Add change management

cmd/cloudbox/config.go

@@ -2,10 +2,13 @@ package main
 
 import (
 	"os"
+	"time"
 
 	"github.com/pkg/errors"
 	log "github.com/sirupsen/logrus"
 	"gopkg.in/yaml.v2"
+
+	"github.com/Luzifer/cloudbox/sync"
 )
 
 type shareConfig struct {
@@ -14,8 +17,9 @@ type shareConfig struct {
 }
 
 type syncConfig struct {
-	LocalDir  string `yaml:"local_dir"`
-	RemoteURI string `yaml:"remote_uri"`
+	LocalDir  string          `yaml:"local_dir"`
+	RemoteURI string          `yaml:"remote_uri"`
+	Settings  sync.SyncConfig `yaml:"settings"`
 }
 
 type configFile struct {
@@ -43,6 +47,11 @@ func (c configFile) validate() error {
 func defaultConfig() *configFile {
 	return &configFile{
 		ControlDir: "~/.cache/cloudbox",
+		Sync: syncConfig{
+			Settings: sync.SyncConfig{
+				ScanInterval: time.Minute,
+			},
+		},
 	}
 }
 

cmd/cloudbox/providers.go

@@ -20,7 +20,7 @@ func providerFromURI(uri string) (providers.CloudProvider, error) {
 		cp, err := f(uri)
 		switch err {
 		case nil:
-			if cp.Capabilities()&providers.CapBasic == 0 {
+			if !cp.Capabilities().Has(providers.CapBasic) {
 				return nil, errors.Errorf("Provider %s does not support basic capabilities", cp.Name())
 			}
 

cmd/cloudbox/sync.go

@@ -3,7 +3,9 @@ package main
 import (
 	"database/sql"
 	"os"
+	"os/signal"
 	"path"
+	"syscall"
 
 	_ "github.com/mattn/go-sqlite3"
 	"github.com/pkg/errors"
@@ -37,7 +39,16 @@ func execSync() error {
 		return errors.Wrap(err, "Unable to establish database connection")
 	}
 
-	s := sync.New(local, remote, db)
+	s := sync.New(local, remote, db, conf.Sync.Settings)
+
+	sigchan := make(chan os.Signal, 1)
+	signal.Notify(sigchan, syscall.SIGINT, syscall.SIGTERM)
+
+	go func() {
+		for range sigchan {
+			s.Stop()
+		}
+	}()
 
 	log.Info("Starting sync run...")
 	return errors.Wrap(s.Run(), "Unable to sync")

providers/file.go

@@ -1,6 +1,7 @@
 package providers
 
 import (
+	"hash"
 	"io"
 	"time"
 
@@ -11,7 +12,7 @@ var ErrFileNotFound = errors.New("File not found")
 
 type File interface {
 	Info() FileInfo
-	Checksum() (string, error)
+	Checksum(hash.Hash) (string, error)
 	Content() (io.ReadCloser, error)
 }
 
@@ -21,3 +22,33 @@ type FileInfo struct {
 	Checksum     string // Expected to be present on CapAutoChecksum
 	Size         uint64
 }
+
+func (f *FileInfo) Equal(other *FileInfo) bool {
+	if f == nil && other == nil {
+		// Both are not present: No change
+		return true
+	}
+
+	if (f != nil && other == nil) || (f == nil && other != nil) {
+		// One is not present, the other is: Change
+		return false
+	}
+
+	if (f.Checksum != "" || other.Checksum != "") && f.Checksum != other.Checksum {
+		// Checksum is present in one, doesn't match: Change
+		return false
+	}
+
+	if f.Size != other.Size {
+		// No checksums present, size differs: Change
+		return false
+	}
+
+	if !f.LastModified.Equal(other.LastModified) {
+		// LastModified date differs: Change
+		return false
+	}
+
+	// No changes detected yet: No change
+	return true
+}

providers/interface.go

@@ -1,6 +1,8 @@
 package providers
 
 import (
+	"hash"
+
 	"github.com/pkg/errors"
 )
 
