numam-dpdk/lib/member/rte_member.h
Stephen Hemminger 448e01f1b5 lib: document free functions
Make sure all functions which use the convention that XXX_free(NULL)
is a nop are all documented.

The wording is chosen to match the documentation of free(3).
"If ptr is NULL, no operation is performed."

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Chengwen Feng <fengchengwen@huawei.com>
[David: squashed with other series updates, unified wording]
2022-06-24 14:50:34 +02:00

491 lines
17 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2017 Intel Corporation
*/
/**
* @file
*
* RTE Membership Library
*
* The Membership Library is an extension and generalization of a traditional
* filter (for example Bloom Filter and cuckoo filter) structure that has
* multiple usages in a variety of workloads and applications. The library is
* used to test if a key belongs to certain sets. Two types of such
* "set-summary" structures are implemented: hash-table based (HT) and vector
* bloom filter (vBF). For HT setsummary, two subtypes or modes are available,
* cache and non-cache modes. The table below summarize some properties of
* the different implementations.
*
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*/
/**
* <!--
* +==========+=====================+================+=========================+
* | type | vbf | HT-cache | HT-non-cache |
* +==========+=====================+==========================================+
* |structure | bloom-filter array | hash-table like without storing key |
* +----------+---------------------+------------------------------------------+
* |set id | limited by bf count | [1, 0x7fff] |
* | | up to 32. | |
* +----------+---------------------+------------------------------------------+
* |usages & | small set range, | can delete, | cache most recent keys, |
* |properties| user-specified | big set range, | have both false-positive|
* | | false-positive rate,| small false | and false-negative |
* | | no deletion support.| positive depend| depend on table size, |
* | | | on table size, | automatic overwritten. |
* | | | new key does | |
* | | | not overwrite | |
* | | | existing key. | |
* +----------+---------------------+----------------+-------------------------+
* -->
*/
#ifndef _RTE_MEMBER_H_
#define _RTE_MEMBER_H_
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <rte_common.h>
/** The set ID type that stored internally in hash table based set summary. */
typedef uint16_t member_set_t;
/** Invalid set ID used to mean no match found. */
#define RTE_MEMBER_NO_MATCH 0
/** Maximum size of hash table that can be created. */
#define RTE_MEMBER_ENTRIES_MAX (1 << 30)
/** Maximum number of keys that can be searched as a bulk */
#define RTE_MEMBER_LOOKUP_BULK_MAX 64
/** Entry count per bucket in hash table based mode. */
#define RTE_MEMBER_BUCKET_ENTRIES 16
/** Maximum number of characters in setsum name. */
#define RTE_MEMBER_NAMESIZE 32
/** @internal Hash function used by membership library. */
#if defined(RTE_ARCH_X86) || defined(__ARM_FEATURE_CRC32)
#include <rte_hash_crc.h>
#define MEMBER_HASH_FUNC rte_hash_crc
#else
#include <rte_jhash.h>
#define MEMBER_HASH_FUNC rte_jhash
#endif
extern int librte_member_logtype;
#define RTE_MEMBER_LOG(level, ...) \
rte_log(RTE_LOG_ ## level, \
librte_member_logtype, \
RTE_FMT("%s(): " RTE_FMT_HEAD(__VA_ARGS__,), \
__func__, \
RTE_FMT_TAIL(__VA_ARGS__,)))
/** @internal setsummary structure. */
struct rte_member_setsum;
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Parameter struct used to create set summary
*/
struct rte_member_parameters;
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Define different set summary types
*/
enum rte_member_setsum_type {
RTE_MEMBER_TYPE_HT = 0, /**< Hash table based set summary. */
RTE_MEMBER_TYPE_VBF, /**< Vector of bloom filters. */
RTE_MEMBER_NUM_TYPE
};
/** @internal compare function for different arch. */
enum rte_member_sig_compare_function {
RTE_MEMBER_COMPARE_SCALAR = 0,
RTE_MEMBER_COMPARE_AVX2,
RTE_MEMBER_COMPARE_NUM
};
/** @internal setsummary structure. */
struct rte_member_setsum {
enum rte_member_setsum_type type; /* Type of the set summary. */
uint32_t key_len; /* Length of key. */
uint32_t prim_hash_seed; /* Primary hash function seed. */
uint32_t sec_hash_seed; /* Secondary hash function seed. */
/* Hash table based. */
uint32_t bucket_cnt; /* Number of buckets. */
uint32_t bucket_mask; /* Bit mask to get bucket index. */
/* For runtime selecting AVX, scalar, etc for signature comparison. */
enum rte_member_sig_compare_function sig_cmp_fn;
uint8_t cache; /* If it is cache mode for ht based. */
/* Vector bloom filter. */
uint32_t num_set; /* Number of set (bf) in vbf. */
uint32_t bits; /* Number of bits in each bf. */
uint32_t bit_mask; /* Bit mask to get bit location in bf. */
uint32_t num_hashes; /* Number of hash values to index bf. */
uint32_t mul_shift; /* vbf internal variable used during bit test. */
uint32_t div_shift; /* vbf internal variable used during bit test. */
void *table; /* This is the handler of hash table or vBF array. */
/* Second cache line should start here. */
uint32_t socket_id; /* NUMA Socket ID for memory. */
char name[RTE_MEMBER_NAMESIZE]; /* Name of this set summary. */
} __rte_cache_aligned;
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Parameters used when create the set summary table. Currently user can
* specify two types of setsummary: HT based and vBF. For HT based, user can
* specify cache or non-cache mode. Here is a table to describe some differences
*
*/
struct rte_member_parameters {
const char *name; /**< Name of the hash. */
/**
* User to specify the type of the setsummary from one of
* rte_member_setsum_type.
