# Code coverage report for lib/services/client/read.js

## Statements: 93.28% (111 / 119) Branches: 79.63% (43 / 54) Functions: 100% (24 / 24) Lines: 93.28% (111 / 119)

All files » lib/services/client/ » read.js

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    206
    207
    208
    209
    210
    211
    212
    213
    214
    215
    216
    217
    218
    219
    220
    221
    222
    223
    224
    225
    226
    227
    228
    229
    230
    231
    232
    233
    234
    235
    236
    237
    238
    239
    240
    241
    242
    243
    244
    245
    246
    247
    248
    249
    250
    251
    252
    253
    254
    255
    256
    257
    258
    259
    260
    261
    262
    263
    264
    265
    266
    267
    268
    269
    270
    271
    272
    273
    274
    275
    276
    277
    278
    279
    280
    281
    282
    283
    284
    285
    286
    287
    288
    289
    290
    291
    292
    293
    294
    295
    296
    297
    298
    299
    300
    301
    302
    303
    304
    305
    306
    307
    308
    309
    310
    311
    312
    313
    314
    315
    316
    317
    318
    319
    320
    321
    322
    323
    324
    325
    326
    327
    328
    329
    330

    1

    1

    1
    26
    20

    20
    6
    6

    1
    11
    7

    7
    7

    4

    1
    26
    26

    26
    11
    11

    15
    15

    26
    15
    15

    11

    1
    10

    29
    21
    21
    21
    21

    1
    76
    76
    67

    9

    10
    10

    10
    1
    1
    76

    9

    10

    1
    11
    10
    10

    11

    1
    18

    1
    3
    3

    3

    3
    1

    3

    1
    3

    3

    3
    1

    2

    2
    1

    2
    2

    2

    1
    3

    3

    3

    3

    3
    1

    3
    2
    2

    3

    1
    26
    26

    26
    9
    3
    6
    3

    3

    17

    1
    1
    1
    1

    1
    1

    1
    1

    1

    1
    1

    1
    8

    8

    8

    1
    1
    1
    1/*
     * Copyright 2014 Telefonica Investigación y Desarrollo, S.A.U
     *
     * This file is part of iotagent-lwm2m-lib
     *
     * iotagent-lwm2m-lib is free software: you can redistribute it and/or
     * modify it under the terms of the GNU Affero General Public License as
     * published by the Free Software Foundation, either version 3 of the License,
     * or (at your option) any later version.
     *
     * iotagent-lwm2m-lib is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
     * See the GNU Affero General Public License for more details.
     *
     * You should have received a copy of the GNU Affero General Public
     * License along with iotagent-lwm2m-lib.
     * If not, seehttp://www.gnu.org/licenses/.
     *
     * For those usages not covered by the GNU Affero General Public License
     * please contact with::[contacto@tid.es]
     */

    'use strict';

    var async = require('async'),
        apply = async.apply,
        objectRegistry = require('./objectRegistry'),
        errors = require('../../errors'),
        logger = require('logops'),
        _ = require('underscore'),
        observers = {};

    /**
     * Extract Object type and id from the request URI, returning it using the callback.
     *
     * @param {Object} req          Arriving COAP Request to be handled.
     * @param {Object} res          Outgoing COAP Response.
     */
    function extractUriInfo(req, res, callback) {
        if (req.urlObj.pathname.match(/\/\d+\/\d+\/\d+/)) {
            var resourceIndex = req.urlObj.pathname.lastIndexOf('/'),
                resourceId = req.urlObj.pathname.substring(resourceIndex + 1),
                objectUri = req.urlObj.pathname.substring(0, resourceIndex);

            callback(null, objectUri, resourceId);
        } else Eif (req.urlObj.pathname.match(/\/\d+(\/\d+)?/)) {
            callback(null, req.urlObj.pathname, null);
        } else {
            callback(new errors.WrongObjectUri(req.urlObj.pathname));
        }
    }

