/* Level-Compressed Tree Bitmap (LC-TBM) Trie implementation * * Contributed by Geoffrey T. Dairiki * * This file is released under a "Three-clause BSD License". * * Copyright (c) 2013, Geoffrey T. Dairiki * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * * Neither the name of Geoffrey T. Dairiki nor the names of other * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GEOFFREY * T. DAIRIKI BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH * DAMAGE. */ /***************************************************************** * * This code implements a routing table conceptually based on a binary * trie structure. Internally, the trie is represented by two types * of compound nodes: "multibit nodes", which contain the top few * levels of an entire binary subtree; and "level compression" (LC) * nodes which represent a (potentially long) chain of out-degree one * (single child) binary nodes (possibly ending at a terminal node). * * The multibit nodes are represented using a "Tree Bitmap" structure * (more on this below), which is very efficient --- both in terms of * memory usage and lookup speed --- at representing densely branching * parts of the trie. The LC nodes can efficiently represent long * non-branching chains of binary trie nodes. Using both node types * together results in efficient representation of both the sparse and * dense parts of a binary trie. * * Graphically, here's the rough idea: * * ........ * .LC o . * . / . LC nodes can * . o . <= represent long chains * . \ . of (non-branching) binary * . o . trie nodes * . / . * . o . * ......../..... * .TBM o . * . / \ . TBM nodes can represent * . o * . <= several levels of densely * . / \ . branching binary trie nodes * . o o . * ......./.....\....... * .TBM o .. o LC. * . / \ .. \ . * . o o .. o . * . / / \ .. \ . * . * o *.. o . * ...../....... / . * . o LC. . o . * . \ . .....\...... * . * . . o TBM. * ........ . / \ . * . o o . * . / \ \ . * .* * *. * ........... * * Terminology * ----------- * * node * Usually, in the comments below, "node" will be used to refer to * a compound node: either a multibit (TBM) node or an LC node. * * "internal node" or "prefix" * The terms "prefix" or "internal node" are used to refer to * a node in the binary trie which is internal to a multibit (TBM) * node. * * ---------------------------------------------------------------- * * Internal Representation of the Nodes * ==================================== * * Multibit (TBM) Nodes * ~~~~~~~~~~~~~~~~~~~~ * * The multibit nodes are represented using a "Tree Bitmap" (TBM) * structure as described by Eatherton, Dittia and Varghese[1]. See * the paper referenced below for basic details. * * A multibit node, represents several levels of a binary trie. * For example, here is a multibit node of stride 2 (which represent * two levels of a binary trie. * * +------- | ------+ * | multi o | * | bit / \ | * | node / \ | * | o * | * +--- / \ - / \ --+ * O * * Note that, for a multibit node of stride S, there are 2^S - 1 internal * nodes, each of which may have data (or not) associated with them, and * 2^S "external paths" leading to other (possibly compound nodes). * (In the diagram above, one of three internal node (the one denoted by "*") * has data, and one of four extending paths leads to an external node * (denoted by the 'O').) * * The TBM structure can represent these bitmaps in a very memory-efficient * manner. * * Each TBM node consists of two bitmaps --- the "internal bitmap" and the * "extending paths bitmap" --- and a pointer which points to an array * which contains both the extending path ("child") nodes and any * internal prefix data for the TBM node. * * +--------+--------+ * TBM | ext bm | int bm | * Node +--------+--------+ * | pointer |----+ * +-----------------+ | * | * | * +-----------------+ | * | extending path | | * | node[N-1] | | * +-----------------+ | * / ... / | * / ... / | * +-----------------+ | * | extending path | | * | node[0] | | * +-----------------+<---+ * | int. data[M-1] | * +-----------------+ * / ... / * +-----------------+ * | int. data[0] | * +-----------------+ * * The extending paths bitmap (or "ext bitmap") has one bit for each * possible "extending path" from the bottom of the multibit node. To * check if a particular extending path is present, one checks to see if * the corresponding bit is set in the ext bitmap. The index into the * array of children for that path can be found by counting the number * of set bits to the left of that bit. * * Similarly, the internal bitmap has one bit for each binary node * which is internal to the multibit node. To