Feature: Data history manager engine subsystem (#693)

* Adds lovely initial concept for historical data doer

* Adds ability to save tasks. Adds config. Adds startStop to engine

* Has a database microservice without use of globals! Further infrastructure design. Adds readme

* Commentary to help design

* Adds migrations for database

* readme and adds database models

* Some modelling that doesn't work end of day

* Completes datahistoryjob sql.Begins datahistoryjobresult

* Adds datahistoryjob functions to retreive job results. Adapts subsystem

* Adds process for upserting jobs and job results to the database

* Broken end of day weird sqlboiler crap

* Fixes issue with SQL generation.

* RPC generation and addition of basic upsert command

* Renames types

* Adds rpc functions

* quick commit before context swithc. Exchanges aren't being populated

* Begin the tests!

* complete sql tests. stop failed jobs. CLI command creation

* Defines rpc commands

* Fleshes out RPC implementation

* Expands testing

* Expands testing, removes double remove

* Adds coverage of data history subsystem, expands errors and nil checks

* Minor logic improvement

* streamlines datahistory test setup

* End of day minor linting

* Lint, convert simplify, rpc expansion, type expansion, readme expansion

* Documentation update

* Renames for consistency

* Completes RPC server commands

* Fixes tests

* Speeds up testing by reducing unnecessary actions. Adds maxjobspercycle config

* Comments for everything

* Adds missing result string. checks interval supported. default start end cli

* Fixes ID problem. Improves binance trade fetch. job ranges are processed

* adds dbservice coverage. adds rpcserver coverage

* docs regen, uses dbcon interface, reverts binance, fixes races, toggle manager

* Speed up tests, remove bad global usage, fix uuid check

* Adds verbose. Updates docs. Fixes postgres

* Minor changes to logging and start stop

* Fixes postgres db tests, fixes postgres column typo

* Fixes old string typo,removes constraint,error parsing for nonreaders

* prevents dhm running when table doesn't exist. Adds prereq documentation

* Adds parallel, rmlines, err fix, comment fix, minor param fixes

* doc regen, common time range check and test updating

* Fixes job validation issues. Updates candle range checker.

* Ensures test cannot fail due to time.Now() shenanigans

* Fixes oopsie, adds documentation and a warn

* Fixes another time test, adjusts copy

* Drastically speeds up data history manager tests via function overrides

* Fixes summary bug and better logs

* Fixes local time test, fixes websocket tests

* removes defaults and comment,updates error messages,sets cli command args

* Fixes FTX trade processing

* Fixes issue where jobs got stuck if data wasn't returned but retrieval was successful

* Improves test speed. Simplifies trade verification SQL. Adds command help

* Fixes the oopsies

* Fixes use of query within transaction. Fixes trade err

* oopsie, not needed

* Adds missing data status. Properly ends job even when data is missing

* errors are more verbose and so have more words to describe them

* Doc regen for new status

* tiny test tinkering

* str := string("Removes .String()").String()

* Merge fixups

* Fixes a data race discovered during github actions

* Allows websocket test to pass consistently

* Fixes merge issue preventing datahistorymanager from starting via config

* Niterinos cmd defaults and explanations

* fixes default oopsie

* Fixes lack of nil protection

* Additional oopsie

* More detailed error for validating job exchange

engine/database_connection.go

@@ -16,9 +16,7 @@ import (
 // DatabaseConnectionManagerName is an exported subsystem name
 const DatabaseConnectionManagerName = "database"
 
-var (
-	errDatabaseDisabled = errors.New("database support disabled")
-)
+var errDatabaseDisabled = errors.New("database support disabled")
 
 // DatabaseConnectionManager holds the database connection and its status
 type DatabaseConnectionManager struct {
@@ -43,6 +41,15 @@ func (m *DatabaseConnectionManager) IsRunning() bool {
 	return atomic.LoadInt32(&m.started) == 1
 }
 
+// GetInstance returns a limited scoped database instance
+func (m *DatabaseConnectionManager) GetInstance() database.IDatabase {
+	if m == nil || atomic.LoadInt32(&m.started) == 0 {
+		return nil
+	}
+
+	return m.dbConn
+}
+
 // SetupDatabaseConnectionManager creates a new database manager
 func SetupDatabaseConnectionManager(cfg *database.Config) (*DatabaseConnectionManager, error) {
 	if cfg == nil {
@@ -67,6 +74,14 @@ func SetupDatabaseConnectionManager(cfg *database.Config) (*DatabaseConnectionMa
 	return m, nil
 }
 
+// IsConnected is an exported check to verify if the database is connected
+func (m *DatabaseConnectionManager) IsConnected() bool {
+	if m == nil || atomic.LoadInt32(&m.started) == 0 {
+		return false
+	}
+	return m.dbConn.IsConnected()
+}
+
 // Start sets up the database connection manager to maintain a SQL connection
 func (m *DatabaseConnectionManager) Start(wg *sync.WaitGroup) (err error) {
 	if m == nil {
@@ -92,14 +107,14 @@ func (m *DatabaseConnectionManager) Start(wg *sync.WaitGroup) (err error) {
 				m.host,
 				m.database,
 				m.driver)
-			m.dbConn, err = dbpsql.Connect()
+			m.dbConn, err = dbpsql.Connect(m.dbConn.GetConfig())
 		case database.DBSQLite,
 			database.DBSQLite3:
 			log.Debugf(log.DatabaseMgr,
 				"Attempting to establish database connection to %s utilising %s driver\n",
 				m.database,
 				m.driver)
-			m.dbConn, err = dbsqlite3.Connect()
+			m.dbConn, err = dbsqlite3.Connect(m.database)
 		default:
 			return database.ErrNoDatabaseProvided
 		}