| 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 |
2×
2×
2×
2×
308×
308×
308×
308×
308×
308×
308×
107×
107×
638×
282×
356×
638×
107×
841×
107×
107×
107×
2×
105×
107×
107×
107×
140×
1×
107×
107×
107×
638×
638×
638×
107×
107×
56×
56×
4×
56×
4×
56×
56×
107×
107×
107×
107×
107×
107×
107×
107×
1×
| /**
* Module dependencies
*/
var _ = require('lodash');
var async = require('async');
var getRelations = require('../../../utils/getRelations');
/**
* Try and synchronize the underlying physical-layer schema
* to work with our app's collections. (i.e. models)
*
* @param {Function} cb
*/
module.exports = function(cb) {
var self = this;
// Refuse to run this migration strategy in production.
Iif (process.env.NODE_ENV === 'production') {
return cb(new Error('`migrate: "alter"` strategy is not supported in production, please change to `migrate: "safe"`.'));
}
// Find any junctionTables that reference this collection
var relations = getRelations({
schema: self.query.offshore.schema,
parentCollection: self.collection
});
var backupData;
// Check that collection exists--
self.describe(function afterDescribe(err, attrs) {
Iif (err) return cb(err);
// if it doesn't go ahead and add it and get out
if (!attrs) return self.define(cb);
var collectionName = _.find(self.query.offshore.schema, {tableName: self.collection}).identity;
// Create a mapping of column names -> attribute names
var columnNamesMap = _.reduce(self.query.offshore.schema[collectionName].attributes, function(memo, val, key) {
// If the attribute has a custom column name, use it as the key for the mapping
if (val.columnName) {
memo[val.columnName] = key;
// Otherwise just use the attribute name
} else {
memo[key] = key;
}
return memo;
}, {});
// Transform column names into attribute names using the columnNamesMap,
// removing attributes that no longer exist (they will be dropped)
attrs = _.compact(_.keys(attrs).map(function(key) {
return columnNamesMap[key];
}));
//
// TODO:
// Take a look and see if anything important has changed.
// If it has (at all), we still have to follow the naive strategy below,
// but it will at least save time in the general case.
// (because it really sucks to have to wait for all of this to happen
// every time you initialize Offshore.)
//
//
// OK so we have to fix up the schema and migrate the data...
//
// ... we'll let Offshore do it for us.
//
// Load all data from this collection into memory.
// If this doesn't work, crash to avoid corrupting any data.
// (see `offshore/lib/adapter/ddl/README.md` for more info about this)
//
// Make sure we only select the existing keys for the schema.
// The default "find all" will select each attribute in the schema, which
// now includes attributes that haven't been added to the table yet, so
// on SQL databases the query will fail with "unknown field" error.
//
var hasSchema = self.query.hasSchema;
// If we have a schema, make sure we only select the existing keys for the schema.
// The default "find all" will select each attribute in the schema, which
// now includes attributes that haven't been added to the table yet, so
// on SQL databases the query will fail with "unknown field" error.
//
// If we don't have a schema then we need to select all the values to make
// sure we don't lose data in the process.
var queryCriteria;
if (hasSchema) {
queryCriteria = {select: attrs};
} else {
queryCriteria = {};
}
self.query.find(queryCriteria, function(err, existingData) {
Iif (err) {
//
// TODO:
// If this was a memory error, log a more useful error
// explaining what happened.
//
return cb(err);
}
//
// From this point forward, we must be very careful.
//
backupData = _.cloneDeepWith(existingData, function dealWithBuffers(val) {
if (val instanceof Buffer) {
return val.slice();
}
});
// Check to see if there is anything obviously troublesome
// that will cause the drop and redefinition of our schemaful
// collections to fail.