    /**
     * Invoke the user handler for this operation, with all the information from the query parameters as its arguments.
     * This method handling gives the client an opportunity to change or overwrite the values before returning them to
     * the client. The handler must call the callback with the overwritten value it wants to return. If the callback is
     * called without parameters, the original value is returned instead.
     *
     * @param {Object} queryParams      Object containing all the query parameters.
     * @param {Function} handler        User handler to be invoked.
     */
    function applyHandler(resourceId, handler, storedObject, callback) {
        if (storedObject.attributes[resourceId]) {
            handler(
                storedObject.objectType,
                storedObject.objectId,
                resourceId,
                storedObject.attributes[resourceId],

                function handleReadOverwrite(error, result) {
                    Eif (result) {
                        callback(error, result);
                    } else {
                        callback(error, storedObject.attributes[resourceId]);
                    }
                });
        } else {
            callback(new errors.ResourceNotFound(storedObject.objectType, storedObject.objectId, resourceId));
        }
    }

    /**
     * Generates the end of request handler that will generate the final response to the COAP Client.
     *
     * @param {Object} req          Arriving COAP Request to be handled.
     * @param {Object} res          Outgoing COAP Response.
     * @returns {Function}          Request handler, receiving an optional error and the read operation result.
     */
    function endRead(req, res) {
        return function (error, result) {
            var body;

            if (error) {
                res.code = error.code;
                body = '';
            } else {
                res.code = '2.05';
                body = result.toString();
            }

            if (_.some(req.options, _.matches({name: 'Observe'}))) {
                res.setOption('Observe', 1);
                res.write(body);
            } else {
                res.end(body);
            }
        };
    }

    /**
     * Constructs the resource observer. The observer listens in the object registry bus for attribute modifications,
     * sending a new information update to the server each time the selected attribute changes its value.
     *
     * @param {Object} stream           Stream where the new data will be written to the server.
     * @param {Number} resourceId       Resource to read from.
     * @param {Object} storedObject     Object instance to observe.
     * @returns {{uri: (object.objectUri|*|string), stream: *, observation: number}}
     * @constructor
     */
    function ResourceObserver(stream, resourceId, storedObject) {
        var data = {
            id: storedObject.objectUri + '/' + resourceId,
            uri: storedObject.objectUri,
            stream: stream,
            observation: 1,
            listener: function newModification(method, id, value) {
                if (method === 'setResource' && resourceId === id.toString()) {
                    stream.setOption('Observe', data.observation);
                    stream.write(value.toString());
                    data.observation++;
                    data.lastObservation = Date.now();
                }
            }
        };

        function getLastMeasure() {
            objectRegistry.get(storedObject.objectUri, function (error, obj) {
                if (error) {
                    logger.error('Error retrieving the last resource value');
                } else {
                    data.listener('setResource', resourceId, obj.attributes[resourceId]);
                }
            });
        }

        objectRegistry.getAttributes(storedObject.objectUri + '/' + resourceId, function(error, attributes) {
            Iif (error) {
                logger.error('Couldn\'t find attributes for the [%s] resource URI. Falling back to value changed');
            }

            if (attributes) {
                Eif (attributes.pmax) {
                    data.scheduler = setInterval(function handleMaxPeriod() {
                        getLastMeasure(storedObject.objectUri, resourceId);
                    }, attributes.pmax);
                }
            } else {
                objectRegistry.bus.on(storedObject.objectUri, data.listener);
            }
        });

        return data;
    }

    /**
     * If the Read request comes with the observation option, apart from resolving the information request, a subscription
     * has to be created, so every time the selected resource changes in value (or in a timely basis, depending on the
     * configuration), the server is updated on the new value.
     *
     * @param {Object} req              Arriving COAP Request to be handled.
     * @param {Object} res              Outgoing COAP Response.
     * @param {Number} resourceId       ID of the resource to be observed.
     * @param {Object} storedObject     Object instance to be read.
     */
    function createObservers(req, res, resourceId, storedObject, callback) {
        if (_.some(req.options, _.matches({name: 'Observe'}))) {
            var observer = new ResourceObserver(res, resourceId, storedObject);
            observers[observer.id] = observer;
        }

        callback(null, storedObject);
    }

    function addAttribute(previous, value) {
        return previous + ';' + value[0] + '=' + value[1];
    }

