radio/libjs/wController/file/file.js

"use strict";

var Controller = require("../controller");
var WVocabulary = require("../../wType/vocabulary");
var Uint64 = require("../../wType/uint64");
var Blob = require("../../wType/blob");

var File = Controller.inherit({
    "className": "File",
    "constructor": function(addr) {
        Controller.fn.constructor.call(this, addr);
        
        this._hasData = false;
        this._hasAdditional = false;
        this.data = new Blob();
        this._additional = null;
        this._waitingForSlice = false;
        this._need = 0;
        
        this.addHandler("get");
        this.addHandler("getAdditional");
        this.addHandler("getSlice");
    },
    "destructor": function() {
        this.data.destructor();
        if (this._hasAdditional) {
            this._additional.destructor();
        }
        Controller.fn.destructor.call(this);
    },
    "dontNeedData": function() {
        --this._need;
    },
    "hasData": function() {
        return this._hasData
    },
    "_getAdditional": function(add) {
        var ac = !this._hasAdditional || !this._additional["=="](add);
        if (ac) {
            if (this._hasAdditional) {
                this._additional.destructor();
            }
            this._additional = add.clone();
        }
        this._hasAdditional = true;
        return ac;
    },
    "getMimeType": function() {
        return this._additional.at("mimeType").toString();
    },
    "getSize": function() {
        return this._additional.at("size").valueOf();
    },
    "_h_get": function(ev) {
        var dt = ev.getData();
        
        var ac = this._getAdditional(dt.at("additional"));
        if (ac) {
            this.trigger("additionalChange")
        }
        
        this._hasData = true;
        var oldData = this.data;
        this.data = dt.at("data").clone();
        oldData.destructor();
        this.trigger("data");
    },
    "_h_getAdditional": function(ev) {
        var ac = this._getAdditional(ev.getData());
        if (ac) {
            this.trigger("additionalChange");
        }
        
        if (!this.initialized) {
            this.initialized = true;
            this.trigger("ready");
        }
    },
    "_h_getSlice": function(ev) {
        if (this._waitingForSlice) {
            this._waitingForSlice = false;
            var vc = ev.getData();
            if (vc.at("result").valueOf() == 0) {
                var slice = vc.at("slice");
                this.data["+="](slice);
                this.trigger("slice", slice);
                
                if (this.getSize() === this.data.length()) {
                    this._hasData = true;
                    this.trigger("data");
                }
            } else {
                this.trigger("serviceMessage", "Error receiving slice from " + this._pairAddress.toString(), 1);
            }
        }
    },
    "needData": function() {
        if (this._need === 0) {
            var vc = new WVocabulary();
            
            this.send(vc, "get");
        }
        ++this._need;
    },
    "requestSlice": function(size) {
        if (this._hasAdditional) {
            if (this._waitingForSlice) {
                throw new Error("An attempt to request a slice of data from " + this._pairAddress.toString() + " while another request is in progress");
            }
            var begin = this.data.length();
            var newSize = Math.min(size, this.getSize() - begin);
            if (newSize !== size) {
                //TODO may be inform the developer about that?
            }
            if (newSize === 0) {
                return;     //TODO may be inform the developer about that?
            }
            var vc = new WVocabulary();
            vc.insert("begin", new Uint64(begin));
            vc.insert("size", new Uint64(newSize));
            
            this.send(vc, "getSlice");
            this._waitingForSlice = true;
            
        } else {
            throw new Error("An attempt to request a slice of data from " + this._pairAddress.toString() + " before controller got initialized");
        }
    },
    "subscribe": function() {
        Controller.fn.subscribe.call(this);
        
        if (this._need > 0) {
            var vc = new WVocabulary();
            
            this.send(vc, "get");
        }
    }
});

module.exports = File;