rte_hash.h File Reference

#include <stdint.h>
#include <stddef.h>
#include <rte_compat.h>

Go to the source code of this file.

Data Structures
struct	rte_hash_parameters

Macros
#define	RTE_HASH_ENTRIES_MAX   (1 << 30)
#define	RTE_HASH_NAMESIZE   32
#define	RTE_HASH_LOOKUP_BULK_MAX   64
#define	RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT   0x01
#define	RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD   0x02
#define	RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY   0x04
#define	RTE_HASH_EXTRA_FLAGS_EXT_TABLE   0x08
#define	RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL   0x10
#define	RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF   0x20

Typedefs
typedef uint32_t	hash_sig_t
typedef uint32_t(*	rte_hash_function) (const void *key, uint32_t key_len, uint32_t init_val)
typedef int(*	rte_hash_cmp_eq_t) (const void *key1, const void *key2, size_t key_len)

Functions
struct rte_hash *	rte_hash_create (const struct rte_hash_parameters *params)
void	rte_hash_set_cmp_func (struct rte_hash *h, rte_hash_cmp_eq_t func)
struct rte_hash *	rte_hash_find_existing (const char *name)
void	rte_hash_free (struct rte_hash *h)
void	rte_hash_reset (struct rte_hash *h)
int32_t	rte_hash_count (const struct rte_hash *h)
int	rte_hash_add_key_data (const struct rte_hash *h, const void *key, void *data)
int32_t	rte_hash_add_key_with_hash_data (const struct rte_hash *h, const void *key, hash_sig_t sig, void *data)
int32_t	rte_hash_add_key (const struct rte_hash *h, const void *key)
int32_t	rte_hash_add_key_with_hash (const struct rte_hash *h, const void *key, hash_sig_t sig)
int32_t	rte_hash_del_key (const struct rte_hash *h, const void *key)
int32_t	rte_hash_del_key_with_hash (const struct rte_hash *h, const void *key, hash_sig_t sig)
int	rte_hash_get_key_with_position (const struct rte_hash *h, const int32_t position, void **key)
int __rte_experimental	rte_hash_free_key_with_position (const struct rte_hash *h, const int32_t position)
int	rte_hash_lookup_data (const struct rte_hash *h, const void *key, void **data)
int	rte_hash_lookup_with_hash_data (const struct rte_hash *h, const void *key, hash_sig_t sig, void **data)
int32_t	rte_hash_lookup (const struct rte_hash *h, const void *key)
int32_t	rte_hash_lookup_with_hash (const struct rte_hash *h, const void *key, hash_sig_t sig)
hash_sig_t	rte_hash_hash (const struct rte_hash *h, const void *key)
int	rte_hash_lookup_bulk_data (const struct rte_hash *h, const void **keys, uint32_t num_keys, uint64_t *hit_mask, void *data[])
int	rte_hash_lookup_bulk (const struct rte_hash *h, const void **keys, uint32_t num_keys, int32_t *positions)
int32_t	rte_hash_iterate (const struct rte_hash *h, const void **key, void **data, uint32_t *next)

Detailed Description

RTE Hash Table

Definition in file rte_hash.h.

Macro Definition Documentation

#define RTE_HASH_ENTRIES_MAX   (1 << 30)

Maximum size of hash table that can be created.

Definition at line 24 of file rte_hash.h.

#define RTE_HASH_NAMESIZE   32

Maximum number of characters in hash name.

Examples:

examples/server_node_efd/node/node.c.

Definition at line 27 of file rte_hash.h.

#define RTE_HASH_LOOKUP_BULK_MAX   64

Maximum number of keys that can be searched for using rte_hash_lookup_bulk.

Definition at line 30 of file rte_hash.h.

#define RTE_HASH_EXTRA_FLAGS_TRANS_MEM_SUPPORT   0x01

Enable Hardware transactional memory support.

Definition at line 34 of file rte_hash.h.

#define RTE_HASH_EXTRA_FLAGS_MULTI_WRITER_ADD   0x02

Default behavior of insertion, single writer/multi writer

Definition at line 37 of file rte_hash.h.

#define RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY   0x04

Flag to support reader writer concurrency

Definition at line 40 of file rte_hash.h.

#define RTE_HASH_EXTRA_FLAGS_EXT_TABLE   0x08

Flag to indicate the extendable bucket table feature should be used

Definition at line 43 of file rte_hash.h.

#define RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL   0x10

Flag to disable freeing of key index on hash delete. Refer to rte_hash_del_xxx APIs for more details. This is enabled by default when RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled.

Definition at line 50 of file rte_hash.h.

