Swift Record Generator

A record is a collection of named data elements. In Swift 4, records can be implemented using

• tuples
• dictionaries ([String : AnyObject])
• structs (possibly with Copy-on-Write)
• classes

generator randomly builds a record schema and implements the same schema using each data structure. The code is saved in the generated project, which can run the following performance tests:

• "initializing" a new record instance from a given list of random values
• retrieving values of elements
• mutating values of elements
• passing records as function arguments
• serializing records to JSON
• deserializing records from JSON
• sorting a random array of records

Limitations

• The schema randomization is controlled by hard-coded constants in the main.swift files of each project.

• Tuples are only really meant for lightweight records of up to 6 elements, so they are not included in these tests.

• A "mutation" test on a constant is done by copying it to a variable first, then modifying the variable. (The only exception is for class instances, whose elements are mutable even if the instance is constant.)

• For each test, only the mean time taken per run is reported.

Quick Start

1. clone this repository
2. change the working directory to the root folder of this repository
3. build and run the generator project
4. choose your desired build settings for the Generated project at generated/Generated.xcodeproj.
5. Run the Generated project.

If you choose to have verbose output, below is a result of a sample run of the Swift Record Generator. SANITY_CHECKS_ENABLED: true indicates that there will be a fatal crash if a record's data is observed to be inconsistent with the program's expectations at any point.

(let) refers to a record instance stored in a constant.

(var) refers to a record instance stored in a variable.

        ELEMENT_COUNT: 16
MUTABLE_ELEMENT_COUNT: 3
           TEST_COUNT: 256
           ARRAY_SIZE: 256
     ARRAY_TEST_COUNT: 16

    MAX_STRING_LENGTH: 64
      MIN_NAME_LENGTH: 4
      MAX_NAME_LENGTH: 24
  MAX_COLLECTION_SIZE: 16

SANITY_CHECKS_ENABLED: true

ELEMENTS:
let rk3kkwfz46cguu1: [Date]
var b0yjdl3stwqzi0rvcfwpt: [String : Double]?
let m0rp91: String
let ed8de04k2fx5nqdv0hf_sw: Int
let urtedt0kcjfl5ml7wh: [String : Int]
let ghjxupry5fzo38d42v2bz: [Bool]
let jqluo1fzkwxnc0t1kvs: [String]
let byrrquq5e: [Int]
let _8uybhb6b1i18aahc1: [String : String]
let jkaav8ts69oe: Int
let r5he1u4sepvqehupah0a57js: [String : Int]
let npzv53sg46gh04mew: String
let ug0ca43e7w2: Double
var m3sjahsez: Int
let qb526mnbzr7_: Double
var k0jz8190pgda31q_xty: [String : Int]

MEAN TIME TO HASH A DICTIONARY KEY
153.33740234375 ns

MEAN TIME TO INITIALIZE, PER ELEMENT
   dictionary (let): 6472.580322265625 ns
   dictionary (var): 7429.5634765625 ns
    structure (let): 15.75927734375 ns
    structure (var): 22.759765625 ns
COW structure (let): 74.70068359375 ns
COW structure (var): 89.839599609375 ns
        class (let): 52.75927734375 ns
        class (var): 54.389892578125 ns

MEAN TIME TO RETRIEVE AN ELEMENT
   dictionary (let): 19630.7578125 ns
   dictionary (var): 21008.837646484375 ns
    structure (let): 15.383544921875 ns
    structure (var): 14.359619140625 ns
COW structure (let): 276.404541015625 ns
COW structure (var): 278.75341796875 ns
        class (let): 22.0751953125 ns
        class (var): 23.7880859375 ns

MEAN TIME TO MUTATE AN ELEMENT
   dictionary (let): 1859.8229166666667 ns
   dictionary (var): 1822.2135416666667 ns
    structure (let): 104.95182291666667 ns
    structure (var): 35.83203125 ns
COW structure (let): 791.94140625 ns
COW structure (var): 758.60546875 ns
        class (let): 599.4791666666666 ns
        class (var): 659.69140625 ns

MEAN TIME TO PASS AS FUNCTION ARGUMENT
   dictionary (let): 45.6640625 ns
   dictionary (var): 78.92578125 ns
    structure (let): 41.9453125 ns
    structure (var): 159.90234375 ns
COW structure (let): 45.4609375 ns
COW structure (var): 62.578125 ns
        class (let): 159.3359375 ns
        class (var): 61.80078125 ns

MEAN TIME TO SERIALIZE TO JSON, PER ELEMENT
   dictionary (let): 7595.759765625 ns
   dictionary (var): 7470.516357421875 ns
    structure (let): 23144.01416015625 ns
    structure (var): 23278.771484375 ns
COW structure (let): 23699.650146484375 ns
COW structure (var): 23269.886474609375 ns
        class (let): 23194.10888671875 ns
        class (var): 23470.774169921875 ns

MEAN TIME TO DESERIALIZE FROM JSON, PER ELEMENT
   dictionary (let): 7563.54541015625 ns
   dictionary (var): 7710.93359375 ns
    structure (let): 29372.016845703125 ns
    structure (var): 29071.224609375 ns
COW structure (let): 29380.45947265625 ns
COW structure (var): 29096.40283203125 ns
        class (let): 28830.109130859375 ns
        class (var): 30130.084716796875 ns

MEAN TIME TO SORT ARRAY OF 256 RECORDS
   dictionary (let): 31345303.125 ns
   dictionary (var): 30099811.5625 ns
    structure (let): 1881485.0625 ns
    structure (var): 1787431.0 ns
COW structure (let): 2681041.8125 ns
COW structure (var): 2612785.625 ns
        class (let): 521543.75 ns
        class (var): 505356.3125 ns

GLOBAL COUNTER: 165888
Program ended with exit code: 0