Size limit for GraphQL scalar String - graphql

I want to send images as Base64 encoded strings. However, the size of each generated string turns out to be very large. My question is therefore, does GraphQL restrict the scalar String to a certain length, i.e. is it possible for me to send my images as strings using GraphQL?

As per last available specs, GraphQL does not restrict the scalar String to a certain length, i.e. it's possible for you to send it as a String.

Related

How does GitHub encode their graphQL cursors?

GitHub's graphql cursors are intentionally opaque, so they shouldn't ever be decode by a client. However I'd like to know their approach towards pagination, especially when combined with sorting.
There are multiple layers of encoding for the encoding used for pagination cursors used by GitHub. I will list them in order from the perspective of a decoder:
The cursor string is encoded using URL safe base64 meaning it uses - and _ instead of + and /. This might be to have consistency with their REST based API.
Decoding the base64 string gives us another string in the format of cursor:v2:[something] so the next step is decoding the something.
The 'something' is a binary encoded piece of data containing the actual cursor properties. The first byte defines the cursor type:
0x91 => We don't use any sorting, the cursor contains the length of the id field and the id itself. 0xcd seems to indicate a two-byte id, 0xce a four-byte id. This is followed by the id itself, which can be verified by decoding the base64 id graphql field.
0x92 => A composite cursor containing the sorted property and the id. This is either a length-prefixed ordinal number or two bytes plus a string or ISO date string followed by the length-prefixed id.

How to decode base64 & hexadecimal response from query

The query comes as
"returnData": [
"zWCLtKpUXZbkWNM9deAVPizTxXASOjX63ubdUHDN+vw=",
"zWCLtKpUXZbkWNM9deAVPizTxXASOjX63ubdUHDN+vw="
],
How can I decode that string? I can see it is decodable base64 first, but I get a very weird string after. Can someone show me the steps to follow to receive the decoded final string?
Base64 encodes binary data, which means if you send data that is not a string you won't be able to retrieve a string back. So to properly parse the return data you will need to know what data types were actually returned.
It might also be helpful to use a base64 to hex decoder first, so you get the hex representation of your data.
To give you more concrete recommendations we would need to know what data you expected, preferably showing the whole endpoint definition as well as any custom structs that might be involved.

How to limit the length of a JSON string after encoding?

I am using go to collect responses from URLs and store them in JSON for later processing. I want to enforce a limit on the size of the responses I store, however I've been unable to enforce this limit properly as when the JSON is marshalled the string is escaped which pushes it's length over the limit.
How do I limit the length of the string including the escape characters when marshaling?
How do I limit the length of the string including the escape characters when marshaling?
You cannot. Dead simple.

Encode array to fixed length string

I'm trying to implement a similar function to PCPartPicker's list permalink function.
https://au.pcpartpicker.com/list/
basically generate a permalink based on the items in the list. The key part is to generate a string which should be:
unique
persistent
fixed length
I'm thinking about encoding an array contains product id, but can't find the right way to implement it.
Base64 and the similar (like Hashids library) can ensure it's unique and persistent, but it ends up quite long when the array has many items.
Is there other way to encode the array or is there other direction I can implement this function?
Thank you in advance.
One can't generate unique fixed length string for arbitrary length list that will contain all info - there is always some length that can't fit.
Since your site has database, you can generate UUID and store list in DB along with UUID. To save space and efforts you can save it into DB only when user presses "get permalink" button or something like that.

Compression algorithms for Strings

I have to generate QRCodes using concatenated object properties. These strings might be long, that's why I'd like to know which compression algorithm to use knowing that my String's length is between 25 an 100+ characters
thanks in advance,
Jerec
I am assuming that since you are going to use compression before you store the strings that these QR codes will not be readable by any client, it would have to be an application that you wrote (b/c you are storing character with an unknown encoding, the client won't be able to decode).
Instead of compressing and storing the long string in the QR code, have your application create a URI (like a GUID or a URL) and when your application decodes that URI it looks up all the values (uncompressed) that you wanted to store in the QR code. Then your app can just look up the format in any way it wants.
For example, assuming your persistant storage is an xml file, but it could be anything:
<URI = "http://mydomain.com/790C9704-8C61-435F-991D-CDBB5767AA3D">
<MyElement>14523</MyElement>
<MyElement>67548</MyElement>
...
<MyElement>46167</MyElement>
</URI>
Encoded on QR code: "http://mydomain.com/790C9704-8C61-435F-991D-CDBB5767AA3D", values can then be looked up.
The algorithm used to encode QR codes is dependent on the type of data you encode. See http://www.swetake.com/qr/qr1_en.html.
If you know, for example, that you always have the same number of digits per id and therefor could just string them together without punctuation, you can encode them as purely numeric and you'll use 10 bits for every three characters.
If you need some kind of separator, if you use something in "0-9A-Z $%*+-./:", you'll stay alphanumeric and get 2 characters in 11 bits.
If you give it arbitrary data (note that this includes any lower case: the list above does not include lower case letters) you're going to be using 8 bits per characters.
So numeric only would end up being 60% smaller.

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