hashcode

Documentation

Index

• func Combine(values ...any) uint64
• func CombineHashes(values ...uint64) uint64
• func Compute(value any) uint64

Functions

func Combine

func Combine(values ...any) uint64

Combine computes a combined hash code from multiple values using the same algorithm as Composite comparer.

Parameters:

values - variadic list of values to combine into a single hash code

Returns:

A uint64 hash code computed by combining all input values

⚠️ Performance note: Time complexity is O(n) where n is the number of values.

func CombineHashes

func CombineHashes(values ...uint64) uint64

CombineHashes computes a combined hash code from multiple individual hash codes using a prime-based combination algorithm. This function provides a standardized way to combine multiple hash codes into a single hash value with good distribution properties, similar to HashCode.Combine() in C# or Guava's HashCode.combine().

Parameters:

values - variadic list of uint64 hash codes to combine

Returns:

A uint64 hash code computed by combining all input hash codes

⚠️ Performance note: Time complexity is O(n) where n is the number of values. This is a very fast operation involving only simple arithmetic operations. Memory allocation is zero - no additional memory is required.

func Compute

func Compute(value any) uint64

Compute generates a hash code for any value using type-specific serialization and the FNV-1a 64-bit hash algorithm. This function provides a generic way to compute hash codes for values of any type without using reflection.

Parameters:

value - any value to compute hash code for (can be nil)

Returns:

A uint64 FNV-1a hash code for the provided value

⚠️ Performance note: Performance varies by type:

• Primitive types (int, float, string, bool): O(1) - very fast
• Byte slices: O(n) where n is slice length
• Complex types: O(m) where m is string representation length
• Uses FNV-1a which is fast but not cryptographically secure

⚠️ Memory note: Minimal allocations for primitive types. Byte slices are included directly. Complex types may allocate during fmt.Sprintf conversion.

Notes:

• Thread safe - can be called concurrently
• Consistent results for equal values within the same process
• Handles nil values gracefully with consistent hash codes
• Uses FNV-1a 64-bit hash algorithm for good distribution and speed
• Little-endian byte order for numeric types ensures consistency
• Common use cases include generic collections, caching, and debugging