(int reset);
-int	get_proxy_history_count(void);
-
-#define ZBX_STATS_HISTORY_COUNTER	0
-#define ZBX_STATS_HISTORY_FLOAT_COUNTER	1
-#define ZBX_STATS_HISTORY_UINT_COUNTER	2
-#define ZBX_STATS_HISTORY_STR_COUNTER	3
-#define ZBX_STATS_HISTORY_LOG_COUNTER	4
-#define ZBX_STATS_HISTORY_TEXT_COUNTER	5
-#define ZBX_STATS_NOTSUPPORTED_COUNTER	6
-#define ZBX_STATS_HISTORY_TOTAL		7
-#define ZBX_STATS_HISTORY_USED		8
-#define ZBX_STATS_HISTORY_FREE		9
-#define ZBX_STATS_HISTORY_PUSED		10
-#define ZBX_STATS_HISTORY_PFREE		11
-#define ZBX_STATS_TREND_TOTAL		12
-#define ZBX_STATS_TREND_USED		13
-#define ZBX_STATS_TREND_FREE		14
-#define ZBX_STATS_TREND_PUSED		15
-#define ZBX_STATS_TREND_PFREE		16
-#define ZBX_STATS_HISTORY_INDEX_TOTAL	17
-#define ZBX_STATS_HISTORY_INDEX_USED	18
-#define ZBX_STATS_HISTORY_INDEX_FREE	19
-#define ZBX_STATS_HISTORY_INDEX_PUSED	20
-#define ZBX_STATS_HISTORY_INDEX_PFREE	21
-void	*DCget_stats(int request);
-void	DCget_stats_all(zbx_wcache_info_t *wcache_info);
-
-zbx_uint64_t	DCget_nextid(const char *table_name, int num);
-
 /* initial sync, get all data */
 #define ZBX_DBSYNC_INIT		0
 /* update sync, get changed data */
@@ -800,8 +656,6 @@ void	DCrequeue_items(const zbx_uint64_t *itemids, const int *lastclocks,
 void	DCpoller_requeue_items(const zbx_uint64_t *itemids, const int *lastclocks,
 		const int *errcodes, size_t num, unsigned char poller_type, int *nextcheck);
 void	zbx_dc_requeue_unreachable_items(zbx_uint64_t *itemids, size_t itemids_num);
-int	DCconfig_activate_host(DC_ITEM *item);
-int	DCconfig_deactivate_host(DC_ITEM *item, int now);
 
 int	DCconfig_check_trigger_dependencies(zbx_uint64_t triggerid);
 
@@ -898,7 +752,6 @@ void	zbx_config_get_hk_mode(unsigned char *history_mode, unsigned char *trends_m
 int	DCset_interfaces_availability(zbx_vector_availability_ptr_t *availabilities);
 
 int	DCreset_interfaces_availability(zbx_vector_availability_ptr_t *interfaces);
-void	DCupdate_interfaces_availability(void);
 
 void	zbx_dc_get_actions_eval(zbx_vector_ptr_t *actions, unsigned char opflags);
 
@@ -953,7 +806,6 @@ zbx_hc_item_t;
 void	zbx_free_item_tag(zbx_item_tag_t *item_tag);
 
 int	zbx_dc_get_active_proxy_by_name(const char *name, DC_PROXY *proxy, char **error);
-void	zbx_dc_update_proxy_version(zbx_uint64_t hostid, int version);
 
 typedef struct
 {
@@ -1088,11 +940,6 @@ void	zbx_dc_get_item_tags_by_functionids(const zbx_uint64_t *functionids, size_t
 
 const char	*zbx_dc_get_instanceid(void);
 
-/* diagnostic data */
-void	zbx_hc_get_diag_stats(zbx_uint64_t *items_num, zbx_uint64_t *values_num);
-void	zbx_hc_get_mem_stats(zbx_shmem_stats_t *data, zbx_shmem_stats_t *index);
-void	zbx_hc_get_items(zbx_vector_uint64_pair_t *items);
-
 typedef struct
 {
 	zbx_uint64_t		objectid;
@@ -1116,21 +963,11 @@ void	zbx_dc_get_triggers_by_timers(zbx_hashset_t *trigger_info, zbx_vector_ptr_t
 		const zbx_vector_ptr_t *timers);
 void	zbx_dc_free_timers(zbx_vector_ptr_t *timers);
 
-int	zbx_db_trigger_queue_locked(void);
-void	zbx_db_trigger_queue_unlock(void);
-
 void	zbx_get_host_interfaces_availability(zbx_uint64_t	hostid, zbx_agent_availability_t *agents);
 