// (i.e. violation of uniqueness constraints)
var attrs = self.query.offshore.collections[self.identity]._attributes;
var pk = self.query.offshore.collections[self.identity].primaryKey;
var attrsAsArray = _.reduce(_.cloneDeep(attrs), function(memo, attrDef, attrName) {
attrDef.name = attrName;
memo.push(attrDef);
return memo;
}, []);
var uniqueAttrs = _.filter(attrsAsArray, {unique: true});
async.each(uniqueAttrs, function(uniqueAttr, each_cb) {
var uniqueData = _.uniq(_.map(existingData, uniqueAttr.name));
// Remove any unique values who have their values set to undefined or null
var cleansedExistingData = _.filter(existingData, function(val) {
return [undefined, null].indexOf(val[uniqueAttr.name]) < 0;
});
// Remove any undefined or null values from the unique data
var cleansedUniqueData = _.filter(uniqueData, function(val) {
return [undefined, null].indexOf(val) < 0;
});
Iif (cleansedUniqueData.length < cleansedExistingData.length) {
// Some existing data violates a new uniqueness constraint
var prompt = require('prompt');
prompt.start();
console.log(
'One or more existing records in your database violate ' +
'a new uniqueness constraint\n' +
'on `' + uniqueAttr.name + '` ' +
'in your `' + self.identity + '` model.');
console.log();
console.log('Should we automatically remove duplicates?');
console.log();
console.log('** WARNING: DO NOT TYPE "y" IF YOU ARE WORKING WITH PRODUCTION DATA **');
// var laptimer = setInterval(function beepbeepbeepbeep(){
// process.stdout.write('\u0007');
// }, 1500);
prompt.get(['y/n'], function(err, results) {
// clearInterval(laptimer);
if (err) return each_cb(err);
var wasConfirmedByUser = _.isString(results['y/n']) && results['y/n'].match(/y/);
if (wasConfirmedByUser) {
// Wipe out duplicate records in `backupData` and continue
// to perform the automigration
var diff = _.difference(existingData, _.uniq(existingData, false, uniqueAttr.name));
var destroyCriteria = {};
destroyCriteria[pk] = _.map(diff, pk);
// console.log(diff, '\n', destroyCriteria);
backupData = _.remove(backupData, function(datum) {
return !_.contains(destroyCriteria[pk], datum[pk]);
});
return each_cb();
// console.log(backupData);
// throw new Error();
// self.query.offshore.collections[self.collection].destroy(destroyCriteria).exec(each_cb);
} else return each_cb(new Error('Auto-migration aborted. Please migrate your data manually and then try this again.'));
});
} else return each_cb();
}, function afterAsyncEach(err) {
Iif (err) return cb(err);
// Now we'll drop the collection.
self.drop(relations, function(err) {
Iif (err) return uhoh(err, backupData, cb);
// Now we'll redefine the collection.
self.define(function(err) {
Iif (err) return uhoh(err, backupData, cb);
// Now we'll create the `backupData` again,
// being careful not to run any lifecycle callbacks
// and disable automatic updating of `createdAt` and
// `updatedAt` attributes:
//
// ((((TODO: actually be careful about said things))))
//
self.query.createEach(backupData, function(err) {
Iif (err) return uhoh(err, backupData, cb);
// Done.
return cb();
});
}); // </define>
}); // </drop>
}); // </find>
});
//
// The old way-- (doesn't always work, and is way more
// complex than we should spend time on for now)
//
// || || || || || ||
// \/ \/ \/ \/ \/ \/
//
// Otherwise, if it *DOES* exist, we'll try and guess what changes need to be made
// self.alter(function(err) {
// if (err) return cb(err);
// cb();
// });
});
};
/**
* uh oh.
*
* If we can't persist the data again, we'll log an error message, then
* stream the data to stdout as JSON to make sure that it gets persisted
* SOMEWHERE at least.
*
* (this is another reason this automigration strategy cannot be used in
* production currently..)
*
* @param {[type]} err [description]
* @param {[type]} backupData [description]
* @param {Function} cb [description]
* @return {[type]} [description]
*/
function uhoh(err, backupData, cb) {
console.error('Offshore encountered a fatal error when trying to perform the `alter` auto-migration strategy.');
console.error('In a couple of seconds, the data (cached in memory) will be logged to stdout.');
console.error('(a failsafe put in place to preserve development data)');
console.error();
console.error('In the mean time, here\'s the error:');
console.error();
console.error(err);
console.error();
console.error();
setTimeout(function() {
console.error('================================');
console.error('Data backup:');
console.error('================================');
console.error('');
console.log(backupData);
return cb(err);
}, 1200);
}
|