splitstorage added, WIP

examples/jio_dashboard.html

@@ -162,6 +162,8 @@ var clearlog = function () {
   <script type="text/javascript" src="../lib/jsSha2/sha2.js"></script>
   <script type="text/javascript" src="../src/jio.storage/revisionstorage.js">
   </script>
+  <script type="text/javascript" src="../src/jio.storage/splitstorage.js">
+  </script>
   <script type="text/javascript" src="../lib/sjcl/sjcl.min.js"></script>
   <script type="text/javascript">
     <!--

src/jio.storage/splitstorage.js

+/*
+ * Copyright 2013, Nexedi SA
+ * Released under the LGPL license.
+ * http://www.gnu.org/licenses/lgpl.html
+ */
+
+/*jslint indent:2, maxlen: 80, nomen: true */
+/*global jIO: true, exports: true, define: true */
+
+/**
+ * Provides a split storage for JIO. This storage splits data
+ * and store them in the sub storages defined on the description.
+ *
+ *     {
+ *       "type": "split",
+ *       "storage_list": [<storage description>, ...]
+ *     }
+ */
+(function () {
+  "use strict";
+
+  /**
+   * Get the real type of an object
+   *
+   * @param  {Any} value The value to check
+   * @return {String} The value type
+   */
+  function type(value) {
+    // returns "String", "Object", "Array", "RegExp", ...
+    return (/^\[object ([a-zA-Z]+)\]$/).exec(
+      Object.prototype.toString.call(value)
+    )[1];
+  }
+
+  /**
+   * Generate a new uuid
+   *
+   * @method generateUuid
+   * @private
+   * @return {String} The new uuid
+   */
+  function generateUuid() {
+    function S4() {
+      /* 65536 */
+      var i, string = Math.floor(
+        Math.random() * 0x10000
+      ).toString(16);
+      for (i = string.length; i < 4; i += 1) {
+        string = '0' + string;
+      }
+      return string;
+    }
+    return S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() +
+      S4() + S4();
+  };
+
+  /**
+   * The split storage class used by JIO.
+   *
+   * A split storage instance is able to i/o on several sub storages with
+   * split documents.
+   *
+   * @class splitStorage
+   */
+  function splitStorage(spec, my) {
+    var that = my.basicStorage(spec, my), priv = {};
+
+    /**
+     * The list of sub storages we want to use to store part of documents.
+     *
+     * @attribute storage_list
+     * @private
+     * @type {Array} Array of storage descriptions
+     */
+    priv.storage_list = spec.storage_list;
+
+    //////////////////////////////////////////////////////////////////////
+    // Overrides
+
+    /**
+     * Overrides the original {{#crossLink "storage/specToStore:method"}}
+     * specToStore method{{/crossLink}}.
+     *
+     * @method specToStore
+     * @return {Object} The specificities to store
+     */
+    that.specToStore = function () {
+      return {"storage_list": priv.storage_list};
+    };
+
+    /**
+     * TODO validateState
+     */
+
+    //////////////////////////////////////////////////////////////////////
+    // Tools
+
+    /**
+     * Send a command to all sub storages. All the response are returned
+     * in a list. The index of the response correspond to the storage_list
+     * index. If an error occurs during operation, the callback is called with
+     * `callback(err, undefined)`. The response is given with
+     * `callback(undefined, response_list)`.
+     *
+     * `doc` is the document informations but can also be a list of dedicated
+     * document informations. In this case, each document is associated to one
+     * sub storage.
+     *
+     * @method send
+     * @private
+     * @param  {String} method The command method
+     * @param  {Object,Array} doc The document information to send to each sub
+     *   storages or a list of dedicated document
+     * @param  {Object} option The command option
+     * @param  {Function} callback Called at the end
+     */
+    priv.send = function (method, doc, option, callback) {
+      var i, answer_list = [], failed = false;
+      function onEnd() {
+        i += 1;
+        if (i === priv.storage_list.length) {
+          callback(undefined, answer_list);
+        }
+      }
+      function onSuccess(i) {
+        return function (response) {
+          if (!failed) {
+            answer_list[i] = response;
+          }
+          onEnd();
+        };
+      }
+      function onError(i) {
+        return function (err) {
+          if (!failed) {
+            failed = true;
+            err.index = i;
+            callback(err, undefined);
+          }
+        };
+      }
+      if (type(doc) !== "Array") {
+        for (i = 0; i < priv.storage_list.length; i += 1) {
+          that.addJob(
+            method,
+            priv.storage_list[i],
+            doc,
+            option,
+            onSuccess(i),
+            onError(i)
+          );
+        }
+      } else {
+        for (i = 0; i < priv.storage_list.length; i += 1) {
+          that.addJob(
+            method,
+            priv.storage_list[i],
+            doc[i],
+            option,
+            onSuccess(i),
+            onError(i)
+          );
+        }
+      }
+      i = 0;
+    };
+
+    /**
+     * Split document metadata then store them to the sub storages.
+     *
+     * @method postOrPut
+     * @private
+     * @param  {Object} doc A serialized document object
+     * @param  {Object} option Command option properties
+     */
+    priv.postOrPut = function (doc, option) {
+      var i, data, doc_list = [], doc_underscores = {};
+      if (!doc._id) {
+        doc._id = generateUuid();
+      }
+      for (i in doc) {
+        if (doc.hasOwnProperty(i)) {
+          if (i[0] === "_") {
+            doc_underscores[i] = doc[i];
+            delete doc[i];
+          }
+        }
+      }
+      data = JSON.stringify(doc);
+      for (i = 0; i < priv.storage_list.length; i += 1) {
+        doc_list[i] = JSON.parse(JSON.stringify(doc_underscores));
+        doc_list[i].data = data.slice(
