Benchmark: Prototypal property access vs passing cached value

Script Preparation code:

var Foo = function() {};
Foo.prototype._property = 'foo';
Foo.prototype.propertyAccess = function(param) {
  var property = this._property;
  this.noCache(param);
}
Foo.prototype.noCache = function(param) {
  console.log(this._property + '' + param);
}

var Bar = function() {};
Bar.prototype._property = 'bar';
Bar.prototype.propertyAccess = function(param) {
  var property = this._property;
  this.cache(property, param);
}
Bar.prototype.cache = function(property, param) {
  console.log(property + ' ' + param);
}

Tests:

Property access
var foo = new Foo(), i = 1000; while(i--) { foo.propertyAccess(i); }
Cached value
var bar = new Bar(), i = 1000; while(i--) { bar.propertyAccess(i); }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Property access
Cached value

Fastest: N/A

Slowest: N/A

Latest run results:

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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**Benchmark Explanation**

The provided JSON represents a JavaScript microbenchmark that tests the performance difference between two approaches: **Prototypal property access** and **Passing cached value**.

In this benchmark, we have two classes: `Foo` and `Bar`. Both classes have a private property `_property` initialized with a string value (`'foo'` for `Foo` and `'bar'` for `Bar`). They also have a public method `propertyAccess` which is used to access these properties.

The key difference between the two approaches lies in how the `propertyAccess` method accesses the `_property`. For **Prototypal property access**, the method directly accesses the private property using `this._property`. In contrast, for **Passing cached value**, the method passes the cached value of `_property` as an argument to another method `noCache`, which logs the value and a parameter.

**Comparison Options**

There are two comparison options:

1.  **Prototypal property access**: This approach directly accesses the private property `_property`.
2.  **Passing cached value**: This approach passes the cached value of `_property` as an argument to `noCache`.

**Pros and Cons**

*   **Prototypal property access:**
    *   Pros:
        *   Easier to implement, as no additional caching logic is required.
        *   May be faster for simple use cases where the private property is accessed frequently.
    *   Cons:
        *   May lead to performance issues if the private property needs to be accessed infrequently or with a high frequency, causing cache thrashing.
*   **Passing cached value:**
    *   Pros:
        *   Can improve performance in cases where the private property is accessed infrequently, reducing cache thrashing.
        *   Can be useful when there are multiple instances of an object and accessing the private property through different methods can lead to inconsistent behavior if both methods access the same instance.
    *   Cons:
        *   Requires additional caching logic, which may introduce complexity and performance overhead.
        *   May lead to slower initial performance due to the cache initialization.

**Library and Special JS Features**

There is no explicit library used in this benchmark. However, it's worth noting that some JavaScript engines (like V8) use a technique called "cache thrashing" when dealing with private properties accessed through multiple methods. This can affect performance in certain scenarios.

**Other Alternatives**

For similar benchmarks, you might consider testing other approaches such as:

*   Using getters and setters to access private properties.
*   Utilizing WeakMaps or objects to store cached values.
*   Implementing a cache invalidation strategy to mitigate cache thrashing.

Related benchmarks:

Prototypal property access vs passing cached value (version: 2)

Comparing performance of: Property access vs Cached value

Created: 9 years ago by: Registered User

Jump to the latest result

Property access

Cached value

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):