dsync: Add per-mailbox sync lock that is always used. Both importing and exporting gets the lock before they even sync the mailbox. The lock is kept until the import/export finishes. This guarantees that no matter how dsync is run, two dsyncs can't be working on the same mailbox at the same time. This lock is in addition to the optional per-user lock enabled by the -l parameter. If the -l parameter is used, the same lock timeout is used for the per-mailbox lock. Otherwise 30s timeout is used. This should help to avoid email duplication when replication is enabled for public namespaces, and maybe in some other rare situations as well.

#ifndef STATS_SETTINGS_H
#define STATS_SETTINGS_H

struct stats_settings {
	uoff_t memory_limit;

	unsigned int command_min_time;
	unsigned int session_min_time;
	unsigned int user_min_time;
	unsigned int domain_min_time;
	unsigned int ip_min_time;

	unsigned int carbon_interval;
	const char *carbon_server;
	const char *carbon_name;
};

extern const struct setting_parser_info stats_setting_parser_info;
extern const struct stats_settings *stats_settings;

#endif