Code coverage report for lib/adapters/websql/utils.js

Statements: 23.96% (23 / 96)      Branches: 4.65% (2 / 43)      Functions: 4.17% (1 / 24)      Lines: 23.96% (23 / 96)      Ignored: none     

All files » lib/adapters/websql/ » utils.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    1 1   1   1 1 1             1             1             1               1               1                     1                 1                 1           1                                                                                                                                       1                     1                               1                                 1   1                       1       1       1                        
'use strict';
 
var utils = require('../../utils');
var errors = require('../../deps/errors');
 
var websqlConstants = require('./constants');
 
var BY_SEQ_STORE = websqlConstants.BY_SEQ_STORE;
var ATTACH_STORE = websqlConstants.ATTACH_STORE;
var ATTACH_AND_SEQ_STORE = websqlConstants.ATTACH_AND_SEQ_STORE;
 
// escapeBlob and unescapeBlob are workarounds for a websql bug:
// https://code.google.com/p/chromium/issues/detail?id=422690
// https://bugs.webkit.org/show_bug.cgi?id=137637
// The goal is to never actually insert the \u0000 character
// in the database.
function escapeBlob(str) {
  return str
    .replace(/\u0002/g, '\u0002\u0002')
    .replace(/\u0001/g, '\u0001\u0002')
    .replace(/\u0000/g, '\u0001\u0001');
}
 
function unescapeBlob(str) {
  return str
    .replace(/\u0001\u0001/g, '\u0000')
    .replace(/\u0001\u0002/g, '\u0001')
    .replace(/\u0002\u0002/g, '\u0002');
}
 
function stringifyDoc(doc) {
  // don't bother storing the id/rev. it uses lots of space,
  // in persistent map/reduce especially
  delete doc._id;
  delete doc._rev;
  return JSON.stringify(doc);
}
 
function unstringifyDoc(doc, id, rev) {
  doc = JSON.parse(doc);
  doc._id = id;
  doc._rev = rev;
  return doc;
}
 
// question mark groups IN queries, e.g. 3 -> '(?,?,?)'
function qMarks(num) {
  var s = '(';
  while (num--) {
    s += '?';
    if (num) {
      s += ',';
    }
  }
  return s + ')';
}
 
function select(selector, table, joiner, where, orderBy) {
  return 'SELECT ' + selector + ' FROM ' +
    (typeof table === 'string' ? table : table.join(' JOIN ')) +
    (joiner ? (' ON ' + joiner) : '') +
    (where ? (' WHERE ' +
    (typeof where === 'string' ? where : where.join(' AND '))) : '') +
    (orderBy ? (' ORDER BY ' + orderBy) : '');
}
 
function compactRevs(revs, docId, tx) {
 
  if (!revs.length) {
    return;
  }
 
  var numDone = 0;
  var seqs = [];
 
  function checkDone() {
    if (++numDone === revs.length) { // done
      deleteOrphans();
    }
  }
 
  function deleteOrphans() {
    // find orphaned attachment digests
 
    if (!seqs.length) {
      return;
    }
 
    var sql = 'SELECT DISTINCT digest AS digest FROM ' +
      ATTACH_AND_SEQ_STORE + ' WHERE seq IN ' + qMarks(seqs.length);
 
    tx.executeSql(sql, seqs, function (tx, res) {
 
      var digestsToCheck = [];
      for (var i = 0; i < res.rows.length; i++) {
        digestsToCheck.push(res.rows.item(i).digest);
      }
      if (!digestsToCheck.length) {
        return;
      }
 
      var sql = 'DELETE FROM ' + ATTACH_AND_SEQ_STORE +
        ' WHERE seq IN (' +
        seqs.map(function () { return '?'; }).join(',') +
        ')';
      tx.executeSql(sql, seqs, function (tx) {
 
