When I create a function like this:
v8::Function::New(<Isolate>, <C_Function>, <Data_Value>);
The Data_Value that I supply is useful for many things and I can access that when the function is called, with something like FunctionCallbackInfo->GetData().
But I have found no way to get back this data in a different scenario. Let's say I store that Function in a Persistent object, and then I would like to read which data is currently bound to it. Any ideas?
I don't think it's exposed via the API.
But there's an alternative:
manually construct a v8::FunctionTemplate
set its ->InstanceTemplate()->SetInternalFieldCount(num_fields)
get the v8::Function from the template with template->GetFunction(context),
now you should have function->InternalFieldCount() == num_fields
you can use function->SetInternalField(index, value) and function->GetInternalField(index) to store any data you want.
For complete examples, search for "SetInternalFieldCount" in V8's test-api.cc.
Related
I am working with some coaching using Redis in Nodejs.
here is my code implimentation.
redis.get(key)
if(!key) {
redis.set(key, {"SomeValue": "SomeValue", "SomeAnohterValue":"SomeAnohterValue"}
}
return redis.get(key)
Till here everything works well.
But let's assume a situation where I need to get the value from a function call and set it to Redis and then I keep getting the same value from Redis whenever I want, in this case, I don't need to call the function again and again for getting the value.
But for an instance, the values have been changed or some more values have been added to my actual API call, now I need to call that function again to update the values again inside the Redis corresponding to that same key.
But I don't know how can I do this.
Any help would be appreciated.
Thank you in advanced.
First thing is that your initial code has a bug. You should use the set if not exist functionality that redis provides natively instead of doing check and set calls
What you are describing is called cache invalidation and is one of the hardest parts in software development
You need to do a 'notify' in some way when the value changes so that the fetchers know that it is time to grab the most up to date value.
One simple way would be to have a dirty boolean variable that is set to true when the value is updated and when fetching you check that variable. If dirty then get from redis and set to false else return the vue from prior
I am trying to develop a webapp using Google Apps Script to be embedded into a Google Site which simply displays the contents of a Google Sheet and filters it using some simple parameters. For the time being, at least. I may add more features later.
I got a functional app, but found that filtering could often take a while as the client sometimes had to wait up to 5 seconds for a response from the server. I decided that this was most likely due to the fact that I was loading the spreadsheet by ID using the SpreadsheetApp class every time it was called.
I decided to cache the spreadsheet values in my doGet function using the CacheService and retrieve the data from the cache each time instead.
However, for some reason this has meant that what was a 2-dimensional array is now treated as a 1-dimensional array. And, so, when displaying the data in an HTML table, I end up with a single column, with each cell being occupied by a single character.
This is how I have implemented the caching; as far as I can tell from the API reference I am not doing anything wrong:
function doGet() {
CacheService.getScriptCache().put('data', SpreadsheetApp
.openById('####')
.getActiveSheet()
.getDataRange()
.getValues());
return HtmlService
.createTemplateFromFile('index')
.evaluate()
.setSandboxMode(HtmlService.SandboxMode.IFRAME);
}
function getData() {
return CacheService.getScriptCache().get('data');
}
This is my first time developing a proper application using GAS (I have used it in Sheets before). Is there something very obvious I am missing? I didn't see any type restrictions on the CacheService reference page...
CacheService stores Strings, so objects such as your two-dimensional array will be coerced to Strings, which may not meet your needs.
Use the JSON utility to take control of the results.
myCache.put( 'tag', JSON.stringify( myObj ) );
...
var cachedObj = JSON.parse( myCache.get( 'tag' ) );
Cache expires. The put method, without an expirationInSeconds parameter expires in 10 minutes. If you need your data to stay alive for more than 10 minutes, you need to specify an expirationInSeconds, and the maximum is 6 hours. So, if you specifically do NOT need the data to expire, Cache might not be the best use.
You can use Cache for something like controlling how long a user can be logged in.
You could also try using a global variable, which some people would tell you to never use. To declare a global variable, define the variable outside of any function.