-int	zbx_hc_check_proxy(zbx_uint64_t proxyid);
-
 typedef int (*zbx_trigger_func_t)(zbx_variant_t *, const DC_ITEM *, const char *, const char *,
 		const zbx_timespec_t *, char **);
 
-void	zbx_db_trigger_explain_expression(const ZBX_DB_TRIGGER *trigger, char **expression,
-		zbx_trigger_func_t eval_func_cb, int recovery);
-void	zbx_db_trigger_get_function_value(const ZBX_DB_TRIGGER *trigger, int index, char **value,
-		zbx_trigger_func_t eval_func_cb, int recovery);
-
 /* external user macro cache API */
 
 typedef struct zbx_dc_um_handle_t zbx_dc_um_handle_t;
diff --git a/include/zbxcachehistory.h b/include/zbxcachehistory.h
new file mode 100644
index 00000000000..b944d93294c
--- /dev/null
+++ b/include/zbxcachehistory.h
@@ -0,0 +1,136 @@
+/*
+** Zabbix
+** Copyright (C) 2001-2022 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+#ifndef ZABBIX_CACHEHISTORY_H
+#define ZABBIX_CACHEHISTORY_H
+
+#include "zbxcacheconfig.h"
+#include "zbxshmem.h"
+
+#define ZBX_SYNC_DONE		0
+#define	ZBX_SYNC_MORE		1
+
+extern zbx_uint64_t	CONFIG_HISTORY_CACHE_SIZE;
+extern zbx_uint64_t	CONFIG_HISTORY_INDEX_CACHE_SIZE;
+extern zbx_uint64_t	CONFIG_TRENDS_CACHE_SIZE;
+
+/* value_avg_t structure is used for item average value trend calculations. */
+/*                                                                          */
+/* For double values the average value is calculated on the fly with the    */
+/* following formula: avg = (dbl * count + value) / (count + 1) and stored  */
+/* into dbl member.                                                         */
+/* For uint64 values the item values are summed into ui64 member and the    */
+/* average value is calculated before flushing trends to database:          */
+/* avg = ui64 / count                                                       */
+typedef union
+{
+	double		dbl;
+	zbx_uint128_t	ui64;
+}
+value_avg_t;
+
+typedef struct
+{
+	zbx_uint64_t	itemid;
+	history_value_t	value_min;
+	value_avg_t	value_avg;
+	history_value_t	value_max;
+	int		clock;
+	int		num;
+	int		disable_from;
+	unsigned char	value_type;
+}
+ZBX_DC_TREND;
+
+typedef struct
+{
+	zbx_uint64_t	history_counter;	/* the total number of processed values */
+	zbx_uint64_t	history_float_counter;	/* the number of processed float values */
+	zbx_uint64_t	history_uint_counter;	/* the number of processed uint values */
+	zbx_uint64_t	history_str_counter;	/* the number of processed str values */
+	zbx_uint64_t	history_log_counter;	/* the number of processed log values */
+	zbx_uint64_t	history_text_counter;	/* the number of processed text values */
+	zbx_uint64_t	notsupported_counter;	/* the number of processed not supported items */
+}
+ZBX_DC_STATS;
+
+/* the write cache statistics */
+typedef struct
+{
+	ZBX_DC_STATS	stats;
+	zbx_uint64_t	history_free;
+	zbx_uint64_t	history_total;
+	zbx_uint64_t	index_free;
+	zbx_uint64_t	index_total;
+	zbx_uint64_t	trend_free;
+	zbx_uint64_t	trend_total;
+}
+zbx_wcache_info_t;
+
+void	zbx_sync_history_cache(int *values_num, int *triggers_num, int *more);
+void	zbx_log_sync_history_cache_progress(void);
+
+#define ZBX_SYNC_NONE	0
+#define ZBX_SYNC_ALL	1
+
+int	init_database_cache(char **error);
+void	free_database_cache(int);
+
+void	change_proxy_history_count(int change_count);
+void	reset_proxy_history_count(int reset);
+int	get_proxy_history_count(void);
+
+#define ZBX_STATS_HISTORY_COUNTER	0
+#define ZBX_STATS_HISTORY_FLOAT_COUNTER	1
+#define ZBX_STATS_HISTORY_UINT_COUNTER	2
+#define ZBX_STATS_HISTORY_STR_COUNTER	3
+#define ZBX_STATS_HISTORY_LOG_COUNTER	4
+#define ZBX_STATS_HISTORY_TEXT_COUNTER	5
+#define ZBX_STATS_NOTSUPPORTED_COUNTER	6
+#define ZBX_STATS_HISTORY_TOTAL		7
+#define ZBX_STATS_HISTORY_USED		8
+#define ZBX_STATS_HISTORY_FREE		9
+#define ZBX_STATS_HISTORY_PUSED		10
+#define ZBX_STATS_HISTORY_PFREE		11
+#define ZBX_STATS_TREND_TOTAL		12
+#define ZBX_STATS_TREND_USED		13
+#define ZBX_STATS_TREND_FREE		14
+#define ZBX_STATS_TREND_PUSED		15
+#define ZBX_STATS_TREND_PFREE		16
+#define ZBX_STATS_HISTORY_INDEX_TOTAL	17
+#define ZBX_STATS_HISTORY_INDEX_USED	18
+#define ZBX_STATS_HISTORY_INDEX_FREE	19
+#define ZBX_STATS_HISTORY_INDEX_PUSED	20
+#define ZBX_STATS_HISTORY_INDEX_PFREE	21
+void	*DCget_stats(int request);
+void	DCget_stats_all(zbx_wcache_info_t *wcache_info);
+
+zbx_uint64_t	DCget_nextid(const char *table_name, int num);
+
+void	DCupdate_interfaces_availability(void);
+
+void	zbx_hc_get_diag_stats(zbx_uint64_t *items_num, zbx_uint64_t *values_num);
+void	zbx_hc_get_mem_stats(zbx_shmem_stats_t *data, zbx_shmem_stats_t *index);
