fireblade-ecs/Tests/FirebladeECSTests/HashingTests.swift

66 lines
2.2 KiB
Swift

//
// HashingTests.swift
// FirebladeECSTests
//
// Created by Christian Treffs on 16.10.17.
//
@testable import FirebladeECS
import XCTest
class HashingTests: XCTestCase {
func makeComponent() -> Int {
let upperBound: Int = 44
let range = UInt32.min...UInt32.max
let high = UInt(UInt32.random(in: range)) << UInt(upperBound)
let low = UInt(UInt32.random(in: range))
XCTAssertTrue(high.leadingZeroBitCount < 64 - upperBound)
XCTAssertTrue(high.trailingZeroBitCount >= upperBound)
XCTAssertTrue(low.leadingZeroBitCount >= 32)
XCTAssertTrue(low.trailingZeroBitCount <= 32)
let rand: UInt = high | low
let cH = Int(bitPattern: rand)
return cH
}
func testCollisionsInCritialRange() {
var hashSet: Set<Int> = Set<Int>()
var range: CountableRange<UInt32> = 0 ..< 1_000_000
let maxComponents: Int = 1000
let components: [Int] = (0..<maxComponents).map { _ in makeComponent() }
var index: Int = 0
while let idx: UInt32 = range.popLast() {
let eId = EntityIdentifier(idx)
let entityId: EntityIdentifier = eId
let c = (index % maxComponents)
index += 1
let cH: ComponentTypeHash = components[c]
let h: Int = EntityComponentHash.compose(entityId: entityId, componentTypeHash: cH)
let (collisionFree, _) = hashSet.insert(h)
XCTAssert(collisionFree)
XCTAssert(EntityComponentHash.decompose(h, with: cH) == entityId)
XCTAssert(EntityComponentHash.decompose(h, with: entityId) == cH)
}
}
func testStringHashes() throws {
let string = "EiMersaufEn1"
XCTAssertEqual(StringHashing.bernstein_djb2(string), 13_447_802_024_599_246_090)
XCTAssertEqual(StringHashing.singer_djb2(string), 5_428_736_256_651_916_664)
XCTAssertEqual(StringHashing.sdbm(string), 15_559_770_072_020_577_201)
XCTAssertEqual(StringHashing.bernstein_djb2("gamedev"), 229_466_792_000_542)
XCTAssertEqual(StringHashing.singer_djb2("gamedev"), 2_867_840_411_746_895_486)
XCTAssertEqual(StringHashing.sdbm("gamedev"), 2_761_443_862_055_442_870)
}
}