@@ -12,6 +14,8 @@ const (
 	CapAutoChecksum
 )
 
+func (c Capability) Has(test Capability) bool { return c&test != 0 }
+
 var (
 	ErrInvalidURI          = errors.New("Spefified URI is invalid for this provider")
 	ErrFeatureNotSupported = errors.New("Feature not supported")
@@ -21,10 +25,11 @@ type CloudProviderInitFunc func(string) (CloudProvider, error)
 
 type CloudProvider interface {
 	Capabilities() Capability
-	Name() string
 	DeleteFile(relativeName string) error
+	GetChecksumMethod() hash.Hash
 	GetFile(relativeName string) (File, error)
 	ListFiles() ([]File, error)
-	PutFile(File) error
+	Name() string
+	PutFile(File) (File, error)
 	Share(relativeName string) (string, error)
 }

providers/local/file.go

@@ -2,8 +2,8 @@ package local
 
 import (
 	"bytes"
-	"crypto/sha256"
 	"fmt"
+	"hash"
 	"io"
 	"os"
 
@@ -26,7 +26,7 @@ func (f File) Info() providers.FileInfo {
 	}
 }
 
-func (f File) Checksum() (string, error) {
+func (f File) Checksum(h hash.Hash) (string, error) {
 	fc, err := f.Content()
 	if err != nil {
 		return "", errors.Wrap(err, "Unable to get file contents")
@@ -37,7 +37,7 @@ func (f File) Checksum() (string, error) {
 		return "", errors.Wrap(err, "Unable to read file contents")
 	}
 
-	return fmt.Sprintf("%x", sha256.Sum256(buf.Bytes())), nil
+	return fmt.Sprintf("%x", h.Sum(buf.Bytes())), nil
 }
 
 func (f File) Content() (io.ReadCloser, error) {

providers/local/provider.go

@@ -1,6 +1,8 @@
 package local
 
 import (
+	"crypto/sha256"
+	"hash"
 	"io"
 	"os"
 	"path"
@@ -26,6 +28,7 @@ type Provider struct {
 
 func (p Provider) Capabilities() providers.Capability { return providers.CapBasic }
 func (p Provider) Name() string                       { return "local" }
+func (p Provider) GetChecksumMethod() hash.Hash       { return sha256.New() }
 
 func (p Provider) ListFiles() ([]providers.File, error) {
 	return nil, errors.New("Not implemented")
@@ -53,33 +56,33 @@ func (p Provider) GetFile(relativeName string) (providers.File, error) {
 	}, nil
 }
 
-func (p Provider) PutFile(f providers.File) error {
+func (p Provider) PutFile(f providers.File) (providers.File, error) {
 	fullPath := path.Join(p.directory, f.Info().RelativeName)
 
 	fp, err := os.Create(fullPath)
 	if err != nil {
-		return errors.Wrap(err, "Unable to create file")
+		return nil, errors.Wrap(err, "Unable to create file")
 	}
 
 	rfp, err := f.Content()
 	if err != nil {
-		return errors.Wrap(err, "Unable to get remote file content")
+		return nil, errors.Wrap(err, "Unable to get remote file content")
 	}
 	defer rfp.Close()
 
 	if _, err := io.Copy(fp, rfp); err != nil {
-		return errors.Wrap(err, "Unable to copy file contents")
+		return nil, errors.Wrap(err, "Unable to copy file contents")
 	}
 
 	if err := fp.Close(); err != nil {
-		return errors.Wrap(err, "Unable to close local file")
+		return nil, errors.Wrap(err, "Unable to close local file")
 	}
 
 	if err := os.Chtimes(fullPath, time.Now(), f.Info().LastModified); err != nil {
-		return errors.Wrap(err, "Unable to set last file mod time")
+		return nil, errors.Wrap(err, "Unable to set last file mod time")
 	}
 