determine whether there * is data stored for an internal prefix, one checks the corresponding * bit in the internal bitmap. As for extending paths, the index into * the array of internal data is found by counting the number of set * bits to the left of that bit. * * To save space in the node structure, the node data array is stored * contiguously with the node extending path array. The single * ("children") pointer in the TBM structure points to the beginning * of the array of extending path nodes and to (one past) the end of * the the internal data array. * * The multibit stride is chosen so that the entire TBM node structure fits * in the space of two pointers. On 32 bit machines this means the stride * is four (each of the two bitmaps is 16 bits); on 32 bit machines the * stride is five. * * Note that there are only 2^stride - 1 internal prefixes in a TBM * node. That means there is one unused bit in the internal bitmap. * We require that that bit must always be clear for a TBM node. (If * set, it indicates that the structure represents, instead, an LC * node. See below.) * * ---------------------------------------------------------------- * * Level Compression (LC) Nodes * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * * LC nodes are used to represent a chain of out-degree-one (single * child) prefixes in the binary trie. The are represented by a bit * string (the "relative prefix") along with its length and a pointer * to the extending path (the next node past the LC node.) * * * Non-Terminal LC Node: * * +------------------+-------+ * | relative prefix |1|0|len| * +------------------+-------+ * | ptr.child |--+ * +--------------------------+ | * | * | * +--------------------------+ | * | Next node - | | * | either LC or TBM | | * | | | * +--------------------------+<-+ * * The Relative Prefix * ------------------- * * The maximum relative prefix per LC node is selected so that (again) * the entire node structure fits in the space of two pointers. On 32 bit * machines, the maximum relative prefix is 24 bits; on 62 bit machines * the limit is 56 bits. * * In the LC node structure, the relative prefix is stored as an array * of bytes. To avoid some bit-shifting during tree searches, these * bytes are byte-aligned with the global prefix. In other words, in * general there are (pos % 8) "pad" bits at the beginning of the * relative prefix --- where pos "starting bit" (or depth in the * binary tree) of the LC node --- which really belong to the parent * node(s) of the LC node. For efficiency (so that we don't have to * mask them out when matching) we require that these pad bits be * correct --- they must match the path which leads to the LC node. * * The relative prefix length stored in the LC node structure does not * count the pad bits. * * Terminal Node Compression * ------------------------- * * For memory efficiency, we also support "terminal LC" nodes. When * the extension path from an LC node consists a single terminal node, * we store that terminal nodes data directly in the parent LC node. * * Instead of this: * * +------------------+-------+ * | relative prefix |1|0|len| * +------------------+-------+ * | ptr.child |--+ * +--------------------------+ | * | * +--------------------------+ | * | Terminal Node (TBM node, | | * | empty except for the | | * +--| root internal node.) | | * | +--------------------------+<-+ * | * +->+--------------------------+ * | terminal node data | * +--------------------------+ * * We can do this: * * +------------------+-------+ * | relative prefix |1|1|len| * +------------------+-------+ * | terminal node data | * +--------------------------+ * * Terminal LC nodes are differentiated from non-terminal LC nodes * by the setting of the is_terminal flag. * * Node Structure Packing Details * ------------------------------ * * The LC and TBM node structures are carefully packed so that the * "is_lc" flag (which indicates that a node is an LC node) * corresponds to the one unused bit in the internal bitmap of the TBM * node structure (which we require to be zero for TBM nodes). * * ---------------------------------------------------------------- * * References * ========== * * [1] Will Eatherton, George Varghese, and Zubin Dittia. 