    function discoverResourceAttributes(objectUri, resourceId, callback) {
        objectRegistry.getAttributes(objectUri + '/' + resourceId, function (error, attributes) {
            Iif (error) {
                callback(error);
            } else {
                var payload = '<' + objectUri + '/' + resourceId + '>';

                if (attributes) {
                    payload = _.pairs(attributes).reduce(addAttribute, payload);
                }

                callback(null, payload);
            }
        });
    }

    function discoverObjectResources(objectUri, callback) {
        async.series([
            apply(objectRegistry.get, objectUri),
            apply(objectRegistry.getAttributes, objectUri)
        ], function handleGetObject(error, results) {
            var obj = results[0],
                attributes = results[1];

            if (error) {
                callback(error);
            } else {
                var payload = '<' + objectUri + '>',
                    resources = _.keys(obj.attributes);

                if (attributes) {
                    payload += _.pairs(attributes).reduce(addAttribute, '');
                }

                for (var i = 0; i < resources.length; i++) {
                    payload += ',<' + objectUri + '/' + resources[i] + '>';
                }

                callback(null, payload);
            }
        });
    }

    function discoverObjectTypeInstances(objectTypeUri, callback) {
        async.series([
            objectRegistry.list,
            apply(objectRegistry.getAttributes, objectTypeUri)
        ], function handleListResult(error, results) {
            var objList = results[0],
                attributes = results[1];

            Iif (error) {
                callback(error);
            } else {
                var payload = '<' + objectTypeUri + '>',
                    objectType = objectTypeUri.substring(1);

                if (attributes) {
                    payload += _.pairs(attributes).reduce(addAttribute, '');
                }

                for (var i = 0; i < objList.length; i++) {
                    Eif (objList[i].objectType === objectType) {
                        payload += ',<' + objList[i].objectUri + '>';
                    }
                }

                callback(null, payload);
            }
        });
    }

    /**
     * Handle the read operation.
     *
     * @param {Object} req          Arriving COAP Request to be handled.
     * @param {Object} res          Outgoing COAP Response.
     * @param {Function} handler    User handler to be executed if everything goes ok.
     */
    function handleRead(req, res, handler) {
        extractUriInfo(req, res, function (error, objectUri, resourceId) {
            Iif (error) {
                endRead(req, res)(error);
            } else {
                if (_.some(req.options, _.matches({name: 'Accept', value: 'application/link-format'}))) {
                    if (resourceId) {
                        discoverResourceAttributes(objectUri, resourceId, endRead(req, res));
                    } else if (objectUri.match(/\/\d+\/\d+/)) {
                        discoverObjectResources(objectUri, endRead(req, res));
                    } else {
                        discoverObjectTypeInstances(objectUri, endRead(req, res));
                    }
                } else {
                    async.waterfall([
                        apply(objectRegistry.get, objectUri),
                        apply(createObservers, req, res, resourceId),
                        apply(applyHandler, resourceId, handler)
                    ], endRead(req, res));
                }
            }
        });
    }

    function cancelObservation(objUri, resourceId, callback) {
        Eif (observers[objUri + '/' + resourceId]) {
            Eif (observers[objUri + '/' + resourceId].stream) {
                observers[objUri + '/' + resourceId].stream.end();
            }

            Eif (observers[objUri + '/' + resourceId]) {
                clearInterval(observers[objUri + '/' + resourceId].scheduler);
            }

            objectRegistry.bus.removeListener(objUri, observers[objUri + '/' + resourceId].listener);
            delete observers[objUri + '/' + resourceId];
        } else {
            logger.error('Tried to remove an unexistant observation on obj URI [%s] and resourceId [%s]',
                objUri, resourceId);
        }

        callback(null);
    }

    function listObservers(callback) {
        callback(null, _.values(observers));
    }

    function cancelAllObservers(callback) {
        var observers = _.values(observers),
            cancellations = [];

        for (var i = 0; i < observers.length; i++) {
            cancellations.push(apply(cancelObservation, observers[i].objUri, observers[i].resourceId));
        }

        async.series(cancellations, callback);
    }

    exports.handle = handleRead;
    exports.cancel = cancelObservation;
    exports.list = listObservers;
    exports.cancelAll = cancelAllObservers;