-	return nil
+	return p.GetFile(f.Info().RelativeName)
 }
 
 func (p Provider) Share(relativeName string) (string, error) {

sync/db.go

@@ -0,0 +1,64 @@
+package sync
+
+import (
+	"database/sql"
+	"fmt"
+
+	"github.com/pkg/errors"
+
+	"github.com/Luzifer/cloudbox/providers"
+)
+
+const schema = `
+CREATE TABLE IF NOT EXISTS local_state (
+	relative_name TEXT PRIMARY KEY,
+	last_modified DATETIME,
+	checksum TEXT,
+	size INT
+);
+CREATE TABLE IF NOT EXISTS remote_state (
+	relative_name TEXT PRIMARY KEY,
+	last_modified DATETIME,
+	checksum TEXT,
+	size INT
+);
+`
+
+func (s *Sync) initSchema() error {
+	_, err := s.db.Exec(schema)
+	return err
+}
+
+func (s *Sync) getDBFileInfo(side, relativeName string) (providers.FileInfo, error) {
+	info := providers.FileInfo{}
+
+	stmt, err := s.db.Prepare(fmt.Sprintf("SELECT * from %s_state WHERE relative_name = ?", side))
+	if err != nil {
+		return info, errors.Wrap(err, "Unable to prepare query")
+	}
+
+	row := stmt.QueryRow(relativeName)
+	if err = row.Scan(&info.RelativeName, &info.LastModified, &info.Checksum, &info.Size); err != nil {
+		if err == sql.ErrNoRows {
+			return info, providers.ErrFileNotFound
+		}
+		return info, errors.Wrap(err, "Unable to read response")
+	}
+
+	return info, nil
+}
+
+func (s *Sync) setDBFileInfo(side, info providers.FileInfo) error {
+	stmt, err := s.db.Prepare(fmt.Sprintf(
+		`INSERT INTO %s_state VALUES(?, ?, ?, ?) 
+			ON CONFLICT(relative_name) DO UPDATE SET 
+				last_modified=excluded.last_modified, 
+				checksum=excluded.checksum,
+				size=excluded.size`, side))
+	if err != nil {
+		return errors.Wrap(err, "Unable to prepare query")
+	}
+
+	_, err = stmt.Exec(info.RelativeName, info.LastModified, info.Checksum, info.Size)
+	return errors.Wrap(err, "Unable to upsert file info")
+}