        var sql = 'SELECT digest FROM ' + ATTACH_AND_SEQ_STORE +
          ' WHERE digest IN (' +
          digestsToCheck.map(function () { return '?'; }).join(',') +
          ')';
        tx.executeSql(sql, digestsToCheck, function (tx, res) {
          var nonOrphanedDigests = new utils.Set();
          for (var i = 0; i < res.rows.length; i++) {
            nonOrphanedDigests.add(res.rows.item(i).digest);
          }
          digestsToCheck.forEach(function (digest) {
            if (nonOrphanedDigests.has(digest)) {
              return;
            }
            tx.executeSql(
              'DELETE FROM ' + ATTACH_AND_SEQ_STORE + ' WHERE digest=?',
              [digest]);
            tx.executeSql(
              'DELETE FROM ' + ATTACH_STORE + ' WHERE digest=?', [digest]);
          });
        });
      });
    });
  }
 
  // update by-seq and attach stores in parallel
  revs.forEach(function (rev) {
    var sql = 'SELECT seq FROM ' + BY_SEQ_STORE +
      ' WHERE doc_id=? AND rev=?';
 
    tx.executeSql(sql, [docId, rev], function (tx, res) {
      if (!res.rows.length) { // already deleted
        return checkDone();
      }
      var seq = res.rows.item(0).seq;
      seqs.push(seq);
 
      tx.executeSql(
        'DELETE FROM ' + BY_SEQ_STORE + ' WHERE seq=?', [seq], checkDone);
    });
  });
}
 
function unknownError(callback) {
  return function (event) {
    // event may actually be a SQLError object, so report is as such
    var errorNameMatch = event && event.constructor.toString()
        .match(/function ([^\(]+)/);
    var errorName = (errorNameMatch && errorNameMatch[1]) || event.type;
    var errorReason = event.target || event.message;
    callback(errors.error(errors.WSQ_ERROR, errorReason, errorName));
  };
}
 
function getSize(opts) {
  if ('size' in opts) {
    // triggers immediate popup in iOS, fixes #2347
    // e.g. 5000001 asks for 5 MB, 10000001 asks for 10 MB,
    return opts.size * 1000000;
  }
  // In iOS, doesn't matter as long as it's <= 5000000.
  // Except that if you request too much, our tests fail
  // because of the native "do you accept?" popup.
  // In Android <=4.3, this value is actually used as an
  // honest-to-god ceiling for data, so we need to
  // set it to a decently high number.
  var isAndroid = /Android/.test(window.navigator.userAgent);
  return isAndroid ? 5000000 : 1; // in PhantomJS, if you use 0 it will crash
}
 
function createOpenDBFunction() {
  if (typeof sqlitePlugin !== 'undefined') {
    // The SQLite Plugin started deviating pretty heavily from the
    // standard openDatabase() function, as they started adding more features.
    // It's better to just use their "new" format and pass in a big ol'
    // options object.
    return sqlitePlugin.openDatabase.bind(sqlitePlugin);
  }
 
  if (typeof openDatabase !== 'undefined') {
    return function openDB(opts) {
      // Traditional WebSQL API
      return openDatabase(opts.name, opts.version, opts.description, opts.size);
    };
  }
}
 
var cachedDatabases = {};
 
function openDB(opts) {
 
  var openDBFunction = createOpenDBFunction();
 
  var db = cachedDatabases[opts.name];
  if (!db) {
    db = cachedDatabases[opts.name] = openDBFunction(opts);
    db._sqlitePlugin = typeof sqlitePlugin !== 'undefined';
  }
  return db;
}
 
function valid() {
  // SQLitePlugin leaks this global object, which we can use
  // to detect if it's installed or not. The benefit is that it's
  // declared immediately, before the 'deviceready' event has fired.
  return typeof openDatabase !== 'undefined' ||
    typeof SQLitePlugin !== 'undefined';
}
 
module.exports = {
  escapeBlob: escapeBlob,
  unescapeBlob: unescapeBlob,
  stringifyDoc: stringifyDoc,
  unstringifyDoc: unstringifyDoc,
  qMarks: qMarks,
  select: select,
  compactRevs: compactRevs,
  unknownError: unknownError,
  getSize: getSize,
  openDB: openDB,
  valid: valid
};