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Diffstat (limited to '')
| -rw-r--r-- | src/zstd/contrib/linux-kernel/xxhash_test.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/src/zstd/contrib/linux-kernel/xxhash_test.c b/src/zstd/contrib/linux-kernel/xxhash_test.c new file mode 100644 index 00000000..eb0fb1cd --- /dev/null +++ b/src/zstd/contrib/linux-kernel/xxhash_test.c @@ -0,0 +1,185 @@ +/* + * Copyright (c) 2016-present, Facebook, Inc. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + */ + +/* DO_XXH should be 32 or 64 for xxh32 and xxh64 respectively */ +#define DO_XXH 0 +/* DO_CRC should be 0 or 1 */ +#define DO_CRC 0 +/* Buffer size */ +#define BUFFER_SIZE 4096 + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/uaccess.h> + +#if DO_XXH +#include <linux/xxhash.h> +#endif + +#if DO_CRC +#include <linux/crc32.h> +#endif + +/* Device name to pass to register_chrdev(). */ +#define DEVICE_NAME "xxhash_test" + +/* Dynamically allocated device major number */ +static int device_major; + +/* + * We reuse the same hash state, and thus can hash only one + * file at a time. + */ +static bool device_is_open; + +static uint64_t total_length; + + +#if (DO_XXH == 32) + +#define xxh_state xxh32_state +#define xxh_reset xxh32_reset +#define xxh_update xxh32_update +#define xxh_digest xxh32_digest +#define XXH_FORMAT "XXH32 = 0x%x" + +#elif (DO_XXH == 64) + +#define xxh_state xxh64_state +#define xxh_reset xxh64_reset +#define xxh_update xxh64_update +#define xxh_digest xxh64_digest +#define XXH_FORMAT "XXH64 = 0x%llx" + +#elif DO_XXH + +#error "Invalid value of DO_XXH" + +#endif + +#if DO_XXH + +/* XXH state */ +static struct xxh_state state; + +#endif /* DO_XXH */ + +#if DO_CRC + +static uint32_t crc; + +#endif /* DO_CRC */ + +/* + * Input buffer used to put data coming from userspace. + */ +static uint8_t buffer_in[BUFFER_SIZE]; + +static int xxhash_test_open(struct inode *i, struct file *f) +{ + if (device_is_open) + return -EBUSY; + + device_is_open = true; + + total_length = 0; +#if DO_XXH + xxh_reset(&state, 0); +#endif +#if DO_CRC + crc = 0xFFFFFFFF; +#endif + + printk(KERN_INFO DEVICE_NAME ": opened\n"); + return 0; +} + +static int xxhash_test_release(struct inode *i, struct file *f) +{ + device_is_open = false; + + printk(KERN_INFO DEVICE_NAME ": total_len = %llu\n", total_length); +#if DO_XXH + printk(KERN_INFO DEVICE_NAME ": " XXH_FORMAT "\n", xxh_digest(&state)); +#endif +#if DO_CRC + printk(KERN_INFO DEVICE_NAME ": CRC32 = 0x%08x\n", ~crc); +#endif + printk(KERN_INFO DEVICE_NAME ": closed\n"); + return 0; +} + +/* + * Hash the data given to us from userspace. + */ +static ssize_t xxhash_test_write(struct file *file, const char __user *buf, + size_t size, loff_t *pos) +{ + size_t remaining = size; + + while (remaining > 0) { +#if DO_XXH + int ret; +#endif + size_t const copy_size = min(remaining, sizeof(buffer_in)); + + if (copy_from_user(buffer_in, buf, copy_size)) + return -EFAULT; + buf += copy_size; + remaining -= copy_size; + total_length += copy_size; +#if DO_XXH + if ((ret = xxh_update(&state, buffer_in, copy_size))) { + printk(KERN_INFO DEVICE_NAME ": xxh failure."); + return ret; + } +#endif +#if DO_CRC + crc = crc32(crc, buffer_in, copy_size); +#endif + } + return size; +} +/* register the character device. */ +static int __init xxhash_test_init(void) +{ + static const struct file_operations fileops = { + .owner = THIS_MODULE, + .open = &xxhash_test_open, + .release = &xxhash_test_release, + .write = &xxhash_test_write + }; + + device_major = register_chrdev(0, DEVICE_NAME, &fileops); + if (device_major < 0) { + return device_major; + } + + printk(KERN_INFO DEVICE_NAME ": module loaded\n"); + printk(KERN_INFO DEVICE_NAME ": Create a device node with " + "'mknod " DEVICE_NAME " c %d 0' and write data " + "to it.\n", device_major); + return 0; +} + +static void __exit xxhash_test_exit(void) +{ + unregister_chrdev(device_major, DEVICE_NAME); + printk(KERN_INFO DEVICE_NAME ": module unloaded\n"); +} + +module_init(xxhash_test_init); +module_exit(xxhash_test_exit); + +MODULE_DESCRIPTION("XXHash tester"); +MODULE_VERSION("1.0"); + + +MODULE_LICENSE("Dual BSD/GPL"); |