+void	zbx_hc_get_items(zbx_vector_uint64_pair_t *items);
+
+int	zbx_db_trigger_queue_locked(void);
+void	zbx_db_trigger_queue_unlock(void);
+
+int	zbx_hc_check_proxy(zbx_uint64_t proxyid);
+#endif
diff --git a/include/zbxcachevalue.h b/include/zbxcachevalue.h
new file mode 100644
index 00000000000..8afbb280dfc
--- /dev/null
+++ b/include/zbxcachevalue.h
@@ -0,0 +1,122 @@
+/*
+** Zabbix
+** Copyright (C) 2001-2022 Zabbix SIA
+**
+** This program is free software; you can redistribute it and/or modify
+** it under the terms of the GNU General Public License as published by
+** the Free Software Foundation; either version 2 of the License, or
+** (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+** GNU General Public License for more details.
+**
+** You should have received a copy of the GNU General Public License
+** along with this program; if not, write to the Free Software
+** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+**/
+
+#ifndef ZABBIX_CACHEVALUE_H
+#define ZABBIX_CACHEVALUE_H
+
+#include "zbxtypes.h"
+#include "zbxalgo.h"
+#include "zbxhistory.h"
+#include "zbxshmem.h"
+
+/*
+ * The Value Cache provides read caching of item historical data residing in history
+ * tables. No components must read history tables manually. Instead all history data
+ * must be read from the Value Cache.
+ *
+ * Usage notes:
+ *
+ * Initialization
+ *
+ *   The value cache must be initialized at the start of the program with zbx_vc_init()
+ *   function. To ensure proper removal of shared memory the value cache must be destroyed
+ *   upon a program exit with zbx_vc_destroy() function.
+ *
+ * Adding data
+ *
+ *   Whenever a new item value is added to system (history tables) the item value must be
+ *   also added added to Value Cache with zbx_dc_add_value() function to keep it up to date.
+ *
+ * Retrieving data
+ *
+ *   The history data is accessed with zbx_vc_get_values() and zbx_vc_get_value()
+ *   functions. Afterwards the retrieved history data must be freed by the caller by using
+ *   either zbx_history_record_vector_destroy() function (free the zbx_vc_get_values()
+ *   call output) or zbx_history_record_clear() function (free the zbx_vc_get_value() call output).
+ *
+ * Locking
+ *
+ *   The cache ensures synchronization between processes by using automatic locks whenever
+ *   a cache function (zbx_vc_*) is called and by providing manual cache locking functionality
+ *   with zbx_vc_lock()/zbx_vc_unlock() functions.
+ *
+ */
+
+#define ZBX_VC_MODE_NORMAL	0
+#define ZBX_VC_MODE_LOWMEM	1
+
+/* indicates that all values from database are cached */
+#define ZBX_ITEM_STATUS_CACHED_ALL	1
+
+/* the cache statistics */
+typedef struct
+{
+	/* Value cache misses are new values cached during request and hits are calculated by  */
+	/* subtracting misses from the total number of values returned (0 if the number of     */
+	/* returned values is less than misses.                                                */
+	/* When performing count based requests the number of cached values might be greater   */
+	/* than number of returned values. This can skew the hits/misses ratio towards misses. */
+	zbx_uint64_t	hits;
+	zbx_uint64_t	misses;
+
+	zbx_uint64_t	total_size;
+	zbx_uint64_t	free_size;
+
+	/* value cache operating mode - see ZBX_VC_MODE_* defines */
+	int		mode;
+}
+zbx_vc_stats_t;
+
+/* item diagnostic statistics */
+typedef struct
+{
+	zbx_uint64_t	itemid;
+	int		values_num;
+	int		hourly_num;
+}
+zbx_vc_item_stats_t;
+
+int	zbx_vc_init(char **error);
+
+void	zbx_vc_destroy(void);
+
+void	zbx_vc_reset(void);
+
+void	zbx_vc_enable(void);
+
+void	zbx_vc_disable(void);
+
+int	zbx_vc_get_values(zbx_uint64_t itemid, unsigned char value_type, zbx_vector_history_record_t *values,
+		int seconds, int count, const zbx_timespec_t *ts);
+
+int	zbx_vc_get_value(zbx_uint64_t itemid, unsigned char value_type, const zbx_timespec_t *ts,
+		zbx_history_record_t *value);
+
+int	zbx_vc_add_values(zbx_vector_ptr_t *history, int *ret_flush);
+
+int	zbx_vc_get_statistics(zbx_vc_stats_t *stats);
+
+void	zbx_vc_remove_items_by_ids(zbx_vector_uint64_t *itemids);
+
+void	zbx_vc_get_diag_stats(zbx_uint64_t *items_num, zbx_uint64_t *values_num, int *mode);
+void	zbx_vc_get_mem_stats(zbx_shmem_stats_t *mem);
+void	zbx_vc_get_item_stats(zbx_vector_ptr_t *stats);
+void	zbx_vc_flush_stats(void);
+
+#endif
diff --git a/include/zbxdbhigh.h b/include/zbxdbhigh.h
index cba6dacf19d..03067c163fd 100644
--- a/include/zbxdbhigh.h
+++ b/include/zbxdbhigh.h
@@ -640,10 +640,6 @@ typedef struct
 }
 zbx_item_diff_t;
 
