How to get limited number of documents but all document count from a firebase collection with hooks and Context API?

Question

Well. Assume that I have 100 documents in a firebase collection. I want to fetch 10 of them but also I need to get the total number at the same time to achieve my aim to create a pagination.

    const updateDocuments = useCallback((documents, size) => {
        dispatch({
            type: actions.UPDATE_DOCUMENTS,
            payload: {documents, size}
        });

    }, []);

    useEffect(() => {
       
        const ref = db.collection('documents').orderBy('createdAt', 'desc');

        const unsubscribe = ref.onSnapshot(async snapshot => {   
            const documents = await fetchDocuments(snapshot)
            const length = await fetchDocumentsCount(snapshot)
            updateDocuments(documents, length);
        });

        return () => {
            unsubscribe();
        }
    }, [updateDocuments]);

Ok now it is for sure that the snapshot above will fetch 100 documents and will give me total count as 100 as well. Experts already can guess that I use context api and I will push 100 documents and total number to this object below and I want to use it in whatever component I like.

const state = {
    documents: [],
    size: 0
}

So if I created ref as

const ref = db.collection('documents').orderBy('createdAt', 'desc').limit(10);

Then I would get 10 documents but also the total number of documents become 10.

So how can I get 10 documents but the total number of documents (in this example 100) within same useEffect?

Note:

export const fetchDocuments = data => {   
    const documents= data.docs.map(doc => {
        const { name, email} = doc.data();       

        return {           
            name,
            email,            
        }
    })
    return documents;
}

export const fetchDocumentsCount = data => data.size;