#define RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF   0x20

Flag to support lock free reader writer concurrency. Both single writer and multi writer use cases are supported. Currently, extendable bucket table feature is not supported with this feature.

Definition at line 57 of file rte_hash.h.

Typedef Documentation

typedef uint32_t hash_sig_t

The type of hash value of a key. It should be a value of at least 32bit with fully random pattern.

Definition at line 63 of file rte_hash.h.

typedef uint32_t(* rte_hash_function) (const void *key, uint32_t key_len, uint32_t init_val)

Type of function that can be used for calculating the hash value.

Definition at line 66 of file rte_hash.h.

typedef int(* rte_hash_cmp_eq_t) (const void *key1, const void *key2, size_t key_len)

Type of function used to compare the hash key.

Definition at line 70 of file rte_hash.h.

Function Documentation

struct rte_hash* rte_hash_create

(

const struct rte_hash_parameters *

params

)

Create a new hash table.

Parameters

params

Parameters used to create and initialise the hash table.

Returns

Pointer to hash table structure that is used in future hash table operations, or NULL on error, with error code set in rte_errno. Possible rte_errno errors include:

• E_RTE_NO_CONFIG - function could not get pointer to rte_config structure
• E_RTE_SECONDARY - function was called from a secondary process instance
• ENOENT - missing entry
• EINVAL - invalid parameter passed to function
• ENOSPC - the maximum number of memzones has already been allocated
• EEXIST - a memzone with the same name already exists
• ENOMEM - no appropriate memory area found in which to create memzone

Examples:

examples/ipsec-secgw/ipsec-secgw.c, examples/l3fwd-power/main.c, examples/l3fwd-vf/main.c, examples/l3fwd/l3fwd_em.c, examples/performance-thread/l3fwd-thread/main.c, and examples/server_node_efd/node/node.c.

void rte_hash_set_cmp_func	(	struct rte_hash *	h,
		rte_hash_cmp_eq_t	func
	)

Set a new hash compare function other than the default one.

Note

Function pointer does not work with multi-process, so do not use it in multi-process mode.

Parameters

h	Hash table for which the function is to be changed
func	New compare function

struct rte_hash* rte_hash_find_existing

(

const char *

name

)

Find an existing hash table object and return a pointer to it.

Parameters

name	Name of the hash table as passed to rte_hash_create()

Returns

Pointer to hash table or NULL if object not found with rte_errno set appropriately. Possible rte_errno values include:

• ENOENT - value not available for return

void rte_hash_free

(

struct rte_hash *

h

)

De-allocate all memory used by hash table.

Parameters

h	Hash table to free

void rte_hash_reset

(

struct rte_hash *

h

)

Reset all hash structure, by zeroing all entries. When RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, it is application's responsibility to make sure that none of the readers are referencing the hash table while calling this API.

Parameters

h	Hash table to reset

int32_t rte_hash_count

(

const struct rte_hash *

h

)

Return the number of keys in the hash table

Parameters

h	Hash table to query from

Returns

• -EINVAL if parameters are invalid
• A value indicating how many keys were inserted in the table.

int rte_hash_add_key_data	(	const struct rte_hash *	h,
		const void *	key,
		void *	data
	)

Add a key-value pair to an existing hash table. This operation is not multi-thread safe and should only be called from one thread by default. Thread safety can be enabled by setting flag during table creation. If the key exists already in the table, this API updates its value with 'data' passed in this API. It is the responsibility of the application to manage any memory associated with the old value. The readers might still be using the old value even after this API has returned.

Parameters

h	Hash table to add the key to.
key	Key to add to the hash table.
data	Data to add to the hash table.

Returns

• 0 if added successfully
• -EINVAL if the parameters are invalid.
• -ENOSPC if there is no space in the hash for this key.

Examples:

examples/ipsec-secgw/ipsec-secgw.c.

int32_t rte_hash_add_key_with_hash_data	(	const struct rte_hash *	h,
		const void *	key,
		hash_sig_t	sig,
		void *	data
	)

Add a key-value pair with a pre-computed hash value to an existing hash table. This operation is not multi-thread safe and should only be called from one thread by default. Thread safety can be enabled by setting flag during table creation. If the key exists already in the table, this API updates its value with 'data' passed in this API. It is the responsibility of the application to manage any memory associated with the old value. The readers might still be using the old value even after this API has returned.

Parameters

h	Hash table to add the key to.
key	Key to add to the hash table.
sig	Precomputed hash value for 'key'
data	Data to add to the hash table.

