DPDK  22.07.0-rc3
rte_fbk_hash.h
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1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #ifndef _RTE_FBK_HASH_H_
6 #define _RTE_FBK_HASH_H_
7 
18 #include <stdint.h>
19 #include <errno.h>
20 
21 #ifdef __cplusplus
22 extern "C" {
23 #endif
24 
25 #include <string.h>
26 
27 #include <rte_hash_crc.h>
28 #include <rte_jhash.h>
29 
30 #ifndef RTE_FBK_HASH_INIT_VAL_DEFAULT
31 
32 #define RTE_FBK_HASH_INIT_VAL_DEFAULT 0xFFFFFFFF
33 #endif
34 
36 #define RTE_FBK_HASH_ENTRIES_MAX (1 << 20)
37 
39 #define RTE_FBK_HASH_ENTRIES_PER_BUCKET_MAX 256
40 
42 #define RTE_FBK_HASH_NAMESIZE 32
43 
45 typedef uint32_t (*rte_fbk_hash_fn)(uint32_t key, uint32_t init_val);
46 
49  const char *name;
50  uint32_t entries;
51  uint32_t entries_per_bucket;
52  int socket_id;
54  uint32_t init_val;
55 };
56 
59  uint64_t whole_entry;
60  struct {
61  uint16_t is_entry;
62  uint16_t value;
63  uint32_t key;
64  } entry;
65 };
66 
67 
71  uint32_t entries;
72  uint32_t entries_per_bucket;
73  uint32_t used_entries;
74  uint32_t bucket_mask;
75  uint32_t bucket_shift;
77  uint32_t init_val;
80  union rte_fbk_hash_entry t[];
81 };
82 
93 static inline uint32_t
94 rte_fbk_hash_get_bucket(const struct rte_fbk_hash_table *ht, uint32_t key)
95 {
96  return (ht->hash_func(key, ht->init_val) & ht->bucket_mask) <<
97  ht->bucket_shift;
98 }
99 
116 static inline int
118  uint32_t key, uint16_t value, uint32_t bucket)
119 {
120  /*
121  * The writing of a new value to the hash table is done as a single
122  * 64bit operation. This should help prevent individual entries being
123  * corrupted due to race conditions, but it's still possible to
124  * overwrite entries that have just been made valid.
125  */
126  const uint64_t new_entry = ((uint64_t)(key) << 32) |
127  ((uint64_t)(value) << 16) |
128  1; /* 1 = is_entry bit. */
129  uint32_t i;
130 
131  for (i = 0; i < ht->entries_per_bucket; i++) {
132  /* Set entry if unused. */
133  if (! ht->t[bucket + i].entry.is_entry) {
134  ht->t[bucket + i].whole_entry = new_entry;
135  ht->used_entries++;
136  return 0;
137  }
138  /* Change value if key already exists. */
139  if (ht->t[bucket + i].entry.key == key) {
140  ht->t[bucket + i].entry.value = value;
141  return 0;
142  }
143  }
144 
145  return -ENOSPC; /* No space in bucket. */
146 }
147 
161 static inline int
163  uint32_t key, uint16_t value)
164 {
166  key, value, rte_fbk_hash_get_bucket(ht, key));
167 }
168 
183 static inline int
185  uint32_t key, uint32_t bucket)
186 {
187  uint32_t last_entry = ht->entries_per_bucket - 1;
188  uint32_t i, j;
189 
190  for (i = 0; i < ht->entries_per_bucket; i++) {
191  if (ht->t[bucket + i].entry.key == key) {
192  /* Find last key in bucket. */
193  for (j = ht->entries_per_bucket - 1; j > i; j-- ) {
194  if (! ht->t[bucket + j].entry.is_entry) {
195  last_entry = j - 1;
196  }
197  }
198  /*
199  * Move the last key to the deleted key's position, and
200  * delete the last key. lastEntry and i may be same but
201  * it doesn't matter.