If I do dd(app()) within my app I can see data that is useful to me within the #resolved branch of the service container object that is returned to screen.
A really silly question though; what is the easiest way of iterating through that data ? I've tried things like app()->resolved which don't work.
Well $resolved array is protected for something, however you can use reflection to get it:
$rp = new \ReflectionProperty('\Illuminate\Foundation\Application', 'resolved');
$rp->setAccessible(true);
dd($rp->getValue(app()));
I am trying to develop a webapp using Google Apps Script to be embedded into a Google Site which simply displays the contents of a Google Sheet and filters it using some simple parameters. For the time being, at least. I may add more features later.
I got a functional app, but found that filtering could often take a while as the client sometimes had to wait up to 5 seconds for a response from the server. I decided that this was most likely due to the fact that I was loading the spreadsheet by ID using the SpreadsheetApp class every time it was called.
I decided to cache the spreadsheet values in my doGet function using the CacheService and retrieve the data from the cache each time instead.
However, for some reason this has meant that what was a 2-dimensional array is now treated as a 1-dimensional array. And, so, when displaying the data in an HTML table, I end up with a single column, with each cell being occupied by a single character.
This is how I have implemented the caching; as far as I can tell from the API reference I am not doing anything wrong:
function doGet() {
CacheService.getScriptCache().put('data', SpreadsheetApp
.openById('####')
.getActiveSheet()
.getDataRange()
.getValues());
return HtmlService
.createTemplateFromFile('index')
.evaluate()
.setSandboxMode(HtmlService.SandboxMode.IFRAME);
}
function getData() {
return CacheService.getScriptCache().get('data');
}
This is my first time developing a proper application using GAS (I have used it in Sheets before). Is there something very obvious I am missing? I didn't see any type restrictions on the CacheService reference page...
CacheService stores Strings, so objects such as your two-dimensional array will be coerced to Strings, which may not meet your needs.
Use the JSON utility to take control of the results.
myCache.put( 'tag', JSON.stringify( myObj ) );
...
var cachedObj = JSON.parse( myCache.get( 'tag' ) );
Cache expires. The put method, without an expirationInSeconds parameter expires in 10 minutes. If you need your data to stay alive for more than 10 minutes, you need to specify an expirationInSeconds, and the maximum is 6 hours. So, if you specifically do NOT need the data to expire, Cache might not be the best use.
You can use Cache for something like controlling how long a user can be logged in.
You could also try using a global variable, which some people would tell you to never use. To declare a global variable, define the variable outside of any function.
Does anyone here have experience doing a Webtrends implementation? According to their documentation, their asynchronous event tracking call is made by sending key-value string pairs into their tracking method, like this:
dcsMultiTrack('DCS.dcsuri', 'page.html', 'WT.ti', 'NameOfPage');
However, that model does not lend well to supporting dynamic data. What I would like to do is something like this, so that I can dynamically create the key-value pairs based on the user interaction I am capturing:
var wtString = "'DCS.dcsuri', 'page.html', 'WT.ti', 'NameOfPage'";
dcsMultiTrack(wtString);
In my proof of concept, though, that does not work. The actual webtrends JS mangles the data and the call is not made. (Sifting through their code, it looks like something breaks when assigning the arguments to the Webtrends object. Anyway, I can't edit their code because then they won't support it, so I stopped investigating that end of things.)
So the question is, how can I pass the JS variable as its value? I've done a lot of searching and tried things that I thought would both work and not work: String(), .toString(), .value(), closures, and even the dreaded eval(), but to no avail.
Any help would be MUCH appreciated. I'm at my wits end with this one.
It looks like JavaScript's apply function could help here:
var wtArguments = ['DCS.dcsuri', 'page.html', 'WT.ti', 'NameOfPage'];
dcsMultiTrack.apply(this, wtArguments);
This is effectively the same as calling:
dcsMultiTrack('DCS.dcsuri', 'page.html', 'WT.ti', 'NameOfPage');