sync/state.go

@@ -0,0 +1,141 @@
+package sync
+
+import (
+	"sort"
+	"strings"
+	"sync"
+
+	"github.com/Luzifer/cloudbox/providers"
+)
+
+type Change uint8
+
+const (
+	ChangeLocalAdd Change = 1 << iota
+	ChangeLocalDelete
+	ChangeLocalUpdate
+	ChangeRemoteAdd
+	ChangeRemoteDelete
+	ChangeRemoteUpdate
+)
+
+func (c Change) Changed() bool {
+	return c != 0
+}
+
+func (c *Change) Register(add Change) {
+	*c = *c | add
+}
+
+func (c Change) Has(test Change) bool {
+	return c&test != 0
+}
+
+func (c Change) Is(test Change) bool {
+	return c == test
+}
+
+const (
+	SideLocal  string = "local"
+	SideRemote string = "remote"
+	SourceDB   string = "db"
+	SourceScan string = "scan"
+)
+
+type stateDetail struct {
+	LocalDB,
+	LocalScan,
+	RemoteDB,
+	RemoteScan *providers.FileInfo
+}
+
+type state struct {
+	files map[string]*stateDetail
+	lock  sync.Mutex
+}
+
+func newState() *state {
+	return &state{
+		files: make(map[string]*stateDetail),
+	}
+}
+
+func (s *state) GetChangeFor(relativeName string) (result Change) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	d := s.files[relativeName]
+
+	// No changes detected
+	if d.LocalDB.Equal(d.LocalScan) && d.RemoteDB.Equal(d.RemoteScan) {
+		// Check special case: Something went really wrong and sync state is FUBAR
+		if d.LocalDB == nil && d.RemoteDB != nil {
+			result.Register(ChangeRemoteAdd)
+		}
+		if d.LocalDB != nil && d.RemoteDB == nil {
+			result.Register(ChangeLocalAdd)
+		}
+
+		return
+	}
+
+	// Check for local changes
+	switch {
+	case d.LocalDB == nil && d.LocalScan != nil:
+		result.Register(ChangeLocalAdd)
+
+	case d.LocalDB != nil && d.LocalScan == nil:
+		result.Register(ChangeLocalDelete)
+
+	case !d.LocalDB.Equal(d.LocalScan):
+		result.Register(ChangeLocalUpdate)
+	}
+
+	// Check for remote changes
+	switch {
+	case d.RemoteDB == nil && d.RemoteScan != nil:
+		result.Register(ChangeRemoteAdd)
+
+	case d.RemoteDB != nil && d.RemoteScan == nil:
+		result.Register(ChangeRemoteDelete)
+
+	case !d.RemoteDB.Equal(d.RemoteScan):
+		result.Register(ChangeRemoteUpdate)
+	}
+
+	return
+}
+
+func (s *state) GetRelativeNames() []string {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	out := []string{}
+	for k := range s.files {
+		out = append(out, k)
+	}
+
+	sort.Strings(out)
+
+	return out
+}
+
+func (s *state) Set(side, source, relativeName string, info providers.FileInfo) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	if _, ok := s.files[relativeName]; !ok {
+		s.files[relativeName] = &stateDetail{}
+	}
+
+	switch strings.Join([]string{side, source}, "::") {
+	case "local::db":
+		s.files[relativeName].LocalDB = &info
+	case "local::scan":
+		s.files[relativeName].LocalScan = &info
+	case "remote::db":
+		s.files[relativeName].RemoteDB = &info
+	case "remote::scan":
+		s.files[relativeName].RemoteScan = &info
+	}
+}

sync/sync.go

@@ -2,27 +2,58 @@ package sync
 
 import (
 	"database/sql"
+	"time"
+
+	"github.com/pkg/errors"
 
 	"github.com/Luzifer/cloudbox/providers"
 )
 
-type Sync struct {
-	db            *sql.DB
-	local, remote providers.CloudProvider
+type SyncConfig struct {
+	ForceUseChecksum bool          `yaml:"force_use_checksum"`
+	ScanInterval     time.Duration `yaml:"scan_interval"`
 }
 
-func New(local, remote providers.CloudProvider, db *sql.DB) *Sync {
+type Sync struct {
+	db            *sql.DB
+	conf          SyncConfig
+	local, remote providers.CloudProvider
+
+	stop chan struct{}
+}
+
+func New(local, remote providers.CloudProvider, db *sql.DB, conf SyncConfig) *Sync {
 	return &Sync{
 		db:     db,
+		conf:   conf,
 		local:  local,
 		remote: remote,
+
+		stop: make(chan struct{}),
 	}
 }
 
 func (s *Sync) Run() error {
-	for {
-		select {}
+	if err := s.initSchema(); err != nil {
+		return errors.Wrap(err, "Unable to initialize database schema")
 	}
 
-	return nil
+	var (
+		hashMethod  = s.remote.GetChecksumMethod()
+		refresh     = time.NewTimer(s.conf.ScanInterval)
+		useChecksum = s.remote.Capabilities().Has(providers.CapAutoChecksum) || s.conf.ForceUseChecksum
+	)
+
+	for {
+		select {
+		case <-refresh.C:
+			// TODO: Execute rescan & sync
+			refresh.Reset(s.conf.ScanInterval)
+
+		case <-s.stop:
+			return nil
+		}
+	}
 }
+
+func (s *Sync) Stop() { s.stop <- struct{}{} }