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/*
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 20232025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the StarForth License, Version 1.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
*/
/**
* xxhash64.h - xxHash64 Implementation (Freestanding)
*
* Fast, deterministic 64-bit hash function for capsule content addressing.
* No libc dependency - works in kernel context.
*
* Based on xxHash by Yann Collet (BSD-2-Clause license).
* https://github.com/Cyan4973/xxHash
*/
#ifndef STARKERNEL_XXHASH64_H
#define STARKERNEL_XXHASH64_H
#include <stdint.h>
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
/*===========================================================================
* Constants
*===========================================================================*/
/** Default seed for capsule hashing (deterministic) */
#define XXHASH64_CAPSULE_SEED 0ULL
/*===========================================================================
* One-Shot Hashing
*===========================================================================*/
/**
* xxhash64 - Compute xxHash64 of a buffer
*
* @param data Input data
* @param len Length in bytes
* @param seed Hash seed (use XXHASH64_CAPSULE_SEED for capsules)
* @return 64-bit hash value
*/
uint64_t xxhash64(const void *data, size_t len, uint64_t seed);
/**
* xxhash64_capsule - Hash capsule payload with standard seed
*
* Convenience wrapper using XXHASH64_CAPSULE_SEED.
*
* @param data Capsule payload bytes
* @param len Payload length
* @return Content hash (capsule_id)
*/
static inline uint64_t xxhash64_capsule(const void *data, size_t len) {
return xxhash64(data, len, XXHASH64_CAPSULE_SEED);
}
/*===========================================================================
* Streaming API (for large data)
*===========================================================================*/
/** Streaming state structure */
typedef struct {
uint64_t total_len;
uint64_t v1;
uint64_t v2;
uint64_t v3;
uint64_t v4;
uint8_t buffer[32];
uint32_t buffer_size;
uint64_t seed;
} XXHash64State;
/**
* xxhash64_reset - Initialize streaming state
*
* @param state State to initialize
* @param seed Hash seed
*/
void xxhash64_reset(XXHash64State *state, uint64_t seed);
/**
* xxhash64_update - Feed data into streaming hash
*
* @param state Streaming state
* @param data Input data
* @param len Length in bytes
*/
void xxhash64_update(XXHash64State *state, const void *data, size_t len);
/**
* xxhash64_digest - Finalize and get hash value
*
* @param state Streaming state
* @return 64-bit hash value
*/
uint64_t xxhash64_digest(const XXHash64State *state);
#ifdef __cplusplus
}
#endif
#endif /* STARKERNEL_XXHASH64_H */