# Define a custom class that implements the Hashable trait
class MyClass(Hashable):
    def __init__(self, value):
        self.value = value

    def __hash__(self):
        # Implement your custom hash function logic here
        return hash(self.value.encode('utf-8'))

# Create an instance of your custom class
my_object = MyClass("example")

# Use the hash function to get the hash value of the object
hash_value = hash(my_object)
print(hash_value)

Overview

The hash module provides functionality for generating hash values from data. It is designed for use in data structures that require quick and efficient data retrieval, such as hash maps. The module is not intended for cryptographic purposes but focuses on speed and the distribution of hash values to minimize collisions.

Key Features

• Hashable Trait: Allows custom types to implement a __hash__ method, enabling them to be used with the hash function.
• General Bytes Hashing: Includes a robust implementation for hashing byte sequences, utilizing SIMD vectors for efficiency.
• Adaptability: The module includes specialized implementations for common data types, enhancing performance and reliability in hashing operations.
• Security Considerations: Integrates a random hash secret into the hash calculation to mitigate certain types of attacks, despite not being cryptographically secure.

Use Cases

• Hash Maps: Essential for implementing efficient hash maps, where quick data retrieval is key.
• Data Structures: Useful in various data structures that depend on hash values for organizing data, such as sets or caches.
• Performance Optimization: Can be used to enhance the performance of applications that require fast data lookup or deduplication.

Considerations

• Not Cryptographically Secure: Should not be used for cryptographic applications due to the reversible nature of the hash functions and the potential for hash collisions.
• Runtime Determinism: Hash values are deterministic within a single runtime instance but will vary between runs due to the integration of a hash secret.
• Algorithm Choice: While the module uses the DJBX33A algorithm for its efficiency, users should be aware of its limitations and consider alternatives for more critical applications.

Compatibility

The hash module is designed to be compatible with a broad range of data types through the Hashable trait. However, its efficiency and effectiveness can vary depending on the platform and how well it supports SIMD operations. Users should test and evaluate its performance in their specific environments and use cases.