2004. Tree * bitmap: hardware/software IP lookups with incremental * updates. SIGCOMM Comput. Commun. Rev. 34, 2 (April 2004), * 97-122. DOI=10.1145/997150.997160 * http://doi.acm.org/10.1145/997150.997160 * http://comnet.kaist.ac.kr/yhlee/CN_2008_Spring/readings/Eath-04-tree_bitmap.pdf * ****************************************************************/ #include #include #include #include #if defined(TEST) && defined(NDEBUG) # warning undefining NDEBUG for TEST build # undef NDEBUG #endif #include #include "btrie.h" #include "libutil/mem_pool.h" #ifdef __SIZEOF_POINTER__ #define SIZEOF_VOID_P __SIZEOF_POINTER__ #else #if defined(__ILP32__) || defined(__ILP32) || defined(_ILP32) # define SIZEOF_VOID_P 4 #elif defined(__ILP64__) || defined(__ILP64) || defined(_ILP64) # define SIZEOF_VOID_P 8 #elif defined(__LLP64__) || defined(__LLP64) || defined(_LLP64) || defined(_WIN64) # define SIZEOF_VOID_P 8 #elif defined(__LP64__) || defined(__LP64) || defined(_LP64) # define SIZEOF_VOID_P 8 #elif defined(UINTPTR_MAX) && defined(UINT64_MAX) && (UINTPTR_MAX == UINT64_MAX) # define SIZEOF_VOID_P 8 #else # define SIZEOF_VOID_P 4 #endif #endif #if SIZEOF_VOID_P == 4 # define TBM_STRIDE 4 #elif SIZEOF_VOID_P == 8 # define TBM_STRIDE 5 #else # error "Unsupported word size" #endif #ifndef NO_STDINT_H # if TBM_STRIDE == 4 typedef uint16_t tbm_bitmap_t; # else typedef uint32_t tbm_bitmap_t; # endif #else /* NO_STDINT_H */ # if TBM_STRIDE == 4 # if SIZEOF_SHORT == 2 typedef short unsigned tbm_bitmap_t; # else # error "can not determine type for 16 bit unsigned int" # endif # else /* TBM_STRIDE == 5 */ # if SIZEOF_INT == 4 typedef unsigned tbm_bitmap_t; # elif SIZEOF_LONG == 4 typedef long unsigned tbm_bitmap_t; # else # error "can not determine type for 32 bit unsigned int" # endif # endif #endif #define TBM_FANOUT (1U << TBM_STRIDE) #define LC_BYTES_PER_NODE (SIZEOF_VOID_P - 1) typedef union node_u node_t; /* The tbm_node and lc_node structs must be packed so that the the * high bit (LC_FLAGS_IS_LC) of lc_flags in the the lc_node struct * coincides with bit zero (the most significant bit) of tbm_node's * int_bm. (This bit is how we differentiate between the two node * types. It is always clear for a tbm_node and always set for an * lc_node.) */ struct tbm_node { #ifdef WORDS_BIGENDIAN tbm_bitmap_t int_bm; /* the internal bitmap */ tbm_bitmap_t ext_bm; /* extending path ("external") bitmap */ #else tbm_bitmap_t ext_bm; /* extending path ("external") bitmap */ tbm_bitmap_t int_bm; /* the internal bitmap */ #endif union { node_t *children; /* pointer to array of children */ const void **data_end; /* one past end of internal prefix data array */ } ptr; }; struct lc_node { /* lc_flags contains the LC prefix length and a couple of bit flags * (apparently char-sized bit fields are a gcc extension) */ # define LC_FLAGS_IS_LC 0x80 # define LC_FLAGS_IS_TERMINAL 0x40 # define LC_FLAGS_LEN_MASK 0x3f #ifdef WORDS_BIGENDIAN btrie_oct_t lc_flags; btrie_oct_t prefix[LC_BYTES_PER_NODE]; #else btrie_oct_t prefix[LC_BYTES_PER_NODE]; btrie_oct_t lc_flags; #endif union { node_t *child; /* pointer to child (if !is_terminal) */ const void *data; /* the prefix data (if is_terminal) */ } ptr; }; union node_u { struct tbm_node tbm_node; struct lc_node lc_node; }; struct free_hunk { struct free_hunk *next; }; #define MAX_CHILD_ARRAY_LEN (TBM_FANOUT + TBM_FANOUT / 2) struct btrie { node_t root; rspamd_mempool_t *mp; struct free_hunk *free_list[MAX_CHILD_ARRAY_LEN]; jmp_buf exception; /* mem mgmt stats */ size_t alloc_total; /* total bytes allocated from mempool */ size_t alloc_data; /* bytes allocated for TBM node int. prefix data */ size_t alloc_waste; /* bytes wasted by rounding of data array size */ #ifdef BTRIE_DEBUG_ALLOC size_t alloc_hist[MAX_CHILD_ARRAY_LEN * 2]; /* histogram of alloc sizes */ #endif /* trie stats */ size_t n_entries; /* number of entries */ size_t n_tbm_nodes; /* total number of TBM nodes in tree */ size_t n_lc_nodes; /* total number of LC nodes in tree */ }; /**************************************************************** * * Memory management * * We will need to frequently resize child/data arrays. The current * mempool implementation does not support resizing/freeing, so here * we roll our own. */ static inline void _free_hunk(struct btrie *btrie, void *buf, unsigned n_nodes) { struct free_hunk *hunk = buf; hunk->next = btrie->free_list[n_nodes - 1]; btrie->free_list[n_nodes - 1] = hunk; } static inline void * _get_hunk(struct btrie *btrie, unsigned n_nodes) { struct free_hunk *hunk = btrie->free_list[n_nodes - 1]; if (hunk != NULL) btrie->free_list[n_nodes - 1] = hunk->next; return hunk; } /* Get pointer to uninitialized child/data array. * * Allocates memory for an array of NDATA (void *)s followed by an * array of NCHILDREN (node_t)s. The returned pointer points to to * beginning of the children array (i.e. it points to (one past) the * end of the data array.) */ static node_t * alloc_nodes(struct btrie *btrie, unsigned nchildren, unsigned ndata) { size_t n_nodes = nchildren + (ndata + 1) / 2; node_t *hunk; assert(n_nodes > 0 && n_nodes <= MAX_CHILD_ARRAY_LEN); hunk = _get_hunk (btrie, n_nodes); if (hunk == NULL) { /* Do not have free hunk of exactly the requested size, look for a * larger hunk. (The funny order in which we scan the buckets is * heuristically selected in an attempt to minimize unnecessary * creation of small fragments) */ size_t n, skip = n_nodes > 4 ? 