internetarchive: add support for Metadata

backend/internetarchive/internetarchive.go

@@ -38,6 +38,84 @@ func init() {
 		Name:        "internetarchive",
 		Description: "Internet Archive",
 		NewFs:       NewFs,
+
+		MetadataInfo: &fs.MetadataInfo{
+			System: map[string]fs.MetadataHelp{
+				"name": {
+					Help:    "Full file path, without the bucket part",
+					Type:    "filename",
+					Example: "backend/internetarchive/internetarchive.go",
+				},
+				"source": {
+					Help:    "The source of the file",
+					Type:    "string",
+					Example: "original",
+				},
+				"mtime": {
+					Help:    "Time of last modification, managed by Rclone",
+					Type:    "RFC 3339",
+					Example: "2006-01-02T15:04:05.999999999Z",
+				},
+				"size": {
+					Help:    "File size in bytes",
+					Type:    "decimal number",
+					Example: "123456",
+				},
+				"md5": {
+					Help:    "MD5 hash calculated by Internet Archive",
+					Type:    "string",
+					Example: "01234567012345670123456701234567",
+				},
+				"crc32": {
+					Help:    "CRC32 calculated by Internet Archive",
+					Type:    "string",
+					Example: "01234567",
+				},
+				"sha1": {
+					Help:    "SHA1 hash calculated by Internet Archive",
+					Type:    "string",
+					Example: "0123456701234567012345670123456701234567",
+				},
+				"format": {
+					Help:    "Name of format identified by Internet Archive",
+					Type:    "string",
+					Example: "Comma-Separated Values",
+				},
+				"old_version": {
+					Help:    "Whether the file was replaced and moved by keep-old-version flag",
+					Type:    "boolean",
+					Example: "true",
+				},
+				"viruscheck": {
+					Help:    "The last time viruscheck process was run for the file (?)",
+					Type:    "unixtime",
+					Example: "1654191352",
+				},
+
+				"rclone-ia-mtime": {
+					Help:    "Time of last modification, managed by Internet Archive",
+					Type:    "RFC 3339",
+					Example: "2006-01-02T15:04:05.999999999Z",
+				},
+				"rclone-mtime": {
+					Help:    "Time of last modification, managed by Rclone",
+					Type:    "RFC 3339",
+					Example: "2006-01-02T15:04:05.999999999Z",
+				},
+				"rclone-update-track": {
+					Help:    "Random value used by Rclone for tracking changes inside Internet Archive",
+					Type:    "string",
+					Example: "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+				},
+			},
+			Help: `Metadata fields provided by Internet Archive.
+If there are multiple values for a key, only the first one is returned.
+This is a limitation of Rclone, that supports one value per one key.
+
+Owner is able to add custom keys. Metadata feature grabs all the keys including them.
+`,
+		},
+
 		Options: []fs.Option{{
 			Name: "access_key_id",
 			Help: "IAS3 Access Key.\n\nLeave blank for anonymous access.\nYou can find one here: https://archive.org/account/s3.php",
@@ -90,6 +168,14 @@ Only enable if you need to be guaranteed to be reflected after write operations.
 // maximum size of an item. this is constant across all items
 const iaItemMaxSize int64 = 1099511627776
 
+// metadata keys that are not writeable
+var roMetadataKey = map[string]interface{}{
+	// do not add mtime here, it's a documented exception
+	"name": nil, "source": nil, "size": nil, "md5": nil,
+	"crc32": nil, "sha1": nil, "format": nil, "old_version": nil,
+	"viruscheck": nil,
+}
+
 // Options defines the configuration for this backend
 type Options struct {
 	AccessKeyID     string               `config:"access_key_id"`
@@ -122,6 +208,7 @@ type Object struct {
 	md5     string    // md5 hash of the file presented by the server
 	sha1    string    // sha1 hash of the file presented by the server
 	crc32   string    // crc32 of the file presented by the server
+	rawData json.RawMessage
 }
 
 // IAFile reprensents a subset of object in MetadataResponse.Files
@@ -135,6 +222,8 @@ type IAFile struct {
 	Md5         string          `json:"md5"`
 	Crc32       string          `json:"crc32"`
 	Sha1        string          `json:"sha1"`
+
+	rawData json.RawMessage
 }
 
 // MetadataResponse reprensents subset of the JSON object returned by (frontend)/metadata/
@@ -143,6 +232,12 @@ type MetadataResponse struct {
 	ItemSize int64    `json:"item_size"`
 }
 
+// MetadataResponseRaw is the form of MetadataResponse to deal with metadata
+type MetadataResponseRaw struct {
+	Files    []json.RawMessage `json:"files"`
+	ItemSize int64             `json:"item_size"`
+}
+
 // ModMetadataResponse represents response for amending metadata
 type ModMetadataResponse struct {
 	// https://archive.org/services/docs/api/md-write.html#example
@@ -226,7 +321,10 @@ func NewFs(ctx context.Context, name, root string, m configmap.Mapper) (fs.Fs, e
 	}
 	f.setRoot(root)
 	f.features = (&fs.Features{
-		BucketBased: true,
+		BucketBased:   true,
+		ReadMetadata:  true,
+		WriteMetadata: true,
+		UserMetadata:  true,
 	}).Fill(ctx, f)
 
 	f.srv = rest.NewClient(fshttp.NewClient(ctx))
@@ -307,18 +405,17 @@ func (o *Object) SetModTime(ctx context.Context, t time.Time) (err error) {
 	}
 