*
* HT based setsummary is implemented like a hash table. User should use
* this type when there are many sets.
*
* vBF setsummary is a vector of bloom filters. It is used when number
* of sets is not big (less than 32 for current implementation).
*/
enum rte_member_setsum_type type;
/**
* is_cache is only used for HT based setsummary.
*
* If it is HT based setsummary, user to specify the subtype or mode
* of the setsummary. It could be cache, or non-cache mode.
* Set is_cache to be 1 if to use as cache mode.
*
* For cache mode, keys can be evicted out of the HT setsummary. Keys
* with the same signature and map to the same bucket
* will overwrite each other in the setsummary table.
* This mode is useful for the case that the set-summary only
* needs to keep record of the recently inserted keys. Both
* false-negative and false-positive could happen.
*
* For non-cache mode, keys cannot be evicted out of the cache. So for
* this mode the setsummary will become full eventually. Keys with the
* same signature but map to the same bucket will still occupy multiple
* entries. This mode does not give false-negative result.
*/
uint8_t is_cache;
/**
* For HT setsummary, num_keys equals to the number of entries of the
* table. When the number of keys inserted in the HT setsummary
* approaches this number, eviction could happen. For cache mode,
* keys could be evicted out of the table. For non-cache mode, keys will
* be evicted to other buckets like cuckoo hash. The table will also
* likely to become full before the number of inserted keys equal to the
* total number of entries.
*
* For vBF, num_keys equal to the expected number of keys that will
* be inserted into the vBF. The implementation assumes the keys are
* evenly distributed to each BF in vBF. This is used to calculate the
* number of bits we need for each BF. User does not specify the size of
* each BF directly because the optimal size depends on the num_keys
* and false positive rate.
*/
uint32_t num_keys;
/**
* The length of key is used for hash calculation. Since key is not
* stored in set-summary, large key does not require more memory space.
*/
uint32_t key_len;
/**
* num_set is only used for vBF, but not used for HT setsummary.
*
* num_set is equal to the number of BFs in vBF. For current
* implementation, it only supports 1,2,4,8,16,32 BFs in one vBF set
* summary. If other number of sets are needed, for example 5, the user
* should allocate the minimum available value that larger than 5,
* which is 8.
*/
uint32_t num_set;
/**
* false_positive_rate is only used for vBF, but not used for HT
* setsummary.
*
* For vBF, false_positive_rate is the user-defined false positive rate
* given expected number of inserted keys (num_keys). It is used to
* calculate the total number of bits for each BF, and the number of
* hash values used during lookup and insertion. For details please
* refer to vBF implementation and membership library documentation.
*
* For HT, This parameter is not directly set by users.
* HT setsummary's false positive rate is in the order of:
* false_pos = (1/bucket_count)*(1/2^16), since we use 16-bit signature.
* This is because two keys needs to map to same bucket and same
* signature to have a collision (false positive). bucket_count is equal
* to number of entries (num_keys) divided by entry count per bucket
* (RTE_MEMBER_BUCKET_ENTRIES). Thus, the false_positive_rate is not
* directly set by users for HT mode.
*/
float false_positive_rate;
/**
* We use two seeds to calculate two independent hashes for each key.
*
* For HT type, one hash is used as signature, and the other is used
* for bucket location.
* For vBF type, these two hashes and their combinations are used as
* hash locations to index the bit array.
*/
uint32_t prim_hash_seed;
/**
* The secondary seed should be a different value from the primary seed.
*/
uint32_t sec_hash_seed;
int socket_id; /**< NUMA Socket ID for memory. */
};
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Find an existing set-summary and return a pointer to it.
*
* @param name
* Name of the set-summary.
* @return
* Pointer to the set-summary or NULL if object not found
* with rte_errno set appropriately. Possible rte_errno values include:
* - ENOENT - value not available for return
*/
struct rte_member_setsum *
rte_member_find_existing(const char *name);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Create set-summary (SS).
*
* @param params
* Parameters to initialize the setsummary.
* @return
* Return the pointer to the setsummary.
* Return value is NULL if the creation failed.
*/
struct rte_member_setsum *
rte_member_create(const struct rte_member_parameters *params);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Lookup key in set-summary (SS).
* Single key lookup and return as soon as the first match found
*
* @param setsum
* Pointer of a setsummary.
* @param key
* Pointer of the key to be looked up.
* @param set_id
* Output the set id matches the key.
* @return
* Return 1 for found a match and 0 for not found a match.
