Proposal: ReadBytes

[Allendar]

Because I use github.com/buger/jsonparser, which can search through JSON bytes without memory-overhead I had to make an extra method to just get the bytes back. I was thinking if it might be suitable for the tiedot package itself too. Maybe jsonparser can also be used for lookup stuff under the hood to speed things up even more?

This is the method :

// Find and retrieve bytes of a document by ID.
func (col *Col) ReadBytes(id int) (docB []byte, err error) {
    col.db.schemaLock.RLock()
    part := col.parts[id%col.db.numParts]
    part.Lock.RLock()
    docB, err = part.Read(id)
    part.Lock.RUnlock()
    col.db.schemaLock.RUnlock()
    return
}

It gave me a 1.6x speed boost when just wanting to lookup one field from the result-set (eg password), which was really significant in my API, easily upping requests p/second by hundreds.

Would love to hear your feedback.

Example loop comparison:

k := ""

for id := range queryResult {
    // user, err := App.Cols["Users"].Read(id)
    // if nil != err {
    //  panic(err)
    // }
    //
    // k = user[DBFieldUserPassword].(string)

    user, err := App.Cols["Users"].ReadBytes(id)
    if nil != err {
        panic(err)
    }
    k, err = jsonparser.GetUnsafeString(user, DBFieldUserPassword)
    if nil != err {
        panic(err)
    }
}

[HouzuoGuo]

That's a very good idea. Would you be interested to write a unit test for it as well please? Otherwise I'll perhaps do it in another week.