.

go/xcommon/xnet/lonet/lonet_test.go

+// Copyright (C) 2018  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+package lonet
+
+// TODO test go-go
+// TODO test go-py

go/xcommon/xnet/lonet/registry.go

@@ -21,6 +21,7 @@ package lonet
 // registry of network hosts
 
 import (
+	"context"
 	"errors"
 	"fmt"
 )
@@ -51,7 +52,7 @@ type registry interface {
 	//	- errRegistryDown if registry cannot be accessed	XXX (and its underlying cause?)
 	//	- errHostDup
 	//	- some other error indicating e.g. IO problem.
-	Announce(hostname, osladdr string) error
+	Announce(ctx context.Context, hostname, osladdr string) error
 
 	// Query queries registry for host.
 	//
@@ -64,7 +65,14 @@ type registry interface {
 	//	- errRegistryDown ...	XXX
 	//	- errNoHost       if hostname was not announced to registry,
 	//	- some other error indicating e.g. IO problem.
-	Query(hostname string) (osladdr string, _ error)
+	Query(ctx context.Context, hostname string) (osladdr string, _ error)
+
+	// Close closes access to registry.
+	//
+	// Close interrupts all in-fligh Announce and Query requests started
+	// via closed registry connection. Those interrupted requests will
+	// return with errRegistryDown error cause.
+	Close() error
 }
 
 var errRegistryDown = errors.New("registry is down")
@@ -72,7 +80,7 @@ var errNoHost       = errors.New("no such host")
 var errHostDup      = errors.New("host already registered")
 
 type registryError struct {
-	// XXX name of the network?
+	// XXX name of the network? - XXX yes
 	Registry string		// name of the registry
 	Op       string		// operation that failed
 	Args     interface{}	// operation arguments, if any

go/xcommon/xnet/lonet/registry_sqlite.go

@@ -19,3 +19,145 @@
 
 package lonet
 // registry implemented as shared SQLite file
+
+import (
+	"context"
+
+	"crawshaw.io/sqlite"
+	"crawshaw.io/sqlite/sqliteutil"
+)
+
+// registry schema
+//
+// hosts:
+//	hostname	text !null PK
+//	osladdr		text !null
+//
+// meta:
+//	name		text !null PK
+//	value		text !null
+//
+// "schemaver"	str(int) - version of schema.
+// "network"    text     - name of lonet network this registry serves.
+
+type sqliteRegistry struct {
+	dbpool *sqlite.Pool
+
+	uri    string	// URI db was originally opened with
+}
+
+// openRegistrySqlite opens SQLite registry located at dburi.
+// XXX network name?
+func openRegistrySQLite(dburi string) (_ *sqliteRegistry, err error) {
+	r := &sqliteRegistry{uri: dburi}
+	defer r.regerr(&err, "open")
+
+	dbpool, err := sqlite.Open(dburi, 0, /* poolSize= */16)	// XXX pool size ok?
+	if err != nil {
+		return nil, err
+	}
+
+	r.dbpool = dbpool
+	return r, nil
+
+	// XXX setup
+}
+
+func (r *sqliteRegistry) Close() (err error) {
+	defer r.regerr(&err, "close")
+	return r.dbpool.Close()
+}
+
+func (r *sqliteRegistry) setup(ctx context.Context) (err error) {
+	defer r.regerr(&err, "setup")	// XXX args?
+
+	// XXX get conn
+	var conn *sqlite.Conn
+
+	err = sqliteutil.ExecScript(conn, `
+		CREATE TABLE IF NOT EXISTS hosts (
+			hostname	TEXT NON NULL PRIMARY KEY,
+			osladdr		TEXT NON NULL
+		);
+
+		CREATE TABLE IF NOT EXISTS meta (
+			name		TEXT NON NULL PRIMARY KEY,
+			value		TEXT NON NULL
+		);
+	`)
+	if err != nil {
+		return err
+	}
+
+	// XXX check schemaver
+	// XXX check network name
+
+	return nil
+}
+
+func (r *sqliteRegistry) Announce(ctx context.Context, hostname, osladdr string) (err error) {
+	defer r.regerr(&err, "announce", hostname, osladdr)
+
+	conn := r.dbpool.Get(ctx.Done())
+	if conn == nil {
+		// either ctx cancel or dbpool close
+		if ctx.Err() != nil {
+			return ctx.Err()
+		}
+		return errRegistryDown // db closed
+	}
+	defer r.dbpool.Put(conn)
+
+	//sqliteutil.Exec(conn, "SELECT hostname, osladdr FROM hosts WHERE hostname = ?", func (stmt *sqlite.Stmt) error {
+	err = sqliteutil.Exec(conn, "INSERT INTO hosts (hostname, osladdr) VALUES (?, ?)", nil, hostname, osladdr)
+
+	// XXX -> errNoHost
+	switch sqlite.ErrCode(err) {
+	case sqlite.SQLITE_CONSTRAINT_UNIQUE:	// XXX test
+		err = errHostDup
+	}
+
+	return err
+}
+
+func (r *sqliteRegistry) Query(ctx context.Context, hostname string) (osladdr string, err error) {
+	defer r.regerr(&err, "query", hostname)
+
+	// XXX get conn
+	var conn *sqlite.Conn
+
+	err = sqliteutil.Exec(conn, "SELECT osladdr FROM hosts WHERE hostname = ?", func (stmt *sqlite.Stmt) error {
+		osladdr = stmt.ColumnText(0)
+		return nil
+	})
+
+	/* XXX reenable
+	switch sqlite.ErrCode(err) {
+	case sqlite.XXXNOROW:
+		err = errNoHost
+	}
+	*/
+
+	/*
+	if err != nil {
+		return "", err
+	}
+	*/
+
+	return osladdr, err
+}
+
+// regerr is syntatic sugar to wrap !nil *errp into registryError.
+func (r *sqliteRegistry) regerr(errp *error, op string, args ...interface{}) {
+	if *errp == nil {
+		return
+	}
+
+	// XXX name of the network
+	*errp = &registryError{
+		Registry: r.uri,
+		Op:       op,
+		Args:     args,
+		Err:      *errp,
+	}
+}