Returns

• 0 if added successfully
• -EINVAL if the parameters are invalid.
• -ENOSPC if there is no space in the hash for this key.

int32_t rte_hash_add_key	(	const struct rte_hash *	h,
		const void *	key
	)

Add a key to an existing hash table. This operation is not multi-thread safe and should only be called from one thread by default. Thread safety can be enabled by setting flag during table creation.

Parameters

h	Hash table to add the key to.
key	Key to add to the hash table.

Returns

• -EINVAL if the parameters are invalid.
• -ENOSPC if there is no space in the hash for this key.
• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key.

Examples:

examples/l3fwd-power/main.c, examples/l3fwd-vf/main.c, examples/l3fwd/l3fwd_em.c, examples/performance-thread/l3fwd-thread/main.c, and examples/server_node_efd/node/node.c.

int32_t rte_hash_add_key_with_hash	(	const struct rte_hash *	h,
		const void *	key,
		hash_sig_t	sig
	)

Add a key to an existing hash table. This operation is not multi-thread safe and should only be called from one thread by default. Thread safety can be enabled by setting flag during table creation.

Parameters

h	Hash table to add the key to.
key	Key to add to the hash table.
sig	Precomputed hash value for 'key'.

Returns

• -EINVAL if the parameters are invalid.
• -ENOSPC if there is no space in the hash for this key.
• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key.

int32_t rte_hash_del_key	(	const struct rte_hash *	h,
		const void *	key
	)

Remove a key from an existing hash table. This operation is not multi-thread safe and should only be called from one thread by default. Thread safety can be enabled by setting flag during table creation. If RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL or RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, the key index returned by rte_hash_add_key_xxx APIs will not be freed by this API. rte_hash_free_key_with_position API must be called additionally to free the index associated with the key. rte_hash_free_key_with_position API should be called after all the readers have stopped referencing the entry corresponding to this key. RCU mechanisms could be used to determine such a state.

Parameters

h	Hash table to remove the key from.
key	Key to remove from the hash table.

Returns

• -EINVAL if the parameters are invalid.
• -ENOENT if the key is not found.
• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key, and is the same value that was returned when the key was added.

int32_t rte_hash_del_key_with_hash	(	const struct rte_hash *	h,
		const void *	key,
		hash_sig_t	sig
	)

Remove a key from an existing hash table. This operation is not multi-thread safe and should only be called from one thread by default. Thread safety can be enabled by setting flag during table creation. If RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL or RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, the key index returned by rte_hash_add_key_xxx APIs will not be freed by this API. rte_hash_free_key_with_position API must be called additionally to free the index associated with the key. rte_hash_free_key_with_position API should be called after all the readers have stopped referencing the entry corresponding to this key. RCU mechanisms could be used to determine such a state.

Parameters

h	Hash table to remove the key from.
key	Key to remove from the hash table.
sig	Precomputed hash value for 'key'.

Returns

• -EINVAL if the parameters are invalid.
• -ENOENT if the key is not found.
• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key, and is the same value that was returned when the key was added.

int rte_hash_get_key_with_position	(	const struct rte_hash *	h,
		const int32_t	position,
		void **	key
	)

Find a key in the hash table given the position. This operation is multi-thread safe with regarding to other lookup threads. Read-write concurrency can be enabled by setting flag during table creation.

Parameters

h	Hash table to get the key from.
position	Position returned when the key was inserted.
key	Output containing a pointer to the key

Returns

• 0 if retrieved successfully
• -EINVAL if the parameters are invalid.
• -ENOENT if no valid key is found in the given position.

int __rte_experimental rte_hash_free_key_with_position	(	const struct rte_hash *	h,
		const int32_t	position
	)

Warning

EXPERIMENTAL: this API may change without prior notice

Free a hash key in the hash table given the position of the key. This operation is not multi-thread safe and should only be called from one thread by default. Thread safety can be enabled by setting flag during table creation. If RTE_HASH_EXTRA_FLAGS_NO_FREE_ON_DEL or RTE_HASH_EXTRA_FLAGS_RW_CONCURRENCY_LF is enabled, the key index returned by rte_hash_del_key_xxx APIs must be freed using this API. This API should be called after all the readers have stopped referencing the entry corresponding to this key. RCU mechanisms could be used to determine such a state. This API does not validate if the key is already freed.

Parameters

h	Hash table to free the key from.
position	Position returned when the key was deleted.

Returns

• 0 if freed successfully
• -EINVAL if the parameters are invalid.

int rte_hash_lookup_data	(	const struct rte_hash *	h,
		const void *	key,
		void **	data
	)

Find a key-value pair in the hash table. This operation is multi-thread safe with regarding to other lookup threads. Read-write concurrency can be enabled by setting flag during table creation.

Parameters

h	Hash table to look in.
key	Key to find.
data	Output with pointer to data returned from the hash table.

