Monitoring chrome.storage throttle limits - google-chrome-extension

Question

I'm using chrome.storage in an extension and would like to avoid triggering runtime errors due to exceeding one of the documented throttles for either the sync or local stores. (things like QUOTA_BYTES, QUOTA_BYTES_PER_ITEM)
My first choice would be to intercept these errors prior to a runtime error being generated; alternatively I could track usage on the extension side and try to avoid triggering them.
This feels like an issue that someone must have addressed, but I can't seem to find any solutions - any suggestions appreciated.

Answer 1

Here's a sample of the solution I'm going with (using Angular, so there are promises in here), although having to regex the chrome.runtime.lastError value is pretty ugly IMO:
var service = {
error: function(lastError) {
if((lastError) && (lastError.message)) {
var errorString = lastError.message;
if(/QUOTA_BYTES/.test(errorString)) {
return true;
} else if(/QUOTA_BYTES_PER_ITEM/.test(errorString)) {
return true;
} else if(/MAX_ITEMS/.test(errorString)) {
return true;
} else if(/MAX_WRITE_OPERATIONS_PER_HOUR/.test(errorString)) {
return true;
} else if(/MAX_SUSTAINED_WRITE_OPERATIONS_PER_MINUTE/.test(errorString)) {
return true;
}
return false;
} else {
return false;
}
},
write: function(key, value) {
var deferred = $q.defer();
var data = {};
data[key] = value;
chrome.storage.sync.set(data, function() {
if(service.error(chrome.runtime.lastError)) {
deferred.reject('Write operation failed: '
+ chrome.runtime.lastError.message);
} else {
deferred.resolve();
}
});
return deferred.promise;
}
};
return service;