Pd-redis-base-record NPM

pd-redis-base-record

Simple ORM record model with auto-increment sid

Installation

$ npm install -save pd-redis-base-record

To modify: Model.modify(JSON)

var profileToModify = {
  'pd-sid' : '12' ,
   name : 'Jane Doe',
   gender : 'female'
};
User.modify(profileToModify).then(function(){
   //do something after modification
});

'pd-sid' is not a changeable field, but it has to be assigned to specify which record to be modified.

To remove: Model.remove(sid)

var sid = '12';
User.remove(sid).then(function(){
   //do something after removal
});

To read

To get total amount of records of a model: Model.amount()

User.amount().then(function(amount){ 
   //do something to amount
});

To get a record by specifying sid: Model.findBySid(sid)

User.findBySid(12).then(function(record){
  //record => { email: 'myletter@email.com', name: 'Jane Doe', updatedAt : '12345678901' }
  //Because the data is modified just now, so it automatically got 'updatedAt' field
});

To get a list of records: Model.range(option)

User.range({
  latest: (new Date()).getTime(), //* the ending time point of list
  earliest: 0 ,                   //* the starting time point of list
  limit : [0, 50],                //(optional)[start, offset] 
}).then(function(records){
  //records:
  // [
  //    {'pd-sid' : 1 ,  email : 'myletter1@email.com' ... }, 
  //    {'pd-sid' : 2,  email: 'myletter2@email.com' ...}
  //    .....
  // ]
});

To decide if a record is brand new: Model.checkAbsence(sid)

User.checkAbsence(sid).then(function(){
   //record not found
}).fail(function(err){
   var announcer = require('pd-api-announcer');
   if(announcer.isClientErrorFor(err, 'user', 'taken')) { 
       //record already existed 
   }
});

###To decide if a record already existed: Model.checkPresence(sid)

User.checkPresence(sid).then(function(){
   //record found
}).fail(function(err){
   var announcer = require('pd-api-announcer');
   if(announcer.isClientErrorFor(err, 'user', 'gone')){
      //record not found
   }
});

To lock

To lock a type of records: Model.lock.sidSet(onLockCallback, expiredAfterMilliseconds)

Where the lock is used, every time the same routine visits the locked sid-set, if there is still a locked routine, it will wait until the previous routine is done

var onLockCallback = function(){
    return User.create({
       email: 'myletter@email.com',
       password: 'abc123'
    }); 
};
User.lock.sidSet(onLockCallback); //by default it will expire after 15000 milliseconds

If asynchronous operation is to be added in onLockCallback, the return value of onLockCallback should be a q.Promise object, so that the lock will wait until all operations are over then release the lock.

The returning value of User.lock.sidSet() is also a q.Promise, all code in User.lock.sidSet().then() will be executed after the lock is released

User.lock.sidSet(function(){...}).then(function(){
   //do something after the lock is released
});

To lock one record: Model.lock.dataForSid(sid, onLockCallback, expiredAfterMilliseconds)

Similar to lock.sidSet(), but it only locks operations on a single record, or to be specific, dependent on one sid of a type of records

var sid = '12';
var onLockCallback = function(){
    return User.modify({
       'pd-sid' : sid,
       email: 'myletter@email.com',
       password: 'abc123'
    }); 
};
User.lock.dataForSid(sid, onLockCallback);