+          (data.length / priv.storage_list.length) * i,
+          (data.length / priv.storage_list.length) * (i + 1)
+        );
+      }
+      priv.send('put', doc_list, option, function (err, response) {
+        if (err) {
+          err.message = "Unable to post document";
+          delete err.index;
+          return that.error(err);
+        }
+        that.success({"ok": true, "id": doc_underscores._id});
+      });
+    };
+
+    //////////////////////////////////////////////////////////////////////
+    // JIO commands
+
+    /**
+     * Split document metadata then store them to the sub storages.
+     *
+     * @method post
+     * @param  {Command} command The JIO command
+     */
+    that.post = function (command) {
+      priv.postOrPut(command.cloneDoc(), command.cloneOption());
+    };
+
+    /**
+     * Split document metadata then store them to the sub storages.
+     *
+     * @method put
+     * @param  {Command} command The JIO command
+     */
+    that.put = function (command) {
+      priv.postOrPut(command.cloneDoc(), command.cloneOption());
+    };
+
+    /**
+     * Puts an attachment to the sub storages.
+     *
+     * @method putAttachment
+     * @param  {Command} command The JIO command
+     */
+    that.putAttachment = function (command) {
+      var i, attachment_list = [], data = command.getAttachmentData();
+      for (i = 0; i < priv.storage_list.length; i += 1) {
+        attachment_list[i] = command.cloneDoc();
+        attachment_list[i]._data = data.slice(
+          (data.length / priv.storage_list.length) * i,
+          (data.length / priv.storage_list.length) * (i + 1)
+        );
+      }
+      priv.send(
+        'putAttachment',
+        attachment_list,
+        command.cloneOption(),
+        function (err, response) {
+          if (err) {
+            err.message = "Unable to put attachment";
+            delete err.index;
+            return that.error(err);
+          }
+          that.success({
+            "ok": true,
+            "id": command.getDocId(),
+            "attachment": command.getAttachmentId()
+          });
+        }
+      );
+    };
+
+    /**
+     * Gets splited document metadata then returns real document.
+     *
+     * @method get
+     * @param  {Command} command The JIO command
+     */
+    that.get = function (command) {
+      var doc, option, data, attachments;
+      doc = command.cloneDoc();
+      option = command.cloneOption();
+      priv.send('get', doc, option, function (err, response) {
+        var i, k;
+        if (err) {
+          err.message = "Unable to post document";
+          delete err.index;
+          return that.error(err);
+        }
+        doc = '';
+        for (i = 0; i < response.length; i += 1) {
+          doc += response[i].data;
+        }
+        doc = JSON.parse(doc);
+        for (i = 0; i < response.length; i += 1) {
+          for (k in response[i]) {
+            if (response[i].hasOwnProperty(k)) {
+              if (k[0] === "_") {
+                doc[k] = response[i][k];
+              }
+            }
+          }
+          if (response[i]._attachments) {
+            doc._attachments = doc._attachments || {};
+            for (k in response[i]._attachments) {
+              if (response[i]._attachments.hasOwnProperty(k)) {
+                doc._attachments[k] = doc._attachments[k] || {
+                  "length": 0,
+                  "digest": "",
+                  "content_type": "",
+                };
+                doc._attachments[k].length +=
+                response[i]._attachments[k].length;
+                doc._attachments[k].digest = (
+                  doc._attachments[k].digest ?
+                    doc._attachments[k].digest + " " : ""
+                ) + response[i]._attachments[k].digest;
+                doc._attachments[k].content_type =
+                  response[i]._attachments[k].content_type;
+              }
+            }
+          }
+        }
+        doc._id = command.getDocId();
+        that.success(doc);
+      });
+    };
+
+    /**
+     * Removes a document from the sub storages.
+     *
+     * @method remove
+     * @param  {Command} command The JIO command
+     */
+    that.remove = function (command) {
+      priv.send(
+        'remove',
+        command.cloneDoc(),
+        command.cloneOption(),
+        function (err, response_list) {
+          if (err) {
+            err.message = "Unable to remove document";
+            delete err.index;
+            return that.error(err);
+          }
+          that.success({"id": command.getDocId(), "ok": true});
+        }
+      );
+    };
+
+    /**
+     * Removes an attachment from the sub storages.
+     *
+     * @method removeAttachment
+     * @param  {Command} command The JIO command
+     */
+    that.removeAttachment = function (command) {
+      var doc = command.cloneDoc();
+      priv.send(
+        'removeAttachment',
+        doc,
+        command.cloneOption(),
+        function (err, response_list) {
+          if (err) {
+            err.message = "Unable to remove attachment";
+            delete err.index;
+            return that.error(err);
+          }
+          that.success({
+            "id": doc._id,
+            "attachment": doc._attachment,
+            "ok": true
+          });
+        }
+      );
+    };
+
+    return that;
+  } // end of splitStorage
+
+  //////////////////////////////
+  // exports to JIO
+  if (typeof define === "function" && define.amd) {
+    define(['jio'], function (jio) {
+      jio.addStorageType('split', splitStorage);
+    });
+  } else if (typeof require === "function") {
+    require('jio').addStorageType('split', splitStorage);
+  } else if (typeof jIO === "object") {
+    jIO.addStorageType('split', splitStorage);
+  } else {
+    throw new Error("Unable to export splitStorage to JIO.");
+  }
+}());