go/xcommon/xnet/lonet/registry_sqlite_test.go

+// Copyright (C) 2018  Nexedi SA and Contributors.
+//                     Kirill Smelkov <kirr@nexedi.com>
+//
+// This program is free software: you can Use, Study, Modify and Redistribute
+// it under the terms of the GNU General Public License version 3, or (at your
+// option) any later version, as published by the Free Software Foundation.
+//
+// You can also Link and Combine this program with other software covered by
+// the terms of any of the Free Software licenses or any of the Open Source
+// Initiative approved licenses and Convey the resulting work. Corresponding
+// source of such a combination shall include the source code for all other
+// software used.
+//
+// This program is distributed WITHOUT ANY WARRANTY; without even the implied
+// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+//
+// See COPYING file for full licensing terms.
+// See https://www.nexedi.com/licensing for rationale and options.
+
+package lonet
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"lab.nexedi.com/kirr/go123/exc"
+)
+
+func TestRegistrySQLite(t *testing.T) {
+	X := exc.Raiseif
+
+	work, err := ioutil.TempDir("", "t-registry-sqlite")
+	X(err)
+	defer os.RemoveAll(work)
+
+	dbpath := work + "/1.db"
+
+	r, err := openRegistrySQLite(dbpath)
+	X(err)
+
+	// r.Network() == ...
+	// r.Query("α") == ø
+	// r.Announce("α", "alpha:1234")
+	// r.Query("α") == "alpha:1234")
+	// r.Query("β") == ø
+
+	r2, err := openRegistrySQLite(dbpath)
+	// r2.Network() == ...
+	// r2.Query("α") == "alpha:1234"
+	// r2.Query("β") == ø
+	// r2.Announce("β", "beta:zzz")
+	// r2.Query("β") == "beta:zzz")
+
+	// r.Query("β") == "beta:zzz")
+
+	X(r.Close())
+
+	// r.Query("α") == errRegistryDown
+	// r.Query("β") == errRegistryDown
+	// r.Announce("γ", "gamma:qqq") == errRegistryDown
+	// r.Query("γ") == errRegistryDown
+
+	X(r2.Close())
+}