Benchmark: Long int keys (19 digits)

Script Preparation code:

var keyCount = 65535
var keys = []
var map = new Map()
var obj = {}


// Hide lookup keys to prevent V8 cheating (AKA Optimizing)
var getConspicuousKey = seed => keys[Math.floor(seed * keyCount)]


// Setup out test objects w/ random values
for (let i=0; i<keyCount; i++) {
  let val = Math.random()
  let key = 3000000000000000000+((4000000000000000000*Math.random())|0)
  keys.push(key)
  map.set(key,val)
  obj[key] = val
}

Tests:

Conspicuous Map lookup
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = map.get(key) }
Conspicuous Obj lookup
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = obj[key] }
Conspicuous Map lookup 2
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = map.get(key) }
Conspicuous Obj lookup 2
for (let i=0; i<keyCount; i++) { let seed = Math.random() let key = getConspicuousKey(seed) a = obj[key] }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Conspicuous Map lookup
Conspicuous Obj lookup
Conspicuous Map lookup 2
Conspicuous Obj lookup 2

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):

LLMs can make mistakes. Check important info.

Let's break down what's being tested in this benchmark.

**Benchmark Overview**

The benchmark tests the performance of two data structures: `Map` and `Object`. Both data structures are used to store key-value pairs, but they have different underlying implementation details that affect their performance.

**Key Features and Libraries Used**

* The benchmark uses a custom `getConspicuousKey` function to generate keys for both the `Map` and `Object` data structures. This function is designed to make it difficult for the V8 JavaScript engine to optimize away the memory accesses, which helps prevent "cheating" by optimizing the test.
* Both data structures use random values as keys and store corresponding values.

**Options Being Compared**

The benchmark compares the performance of two approaches:

1. **Conspicuous Map lookup**: This approach uses a `Map` data structure to store key-value pairs, where the key is generated using the `getConspicuousKey` function.
2. **Conspicuous Object lookup**: This approach uses an `Object` data structure to store key-value pairs, where the key is also generated using the `getConspicuousKey` function.

**Pros and Cons of Each Approach**

* **Conspicuous Map Lookup**:
	+ Pros: Maps are optimized for fast lookups, which can lead to better performance.
	+ Cons: The use of a custom `getConspicuousKey` function may still allow the V8 engine to optimize away the memory accesses if it's deemed unnecessary.
* **Conspicuous Object Lookup**:
	+ Pros: Objects are also optimized for fast lookups, but the use of a custom key generation function can help prevent optimization.
	+ Cons: The lookup performance may be lower due to the need to access the property on an object.

**Other Considerations**

The benchmark uses a large dataset (65535 keys) and runs multiple iterations to ensure that the results are representative. This helps to reduce variability and provide more accurate comparisons between the two approaches.

**Alternative Approaches**

There are other data structures that could be used for this benchmark, such as:

* **Arrays**: Using an array of objects or a map-like object (e.g., `Map` or `WeakMap`) instead of a plain object.
* **Set-based Data Structures**: Using a set-based data structure like a `Set` or a `MutableSet` to store the keys and values.

However, these alternatives may not provide the same level of insight into the performance differences between `Map` and `Object` as this benchmark does.

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36

Browser/OS: Chrome 110 on Linux

View result in a separate tab

Test name	Executions per second
Conspicuous Map lookup	23.1 Ops/sec
Conspicuous Obj lookup	14.8 Ops/sec
Conspicuous Map lookup 2	22.4 Ops/sec
Conspicuous Obj lookup 2	13.9 Ops/sec

Related benchmarks:

Long int keys (19 digits) (version: 0)

Based on https://www.measurethat.net/Benchmarks/Show/11290/4/map-vs-object-real-world-performance but with long int keys

Comparing performance of: Conspicuous Map lookup vs Conspicuous Obj lookup vs Conspicuous Map lookup 2 vs Conspicuous Obj lookup 2

Created: one year ago by: Guest

Jump to the latest result

Conspicuous Map lookup

Conspicuous Obj lookup

Conspicuous Map lookup 2

Conspicuous Obj lookup 2

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 26 days ago):