static/url.js

// Copyright (c) 2012-2017, Matt Godbolt
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright notice,
//       this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

define(function (require) {
    "use strict";
    var GoldenLayout = require('goldenlayout');
    var rison = require('rison');
    var $ = require('jquery');
    var Components = require('components');
    var lzstring = require('lzstring');
    var _ = require('underscore');

    function convertOldState(state) {
        var sc = state.compilers[0];
        if (!sc) throw new Error("Unable to determine compiler from old state");
        var content = [];
        var source;
        if (sc.sourcez) {
            source = lzstring.decompressFromBase64(sc.sourcez);
        } else {
            source = sc.source;
        }
        var options = {compileOnChange: true, colouriseAsm: state.filterAsm.colouriseAsm};
        var filters = _.clone(state.filterAsm);
        delete filters.colouriseAsm;
        content.push(Components.getEditorWith(1, source, options));
        content.push(Components.getCompilerWith(1, filters, sc.options, sc.compiler));
        return {version: 4, content: [{type: 'row', content: content}]};
    }

    function loadState(state) {
        if (!state || state.version === undefined) return false;
        switch (state.version) {
            case 1:
                state.filterAsm = {};
                state.version = 2;
            /* falls through */
            case 2:
                state.compilers = [state];
                state.version = 3;
            /* falls through */
            case 3:
                state = convertOldState(state);
                break;  // no fall through
            case 4:
                state = GoldenLayout.unminifyConfig(state);
                break;
            default:
                throw new Error("Invalid version '" + state.version + "'");
        }
        return state;
    }

    function risonify(obj) {
        return rison.quote(rison.encode_object(obj));
    }

    function unrisonify(text) {
        return rison.decode_object(decodeURIComponent(text.replace(/\+/g, '%20')));
    }

    function deserialiseState(stateText) {
        var state;
        var exception;
        try {
            state = unrisonify(stateText);
            if (state && state.z) {
                state = unrisonify(lzstring.decompressFromBase64(state.z));
            }
        } catch (ex) {
            exception = ex;
        }

        if (!state) {
            try {
                state = $.parseJSON(decodeURIComponent(stateText));
            } catch (ex) {
                if (!exception) exception = ex;
            }
        }
        if (!state && exception) throw exception;
        return loadState(state);
    }

    function serialiseState(stateText) {
        var ctx = GoldenLayout.minifyConfig({content: stateText.content});
        ctx.version = 4;
        var uncompressed = risonify(ctx);
        var compressed = risonify({z: lzstring.compressToBase64(uncompressed)});
        var MinimalSavings = 0.20;  // at least this ratio smaller
        if (compressed.length < uncompressed.length * (1.0 - MinimalSavings)) {
            return compressed;
        } else {
            return uncompressed;
        }
    }

    return {
        deserialiseState: deserialiseState,
        serialiseState: serialiseState,
        unrisonify: unrisonify,
        risonify: risonify
    };
});