replicatestorage synchronises alldocs documents

src/jio.storage/replicatestorage.js

@@ -42,7 +42,8 @@
   var Promise = require('rsvp').Promise,
     all = require('rsvp').all,
     addStorageFunction = require('jio').addStorage,
-    uniqueJSONStringify = require('jio').util.uniqueJSONStringify;
+    uniqueJSONStringify = require('jio').util.uniqueJSONStringify,
+    cache = {};
 
   function success(promise) {
     return promise.then(null, function (reason) { return reason; });
@@ -92,6 +93,48 @@
     }, onCancel);
   }
 
+  function allFulfilled(promises) {
+    var length = promises.length;
+
+    function onCancel() {
+      var i;
+      for (i = 0; i < promises.length; i += 1) {
+        if (typeof promises[i].cancel === "function") {
+          promises[i].cancel();
+        }
+      }
+    }
+
+    if (length === 0) {
+      return new Promise(function (done) { done([]); });
+    }
+
+    return new Promise(function (resolve, reject, notify) {
+      var i, count = 0, error_count = 0, results = [];
+      function resolver(i) {
+        return function (value) {
+          count += 1;
+          results[i] = value;
+          if (count === length) {
+            resolve(results);
+          }
+        };
+      }
+
+      function rejecter(err) {
+        error_count += 1;
+        count += 1;
+        if (error_count === length) {
+          reject(err);
+        }
+      }
+
+      for (i = 0; i < length; i += 1) {
+        promises[i].then(resolver(i), rejecter, notify);
+      }
+    }, onCancel);
+  }
+
   // //////////////////////////////////////////////////////////////////////
 
   // /**
@@ -117,9 +160,64 @@
       throw new TypeError("ReplicateStorage(): " +
                           "storage_list is not of type array");
     }
+    var str = uniqueJSONStringify(spec);
+    cache[str] = cache[str] || {};
+    this._cache = cache[str];
     this._storage_list = spec.storage_list;
   }
 
+  ReplicateStorage.prototype.syncAllDocs = function (command, alldocs) {
+    if (this._cache.syncAllDocs) {
+      return this._cache.syncAllDocs;
+    }
+
+    var storage_list = this._storage_list, this_ = this;
+
+    storage_list = storage_list.map(function (description) {
+      return command.storage(description);
+    });
+
+    function returnThe404ReasonsElseNull(reason) {
+      if (reason.status === 404) {
+        return 404;
+      }
+      return null;
+    }
+
+    function getSubStoragesDocument(id) {
+      return all(storage_list.map(function (storage) {
+        return storage.get({"_id": id}).
+          then(null, returnThe404ReasonsElseNull);
+      }));
+    }
+
+    function synchronizeDocument(answers) {
+      return this_.syncGetAnswerList(command, answers);
+    }
+
+    function checkAnswers(answers) {
+      var i;
+      for (i = 0; i < answers.length; i += 1) {
+        if (answers[i].result !== "success") {
+          throw answers[i];
+        }
+      }
+    }
+
+    function deleteCache() {
+      delete this_._cache.syncAllDocs;
+    }
+
+    this._cache.syncAllDocs =
+      jIO.util.forEach(alldocs.data.rows, function (row) {
+        return getSubStoragesDocument(row.id).
+          then(synchronizeDocument).
+          then(checkAnswers);
+      });
+    this._cache.syncAllDocs.then(deleteCache, deleteCache);
+    return this._cache.syncAllDocs;
+  };
+
   ReplicateStorage.prototype.syncGetAnswerList = function (command,
                                                            answer_list) {
     var i, l, answer, answer_modified_date, winner, winner_modified_date,
@@ -251,8 +349,7 @@
    * the other storages in the background.
    */
   ReplicateStorage.prototype.get = function (command, param, option) {
-    var promise_list = [], index, length = this._storage_list.length,
-      answer_list = [], this_ = this;
+    var promise_list = [], index, length = this._storage_list.length;
     for (index = 0; index < length; index += 1) {
       promise_list[index] =
         command.storage(this._storage_list[index]).get(param, option);
@@ -260,36 +357,22 @@
 
     new Promise(function (resolve, reject, notify) {
       var count = 0, error_count = 0;
-      function resolver(index) {
-        return function (answer) {
+      function resolver(answer) {
         count += 1;
         if (count === 1) {
           resolve(answer);
         }
-          answer_list[index] = answer;
-          if (count + error_count === length && count > 0) {
-            this_.syncGetAnswerList(command, answer_list);
-          }
-        };
       }
 
-      function rejecter(index) {
-        return function (reason) {
+      function rejecter(reason) {
         error_count += 1;
-          if (reason.status === 404) {
-            answer_list[index] = 404;
-          }
         if (error_count === length) {
           reject(reason);
         }
-          if (count + error_count === length && count > 0) {
-            this_.syncGetAnswerList(command, answer_list);
-          }
-        };
       }
 
       for (index = 0; index < length; index += 1) {
-        promise_list[index].then(resolver(index), rejecter(index), notify);
+        promise_list[index].then(resolver, rejecter, notify);
       }
     }, function () {
       for (index = 0; index < length; index += 1) {
@@ -308,24 +391,26 @@
       then(command.success, command.error, command.notify);
   };
 
-  ReplicateStorage.prototype.allDocs = function (command, param, option) {
+  ReplicateStorage.prototype._allDocs = function (command, param, option) {
     var promise_list = [], index, length = this._storage_list.length;
     for (index = 0; index < length; index += 1) {
       promise_list[index] =
-        success(command.storage(this._storage_list[index]).allDocs(option));
+        command.storage(this._storage_list[index]).allDocs(option);
     }
-    all(promise_list).then(function (answers) {
+    /*jslint unparam: true */
+    return allFulfilled(promise_list).then(function (answers) {
+      /*jslint unparam: false */
       // merge responses
       var i, j, k, found, rows;
       // browsing answers
       for (i = 0; i < answers.length; i += 1) {
-        if (answers[i].result === "success") {
+        if (answers[i]) {
           rows = answers[i].data.rows;
           break;
         }
       }
       for (i += 1; i < answers.length; i += 1) {
-        if (answers[i].result === "success") {
+        if (answers[i]) {
           // browsing answer rows
           for (j = 0; j < answers[i].data.rows.length; j += 1) {
             found = false;
@@ -343,8 +428,17 @@
         }
       }
       return {"data": {"total_rows": (rows || []).length, "rows": rows || []}};
-    }).then(command.success, command.error, command.notify);
-    /*jslint unparam: true */
+    });
+  };
+
+  ReplicateStorage.prototype.allDocs = function (command, param, option) {
+    var this_ = this;
+    return this._allDocs(command, param, option).
+      then(function (answer) {
+        this_.syncAllDocs(command, answer);
+        return answer;
+      }).
+      then(command.success, command.error, command.notify);
   };
 
   ReplicateStorage.prototype.check = function (command, param, option) {