rclone/fs_drive.go
Nick Craig-Wood fdb1ec4d53 Implement Google Drive interface
* needs writeup of rather complicated api key setup
  * not implemented yet
    * fix for slow directory listing
    * mimetypes for files
2013-01-18 17:11:22 +00:00

639 lines
17 KiB
Go

// Drive interface
package main
// FIXME could make a purge which deleted everything in the container
// easily - rmdir without the checks!
// FIXME list containers equivalent should list directories?
// FIXME drive times only accurate to 1 ms (3 decimal places)
// FIXME perhaps have a drive setup mode where we ask for all the
// params interactively and store them all in one file
// - don't need to store client* apparently
// NB permissions of token file is too open
// FIXME need to deal with some corner cases
// * multiple files with the same name
// * files can be in multiple directories
// * can have directory loops
import (
"code.google.com/p/goauth2/oauth"
"code.google.com/p/google-api-go-client/drive/v2"
"errors"
"flag"
"fmt"
"io"
"log"
"net/http"
"os"
"regexp"
"strings"
"sync"
"time"
)
// FsDrive represents a remote drive server
type FsDrive struct {
svc *drive.Service // the connection to the drive server
root string // the path we are working on
client *http.Client // authorized client
about *drive.About // information about the drive, including the root
rootId string // Id of the root directory
foundRoot sync.Once // Whether we need to find the root directory or not
dirCache lockedMap // Map of directory path to directory id
findDirLock sync.Mutex // Protect findDir from concurrent use
}
// FsObjectDrive describes a drive object
type FsObjectDrive struct {
drive *FsDrive // what this object is part of
remote string // The remote path
info *drive.File // Info from the drive object if known
}
// lockedMap is a map with a mutex
type lockedMap struct {
sync.RWMutex
cache map[string]string
}
// Make a new locked map
func newLockedMap() lockedMap {
return lockedMap{cache: make(map[string]string)}
}
// Get an item from the map
func (m *lockedMap) Get(key string) (value string, ok bool) {
m.RLock()
value, ok = m.cache[key]
m.RUnlock()
return
}
// Put an item to the map
func (m *lockedMap) Put(key, value string) {
m.Lock()
m.cache[key] = value
m.Unlock()
}
// Flush the map of all data
func (m *lockedMap) Flush() {
m.Lock()
m.cache = make(map[string]string)
m.Unlock()
}
// ------------------------------------------------------------
// Constants
const (
// defaultDriveTokenFile = ".google-drive-token" // FIXME root in home directory somehow
driveFolderType = "application/vnd.google-apps.folder"
)
// Globals
var (
// Flags
driveClientId = flag.String("drive-client-id", os.Getenv("GDRIVE_CLIENT_ID"), "Auth URL for server. Defaults to environment var GDRIVE_CLIENT_ID.")
driveClientSecret = flag.String("drive-client-secret", os.Getenv("GDRIVE_CLIENT_SECRET"), "User name. Defaults to environment var GDRIVE_CLIENT_SECRET.")
driveTokenFile = flag.String("drive-token-file", os.Getenv("GDRIVE_TOKEN_FILE"), "API key (password). Defaults to environment var GDRIVE_TOKEN_FILE.")
driveAuthCode = flag.String("drive-auth-code", "", "Pass in when requested to make the drive token file.")
)
// String converts this FsDrive to a string
func (f *FsDrive) String() string {
return fmt.Sprintf("Google drive root '%s'", f.root)
}
// Pattern to match a drive url
var driveMatch = regexp.MustCompile(`^drive://(.*)$`)
// parseParse parses a drive 'url'
func parseDrivePath(path string) (root string, err error) {
parts := driveMatch.FindAllStringSubmatch(path, -1)
if len(parts) != 1 || len(parts[0]) != 2 {
err = fmt.Errorf("Couldn't parse drive url %q", path)
} else {
root = parts[0][1]
root = strings.Trim(root, "/")
}
return
}
// Lists the directory required
//
// Search params: https://developers.google.com/drive/search-parameters
func (f *FsDrive) listAll(dirId string, title string, directoriesOnly bool, filesOnly bool) (items []*drive.File, err error) {
query := fmt.Sprintf("trashed=false and '%s' in parents", dirId)
if title != "" {
// Escaping the backslash isn't documented but seems to work
title = strings.Replace(title, `\`, `\\`, -1)
title = strings.Replace(title, `'`, `\'`, -1)
query += fmt.Sprintf(" and title='%s'", title)
}
if directoriesOnly {
query += fmt.Sprintf(" and mimeType='%s'", driveFolderType)
}
if filesOnly {
query += fmt.Sprintf(" and mimeType!='%s'", driveFolderType)
}
list := f.svc.Files.List().Q(query)
for {
files, err := list.Do()
if err != nil {
return nil, fmt.Errorf("Couldn't list directory: %s", err)
}
items = append(items, files.Items...)