-void	zbx_db_trigger_get_expression(const ZBX_DB_TRIGGER *trigger, char **expression);
-void	zbx_db_trigger_get_recovery_expression(const ZBX_DB_TRIGGER *trigger, char **expression);
-void	zbx_db_trigger_clean(ZBX_DB_TRIGGER *trigger);
-
 typedef struct
 {
 	zbx_uint64_t			hostid;
@@ -775,13 +771,6 @@ void	zbx_load_lld_override_operations(const zbx_vector_uint64_t *overrideids, ch
 
 #define ZBX_TIMEZONE_DEFAULT_VALUE	"default"
 
-void	zbx_db_trigger_get_all_functionids(const ZBX_DB_TRIGGER *trigger, zbx_vector_uint64_t *functionids);
-void	zbx_db_trigger_get_functionids(const ZBX_DB_TRIGGER *trigger, zbx_vector_uint64_t *functionids);
-int	zbx_db_trigger_get_all_hostids(const ZBX_DB_TRIGGER *trigger, const zbx_vector_uint64_t **hostids);
-int	zbx_db_trigger_get_constant(const ZBX_DB_TRIGGER *trigger, int index, char **out);
-int	zbx_db_trigger_get_itemid(const ZBX_DB_TRIGGER *trigger, int index, zbx_uint64_t *itemid);
-void	zbx_db_trigger_get_itemids(const ZBX_DB_TRIGGER *trigger, zbx_vector_uint64_t *itemids);
-
 int	zbx_db_check_version_info(struct zbx_db_version_info_t *info, int allow_unsupported);
 void	zbx_db_version_info_clear(struct zbx_db_version_info_t *version_info);
 
@@ -832,4 +821,19 @@ int	zbx_get_proxy_protocol_version_int(const char *version_str);
 #define ZBX_CONDITION_TYPE_SERVICE			27
 #define ZBX_CONDITION_TYPE_SERVICE_NAME			28
 
+typedef struct
+{
+	zbx_uint64_t	autoreg_hostid;
+	zbx_uint64_t	hostid;
+	char		*host;
+	char		*ip;
+	char		*dns;
+	char		*host_metadata;
+	int		now;
+	unsigned short	port;
+	unsigned short	flag;
+	unsigned int	connection_type;
+}
+zbx_autoreg_host_t;
+
 #endif /* ZABBIX_DBHIGH_H */
diff --git a/include/zbxdbwrap.h b/include/zbxdbwrap.h
index aa3edf00ba3..6c68c328dc6 100644
--- a/include/zbxdbwrap.h
+++ b/include/zbxdbwrap.h
@@ -21,7 +21,7 @@
 #define ZABBIX_DBWRAP_H
 