4 : n_nodes; for (n = n_nodes + skip; n <= MAX_CHILD_ARRAY_LEN; n++) { if ((hunk = _get_hunk (btrie, n)) != NULL) { _free_hunk (btrie, hunk + n_nodes, n - n_nodes); goto DONE; } } for (n = n_nodes + 1; n < n_nodes + skip && n <= MAX_CHILD_ARRAY_LEN; n++) { if ((hunk = _get_hunk (btrie, n)) != NULL) { _free_hunk (btrie, hunk + n_nodes, n - n_nodes); goto DONE; } } /* failed to find free hunk, allocate a fresh one */ hunk = rspamd_mempool_alloc0 (btrie->mp, n_nodes * sizeof(node_t)); if (hunk == NULL) longjmp (btrie->exception, BTRIE_ALLOC_FAILED); btrie->alloc_total += n_nodes * sizeof(node_t); } DONE: btrie->alloc_data += ndata * sizeof(void *); btrie->alloc_waste += (ndata % 2) * sizeof(void *); #ifdef BTRIE_DEBUG_ALLOC btrie->alloc_hist[2 * nchildren + ndata]++; #endif /* adjust pointer to allow room for data array before child array */ return hunk + (ndata + 1) / 2; } /* Free memory allocated by alloc_nodes */ static void free_nodes(struct btrie *btrie, node_t *buf, unsigned nchildren, unsigned ndata) { size_t n_nodes = nchildren + (ndata + 1) / 2; assert(n_nodes > 0 && n_nodes <= MAX_CHILD_ARRAY_LEN); _free_hunk (btrie, buf - (ndata + 1) / 2, n_nodes); btrie->alloc_data -= ndata * sizeof(void *); btrie->alloc_waste -= (ndata % 2) * sizeof(void *); #ifdef BTRIE_DEBUG_ALLOC btrie->alloc_hist[2 * nchildren + ndata]--; #endif } /* Debugging/development only: */ #ifdef BTRIE_DEBUG_ALLOC static void dump_alloc_hist(const struct btrie *btrie) { unsigned bin; size_t total_alloc = 0; size_t total_free = 0; size_t total_bytes = 0; size_t total_waste = 0; size_t total_free_bytes = 0; puts("hunk alloc free alloc wasted free"); puts("size hunks hunks bytes bytes bytes"); puts("==== ====== ====== ======== ======== ========"); for (bin = 1; bin < 2 * MAX_CHILD_ARRAY_LEN; bin++) { size_t n_alloc = btrie->alloc_hist[bin]; size_t bytes = n_alloc * bin * sizeof(void *); size_t waste_bytes = (bin % 2) * n_alloc * sizeof(void *); size_t n_free = 0, free_bytes; if (bin % 2 == 0) { const struct free_hunk *hunk; for (hunk = btrie->free_list[bin / 2 - 1]; hunk; hunk = hunk->next) n_free++; } free_bytes = n_free * bin * sizeof(void *); printf("%3zu: %6zu %6zu %8zu %8zu %8zu\n", bin * sizeof(void *), n_alloc, n_free, bytes, waste_bytes, free_bytes); total_alloc += n_alloc; total_free += n_free; total_bytes += bytes; total_waste += waste_bytes; total_free_bytes += free_bytes; } puts("---- ------ ------ -------- -------- --------"); printf("SUM: %6zu %6zu %8zu %8zu %8zu\n", total_alloc, total_free, total_bytes, total_waste, total_free_bytes); } #endif /**************************************************************** * * Bit twiddling * */ static inline tbm_bitmap_t bit(unsigned b) { return 1U << ((1 << TBM_STRIDE) - 1 - b); } /* count the number of set bits in bitmap * * algorithm from * http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel */ static inline unsigned count_bits(tbm_bitmap_t v) { /* Count set bits in parallel. */ /* v = (v & 0x5555...) + ((v >> 1) & 0x5555...); */ v -= (v >> 1) & (tbm_bitmap_t) ~0UL / 3; /* v = (v & 0x3333...) + ((v >> 2) & 0x3333...); */ v = (v & (tbm_bitmap_t) ~0UL / 5) + ((v >> 2) & (tbm_bitmap_t) ~0UL / 5); /* v = (v & 0x0f0f...) + ((v >> 4) & 0x0f0f...); */ v = (v + (v >> 4)) & (tbm_bitmap_t) ~0UL / 17; /* v = v % 255; */ #if TBM_STRIDE == 4 /* tbm_bitmap_t is uint16_t, avoid the multiply */ return (v + (v >> 8)) & 0x0ff; #else return (v * (tbm_bitmap_t) (~0UL / 255)) >> ((sizeof(tbm_bitmap_t) - 1) * 8); #endif } static inline unsigned count_bits_before(tbm_bitmap_t bm, int b) { return b ? count_bits (bm >> ((1 << TBM_STRIDE) - b)) : 0; } static inline unsigned count_bits_from(tbm_bitmap_t bm, int b) { return count_bits (bm << b); } /* extracts a few bits from bitstring, returning them as an integer */ static inline btrie_oct_t RSPAMD_NO_SANITIZE extract_bits(const btrie_oct_t *prefix, unsigned pos, unsigned nbits) { if (nbits == 0) return 0; else { unsigned v = (prefix[pos / 8] << 8) + prefix[pos / 8 + 1]; return (v >> (16 - nbits - pos % 8)) & ((1U << nbits) - 1); } } static inline unsigned extract_bit(const btrie_oct_t *prefix, int pos) { return (prefix[pos / 8] >> (7 - pos % 8)) & 0x01; } /* get mask for high n bits of a byte */ static inline btrie_oct_t high_bits(unsigned n) { return (btrie_oct_t) -(1U << (8 - n)); } /* determine whether two prefixes are equal */ static inline int prefixes_equal(const btrie_oct_t *pfx1, const btrie_oct_t *pfx2, unsigned len) { return (memcmp (pfx1, pfx2, len / 8) == 0 && (len % 8 == 0 || ((pfx1[len / 8] ^ pfx2[len / 8]) & high_bits (len % 8)) == 0)); } /* determine length of longest common subprefix */ static inline unsigned common_prefix(const btrie_oct_t *pfx1, const btrie_oct_t *pfx2, unsigned len) { /* algorithm adapted from * http://graphics.stanford.edu/~seander/bithacks.html#IntegerLogLookup */ static btrie_oct_t leading_zeros[] = { 8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }; unsigned nb; for (nb = 0; nb < len / 8; nb++) { unsigned diff = *pfx1++ ^ *pfx2++; if (diff != 0) return 8 * nb + leading_zeros[diff]; } if (len % 8) { unsigned n = leading_zeros[*pfx1 ^ *pfx2]; if (n < len % 8) return 8 * nb + n; } return len; } /**************************************************************** */ static inline int is_empty_node(const node_t *node) { return node->tbm_node.ext_bm == 0 && node->tbm_node.int_bm == 0; } static inline int is_lc_node(const node_t *node) { return (node->lc_node.lc_flags & LC_FLAGS_IS_LC) != 0; } static inline int is_tbm_node(const node_t *node) { return !is_lc_node (node); } /* is node a TBM node with internal data? */ static inline int has_data(const node_t *node) { return is_tbm_node (node) && node->tbm_node.int_bm != 0; } static inline unsigned base_index(unsigned pfx, unsigned plen) { assert(plen < TBM_STRIDE); assert(pfx < (1U << plen)); return pfx | (1U << plen); } /* initialize node to an empty TBM node */ static inline void init_empty_node(struct btrie *btrie, node_t *node) { memset(node, 0, sizeof(*node)); btrie->n_tbm_nodes++; } /* get pointer to TBM internal prefix data */ static inline const void ** tbm_data_p(const struct tbm_node *node, unsigned pfx, unsigned plen) { unsigned bi = base_index (pfx, plen); if ((node->int_bm & bit (bi)) == 0) return NULL; /* no data */ else { return &node->ptr.data_end[-(int) count_bits_from (node->int_bm, bi)]; } } /* add an element to the internal data array */ static void tbm_insert_data(struct btrie *btrie, struct tbm_node *node, unsigned pfx, unsigned plen, const void *data) { /* XXX: don't realloc if already big enough? */ unsigned bi = base_index (pfx, plen); unsigned nchildren = count_bits (node->ext_bm); int ndata = count_bits (node->int_bm); unsigned di = count_bits_before (node->int_bm, bi); node_t *old_children = node->ptr.children; const void **old_data_beg = node->ptr.data_end - ndata; const void **data_beg; assert((node->int_bm & bit (bi)) == 0); node->ptr.children = alloc_nodes (btrie, nchildren, ndata + 1); data_beg = node->ptr.data_end - (ndata + 1); data_beg[di] = data; node->int_bm |= bit (bi); if (nchildren != 0 || ndata != 0) { memcpy(data_beg, old_data_beg, di * sizeof(data_beg[0])); memcpy(&data_beg[di + 1], &old_data_beg[di], (ndata - di) * sizeof(data_beg[0]) + nchildren * sizeof(node_t)); free_nodes (btrie, old_children, nchildren, ndata); } } /* determine whether TBM has internal prefix data for pfx/plen or ancestors */ static inline int has_internal_data(const struct tbm_node *node, unsigned pfx, unsigned plen) { # define BIT(n) (1U << ((1 << TBM_STRIDE) - 1 - (n))) # define B0() BIT(1) /* the bit for 0/0 */ # define B1(n) (BIT((n) + 2) | B0()) /* the bits for n/1 and its ancestors */ # define B2(n) (BIT((n) + 4) | B1(n >> 1)) /* the bits for n/2 and ancestors */ # define B3(n) (BIT((n) + 8) | B2(n >> 1)) /* the bits for n/3 and ancestors */ # define B4(n) (BIT((n) + 16) | B3(n >> 1)) /* the bits for n/4 and ancestors */ static tbm_bitmap_t ancestors[] = { 0, B0(), B1(0), B1(1), B2(0), B2(1), B2(2), B2(3), B3(0), B3(1), B3(2), B3(3), B3(4), B3(5), B3(6), B3(7), # if TBM_STRIDE == 5 B4(0), B4(1), B4(2), B4(3), B4(4), B4(5), B4(6), B4(7), B4(8), B4( 9), B4(10), B4(11), B4(12), B4(13), B4(14), B4(15), # elif TBM_STRIDE != 4 # error "unsupported TBM_STRIDE" # endif }; # undef B4 # undef B3 # undef B2 # undef B1 # undef B0 # undef BIT return (node->int_bm & ancestors[base_index (pfx, plen)]) != 0; } /* get pointer to TBM extending path */ static inline node_t * tbm_ext_path(const struct tbm_node *node, unsigned pfx) { if ((node->ext_bm & bit (pfx)) == 0) return NULL; else return &node->ptr.children[count_bits_before (node->ext_bm, pfx)]; } /* resize TBM node child array to make space for new child node */ static node_t * tbm_insert_ext_path(struct