Oracle Security Module

This contract is given a DSValue as a source to read from. You set a time interval with changeDelay. Whenever that updateDelay time has passed, it will let you updateResult. When you updateResult it reads the value from the source and stores it. The previous stored value becomes the current value.

This contracts implements read and getResultWithValidity from DSValue, but it is not one. It also has a new function getNextResultWithValidity to read what the next value will be after a updateResult.

// create
OSM osm = new OSM(DSValue(src));

// can be updated every hour, on the hour
osm.changeDelay(3600);

(val, ok) = osm.getResultWithValidity() // get current value & its validity
(val, ok) = osm.getNextResultWithValidity() // get upcoming value
val       = osm.read() // get current value, or fail

If this DSValue has a valid value on creation, the OSM with start with that same value.

Dampened Security Module

This contract is similar to the OSM although it allows a maximum deviation change between two consecutive price updates (e.g the next price cannot be more than 5% deviated from the last one).

// create a DSM that allows 10% deviation between two consecutive price updates
DSM dsm = new DSM(DSValue(src), 0.9 * 10**18);

// can be updated every hour, on the hour
dsm.changeDelay(3600);

(val, ok) = dsm.getResultWithValidity() // get current value & its validity
(val, ok) = dsm.getNextResultWithValidity() // get upcoming value
val       = dsm.read() // get current value, or fail