*/
int
rte_member_lookup(const struct rte_member_setsum *setsum, const void *key,
member_set_t *set_id);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Lookup bulk of keys in set-summary (SS).
* Each key lookup returns as soon as the first match found
*
* @param setsum
* Pointer of a setsummary.
* @param keys
* Pointer of the bulk of keys to be looked up.
* @param num_keys
* Number of keys that will be lookup.
* @param set_ids
* Output set ids for all the keys to this array.
* User should preallocate array that can contain all results, which size is
* the num_keys.
* @return
* The number of keys that found a match.
*/
int
rte_member_lookup_bulk(const struct rte_member_setsum *setsum,
const void **keys, uint32_t num_keys,
member_set_t *set_ids);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Lookup a key in set-summary (SS) for multiple matches.
* The key lookup will find all matched entries (multiple match).
* Note that for cache mode of HT, each key can have at most one match. This is
* because keys with same signature that maps to same bucket will overwrite
* each other. So multi-match lookup should be used for vBF and non-cache HT.
*
* @param setsum
* Pointer of a set-summary.
* @param key
* Pointer of the key that to be looked up.
* @param max_match_per_key
* User specified maximum number of matches for each key. The function returns
* as soon as this number of matches found for the key.
* @param set_id
* Output set ids for all the matches of the key. User needs to preallocate
* the array that can contain max_match_per_key number of results.
* @return
* The number of matches that found for the key.
* For cache mode HT set-summary, the number should be at most 1.
*/
int
rte_member_lookup_multi(const struct rte_member_setsum *setsum,
const void *key, uint32_t max_match_per_key,
member_set_t *set_id);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Lookup a bulk of keys in set-summary (SS) for multiple matches each key.
* Each key lookup will find all matched entries (multiple match).
* Note that for cache mode HT, each key can have at most one match. So
* multi-match function is mainly used for vBF and non-cache mode HT.
*
* @param setsum
* Pointer of a setsummary.
* @param keys
* Pointer of the keys to be looked up.
* @param num_keys
* The number of keys that will be lookup.
* @param max_match_per_key
* The possible maximum number of matches for each key.
* @param match_count
* Output the number of matches for each key in an array.
* @param set_ids
* Return set ids for all the matches of all keys. Users pass in a
* preallocated 2D array with first dimension as key index and second
* dimension as match index. For example set_ids[bulk_size][max_match_per_key]
* @return
* The number of keys that found one or more matches in the set-summary.
*/
int
rte_member_lookup_multi_bulk(const struct rte_member_setsum *setsum,
const void **keys, uint32_t num_keys,
uint32_t max_match_per_key,
uint32_t *match_count,
member_set_t *set_ids);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Insert key into set-summary (SS).
*
* @param setsum
* Pointer of a set-summary.
* @param key
* Pointer of the key to be added.
* @param set_id
* The set id associated with the key that needs to be added. Different mode
* supports different set_id ranges. 0 cannot be used as set_id since
* RTE_MEMBER_NO_MATCH by default is set as 0.
* For HT mode, the set_id has range as [1, 0x7FFF], MSB is reserved.
* For vBF mode the set id is limited by the num_set parameter when create
* the set-summary.
* @return
* HT (cache mode) and vBF should never fail unless the set_id is not in the
* valid range. In such case -EINVAL is returned.
* For HT (non-cache mode) it could fail with -ENOSPC error code when table is
* full.
* For success it returns different values for different modes to provide
* extra information for users.
* Return 0 for HT (cache mode) if the add does not cause
* eviction, return 1 otherwise. Return 0 for non-cache mode if success,
* -ENOSPC for full, and 1 if cuckoo eviction happens.
* Always returns 0 for vBF mode.
*/
int
rte_member_add(const struct rte_member_setsum *setsum, const void *key,
member_set_t set_id);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* De-allocate memory used by set-summary.
*
* @param setsum
* Pointer to the set summary.
* If setsum is NULL, no operation is performed.
*/
void
rte_member_free(struct rte_member_setsum *setsum);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Reset the set-summary tables. E.g. reset bits to be 0 in BF,
* reset set_id in each entry to be RTE_MEMBER_NO_MATCH in HT based SS.
*
* @param setsum
* Pointer to the set-summary.
*/
void
rte_member_reset(const struct rte_member_setsum *setsum);
/**
* @warning
* @b EXPERIMENTAL: this API may change without prior notice
*
* Delete items from the set-summary. Note that vBF does not support deletion
* in current implementation. For vBF, error code of -EINVAL will be returned.
*
* @param setsum
* Pointer to the set-summary.
* @param key
* Pointer of the key to be deleted.
* @param set_id
* For HT mode, we need both key and its corresponding set_id to
* properly delete the key. Without set_id, we may delete other keys with the
* same signature.
* @return
* If no entry found to delete, an error code of -ENOENT could be returned.
*/
int
rte_member_delete(const struct rte_member_setsum *setsum, const void *key,
member_set_t set_id);
#ifdef __cplusplus
}
#endif
#endif /* _RTE_MEMBER_H_ */