Returns

• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key, and is the same value that was returned when the key was added.
• -EINVAL if the parameters are invalid.
• -ENOENT if the key is not found.

Examples:

examples/ipsec-secgw/ipsec.c.

int rte_hash_lookup_with_hash_data	(	const struct rte_hash *	h,
		const void *	key,
		hash_sig_t	sig,
		void **	data
	)

Find a key-value pair with a pre-computed hash value to an existing hash table. This operation is multi-thread safe with regarding to other lookup threads. Read-write concurrency can be enabled by setting flag during table creation.

Parameters

h	Hash table to look in.
key	Key to find.
sig	Precomputed hash value for 'key'
data	Output with pointer to data returned from the hash table.

Returns

• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key, and is the same value that was returned when the key was added.
• -EINVAL if the parameters are invalid.
• -ENOENT if the key is not found.

int32_t rte_hash_lookup	(	const struct rte_hash *	h,
		const void *	key
	)

Find a key in the hash table. This operation is multi-thread safe with regarding to other lookup threads. Read-write concurrency can be enabled by setting flag during table creation.

Parameters

h	Hash table to look in.
key	Key to find.

Returns

• -EINVAL if the parameters are invalid.
• -ENOENT if the key is not found.
• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key, and is the same value that was returned when the key was added.

Examples:

examples/ipsec-secgw/ipsec-secgw.c, examples/l3fwd-power/main.c, examples/l3fwd-vf/main.c, examples/l3fwd/l3fwd_em.c, and examples/performance-thread/l3fwd-thread/main.c.

int32_t rte_hash_lookup_with_hash	(	const struct rte_hash *	h,
		const void *	key,
		hash_sig_t	sig
	)

Find a key in the hash table. This operation is multi-thread safe with regarding to other lookup threads. Read-write concurrency can be enabled by setting flag during table creation.

Parameters

h	Hash table to look in.
key	Key to find.
sig	Precomputed hash value for 'key'.

Returns

• -EINVAL if the parameters are invalid.
• -ENOENT if the key is not found.
• A positive value that can be used by the caller as an offset into an array of user data. This value is unique for this key, and is the same value that was returned when the key was added.

hash_sig_t rte_hash_hash	(	const struct rte_hash *	h,
		const void *	key
	)

Calc a hash value by key. This operation is not multi-process safe.

Parameters

h	Hash table to look in.
key	Key to find.

Returns

• hash value

int rte_hash_lookup_bulk_data	(	const struct rte_hash *	h,
		const void **	keys,
		uint32_t	num_keys,
		uint64_t *	hit_mask,
		void *	data[]
	)

Find multiple keys in the hash table. This operation is multi-thread safe with regarding to other lookup threads. Read-write concurrency can be enabled by setting flag during table creation.

Parameters

h	Hash table to look in.
keys	A pointer to a list of keys to look for.
num_keys	How many keys are in the keys list (less than RTE_HASH_LOOKUP_BULK_MAX).
hit_mask	Output containing a bitmask with all successful lookups.
data	Output containing array of data returned from all the successful lookups.

Returns

-EINVAL if there's an error, otherwise number of successful lookups.

int rte_hash_lookup_bulk	(	const struct rte_hash *	h,
		const void **	keys,
		uint32_t	num_keys,
		int32_t *	positions
	)

Find multiple keys in the hash table. This operation is multi-thread safe with regarding to other lookup threads. Read-write concurrency can be enabled by setting flag during table creation.

Parameters

h	Hash table to look in.
keys	A pointer to a list of keys to look for.
num_keys	How many keys are in the keys list (less than RTE_HASH_LOOKUP_BULK_MAX).
positions	Output containing a list of values, corresponding to the list of keys that can be used by the caller as an offset into an array of user data. These values are unique for each key, and are the same values that were returned when each key was added. If a key in the list was not found, then -ENOENT will be the value.

Returns

-EINVAL if there's an error, otherwise 0.

Examples:

examples/performance-thread/l3fwd-thread/main.c, and examples/server_node_efd/node/node.c.

int32_t rte_hash_iterate	(	const struct rte_hash *	h,
		const void **	key,
		void **	data,
		uint32_t *	next
	)

Iterate through the hash table, returning key-value pairs.

Parameters

h	Hash table to iterate
key	Output containing the key where current iterator was pointing at
data	Output containing the data associated with key. Returns NULL if data was not stored.
next	Pointer to iterator. Should be 0 to start iterating the hash table. Iterator is incremented after each call of this function.

Returns

Position where key was stored, if successful.

• -EINVAL if the parameters are invalid.
• -ENOENT if end of the hash table.