Add relay support, add ql support

cmd/discosrv/db.go

@@ -2,84 +2,31 @@
 
 package main
 
-import "database/sql"
+import (
+	"database/sql"
+	"fmt"
+)
 
-func setupDB(db *sql.DB) error {
-	var err error
+type setupFunc func(db *sql.DB) error
+type compileFunc func(db *sql.DB) (map[string]*sql.Stmt, error)
 
-	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS Devices (
-		DeviceID CHAR(63) NOT NULL PRIMARY KEY,
-		Seen TIMESTAMP NOT NULL
-	)`)
-	if err != nil {
-		return err
-	}
+var (
+	setupFuncs   = make(map[string]setupFunc)
+	compileFuncs = make(map[string]compileFunc)
+)
 
-	row := db.QueryRow(`SELECT 'DevicesDeviceIDIndex'::regclass`)
-	if err := row.Scan(nil); err != nil {
-		_, err = db.Exec(`CREATE INDEX DevicesDeviceIDIndex ON Devices (DeviceID)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	row = db.QueryRow(`SELECT 'DevicesSeenIndex'::regclass`)
-	if err := row.Scan(nil); err != nil {
-		_, err = db.Exec(`CREATE INDEX DevicesSeenIndex ON Devices (Seen)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS Addresses (
-		DeviceID CHAR(63) NOT NULL,
-		Seen TIMESTAMP NOT NULL,
-		Address VARCHAR(42) NOT NULL,
-		Port INTEGER NOT NULL
-	)`)
-	if err != nil {
-		return err
-	}
-
-	row = db.QueryRow(`SELECT 'AddressesDeviceIDSeenIndex'::regclass`)
-	if err := row.Scan(nil); err != nil {
-		_, err = db.Exec(`CREATE INDEX AddressesDeviceIDSeenIndex ON Addresses (DeviceID, Seen)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	row = db.QueryRow(`SELECT 'AddressesDeviceIDAddressPortIndex'::regclass`)
-	if err := row.Scan(nil); err != nil {
-		_, err = db.Exec(`CREATE INDEX AddressesDeviceIDAddressPortIndex ON Addresses (DeviceID, Address, Port)`)
-	}
-	if err != nil {
-		return err
-	}
-
-	return nil
+func register(name string, setup setupFunc, compile compileFunc) {
+	setupFuncs[name] = setup
+	compileFuncs[name] = compile
 }
 
-func compileStatements(db *sql.DB) (map[string]*sql.Stmt, error) {
-	stmts := map[string]string{
-		"cleanAddress":  "DELETE FROM Addresses WHERE Seen < now() - '2 hour'::INTERVAL",
-		"cleanDevice":   "DELETE FROM Devices WHERE Seen < now() - '24 hour'::INTERVAL",
-		"countAddress":  "SELECT count(*) FROM Addresses",
-		"countDevice":   "SELECT count(*) FROM Devices",
-		"insertAddress": "INSERT INTO Addresses (DeviceID, Seen, Address, Port) VALUES ($1, now(), $2, $3)",
-		"insertDevice":  "INSERT INTO Devices (DeviceID, Seen) VALUES ($1, now())",
-		"selectAddress": "SELECT Address, Port from Addresses WHERE DeviceID=$1 AND Seen > now() - '1 hour'::INTERVAL ORDER BY random() LIMIT 16",
-		"updateAddress": "UPDATE Addresses SET Seen=now() WHERE DeviceID=$1 AND Address=$2 AND Port=$3",
-		"updateDevice":  "UPDATE Devices SET Seen=now() WHERE DeviceID=$1",
+func setup(backend string, db *sql.DB) (map[string]*sql.Stmt, error) {
+	setup, ok := setupFuncs[backend]
+	if !ok {
+		return nil, fmt.Errorf("Unsupported backend")
 	}
-
-	res := make(map[string]*sql.Stmt, len(stmts))
-	for key, stmt := range stmts {
-		prep, err := db.Prepare(stmt)
-		if err != nil {
-			return nil, err
-		}
-		res[key] = prep
+	if err := setup(db); err != nil {
+		return nil, err
 	}
-	return res, nil
+	return compileFuncs[backend](db)
 }