if files.NextPageToken == "" {
break
}
list.PageToken(files.NextPageToken)
}
return
}
// Ask the user for a new auth
func MakeNewToken(t *oauth.Transport) error {
if *driveAuthCode == "" {
// Generate a URL to visit for authorization.
authUrl := t.Config.AuthCodeURL("state")
fmt.Fprintf(os.Stderr, "Go to the following link in your browser\n")
fmt.Fprintf(os.Stderr, "%s\n", authUrl)
fmt.Fprintf(os.Stderr, "Log in, then re-run this program with the -drive-auth-code parameter\n")
fmt.Fprintf(os.Stderr, "You only need this parameter once until the drive token file has been created\n")
return errors.New("Re-run with --drive-auth-code")
}
// Read the code, and exchange it for a token.
//fmt.Printf("Enter verification code: ")
//var code string
//fmt.Scanln(&code)
_, err := t.Exchange(*driveAuthCode)
return err
}
// NewFsDrive contstructs an FsDrive from the path, container:path
func NewFsDrive(path string) (*FsDrive, error) {
if *driveClientId == "" {
return nil, errors.New("Need -drive-client-id or environmental variable GDRIVE_CLIENT_ID")
}
if *driveClientSecret == "" {
return nil, errors.New("Need -drive-client-secret or environmental variable GDRIVE_CLIENT_SECRET")
}
if *driveTokenFile == "" {
return nil, errors.New("Need -drive-token-file or environmental variable GDRIVE_TOKEN_FILE")
}
// Settings for authorization.
var driveConfig = &oauth.Config{
ClientId: *driveClientId,
ClientSecret: *driveClientSecret,
Scope: "https://www.googleapis.com/auth/drive",
RedirectURL: "urn:ietf:wg:oauth:2.0:oob",
AuthURL: "https://accounts.google.com/o/oauth2/auth",
TokenURL: "https://accounts.google.com/o/oauth2/token",
TokenCache: oauth.CacheFile(*driveTokenFile),
}
root, err := parseDrivePath(path)
if err != nil {
return nil, err
}
f := &FsDrive{root: root, dirCache: newLockedMap()}
t := &oauth.Transport{
Config: driveConfig,
Transport: http.DefaultTransport,
}
// Try to pull the token from the cache; if this fails, we need to get one.
token, err := driveConfig.TokenCache.Token()
if err != nil {
err := MakeNewToken(t)
if err != nil {
return nil, fmt.Errorf("Failed to authorise: %s", err)
}
} else {
if *driveAuthCode != "" {
return nil, fmt.Errorf("Only supply -drive-auth-code once")
}
}
t.Token = token
// Create a new authorized Drive client.
f.client = t.Client()
f.svc, err = drive.New(f.client)
if err != nil {
return nil, fmt.Errorf("Couldn't create Drive client: %s", err)
}
// Read About so we know the root path
f.about, err = f.svc.About.Get().Do()
if err != nil {
return nil, fmt.Errorf("Couldn't read info about Drive: %s", err)
}
// Find the Id of the root directory and the Id of its parent
f.rootId = f.about.RootFolderId
return f, nil
}
// Return an FsObject from a path
//
// May return nil if an error occurred
func (f *FsDrive) NewFsObjectWithInfo(remote string, info *drive.File) FsObject {
fs := &FsObjectDrive{
drive: f,
remote: remote,
}
if info != nil {
fs.info = info
} else {
err := fs.readMetaData() // reads info and meta, returning an error
if err != nil {
// logged already FsDebug("Failed to read info: %s", err)
return nil
}
}
return fs
}
// Return an FsObject from a path
//
// May return nil if an error occurred
func (f *FsDrive) NewFsObject(remote string) FsObject {
return f.NewFsObjectWithInfo(remote, nil)
}
// Path should be directory path either "" or "path/"
func (f *FsDrive) listDir(dirId string, path string, out FsObjectsChan) error {
// Make the API request
items, err := f.listAll(dirId, "", false, false)
if err != nil {
return err
}
for _, item := range items {
// Recurse on directories
// FIXME should do this in parallel
// use a wg to sync then collect error
if item.MimeType == driveFolderType {
err := f.listDir(item.Id, path+item.Title+"/", out)
if err != nil {
return err
}
} else {
// If item has no MD5 sum it isn't stored on drive, so ignore it
if item.Md5Checksum == "" {
continue
}
if fs := f.NewFsObjectWithInfo(path+item.Title, item); fs != nil {
out <- fs
}
}
}
return nil
}
// Splits a path into directory, leaf
//
// Path shouldn't start or end with a /
//
// If there are no slashes then directory will be "" and leaf = path
func splitPath(path string) (directory, leaf string) {
lastSlash := strings.LastIndex(path, "/")
