mirror of
https://gitlab.nic.cz/labs/bird.git
synced 2024-11-10 13:18:42 +00:00
93 lines
2.5 KiB
C
93 lines
2.5 KiB
C
/*
|
|
* Trie index for efficient trie storage
|
|
*
|
|
* (c) 2019 Maria Matejka <mq@jmq.cz>
|
|
* (c) 2019 CZ.NIC z.s.p.o.
|
|
*
|
|
* Can be freely distributed and used under the terms of the GNU GPL.
|
|
*/
|
|
|
|
#include "nest/bird.h"
|
|
|
|
/**
|
|
* Allocate a new trie index from the given pool
|
|
* @p: pool to allocate from
|
|
*
|
|
* Returns the allocated tindex structure.
|
|
*/
|
|
struct tindex* tindex_new(pool *p);
|
|
|
|
#define TINDEX_CREATE (~(0ULL))
|
|
#define TINDEX_FIND 0
|
|
|
|
/**
|
|
* Find an index
|
|
* @ti: the tindex to look into
|
|
* @bits_in: data
|
|
* @blen: number of bits to extract from bits_in.
|
|
* If @blen is not multiple of 64, the LSB's of the last u64 are ignored.
|
|
* @create: TINDEX_FIND to find existing, TINDEX_CREATE to create new records,
|
|
* every other value is for internal use
|
|
*
|
|
* Return value: 0 for not found; nonzero = the index
|
|
*/
|
|
|
|
u64 tindex_find(struct tindex *ti, const u32 *bits_in, const uint blen, const u64 create);
|
|
|
|
/**
|
|
* Delete an index.
|
|
* @ti: the tindex to use
|
|
* @idx: the index to delete
|
|
**/
|
|
|
|
u64 tindex_delete(struct tindex *ti, const u64 idx);
|
|
|
|
#define TINDEX_WALK_NOMAXLEN (((uint) 0) - 1)
|
|
|
|
struct tindex_walk_params {
|
|
u64 begin; /* Index to begin at. Root is 1. */
|
|
uint maxlen; /* Maximal data length; skip longer branches. */
|
|
uint internal:1; /* Return internal nodes with no data. */
|
|
u32 *data; /* Where to store the current bits. */
|
|
uint *dlen; /* Where to store the current bit length. */
|
|
};
|
|
|
|
/**
|
|
* Walk the trie (prefix order): Get first node, return the walk context.
|
|
* @ti: the index to use
|
|
* @twp: walk parameters
|
|
*
|
|
* Returns the tindex walk context. Run tindex_walk_next() repeatedly to get single items.
|
|
**/
|
|
|
|
struct tindex_walk *tindex_walk_init(const struct tindex *ti, const struct tindex_walk_params *twp);
|
|
|
|
/**
|
|
* Get next node.
|
|
* @ctx: walk context
|
|
*
|
|
* Returns next eligible index in trie. Returns 0 and frees the context if no more nodes are available.
|
|
**/
|
|
u64 tindex_walk_next(struct tindex_walk *ctx);
|
|
|
|
/**
|
|
* Finish the trie walk. This must be called to return the allocated structures
|
|
* if you break the walk prematurely by other means than the break clause.
|
|
*
|
|
* Breaking the walk by break is sane and safe.
|
|
*
|
|
* @ctx: walk context to free
|
|
**/
|
|
|
|
void tindex_walk_free(struct tindex_walk *ctx);
|
|
|
|
#define TINDEX_WALK(ti, twp) \
|
|
for (struct tindex_walk *_ti_ctx = tindex_walk_init(ti, twp); _ti_ctx; _ti_ctx = NULL) \
|
|
for (u64 idx; idx = tindex_walk_next(ti, _ti_ctx); )
|
|
|
|
/**
|
|
* Dump the index. Useful for debugging.
|
|
*/
|
|
|
|
void tindex_dump(const struct tindex *ti);
|