Devex 1440 xattr write (#42)

Supporting writing and removing xattrs

README.md

@@ -137,22 +137,39 @@ sudo umount MOUNT-POINT
 
 ## Extended attributes (xattrs)
 
-DNXa data objects have properties and tags, these are exposed as POSIX extended attributes. To list all attributes for a file you can do:
+DNXa data objects have properties and tags, these are exposed as POSIX extended attributes. The package we use for testing is `xattr` which is native on MacOS (OSX), and can be installed with `sudo apt-get install xattr` on Linux. Xattrs can be written and removed. The examples here use `xattr`, although other tools will work just as well.
 
+DNAx tags and properties are prefixed. For example, if `zebra.txt` is a file then `xattr -l zebra.txt` will print out all the tags, properties, and attributes that have no POSIX equivalent. These are split into three correspnding prefixes _tag_, _prop_, and _base_ all under the `user` Linux namespace.
+
+Here `zebra.txt` has no properties or tags.
+```
+$ xattr -l zebra.txt
+
+base.state: closed
+base.archivalState: live
+base.id: file-xxxx
+```
+
+Add a property named `family` with value `mammal`
+```
+$ xattr -w prop.family mammal zebra.txt
+```
+
+Add a tag `africa`
 ```
-$ getfattr -d -m - FILENAME
+$ xattr -w tag.africa XXX zebra.txt
 ```
 
-The `getattr` utility is part of the ubuntu attr apt package. It can be installed with:
+Remove the `family` property:
 ```
-$ sudo apt-get install attr
+$ xattr -d prop.family zebra.txt
 ```
 
-Currently, read-only access is provided for tags and attributes; they cannot be set. The `state`, `archivalState`, and `id` are also exposed as xattrs.
+You cannot modify any _base.*_ attribute, these are read-only. Currently, setting and deleting xattrs can be done only for files that are closed on the platform.
 
 ## Mac OS (OSX)
 
-For OSX you will need to install [OSXFUSE](http://osxfuse.github.com/).
+For OSX you will need to install [OSXFUSE](http://osxfuse.github.com/). Note that Your Milage May Vary (YMMV) on this platform, we are focused on Linux currently.
 
 # Common problems
 

RELEASE_NOTES.md

@@ -1,5 +1,29 @@
 # Release Notes
 
+## v0.19
+Improvements to extended attributes (xattrs). The testing tool we use is `xattr`, which is native on MacOS (OSX), and can be installed with `sudo apt-get install xattr` on Linux.
+
+- Xattrs can be written and removed, with the current limitation that this works only for closed files.
+- Tags and properties are namespaced. For example, if `zebra.txt` is a normal text file with no DNAx tags or properties then `xattr -l` will print out all the tags, properties, and extra attributes that have no POSIX equivalent. This is split into three namespaces: _base_, _prop_, and _tag_.
+
+```
+$ xattr -l zebra.txt
+
+base.state: closed
+base.archivalState: live
+base.id: file-Fjj89YQ04J96Yg3K51FKf9f7
+```
+
+Add a property named `family` with value `mammal`
+```
+$ xattr -w prop.family mammal zebra.txt
+```
+
+Add a tag `africa`
+```
+$ xattr -w tag.africa XXX zebra.txt
+```
+
 ## v0.18
 - Showing archived and open files; these were previously hidden. Trying to read or write from an archived
 or non-closed file will cause an EACCES error.

dx_ops.go

@@ -508,3 +508,134 @@ func (ops *DxOps) DxClone(
 
 	return true, nil
 }
+
+type RequestSetProperties struct {
+	ProjId     string               `json:"project"`
+	Properties map[string](*string) `json:"properties"`
+}
+
+type ReplySetProperties struct {
+	Id  string `json:"id"`
+}
+
+func (ops *DxOps) DxSetProperty(
+	ctx context.Context,
+	httpClient *retryablehttp.Client,
+	projId string,
+	objId string,
+	key string,
+	value *string) error {
+
+	var request RequestSetProperties
+	request.ProjId = projId
+	props := make(map[string](*string))
+	props[key] = value
+	request.Properties = props
+
+	payload, err := json.Marshal(request)
+	if err != nil {
+		return err
+	}
+
+	repJs, err := dxda.DxAPI(
+		ctx, httpClient, NumRetriesDefault, &ops.dxEnv,
+		fmt.Sprintf("%s/setProperties", objId),
+		string(payload))
+	if err != nil {
+		return err
+	}
+
+	var reply ReplySetProperties
+	if err := json.Unmarshal(repJs, &reply); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+type RequestAddTags struct {
+	ProjId    string  `json:"project"`
+	Tags    []string  `json:"tags"`
+}
+
+type ReplyAddTags struct {
+	Id  string `json:"id"`
+}
+
+func (ops *DxOps) DxAddTag(
+	ctx context.Context,
+	httpClient *retryablehttp.Client,
+	projId string,
+	objId string,
+	key string) error {
+
+	var request RequestAddTags
+	request.ProjId = projId
+	tags := make([]string, 1)
+	tags[0] = key
+	request.Tags = tags
+
+	payload, err := json.Marshal(request)
+	if err != nil {
+		return err
+	}
+
+	repJs, err := dxda.DxAPI(
+		ctx, httpClient, NumRetriesDefault, &ops.dxEnv,
+		fmt.Sprintf("%s/addTags", objId),
+		string(payload))
+	if err != nil {
+		return err
+	}
+
+	var reply ReplyAddTags
+	if err := json.Unmarshal(repJs, &reply); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+
+type RequestRemoveTags struct {
+	ProjId    string  `json:"project"`
+	Tags    []string  `json:"tags"`
+}
+
+type ReplyRemoveTags struct {
+	Id  string `json:"id"`
+}
+
+func (ops *DxOps) DxRemoveTag(
+	ctx context.Context,
+	httpClient *retryablehttp.Client,
+	projId string,
+	objId string,
+	key string) error {
+
+	var request RequestRemoveTags
+	request.ProjId = projId
+	tags := make([]string, 1)
+	tags[0] = key
+	request.Tags = tags
+
+	payload, err := json.Marshal(request)
+	if err != nil {
+		return err
+	}
+
+	repJs, err := dxda.DxAPI(
+		ctx, httpClient, NumRetriesDefault, &ops.dxEnv,
+		fmt.Sprintf("%s/removeTags", objId),
+		string(payload))
+	if err != nil {
+		return err
+	}
+
+	var reply ReplyRemoveTags
+	if err := json.Unmarshal(repJs, &reply); err != nil {
+		return err
+	}
+
+	return nil
+}