From a68848db159cc1cafa82f9d383432fda459c8745 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 17 Jul 2021 09:11:16 +0200 Subject: Merging upstream version 1.2.1. Signed-off-by: Daniel Baumann --- include/dnsjit/lib/trie.hh | 118 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 include/dnsjit/lib/trie.hh (limited to 'include/dnsjit/lib/trie.hh') diff --git a/include/dnsjit/lib/trie.hh b/include/dnsjit/lib/trie.hh new file mode 100644 index 0000000..60c8f8a --- /dev/null +++ b/include/dnsjit/lib/trie.hh @@ -0,0 +1,118 @@ +/* + * Copyright (C) 2017-2019 CZ.NIC, z.s.p.o. + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +/* Memory allocation function prototypes. */ +typedef void* (*knot_mm_alloc_t)(void* ctx, size_t len); +typedef void (*knot_mm_free_t)(void* p); + +/*! \brief Memory allocation context. */ +typedef struct knot_mm { + void* ctx; /* \note Must be first */ + knot_mm_alloc_t alloc; + knot_mm_free_t free; +} knot_mm_t; + +/*! + * \brief Native API of QP-tries: + * + * - keys are uint8_t strings, not necessarily zero-terminated, + * the structure copies the contents of the passed keys + * - values are void* pointers, typically you get an ephemeral pointer to it + * - key lengths are limited by 2^32-1 ATM + */ + +/*! \brief Element value. */ +typedef void* trie_val_t; + +/*! \brief Opaque structure holding a QP-trie. */ +typedef struct trie trie_t; + +/*! \brief Opaque type for holding a QP-trie iterator. */ +typedef struct trie_it trie_it_t; + +/*! \brief Create a trie instance. Pass NULL to use malloc+free. */ +trie_t* trie_create(knot_mm_t* mm); + +/*! \brief Free a trie instance. */ +void trie_free(trie_t* tbl); + +/*! \brief Clear a trie instance (make it empty). */ +void trie_clear(trie_t* tbl); + +/*! \brief Return the number of keys in the trie. */ +size_t trie_weight(const trie_t* tbl); + +/*! \brief Search the trie, returning NULL on failure. */ +trie_val_t* trie_get_try(trie_t* tbl, const uint8_t* key, uint32_t len); + +/*! + * \brief Return pointer to the minimum. Optionally with key and its length. */ +trie_val_t* trie_get_first(trie_t* tbl, uint8_t** key, uint32_t* len); + +/*! \brief Search the trie, inserting NULL trie_val_t on failure. */ +trie_val_t* trie_get_ins(trie_t* tbl, const uint8_t* key, uint32_t len); + +/*! + * \brief Search for less-or-equal element. + * + * \param tbl Trie. + * \param key Searched key. + * \param len Key length. + * \param val Must be valid; it will be set to NULL if not found or errored. + * \return KNOT_EOK for exact match, 1 for previous, KNOT_ENOENT for not-found, + * or KNOT_E*. + */ +int trie_get_leq(trie_t* tbl, const uint8_t* key, uint32_t len, trie_val_t** val); + +/*! + * \brief Apply a function to every trie_val_t, in order. + * + * \param d Parameter passed as the second argument to f(). + * \return First nonzero from f() or zero (i.e. KNOT_EOK). + */ +int trie_apply(trie_t* tbl, int (*f)(trie_val_t*, void*), void* d); + +/*! \brief Create a new iterator pointing to the first element (if any). */ +trie_it_t* trie_it_begin(trie_t* tbl); + +/*! + * \brief Advance the iterator to the next element. + * + * Iteration is in ascending lexicographical order. + * In particular, the empty string would be considered as the very first. + * + * \note You may not use this function if the trie's key-set has been modified + * during the lifetime of the iterator (modifying values only is OK). + */ +void trie_it_next(trie_it_t* it); + +/*! \brief Test if the iterator has gone past the last element. */ +bool trie_it_finished(trie_it_t* it); + +/*! \brief Free any resources of the iterator. It's OK to call it on NULL. */ +void trie_it_free(trie_it_t* it); + +/*! + * \brief Return pointer to the key of the current element. + * + * \note The optional len is uint32_t internally but size_t is better for our usage, + * as it is without an additional type conversion. + */ +const uint8_t* trie_it_key(trie_it_t* it, size_t* len); + +/*! \brief Return pointer to the value of the current element (writable). */ +trie_val_t* trie_it_val(trie_it_t* it); -- cgit v1.2.3