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MXS-1744 Rename and clean up gtid code, move to separate file

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Renamed the two gtid-classes to better match MariaDB documentation. One
domain-server-sequence-combination is now a "Gtid", as these identify
a transaction. A "GtidList" contains a list of Gtid:s for handling multi-domain
server variables composed of multiple comma separated Gtid:s.

Removed unused methods and renamed some existing ones. Moved the Gtid-code
to its own file.
This commit is contained in:
Esa Korhonen
2018-04-04 17:34:14 +03:00
parent e43678bed9
commit 174db469f3
9 changed files with 423 additions and 441 deletions
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150
server/modules/monitor/mariadbmon/utilities.hh
View File

@ -16,7 +16,6 @@
#include <maxscale/cppdefs.hh>
#include <string>
#include <vector>
#include <maxscale/monitor.h>
/** Utility macro for printing both MXS_ERROR and json error */
@ -72,145 +71,6 @@ string get_connection_errors(const ServerVector& servers);
*/
string monitored_servers_to_string(const ServerVector& array);
/**
* Class which encapsulates a gtid triplet (one <domain>-<server>-<sequence>)
*/
class GtidTriplet
{
public:
uint32_t domain;
int64_t server_id; // Is actually 32bit unsigned. 0 is only used by server versions <= 10.1
uint64_t sequence;
GtidTriplet();
GtidTriplet(uint32_t _domain, int64_t _server_id, uint64_t _sequence);
/**
* Parse a Gtid-triplet from a string. In case of a multi-triplet value, only the triplet with
* the given domain is returned. TODO: Remove once no longer used
*
* @param str Gtid string
* @param search_domain The Gtid domain whose triplet should be returned. Negative domain stands for
* autoselect, which is only allowed when the string contains one triplet.
*/
GtidTriplet(const char* str, int64_t search_domain = -1);
/**
* Parse one triplet from null-terminated string. Handles multi-domain gtid:s properly. Should be called
* repeatedly for a multi-domain gtid string by giving the value of @c endptr as @c str.
*
* @param str First number of a triplet in a gtid-string
* @param endptr A pointer to save the position at after the last parsed character.
* @return A new GtidTriplet. If an error occurs, the server_id of the returned triplet is -1.
*/
static GtidTriplet parse_one_triplet(const char* str, char** endptr);
bool eq(const GtidTriplet& rhs) const;
std::string to_string() const;
/**
* Comparator, used when sorting by domain id.
*
* @param triplet1 Left side
* @param triplet2 Right side
* @return True if left < right
*/
static bool compare_domains(const GtidTriplet& triplet1, const GtidTriplet& triplet2)
{
return triplet1.domain < triplet2.domain;
}
private:
void parse_triplet(const char* str);
};
inline bool operator == (const GtidTriplet& lhs, const GtidTriplet& rhs)
{
return lhs.eq(rhs);
}
class Gtid
{
public:
enum substraction_mode_t
{
MISSING_DOMAIN_IGNORE,
MISSING_DOMAIN_LHS_ADD
};
/**
* Parse the gtid string and return an object. Orders the triplets by domain id.
*
* @param gtid_string gtid as given by server. String must not be empty.
* @return The parsed (possibly multidomain) gtid. In case of error, the gtid will be empty.
*/
static Gtid from_string(const std::string& gtid_string);
/**
* Return a string version of the gtid.
*
* @return A string similar in form to how the server displays it
*/
std::string to_string() const;
/**
* Check if a server with this gtid can replicate from a master with a given gtid. Only considers
* gtid:s and only detects obvious errors. The non-detected errors will mostly be detected once
* the slave tries to start replicating.
*
* TODO: Add support for Replicate_Do/Ignore_Id:s
*
* @param master_gtid Master server gtid
* @return True if replication looks possible
*/
bool can_replicate_from(const Gtid& master_gtid);
/**
* Is the gtid empty.
*
* @return True if gtid has 0 triplets
*/
bool empty() const;
/**
* Full comparison.
*
* @param rhs Other gtid
* @return True if both gtid:s have identical triplets or both are empty
*/
bool operator == (const Gtid& rhs) const;
/**
* Calculate the number of events between two gtid:s with possibly multiple triplets. The
* result is always 0 or greater: if a sequence number of a domain on rhs is greater than on the same
* domain on lhs, the sequences are considered identical. Missing domains are handled depending on the
* value of @c domain_substraction_mode.
*
* @param lhs The value substracted from
* @param io_pos The value doing the substracting
* @param domain_substraction_mode How domains that exist on one side but not the other are handled. If
* MISSING_DOMAIN_IGNORE, these are simply ignored. If MISSING_DOMAIN_LHS_ADD, the sequence number on lhs
* is added to the total difference.
* @return The number of events between the two gtid:s
*/
static uint64_t events_ahead(const Gtid& lhs, const Gtid& rhs,
substraction_mode_t domain_substraction_mode);
/**
* Generate a MASTER_GTID_WAIT()-query to this gtid.
*
* @param timeout Maximum wait time in seconds
* @return The query
*/
std::string generate_master_gtid_wait_cmd(double timeout) const;
GtidTriplet get_triplet(uint32_t domain) const;
private:
std::vector<GtidTriplet> m_triplets;
};
/**
* Helper class for simplifying working with resultsets. Used in MariaDBServer.
*/
@ -278,16 +138,6 @@ public:
*/
bool get_bool(int64_t column_ind) const;
/**
* Read a gtid values from the current row and given column. If the field is empty, will return an invalid
* gtid.
*
* @param column_ind Column index
* @param gtid_domain Which gtid domain to parse
* @return Value as a gtid.
*/
GtidTriplet get_gtid(int64_t column_ind, int64_t gtid_domain) const;
private:
MYSQL_RES* m_resultset; // Underlying result set, freed at dtor.
std::tr1::unordered_map<string, int64_t> m_col_indexes; // Map of column name -> index