betajs/betajs-data

Scoped.define("module:Stores.ShardedStore", [
    "module:Stores.BaseStore",
    "module:Queries.Constrained",
    "module:Stores.ConcatStore"
], function (BaseStore, Constrained, ConcatStore, scoped) {
    return BaseStore.extend({scoped: scoped}, function (inherited) {            
        return {

            constructor: function (options) {
                inherited.constructor.call(this, options);
                this.__context = options.context || this;
                this.__shardSelector = options.shardSelector;
                this.__allShards = options.allShards;
                if (this.__allShards) {
                    this.__allShards.forEach(function (shard) {
                        this.delegateEvents(["insert", "update", "remove"], shard);
                    }, this);
                }
            },
            
            _selectShards: function (data, ctx, countExpected) {
                var shards = this.__shardSelector.call(this.__context, data, ctx);
                if (countExpected !== undefined && shards.length !== countExpected)
                    throw "Count of shards do not match.";
                return shards;
            },

            _selectSingleShard: function (data, ctx) {
                return (this._selectShards(data, ctx, 1))[0];
            },

            _selectShardById: function (id, ctx) {
                return this._selectSingleShard(this.id_row(id), ctx);
            },

            _query_capabilities: function () {
                return Constrained.fullConstrainedQueryCapabilities();
            },

            _insert: function (data, ctx) {
                return this._selectSingleShard(data, ctx).insert(data, ctx);
            },
            
            _remove: function (id, ctx) {
                return this._selectShardById(id, ctx).remove(id, ctx);
            },

            _get: function (id, ctx) {
                return this._selectShardById(id, ctx).get(id, ctx);
            },

            _update: function (id, data, ctx) {
                return this._selectShardById(id, ctx).update(id, data, ctx);
            },

            _query: function (query, options, ctx) {
                return ConcatStore.queryOnMultipleStores(this._selectShards(query, ctx), query, options, ctx);
            }

        };
    });
});