202  */
203  ht->t[bucket + i].whole_entry =
204  ht->t[bucket + last_entry].whole_entry;
205  ht->t[bucket + last_entry].whole_entry = 0;
206 
207  ht->used_entries--;
208  return 0;
209  }
210  }
211 
212  return -ENOENT; /* Key didn't exist. */
213 }
214 
226 static inline int
228 {
230  key, rte_fbk_hash_get_bucket(ht, key));
231 }
232 
246 static inline int
248  uint32_t key, uint32_t bucket)
249 {
250  union rte_fbk_hash_entry current_entry;
251  uint32_t i;
252 
253  for (i = 0; i < ht->entries_per_bucket; i++) {
254  /* Single read of entry, which should be atomic. */
255  current_entry.whole_entry = ht->t[bucket + i].whole_entry;
256  if (! current_entry.entry.is_entry) {
257  return -ENOENT; /* Error once we hit an empty field. */
258  }
259  if (current_entry.entry.key == key) {
260  return current_entry.entry.value;
261  }
262  }
263  return -ENOENT; /* Key didn't exist. */
264 }
265 
276 static inline int
277 rte_fbk_hash_lookup(const struct rte_fbk_hash_table *ht, uint32_t key)
278 {
280  key, rte_fbk_hash_get_bucket(ht, key));
281 }
282 
290 static inline void
292 {
293  memset(ht->t, 0, sizeof(ht->t[0]) * ht->entries);
294  ht->used_entries = 0;
295 }
296 
305 static inline double
307 {
308  return (double)ht->used_entries / (double)ht->entries;
309 }
310 
324 
342 struct rte_fbk_hash_table * \
343 rte_fbk_hash_create(const struct rte_fbk_hash_params *params);
344 
352 void rte_fbk_hash_free(struct rte_fbk_hash_table *ht);
353 
354 #ifdef __cplusplus
355 }
356 #endif
357 
358 #endif /* _RTE_FBK_HASH_H_ */
uint16_t is_entry
Definition: rte_fbk_hash.h:61
union rte_fbk_hash_entry t[]
Definition: rte_fbk_hash.h:80
uint32_t used_entries
Definition: rte_fbk_hash.h:73
Definition: rte_fbk_hash.h:58
static int rte_fbk_hash_add_key_with_bucket(struct rte_fbk_hash_table *ht, uint32_t key, uint16_t value, uint32_t bucket)
Definition: rte_fbk_hash.h:117
static int rte_fbk_hash_delete_key(struct rte_fbk_hash_table *ht, uint32_t key)
Definition: rte_fbk_hash.h:227
rte_fbk_hash_fn hash_func
Definition: rte_fbk_hash.h:53
static double rte_fbk_hash_get_load_factor(struct rte_fbk_hash_table *ht)
Definition: rte_fbk_hash.h:306
uint32_t(* rte_fbk_hash_fn)(uint32_t key, uint32_t init_val)
Definition: rte_fbk_hash.h:45
void rte_fbk_hash_free(struct rte_fbk_hash_table *ht)
static void rte_fbk_hash_clear_all(struct rte_fbk_hash_table *ht)
Definition: rte_fbk_hash.h:291
static int rte_fbk_hash_lookup_with_bucket(const struct rte_fbk_hash_table *ht, uint32_t key, uint32_t bucket)
Definition: rte_fbk_hash.h:247
uint32_t entries_per_bucket
Definition: rte_fbk_hash.h:51
static uint32_t rte_fbk_hash_get_bucket(const struct rte_fbk_hash_table *ht, uint32_t key)
Definition: rte_fbk_hash.h:94
const char * name
Definition: rte_fbk_hash.h:49
uint32_t key
Definition: rte_fbk_hash.h:63
uint32_t entries_per_bucket
Definition: rte_fbk_hash.h:72
static int rte_fbk_hash_add_key(struct rte_fbk_hash_table *ht, uint32_t key, uint16_t value)
Definition: rte_fbk_hash.h:162
static int rte_fbk_hash_lookup(const struct rte_fbk_hash_table *ht, uint32_t key)
Definition: rte_fbk_hash.h:277
uint32_t bucket_mask
Definition: rte_fbk_hash.h:74
uint64_t whole_entry
Definition: rte_fbk_hash.h:59
struct rte_fbk_hash_entry::@232 entry
uint16_t value
Definition: rte_fbk_hash.h:62
#define RTE_FBK_HASH_NAMESIZE
Definition: rte_fbk_hash.h:42
static int rte_fbk_hash_delete_key_with_bucket(struct rte_fbk_hash_table *ht, uint32_t key, uint32_t bucket)
Definition: rte_fbk_hash.h:184
uint32_t bucket_shift
Definition: rte_fbk_hash.h:75
struct rte_fbk_hash_table * rte_fbk_hash_find_existing(const char *name)
rte_fbk_hash_fn hash_func
Definition: rte_fbk_hash.h:76