Increment by N, return previous¶
Atomically adds the given value to the current value and returns the previous value of the counter. It is possible that multiple concurrent client requests may receive the same previous value. This occurs since only the incrementing part of the logic is atomic, the retrieval of the value before it is incremented is not.
// *******************************************
// Backendless.Counters approach
// *******************************************
Backendless.Counters.getAndAdd( counterName, value )
.then( function( result ) {
})
.catch( function( error ) {
});
// *******************************************
// Backendless.Counters.of() approach
// *******************************************
var counter = Backendless.Counters.of( counterName );
counter.getAndAdd( value )
.then( function( result ) {
})
.catch( function( error ) {
});
where:
Argument | Description |
---|---|
counterName |
name of the counter to increment. |
value |
number to add to the current counter value |
Example¶
var successCallback = function( response ) {
console.log( "counter value is - " + response );
};
var failureCallback = function( fault ) {
console.log( "error - " + fault.message );
};
// ************************************************
// Backendless.Counters approach
// ************************************************
Backendless.Counters.getAndAdd( "my counter", 1000 )
.then( successCallback )
.catch( failureCallback );
// ************************************************
// Backendless.Counters.of() approach
// ************************************************
var myCounter = Backendless.Counters.of( "my counter" );
myCounter.getAndAdd( 1000 )
.then( successCallback )
.catch( failureCallback );