 	// https://archive.org/services/docs/api/md-write.html
-	var patch = []interface{}{
+	// the following code might be useful for modifying metadata of an uploaded file
+	patch := []map[string]string{
 		// we should drop it first to clear all rclone-provided mtimes
-		struct {
-			Op   string `json:"op"`
-			Path string `json:"path"`
-		}{"remove", "/rclone-mtime"},
-		struct {
-			Op    string `json:"op"`
-			Path  string `json:"path"`
-			Value string `json:"value"`
-		}{"add", "/rclone-mtime", t.Format(time.RFC3339Nano)},
-	}
+		{
+			"op":   "remove",
+			"path": "/rclone-mtime",
+		}, {
+			"op":    "add",
+			"path":  "/rclone-mtime",
+			"value": t.Format(time.RFC3339Nano),
+		}}
 	res, err := json.Marshal(patch)
 	if err != nil {
 		return err
@@ -685,6 +782,23 @@ func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, op
 		headers["Content-Length"] = fmt.Sprintf("%d", size)
 		headers["x-archive-size-hint"] = fmt.Sprintf("%d", size)
 	}
+	var mdata fs.Metadata
+	mdata, err = fs.GetMetadataOptions(ctx, src, options)
+	if err == nil && mdata != nil {
+		for mk, mv := range mdata {
+			mk = strings.ToLower(mk)
+			if strings.HasPrefix(mk, "rclone-") {
+				fs.LogPrintf(fs.LogLevelWarning, o, "reserved metadata key %s is about to set", mk)
+			} else if _, ok := roMetadataKey[mk]; ok {
+				fs.LogPrintf(fs.LogLevelWarning, o, "setting or modifying read-only key %s is requested, skipping", mk)
+				continue
+			} else if mk == "mtime" {
+				// redirect to make it work
+				mk = "rclone-mtime"
+			}
+			headers[fmt.Sprintf("x-amz-filemeta-%s", mk)] = mv
+		}
+	}
 
 	// read the md5sum if available
 	var md5sumHex string
@@ -762,6 +876,34 @@ func (o *Object) String() string {
 	return o.remote
 }
 
+// Metadata returns all file metadata provided by Internet Archive
+func (o *Object) Metadata(ctx context.Context) (m fs.Metadata, err error) {
+	if o.rawData == nil {
+		return nil, nil
+	}
+	raw := make(map[string]json.RawMessage)
+	err = json.Unmarshal(o.rawData, &raw)
+	if err != nil {
+		// fatal: json parsing failed
+		return
+	}
+	for k, v := range raw {
+		items, err := listOrString(v)
+		if len(items) == 0 || err != nil {
+			// skip: an entry failed to parse
+			continue
+		}
+		m.Set(k, items[0])
+	}
+	// move the old mtime to an another key
+	if v, ok := m["mtime"]; ok {
+		m["rclone-ia-mtime"] = v
+	}
+	// overwrite with a correct mtime
+	m["mtime"] = o.modTime.Format(time.RFC3339Nano)
+	return
+}
+
 func (f *Fs) shouldRetry(resp *http.Response, err error) (bool, error) {
 	if resp != nil {
 		for _, e := range retryErrorCodes {
@@ -788,7 +930,7 @@ func (o *Object) split() (bucket, bucketPath string) {
 	return o.fs.split(o.remote)
 }
 
-func (f *Fs) requestMetadata(ctx context.Context, bucket string) (result MetadataResponse, err error) {
+func (f *Fs) requestMetadata(ctx context.Context, bucket string) (result *MetadataResponse, err error) {
 	var resp *http.Response
 	// make a GET request to (frontend)/metadata/:item/
 	opts := rest.Opts{
@@ -796,12 +938,15 @@ func (f *Fs) requestMetadata(ctx context.Context, bucket string) (result Metadat
 		Path:   path.Join("/metadata/", bucket),
 	}
 
+	var temp MetadataResponseRaw
 	err = f.pacer.Call(func() (bool, error) {
-		resp, err = f.front.CallJSON(ctx, &opts, nil, &result)
+		resp, err = f.front.CallJSON(ctx, &opts, nil, &temp)
 		return f.shouldRetry(resp, err)
 	})
-
-	return result, err
+	if err != nil {
+		return
+	}
+	return temp.unraw()
 }
 
 // list up all files/directories without any filters
@@ -998,6 +1143,7 @@ func makeValidObject(f *Fs, remote string, file IAFile, mtime time.Time, size in
 		md5:     file.Md5,
 		crc32:   file.Crc32,
 		sha1:    file.Sha1,
+		rawData: file.rawData,
 	}
 }
 
@@ -1045,6 +1191,23 @@ func (file IAFile) parseMtime() (mtime time.Time) {
 	return mtime
 }
 
+func (mrr *MetadataResponseRaw) unraw() (_ *MetadataResponse, err error) {
+	var files []IAFile
+	for _, raw := range mrr.Files {
+		var parsed IAFile
+		err = json.Unmarshal(raw, &parsed)
+		if err != nil {
+			return nil, err
+		}
+		parsed.rawData = raw
+		files = append(files, parsed)
+	}
+	return &MetadataResponse{
+		Files:    files,
+		ItemSize: mrr.ItemSize,
+	}, nil
+}
+
 func compareSize(a, b int64) bool {
 	if a < 0 || b < 0 {
 		// we won't compare if any of them is not known
@@ -1106,4 +1269,5 @@ var (
 	_ fs.PublicLinker = &Fs{}
 	_ fs.Abouter      = &Fs{}
 	_ fs.Object       = &Object{}
+	_ fs.Metadataer   = &Object{}
 )