s-aska/MutableDataScanner

MutableDataScanner

A simple text scanner which can parse NSMutableData using delimiter.

Faster because it does not have to do a NSData <-> String conversion.

It can be easily and reliably parse of the Twitter Streaming API and other stream.

Performance

Test: https://github.com/s-aska/MutableDataScanner/blob/master/MutableDataScannerTests/MutableDataScannerTests.swift

• MutableDataScanner specific delimiter ... average: 0.071
• MutableDataScanner line delimiter ( CRLF or LF ) ... average: 0.092
• String#componentsSeparatedByString ... average: 0.304

Usage

for Twitter Streaming API

See Processing streaming data for information about the Parsing responses you will receive from the streaming API.

import Foundation
import MutableDataScanner
import SwiftyJSON

class TwitterAPIStreamingRequest: NSObject, NSURLSessionDataDelegate {

    let scanner = MutableDataScanner(delimiter: "\r\n")

    // ...

    func connection(connection: NSURLConnection, didReceiveData data: NSData) {
        self.scanner.appendData(data)
        while let data = self.scanner.next() {
            if data.length > 0 {
                let json = JSON(data: data)
            }
        }
    }
}

Bytes

• read(length: Int) -> NSData?

let data = "0123456789abcdefghijklmnopqrstuvwxyz".dataUsingEncoding(NSUTF8StringEncoding)!
let scanner = MutableDataScanner(data: data)

scanner.read(length: 10) // => 0123456789
scanner.read(length: 10) // => abcdefghij
scanner.read(length: 10) // => klmnopqrst
scanner.read(length: 10) // => uvwxyz
scanner.read(length: 10) // => (nil)

• read(offset: Int, length: Int) -> NSData?

let data = "0123456789abcdefghijklmnopqrstuvwxyz".dataUsingEncoding(NSUTF8StringEncoding)!
let scanner = MutableDataScanner(data: data)

scanner.read(offset: 5, length: 5) // => 56789
scanner.read(offset: 5, length: 5) // => fghij
scanner.read(offset: 5, length: 5) // => pqrst
scanner.read(offset: 5, length: 5) // => z
scanner.read(offset: 5, length: 5) // => (nil)

Delimiter

Specify the delimiter in the properties.

• init(data: NSMutableData = default, delimiter: NSData)
• init(data: NSMutableData = default, delimiter: String)
• next() -> NSData?
• hasNext() -> Bool

let data = "0123456789\nabcdefghijklmnopqrstuvwxyz\n0123".dataUsingEncoding(NSUTF8StringEncoding)!
let scanner = MutableDataScanner(data: data, delimiter: "\n")

scanner.data // => 0123456789\nabcdefghijklmnopqrstuvwxyz\n0123

scanner.hasNext() // => true
scanner.next() // => 0123456789
scanner.data // => abcdefghijklmnopqrstuvwxyz\n0123

scanner.hasNext() // => true
scanner.next() // => abcdefghijklmnopqrstuvwxyz
scanner.data // => 0123

scanner.hasNext() // => false
scanner.next() // => (nil)

Specify the delimiter in the arguments.

• next(delimiter: NSData) -> NSData?
• hasNext(delimiter: NSData) -> Bool
• next(delimiter: String) -> NSData?
• hasNext(delimiter: String) -> Bool

let data = "0123456789\nabcdefghijklmnopqrstuvwxyz\n0123".dataUsingEncoding(NSUTF8StringEncoding)!
let scanner = MutableDataScanner(data: data)

scanner.data // => 0123456789\nabcdefghijklmnopqrstuvwxyz\n0123

scanner.hasNext("\r\n") // => false
scanner.hasNext("\n") // => true
scanner.next("\r\n") // => (nil)
scanner.next("\n") // => 0123456789
scanner.data // => abcdefghijklmnopqrstuvwxyz\n0123

CRLF or LF

• nextLine() -> NSData?
• hasNextLine -> Bool

let data = "0123456789\r\nabcdefghijklmnopqrstuvwxyz\n0123".dataUsingEncoding(NSUTF8StringEncoding)!
let scanner = MutableDataScanner(data: data)

scanner.data // => 0123456789\r\nabcdefghijklmnopqrstuvwxyz\n0123

scanner.hasNextLine() // => true
scanner.nextLine() // => 0123456789
scanner.data // => abcdefghijklmnopqrstuvwxyz\n0123

scanner.hasNextLine() // => true
scanner.nextLine() // => abcdefghijklmnopqrstuvwxyz
scanner.data // => 0123

scanner.hasNextLine() // => false
scanner.nextLine() // => (nil)

Requirements

• iOS 8.0+ / Mac OS X 10.10+
• Xcode 8+ / Swift 3+

Installation

Carthage

Add the following line to your Cartfile

github "s-aska/MutableDataScanner"

CocoaPods

Add the following line to your Podfile

use_frameworks!
pod 'MutableDataScanner'

License

MutableDataScanner is released under the MIT license. See LICENSE for details.