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| /* | |
| * crit-bit tree implementation, does no allocations internally | |
| * For more information on crit-bit trees: https://cr.yp.to/critbit.html | |
| * Based on Adam Langley's adaptation of Dan Bernstein's public domain code | |
| * git clone https://github.com/agl/critbit.git | |
| * | |
| * This is adapted to store arbitrary data (not just NUL-terminated C strings | |
| * and allocates no memory internally. The user needs to allocate | |
| * "struct cb_node" and fill cb_node.k[] with arbitrary match data | |
| * for memcmp. | |
| * If "klen" is variable, then it should be embedded into "c_node.k[]" | |
| * Recursion is bound by the maximum value of "klen" used. | |
| */ | |
| #ifndef CBTREE_H | |
| #define CBTREE_H | |
| #include "git-compat-util.h" | |
| struct cb_node; | |
| struct cb_node { | |
| struct cb_node *child[2]; | |
| /* | |
| * n.b. uint32_t for `byte' is excessive for OIDs, | |
| * we may consider shorter variants if nothing else gets stored. | |
| */ | |
| uint32_t byte; | |
| uint8_t otherbits; | |
| uint8_t k[FLEX_ARRAY]; /* arbitrary data, unaligned */ | |
| }; | |
| struct cb_tree { | |
| struct cb_node *root; | |
| }; | |
| enum cb_next { | |
| CB_CONTINUE = 0, | |
| CB_BREAK = 1 | |
| }; | |
| #define CBTREE_INIT { 0 } | |
| static inline void cb_init(struct cb_tree *t) | |
| { | |
| struct cb_tree blank = CBTREE_INIT; | |
| memcpy(t, &blank, sizeof(*t)); | |
| } | |
| struct cb_node *cb_lookup(struct cb_tree *, const uint8_t *k, size_t klen); | |
| struct cb_node *cb_insert(struct cb_tree *, struct cb_node *, size_t klen); | |
| typedef enum cb_next (*cb_iter)(struct cb_node *, void *arg); | |
| void cb_each(struct cb_tree *, const uint8_t *kpfx, size_t klen, | |
| cb_iter, void *arg); | |
| #endif /* CBTREE_H */ |