Add removeRecursive and listSubTreeBFS methods

README.md

@@ -24,8 +24,10 @@ This module has been tested to work with ZooKeeper version 3.4.*.
         + [close](#void-close)
         + [create](#void-createpath-data-acls-mode-callback)
         + [remove](#void-removepath-version-callback)
+        + [removeRecursive](#void-removerecursivepath-version-callback)
         + [exists](#void-existspath-watcher-callback)
         + [getChildren](#void-getchildrenpath-watcher-callback)
+        + [listSubTreeBFS](#void-listsubtreebfspath-callback)
         + [getData](#void-getdatapath-watcher-callback)
         + [setData](#void-setdatapath-data-version-callback)
         + [getACL](#void-getaclpath-callback)
@@ -225,7 +227,7 @@ Create a node with given path, data, acls and mode.
 * path `String` - Path of the node.
 * data `Buffer` - The data buffer, optional, defaults to null.
 * acls `Array` - An array of [ACL](#acl) objects, optional, defaults to
-  `ACL.OPEN_ACL_UNSAFE` 
+  `ACL.OPEN_ACL_UNSAFE`
 * mode `CreateMode` -  The creation mode, optional, defaults to
   `CreateMode.PERSISTENT`
 * callback(error, path) `Function` - The callback function.
@@ -277,6 +279,31 @@ zookeeper.remove('/test/demo', -1, function (error) {
 
 ---
 
+#### void removeRecursive(path, [version], callback)
+
+Deletes a node and all its children with the given path and version.
+
+**Arguments**
+
+* path `String` - Path of the node.
+* version `Number` - The version of the node, optional, defaults to -1.
+* callback(error) `Function` - The callback function.
+
+**Example**
+
+```javascript
+zookeeper.removeRecursive('/test/demo', -1, function (error) {
+    if (error) {
+        console.log(error.stack);
+        return;
+    }
+
+    console.log('Nodes removed.');
+});
+```
+
+---
+
 #### void exists(path, [watcher], callback)
 