if lastSlash >= 0 {
directory = path[:lastSlash]
leaf = path[lastSlash+1:]
} else {
directory = ""
leaf = path
}
return
}
// Finds the directory passed in returning the directory Id starting from pathId
//
// Path shouldn't start or end with a /
//
// If create is set it will make the directory if not found
//
// Algorithm:
// Look in the cache for the path, if found return the pathId
// If not found strip the last path off the path and recurse
// Now have a parent directory id, so look in the parent for self and return it
func (f *FsDrive) findDir(path string, create bool) (pathId string, err error) {
pathId = f._findDirInCache(path)
if pathId != "" {
return
}
f.findDirLock.Lock()
defer f.findDirLock.Unlock()
return f._findDir(path, create)
}
// Look for the root and in the cache - safe to call without the findDirLock
func (f *FsDrive) _findDirInCache(path string) string {
// fmt.Println("Finding",path,"create",create,"cache",cache)
// If it is the root, then return it
if path == "" {
// fmt.Println("Root")
return f.rootId
}
// If it is in the cache then return it
pathId, ok := f.dirCache.Get(path)
if ok {
// fmt.Println("Cache hit on", path)
return pathId
}
return ""
}
// Unlocked findDir - must have findDirLock
func (f *FsDrive) _findDir(path string, create bool) (pathId string, err error) {
pathId = f._findDirInCache(path)
if pathId != "" {
return
}
// Split the path into directory, leaf
directory, leaf := splitPath(path)
// Recurse and find pathId for directory
pathId, err = f._findDir(directory, create)
if err != nil {
return pathId, err
}
// Find the leaf in pathId
items, err := f.listAll(pathId, leaf, true, false)
if err != nil {
return pathId, err
}
found := false
for _, file := range items {
if file.Title == leaf {
pathId = file.Id
found = true
break
}
}
// If not found create the directory if required or return an error
if !found {
if create {
// fmt.Println("Making", path)
// Define the metadata for the directory we are going to create.
info := &drive.File{
Title: leaf,
Description: leaf,
MimeType: driveFolderType,
Parents: []*drive.ParentReference{{Id: pathId}},
}
info, err := f.svc.Files.Insert(info).Do()
if err != nil {
return pathId, fmt.Errorf("Failed to make directory")
}
pathId = info.Id
} else {
return pathId, fmt.Errorf("Couldn't find directory: %q", path)
}
}
// Store the directory in the cache
f.dirCache.Put(path, pathId)
// fmt.Println("Dir", path, "is", pathId)
return pathId, nil
}
// Finds the root directory if not already found
//
// Resets the root directory
//
// If create is set it will make the directory if not found
func (f *FsDrive) findRoot(create bool) error {
var err error
f.foundRoot.Do(func() {
f.rootId, err = f.findDir(f.root, create)
f.dirCache.Flush()
})
return err
}
// Walk the path returning a channel of FsObjects
func (f *FsDrive) List() FsObjectsChan {
out := make(FsObjectsChan, *checkers)
go func() {
defer close(out)
err := f.findRoot(false)
if err != nil {
stats.Error()
log.Printf("Couldn't find root: %s", err)
} else {
err = f.listDir(f.rootId, "", out)
if err != nil {
stats.Error()
log.Printf("List failed: %s", err)
}
}
}()
return out
}
// Put the FsObject into the container
//
// Copy the reader in to the new object which is returned
//
// The new object may have been created
func (f *FsDrive) Put(in io.Reader, remote string, modTime time.Time, size int64) (FsObject, error) {
// Temporary FsObject under construction
fs := &FsObjectDrive{drive: f, remote: remote}
directory, leaf := splitPath(remote)
directoryId, err := f.findDir(directory, true)
if err != nil {
return nil, fmt.Errorf("Couldn't find or make directory: %s", err)
}
// Define the metadata for the file we are going to create.
info := &drive.File{
Title: leaf,
Description: leaf,
Parents: []*drive.ParentReference{{Id: directoryId}},
// FIXME set mimeType:
}
// FIXME can't set modified date on initial upload as no
// .SetModifiedDate(). This agrees with the API docs, but not
// with the comment on
// https://developers.google.com/drive/v2/reference/files/insert
//
// modifiedDate datetime Last time this file was modified by
// anyone (formatted RFC 3339 timestamp). This is only mutable
// on update when the setModifiedDate parameter is set.