 #include "zbxdbhigh.h"
-#include "dbcache.h"
+#include "zbxcachehistory.h"
 
 #define ZBX_PROXYMODE_ACTIVE	0
 #define ZBX_PROXYMODE_PASSIVE	1
@@ -101,4 +101,23 @@ void	zbx_db_free_event(ZBX_DB_EVENT *event);
 void	zbx_db_get_eventid_r_eventid_pairs(zbx_vector_uint64_t *eventids, zbx_vector_uint64_pair_t *event_pairs,
 		zbx_vector_uint64_t *r_eventids);
 
+void	zbx_db_trigger_get_all_functionids(const ZBX_DB_TRIGGER *trigger, zbx_vector_uint64_t *functionids);
+void	zbx_db_trigger_get_functionids(const ZBX_DB_TRIGGER *trigger, zbx_vector_uint64_t *functionids);
+int	zbx_db_trigger_get_constant(const ZBX_DB_TRIGGER *trigger, int index, char **out);
+int	zbx_db_trigger_get_all_hostids(const ZBX_DB_TRIGGER *trigger, const zbx_vector_uint64_t **hostids);
+int	zbx_db_trigger_get_itemid(const ZBX_DB_TRIGGER *trigger, int index, zbx_uint64_t *itemid);
+void	zbx_db_trigger_get_itemids(const ZBX_DB_TRIGGER *trigger, zbx_vector_uint64_t *itemids);
+
+void	zbx_db_trigger_get_expression(const ZBX_DB_TRIGGER *trigger, char **expression);
+void	zbx_db_trigger_get_recovery_expression(const ZBX_DB_TRIGGER *trigger, char **expression);
+void	zbx_db_trigger_clean(ZBX_DB_TRIGGER *trigger);
+
+typedef int (*zbx_trigger_func_t)(zbx_variant_t *, const DC_ITEM *, const char *, const char *,
+		const zbx_timespec_t *, char **);
+
+void	zbx_db_trigger_explain_expression(const ZBX_DB_TRIGGER *trigger, char **expression,
+		zbx_trigger_func_t eval_func_cb, int recovery);
+void	zbx_db_trigger_get_function_value(const ZBX_DB_TRIGGER *trigger, int index, char **value,
+		zbx_trigger_func_t eval_func_cb, int recovery);
+
 #endif /* ZABBIX_DBWRAP_H */
diff --git a/include/zbxhistory.h b/include/zbxhistory.h
index e5407471841..ce2b7097d31 100644
--- a/include/zbxhistory.h
+++ b/include/zbxhistory.h
@@ -67,4 +67,18 @@ void	zbx_history_check_version(struct zbx_json *json, int *result);
 #define FLUSH_FAIL		-1
 #define FLUSH_DUPL_REJECTED	-2
 
+typedef struct
+{
+	zbx_uint64_t	itemid;
+	history_value_t	value;
+	zbx_uint64_t	lastlogsize;
+	zbx_timespec_t	ts;
+	int		mtime;
+	unsigned char	value_type;
+	unsigned char	flags;		/* see ZBX_DC_FLAG_* */
+	unsigned char	state;
+	int		ttl;		/* time-to-live of the history value */
+}
+ZBX_DC_HISTORY;
+
 #endif
diff --git a/include/zbxserver.h b/include/zbxserver.h
index 3ee7a23f38f..2f164e5caf2 100644
--- a/include/zbxserver.h
+++ b/include/zbxserver.h
@@ -20,7 +20,7 @@
 #ifndef ZABBIX_ZBXSERVER_H
 #define ZABBIX_ZBXSERVER_H
 
-#include "dbcache.h"
+#include "zbxcachehistory.h"
 #include "zbxvariant.h"
 
 #define MACRO_TYPE_MESSAGE_NORMAL	0x00000001
diff --git a/include/zbxtrends.h b/include/zbxtrends.h
index cfda9865b6f..b3e097a9633 100644
--- a/include/zbxtrends.h
+++ b/include/zbxtrends.h
@@ -20,7 +20,7 @@
 #ifndef ZABBIX_ZBXTRENDS_H
 #define ZABBIX_ZBXTRENDS_H
 
-#include "dbcache.h"
+#include "zbxcachehistory.h"
 #include "zbxtime.h"
 
 int	zbx_trends_parse_base(const char *params, zbx_time_unit_t *base, char **error);