 Check the existence of a node. The callback will be invoked with the
@@ -346,6 +373,33 @@ zookeeper.getChildren('/test/demo', function (error, children, stats) {
 });
 ```
 
+---
+
+#### void listSubTreeBFS(path, callback)
+
+Retrieve a list of all children including itself for the given node path.
+
+**Arguments**
+
+* path `String` - Path of the node.
+* callback(error, children) `Function` - The callback function. The
+  children is an array of strings.
+
+**Example**
+
+```javascript
+zookeeper.listSubTreeBFS('/test/demo', function (error, children) {
+    if (error) {
+        console.log(error.stack);
+        return;
+    }
+
+    console.log('Children are: %j.', children);
+});
+```
+
+---
+
 #### void getData(path, [watcher], callback)
 
 Retrieve the data and the stat of the node of the given path. If the watcher
@@ -502,7 +556,7 @@ Create given path in a way similar to `mkdir -p`.
 * path `String` - Path of the node.
 * data `Buffer` - The data buffer, optional, defaults to `null`.
 * acls `Array` - An array of [ACL](#acl) objects, optional, defaults to
-  `ACL.OPEN_ACL_UNSAFE` 
+  `ACL.OPEN_ACL_UNSAFE`
 * mode `CreateMode` -  The creation mode, optional, defaults to
   `CreateMode.PERSISTENT`
 * callback(error, path) `Function` - The callback function.
@@ -590,7 +644,7 @@ var pwd = client.getSessionPassword();
 ---
 
 #### Number getSessionTimeout()
- 
+
 Returns the *negotiated* session timeout (in milliseconds) for this client
 instance. The value returned is not valid until the client connects to a server
 and may change after a re-connect.
@@ -660,7 +714,7 @@ Optionally, you can register watcher functions when calling
 [`exists`](#void-existspath-watcher-callback),
 [`getChildren`](#void-getchildrenpath-watcher-callback) and
 [`getData`](#void-getdatapath-watcher-callback) methods. The watcher function
-will be called with an instance of `Event`. 
+will be called with an instance of `Event`.
 
 **Properties**
 
@@ -743,7 +797,7 @@ Add a create operation with given path, data, acls and mode.
 * path `String` - Path of the node.
 * data `Buffer` - The data buffer, optional, defaults to null.
 * acls `Array` - An array of [ACL](#acl) objects, optional, defaults to
-  `ACL.OPEN_ACL_UNSAFE` 
+  `ACL.OPEN_ACL_UNSAFE`
 * mode `CreateMode` -  The creation mode, optional, defaults to
   `CreateMode.PERSISTENT`
 
@@ -773,7 +827,7 @@ Add a check (existence) operation with given path and optional version.
 ---
 
 #### Transaction remove(path, data, version)
- 
+
 Add a delete operation with the given path and optional version.
 
 **Arguments**
@@ -841,7 +895,7 @@ zookeeper.create('/test/demo', function (error, path) {
 
 #### Number getCode()
 
-Return the error code of the exception. 
+Return the error code of the exception.
 
 ---
 

examples/listSubTreeBFS.js

@@ -0,0 +1,20 @@
+var zookeeper = require('../index.js');
+
+var client = zookeeper.createClient(process.argv[2]);
+var path = process.argv[3];
+
+client.once('connected', function () {
+    console.log('Connected to the server.');
+
+    client.listSubTreeBFS(path, function (error, children) {
+        if (error) {
+            console.log('Failed to list all child nodes of %s due to:', path, error);
+            return;
+        }
+        console.log('All child nodes of %s are: %j', path, children);
+
+        client.close();
+    });
+});
+
+client.connect();

examples/removeRecursive.js

@@ -0,0 +1,20 @@
+var zookeeper = require('../index.js');
+
+var client = zookeeper.createClient(process.argv[2]);
+var path = process.argv[3];
+
+client.once('connected', function () {
+    console.log('Connected to the server.');
+
+    client.removeRecursive(path, function (error) {
+        if (error) {
+            console.log('Failed to remove all nodes for %s: %s', path, error);
+        } else {
+            console.log('Removed all nodes for: %s', path);
+        }
+
+        client.close();
+    });
+});
+
+client.connect();

index.js

@@ -467,6 +467,45 @@ Client.prototype.remove = function (path, version, callback) {
     );
 };
 
+/**
+ * Deletes a node and all its children.
+ *
+ * @param path {String} The node path.
+ * @param [version=-1] {Number} The version of the node.
+ * @param callback {Function} The callback function.
+ */
+Client.prototype.removeRecursive = function(path, version, callback) {
+    if (!callback) {
+        callback = version;
+        version = -1;
+    }
+
+    Path.validate(path);
+
+    assert(typeof callback === 'function', 'callback must be a function.');
+    assert(typeof version === 'number', 'version must be a number.');
+
+    var self = this;
+
+    self.listSubTreeBFS(path, function (error, children) {
+        if (error) {
+            callback(error);
+            return;
+        }
+        async.eachSeries(children.reverse(), function (nodePath, next) {
+            self.remove(nodePath, version, function(err) {
+                // Skip NO_NODE exception
+                if (err && err.getCode() === Exception.NO_NODE) {
+                    next(null);
+                    return;
+                }
+
+                next(err);
+            });
+        }, callback);
+    });
+};
+
 /**
  * Set the data for the node of the given path if such a node exists and the
  * optional given version matches the version of the node (if the given
@@ -814,6 +853,45 @@ Client.prototype.getChildren = function (path, watcher, callback) {
     );
 };
 
+/**
+ * BFS list of the system under path. Note that this is not an atomic snapshot of
+ * the tree, but the state as it exists across multiple RPCs from clients to the
+ * ensemble.
+ *
+ * @method listSubTreeBFS
+ * @param path {String} The node path.
+ * @param callback {Function} The callback function.
+ */
+Client.prototype.listSubTreeBFS = function(path, callback) {
+    Path.validate(path);
+    assert(typeof callback === 'function', 'callback must be a function.');
+
+    var self = this;
+    var tree = [path];
+
+    async.reduce(tree, tree, function(memo, item, next) {
+        self.getChildren(item, function (error, children) {
+            if (error) {
+                next(error);
+                return;
+            }
+            if (!children || !Array.isArray(children) || !children.length) {
+                next(null, tree);
+                return;
+            }
+            children.forEach(function(child) {
+                var childPath = item + '/' + child;
+
+                if (item === '/') {
+                    childPath = item + child;
+                }
+                tree.push(childPath);
+            });
+            next(null, tree);
+        });
+    }, callback);
+};
+
 /**
  * Create node path in the similar way of `mkdir -p`
  *