function hashCode1(str){
var hash = 0;
if (str.length == 0) return hash;
for (i = 0; i < str.length; i++) {
char = str.charCodeAt(i);
hash = ((hash<<5)-hash)+char;
hash = hash & hash; // Convert to 32bit integer
}
return hash;
}
function hashCode2(str) {
var hash = 0, i, chr;
if (str.length === 0) return hash;
for (i = 0; i < str.length; i++) {
chr = str.charCodeAt(i);
hash = ((hash << 5) - hash) + chr;
hash |= 0; // Convert to 32bit integer
}
return hash;
};
function hashCode3(str) {
var hash = 5381,
i = str.length;
while(i) {
hash = (hash * 33) ^ str.charCodeAt(--i);
}
return hash >>> 0;
}
hashCode1('qwerty')
hashCode2('qwerty')
hashCode3('qwerty')
--enable-precise-memory-info
flag.
Test case name | Result |
---|---|
hashCode1 | |
hashCode2 | |
hashCode3 |
Test name | Executions per second |
---|---|
hashCode1 | 577716.1 Ops/sec |
hashCode2 | 12134375.0 Ops/sec |
hashCode3 | 12714440.0 Ops/sec |
I'll break down the provided JSON and explain what's being tested, compared, and other considerations.
Benchmark Definition
The benchmark definition represents three different hash functions: hashCode1
, hashCode2
, and hashCode3
. These functions take a string input and return a 32-bit integer hash code. The goal is to compare the performance of these three implementations.
Hash Functions
hashCode1(str)
:hashCode2(str)
:hashCode1
, but with some minor differences in variable names and bitwise operations.hashCode1
due to optimized bit manipulation.hashCode1
.hashCode3(str)
:Comparison
The benchmark is comparing the performance of these three hash function implementations. The test results show that hashCode3
performs significantly better than the other two, while hashCode2
outperforms hashCode1
.
Library and Special JS Features
None of the provided code uses any libraries or special JavaScript features beyond standard ES6 syntax.
Alternatives
If you're interested in exploring alternative hash function implementations or testing different algorithms, consider the following:
Keep in mind that these alternatives might not be as simple to implement as the provided code, but they can offer improved performance and security characteristics.
Other Considerations
When working with hash functions, it's essential to consider factors like:
For most use cases, a well-designed and optimized hash function like hashCode3
should suffice. However, if you're working with critical applications or require extremely high performance, exploring alternative algorithms might be necessary.