// writable
//
// There is no setModifiedDate parameter though
// Make the API request to upload infodata and file data.
info, err = f.svc.Files.Insert(info).Media(in).Do()
if err != nil {
return nil, fmt.Errorf("Upload failed: %s", err)
}
// Set modified date
info.ModifiedDate = modTime.Format(time.RFC3339Nano)
_, err = f.svc.Files.Update(info.Id, info).SetModifiedDate(true).Do()
if err != nil {
return nil, fmt.Errorf("Failed to set mtime: %s", err)
}
return fs, nil
}
// Mkdir creates the container if it doesn't exist
func (f *FsDrive) Mkdir() error {
return f.findRoot(true)
}
// Rmdir deletes the container
//
// Returns an error if it isn't empty
func (f *FsDrive) Rmdir() error {
if f.root == "" {
return fmt.Errorf("Can't delete root directory")
}
err := f.findRoot(false)
if err != nil {
return err
}
children, err := f.svc.Children.List(f.rootId).MaxResults(10).Do()
if err != nil {
return err
}
if len(children.Items) > 0 {
return fmt.Errorf("Directory not empty: %#v", children.Items)
}
err = f.svc.Files.Delete(f.rootId).Do()
if err != nil {
return err
}
return nil
}
// ------------------------------------------------------------
// Return the remote path
func (fs *FsObjectDrive) Remote() string {
return fs.remote
}
// Md5sum returns the Md5sum of an object returning a lowercase hex string
func (fs *FsObjectDrive) Md5sum() (string, error) {
return strings.ToLower(fs.info.Md5Checksum), nil
}
// Size returns the size of an object in bytes
func (fs *FsObjectDrive) Size() int64 {
return fs.info.FileSize
}
// readMetaData gets the info if it hasn't already been fetched
//
// it also sets the info
func (fs *FsObjectDrive) readMetaData() (err error) {
if fs.info != nil {
return nil
}
directory, leaf := splitPath(fs.remote)
directoryId, err := fs.drive.findDir(directory, false)
if err != nil {
FsDebug(fs, "Couldn't find directory: %s", err)
return fmt.Errorf("Couldn't find directory: %s", err)
}
items, err := fs.drive.listAll(directoryId, leaf, false, true)
if err != nil {
return err
}
for _, file := range items {
if file.Title == leaf {
fs.info = file
return nil
}
}
FsDebug(fs, "Couldn't find object")
return fmt.Errorf("Couldn't find object")
}
// ModTime returns the modification time of the object
//
//
// It attempts to read the objects mtime and if that isn't present the
// LastModified returned in the http headers
func (fs *FsObjectDrive) ModTime() time.Time {
err := fs.readMetaData()
if err != nil {
FsLog(fs, "Failed to read metadata: %s", err)
return time.Now()
}
modTime, err := time.Parse(time.RFC3339, fs.info.ModifiedDate)
if err != nil {
FsLog(fs, "Failed to read mtime from object: %s", err)
return time.Now()
}
return modTime
}
// Sets the modification time of the local fs object
func (fs *FsObjectDrive) SetModTime(modTime time.Time) {
err := fs.readMetaData()
if err != nil {
stats.Error()
FsLog(fs, "Failed to read metadata: %s", err)
return
}
// Set modified date
fs.info.ModifiedDate = modTime.Format(time.RFC3339Nano)
_, err = fs.drive.svc.Files.Update(fs.info.Id, fs.info).SetModifiedDate(true).Do()
if err != nil {
stats.Error()
FsLog(fs, "Failed to update remote mtime: %s", err)
}
}
// Is this object storable
func (fs *FsObjectDrive) Storable() bool {
return true
}
// Open an object for read
func (fs *FsObjectDrive) Open() (in io.ReadCloser, err error) {
req, _ := http.NewRequest("GET", fs.info.DownloadUrl, nil)
req.Header.Set("User-Agent", "swiftsync/1.0")
res, err := fs.drive.client.Do(req)
if err != nil {
return nil, err
}
if res.StatusCode != 200 {
res.Body.Close()
return nil, fmt.Errorf("Bad response: %d: %s", res.StatusCode, res.Status)
}
return res.Body, nil
}
// Remove an object
func (fs *FsObjectDrive) Remove() error {
return fs.drive.svc.Files.Delete(fs.info.Id).Do()
}
// Check the interfaces are satisfied
var _ Fs = &FsDrive{}
var _ FsObject = &FsObjectDrive{}