btrie *btrie, struct tbm_node *node, unsigned pfx) { unsigned nchildren = count_bits (node->ext_bm); unsigned ci = count_bits_before (node->ext_bm, pfx); int ndata = count_bits (node->int_bm); node_t *old_children = node->ptr.children; const void **old_data_beg = node->ptr.data_end - ndata; assert((node->ext_bm & bit (pfx)) == 0); node->ptr.children = alloc_nodes (btrie, nchildren + 1, ndata); init_empty_node (btrie, &node->ptr.children[ci]); node->ext_bm |= bit (pfx); if (nchildren != 0 || ndata != 0) { const void **data_beg = node->ptr.data_end - ndata; memcpy(data_beg, old_data_beg, ndata * sizeof(data_beg[0]) + ci * sizeof(node_t)); memcpy(&node->ptr.children[ci + 1], &old_children[ci], (nchildren - ci) * sizeof(old_children[0])); free_nodes (btrie, old_children, nchildren, ndata); } return &node->ptr.children[ci]; } static inline int lc_is_terminal(const struct lc_node *node) { return (node->lc_flags & LC_FLAGS_IS_TERMINAL) != 0; } static inline unsigned lc_len(const struct lc_node *node) { return node->lc_flags & LC_FLAGS_LEN_MASK; } static inline void lc_init_flags(struct lc_node *node, int is_terminal, unsigned len) { assert((len & ~LC_FLAGS_LEN_MASK) == 0); node->lc_flags = LC_FLAGS_IS_LC | len; if (is_terminal) node->lc_flags |= LC_FLAGS_IS_TERMINAL; } static inline void lc_add_to_len(struct lc_node *node, int increment) { unsigned new_len = lc_len (node) + increment; assert((new_len & ~LC_FLAGS_LEN_MASK) == 0); node->lc_flags = (node->lc_flags & ~LC_FLAGS_LEN_MASK) | new_len; } static inline unsigned lc_shift(unsigned pos) { return pos / 8; } static inline unsigned lc_base(unsigned pos) { return 8 * lc_shift (pos); } static inline unsigned lc_bits(const struct lc_node *node, unsigned pos) { return pos % 8 + lc_len (node); } static inline unsigned lc_bytes(const struct lc_node *node, unsigned pos) { return (lc_bits (node, pos) + 7) / 8; } static inline unsigned lc_leading_bits(const struct lc_node *node, unsigned pos, unsigned nbits) { return extract_bits (node->prefix, pos % 8, nbits); } /* Initialize a new terminal LC node * * If prefix is too long to fit in a single LC node, then a chain * of LC nodes will be created. */ static void init_terminal_node(struct btrie *btrie, node_t *dst, unsigned pos, const btrie_oct_t *prefix, unsigned len, const void *data) { struct lc_node *node = &dst->lc_node; unsigned nbytes = (len + 7) / 8; while (nbytes - lc_shift (pos) > LC_BYTES_PER_NODE) { memcpy(node->prefix, prefix + lc_shift (pos), LC_BYTES_PER_NODE); lc_init_flags (node, 0, 8 * LC_BYTES_PER_NODE - pos % 8); node->ptr.child = alloc_nodes (btrie, 1, 0); pos += lc_len (node); node = &node->ptr.child->lc_node; btrie->n_lc_nodes++; } memcpy(node->prefix, prefix + lc_shift (pos), nbytes - lc_shift (pos)); lc_init_flags (node, 1, len - pos); node->ptr.data = data; btrie->n_lc_nodes++; } /* merge chains of multiple LC nodes into a single LC node, if possible. * * also ensure that the leading nodes in the LC chain have maximum length. */ static void coalesce_lc_node(struct btrie *btrie, struct lc_node *node, unsigned pos) { while (!lc_is_terminal (node) && lc_bits (node, pos) < 8 * LC_BYTES_PER_NODE && is_lc_node (node->ptr.child)) { struct lc_node *child = &node->ptr.child->lc_node; unsigned spare_bits = 8 * LC_BYTES_PER_NODE - lc_bits (node, pos); unsigned end = pos + lc_len (node); unsigned shift = lc_shift (end) - lc_shift (pos); if (lc_len (child) <= spare_bits) { /* node plus child will fit in single node - merge */ memcpy(node->prefix + shift, child->prefix, lc_bytes (child, end)); lc_init_flags (node, lc_is_terminal (child), lc_len (node) + lc_len (child)); node->ptr = child->ptr; free_nodes (btrie, (node_t *) child, 1, 0); btrie->n_lc_nodes--; } else { /* can't merge, but can take some of children bits */ unsigned cshift = lc_shift (end + spare_bits) - lc_shift (end); memcpy(node->prefix + shift, child->prefix, LC_BYTES_PER_NODE - shift); lc_add_to_len (node, spare_bits); if (cshift) memmove(child->prefix, child->prefix + cshift, lc_bytes (child, end) - cshift); assert(lc_len (child) > spare_bits); lc_add_to_len (child, -spare_bits); pos += lc_len (node); node = child; } } } static void init_tbm_node(struct btrie *btrie, node_t *node, unsigned pos, const btrie_oct_t pbyte, const void **root_data_p, node_t *left, node_t *right); /* given an LC node at orig_pos, create a new (shorter) node at pos */ static void shorten_lc_node(struct btrie *btrie, node_t *dst, unsigned pos, struct lc_node *src, unsigned orig_pos) { assert(orig_pos < pos); assert(lc_len (src) >= pos - orig_pos); assert(dst != (node_t * )src); if (lc_len (src) == pos - orig_pos && !lc_is_terminal (src)) { /* just steal the child */ node_t *child = src->ptr.child; *dst = *child; free_nodes (btrie, child, 1, 0); btrie->n_lc_nodes--; } else { struct lc_node *node = &dst->lc_node; unsigned shift = lc_shift (pos) - lc_shift (orig_pos); if (shift) { memmove(node->prefix, src->prefix + shift, lc_bytes (src, orig_pos) - shift); node->lc_flags = src->lc_flags; node->ptr = src->ptr; } else { *node = *src; } lc_add_to_len (node, -(pos - orig_pos)); coalesce_lc_node (btrie, node, pos); } } /* convert LC node to non-terminal LC node of length len *in place* * * on entry, node must have length at least len */ static void split_lc_node(struct btrie *btrie, struct lc_node *node, unsigned pos, unsigned len) { node_t *child = alloc_nodes (btrie, 1, 0); assert(lc_len (node) >= len); shorten_lc_node (btrie, child, pos + len, node, pos); lc_init_flags (node, 0, len); node->ptr.child = child; btrie->n_lc_nodes++; } /* convert non-terminal LC node of length one to a TBM node *in place* */ static void convert_lc_node_1(struct btrie *btrie, struct lc_node *node, unsigned pos) { btrie_oct_t pbyte = node->prefix[0]; node_t *child = node->ptr.child; node_t *left, *right; assert(lc_len (node) == 1); assert(!lc_is_terminal (node)); if (extract_bit (node->prefix, pos % 8)) left = NULL, right = child; else left = child, right = NULL; init_tbm_node (btrie, (node_t *) node, pos, pbyte, NULL, left, right); free_nodes (btrie, child, 1, 0); btrie->n_lc_nodes--; } /* convert an LC node to TBM node *in place* */ static void convert_lc_node(struct btrie *btrie, struct lc_node *node, unsigned pos) { unsigned len = lc_len (node); if (len >= TBM_STRIDE) { unsigned pfx = lc_leading_bits (node, pos, TBM_STRIDE); struct tbm_node *result = (struct tbm_node *) node; /* split to LC of len TBM_STRIDE followed by child (extending path) */ split_lc_node (btrie, node, pos, TBM_STRIDE); /* then convert leading LC node to TBM node */ result->int_bm = 0; result->ext_bm = bit (pfx); btrie->n_lc_nodes--; btrie->n_tbm_nodes++; } else if (lc_is_terminal (node)) { /* convert short terminal LC to TBM (with internal data) */ unsigned pfx = lc_leading_bits (node, pos, len); const void *data = node->ptr.data; node_t *result = (node_t *) node; init_empty_node (btrie, result); tbm_insert_data (btrie, &result->tbm_node, pfx, len, data); btrie->n_lc_nodes--; } else { assert(len > 0); for (; len > 1; len--) { split_lc_node (btrie, node, pos, len - 1); convert_lc_node_1 (btrie, &node->ptr.child->lc_node, pos + len - 1); } convert_lc_node_1 (btrie, node, pos); } } static void insert_lc_node(struct btrie *btrie, node_t *dst, unsigned pos, btrie_oct_t pbyte, unsigned last_bit, node_t *tail) { struct lc_node *node = &dst->lc_node; btrie_oct_t mask = 1 << (7 - (pos % 8)); btrie_oct_t bit = last_bit ? mask : 0; if (mask != 0x01 && is_lc_node (tail)) { /* optimization: LC tail has room for the extra bit (without shifting) */ assert((tail->lc_node.prefix[0] & mask) == bit); *node = tail->lc_node; lc_add_to_len (node, 1); return; } /* add new leading LC node of len 1 */ node->prefix[0] = pbyte | bit; lc_init_flags (node, 0, 1); node->ptr.child = alloc_nodes (btrie, 1, 0); node->ptr.child[0] = *tail; btrie->n_lc_nodes++; if (is_lc_node (tail)) coalesce_lc_node (btrie, node, pos); } /* given: * pbyte: the bits in the prefix between lc_base(pos) and pos * pfx: the next TBM_STRIDE bits in the prefix starting at pos * returns: * the bits in the prefix between lc_base(pos + plen) and pos + plen */ static inline btrie_oct_t next_pbyte(btrie_oct_t pbyte, unsigned pos, unsigned pfx) { unsigned end = pos + TBM_STRIDE; if (end % 8 != 0) { btrie_oct_t nbyte = (btrie_oct_t) pfx << (8 - end % 8); if (end % 8 > TBM_STRIDE) nbyte |= pbyte & high_bits (pos % 8); return nbyte; } return 0; } /* construct a new TBM node, given the data and children of the * root prefix of the new node. */ static void init_tbm_node(struct btrie *btrie, node_t *dst, unsigned pos, const btrie_oct_t pbyte, const void **root_data_p, node_t *left, node_t *right) { struct tbm_node *node = &dst->tbm_node; unsigned nchildren = 0; unsigned ndata = 0; node_t children[TBM_FANOUT]; const void *data[TBM_FANOUT - 1]; tbm_bitmap_t ext_bm = 0; tbm_bitmap_t int_bm = 0; unsigned i, d, pfx_base; if (left && is_lc_node (left) && lc_len (&left->lc_node) < TBM_STRIDE) convert_lc_node (btrie, &left->lc_node, pos + 1); if (right && is_lc_node (right) && lc_len (&right->lc_node) < TBM_STRIDE) convert_lc_node (btrie, &right->lc_node, pos + 1); /* set internal data for root prefix */ if (root_data_p) { data[ndata++] = *root_data_p; int_bm |= bit (base_index (0, 0)); } /* copy internal data from children */ for (d = 0; d < TBM_STRIDE - 1; d++) { if (left && has_data (left)) { for (i = 0; i < 1U << d; i++) { const void **data_p = tbm_data_p (&left->tbm_node, i, d); if (data_p) { data[ndata++] = *data_p; int_bm |= bit (base_index (i, d + 1)); } } } if (right && has_data (right)) { for (i = 0; i < 1U << d; i++) { const void **data_p = tbm_data_p (&right->tbm_node, i, d); if (data_p) { data[ndata++] = *data_p; int_bm |= bit (base_index (i + (1 << d), d + 1)); } } } } /* copy extending paths */ for (pfx_base = 0; pfx_base < TBM_FANOUT; pfx_base += TBM_FANOUT / 2) { node_t *child = pfx_base ? right : left; if (child == NULL) { continue; } else if (is_lc_node (child)) { unsigned pfx = pfx_base + lc_leading_bits (&child->lc_node, pos + 1, TBM_STRIDE - 1); /* child is LC node, just shorten it by TBM_STRIDE - 1 */ shorten_lc_node (btrie, &children[nchildren++], pos + TBM_STRIDE, &child->lc_node, pos + 1); ext_bm |= bit (pfx); } else if (!is_empty_node (child)) { /* convert deepest internal prefixes of child to extending paths * of the new node */ for (i = 0; i < TBM_FANOUT / 2; i++) { const void **data_p = tbm_data_p (&child->tbm_node, i, TBM_STRIDE - 1); node_t *left_ext = tbm_ext_path (&child->tbm_node, 2 * i); node_t *right_ext = tbm_ext_path (&child->tbm_node, 2 * i + 1); if (data_p || left_ext || right_ext) { node_t *ext_path = &children[nchildren++]; unsigned pfx = pfx_base + i; btrie_oct_t npbyte = next_pbyte (pbyte, pos, pfx); ext_bm |= bit (pfx); if (left_ext == NULL && right_ext == NULL) { /* only have data - set ext_path to zero-length terminal LC node */ lc_init_flags (&ext_path->lc_node, 1, 0); ext_path->lc_node.prefix[0] = npbyte; ext_path->lc_node.ptr.data = *data_p; btrie->n_lc_nodes++; } else if (data_p || (left_ext && right_ext)) { /* have at least two of data, left_ext, right_ext * ext_path must be a full TBM node */ init_tbm_node (btrie, ext_path, pos + TBM_STRIDE, npbyte, data_p, left_ext, right_ext); } else if (left_ext) { /* have only left_ext, insert length-one LC node */ insert_lc_node (btrie, ext_path, pos + TBM_STRIDE, npbyte, 0, left_ext); } else { /* have only right_ext, insert length-one LC node */ insert_lc_node (btrie, ext_path, pos + TBM_STRIDE, npbyte, 1, right_ext); } } } btrie->n_tbm_nodes--; free_nodes (btrie, child->tbm_node.ptr.children, count_bits (child->tbm_node.ext_bm), count_bits (child->tbm_node.int_bm)); } } assert(count_bits (int_bm) == ndata); assert(count_bits (ext_bm) == nchildren); node->ptr.children = alloc_nodes (btrie, nchildren, ndata); memcpy(node->ptr.data_end - (int )ndata, data, ndata * sizeof(data[0])); memcpy(node->ptr.children, children, nchildren * sizeof(children[0])); node->ext_bm = ext_bm; node->int_bm = int_bm; btrie->n_tbm_nodes++; } static enum btrie_result add_to_trie(struct btrie *btrie, node_t *node, unsigned pos, const btrie_oct_t *prefix, unsigned len, const void *data) { for (;;) { if (is_lc_node (node)) { struct lc_node *lc_node = &node->lc_node; unsigned end = pos + lc_len (lc_node); unsigned cbits = common_prefix (prefix + lc_shift (pos), lc_node->prefix, (len < end ? len : end) - lc_base (pos)); unsigned clen = lc_base (pos) + cbits; /* position of first mismatch */ if (clen == end && !lc_is_terminal (lc_node)) { /* matched entire prefix of LC node, proceed to child */ assert(lc_len (lc_node) > 0); node = lc_node->ptr.child; pos = end; } else if (clen == end && len == end && lc_is_terminal (lc_node)) { /* exact match for terminal node - already have data for prefix */ return BTRIE_DUPLICATE_PREFIX; } else { assert(clen < end || (lc_is_terminal (lc_node) && len > end)); /* Need to insert new TBM node at clen */ if (clen > pos) { split_lc_node (btrie, lc_node, pos, clen - pos); node = lc_node->ptr.child; assert(is_lc_node (node)); pos = clen; } convert_lc_node (btrie, &node->lc_node, pos); } } else if (is_empty_node (node)) { /* at empty TBM node - just replace with terminal LC node */ init_terminal_node (btrie, node, pos, prefix, len, data); btrie->n_entries++; btrie->n_tbm_nodes--; return BTRIE_OKAY; } else { struct tbm_node *tbm_node = &node->tbm_node; unsigned end = pos + TBM_STRIDE; if (len < end) { unsigned plen = len - pos; unsigned pfx = extract_bits (prefix, pos, plen); if (tbm_data_p (tbm_node, pfx, plen) != NULL) return BTRIE_DUPLICATE_PREFIX; /* prefix already has data */ else { tbm_insert_data (btrie, tbm_node, pfx, plen, data); btrie->n_entries++; return BTRIE_OKAY; } } else { unsigned pfx = extract_bits (prefix, pos, TBM_STRIDE); /* follow extending path */ node = tbm_ext_path (tbm_node, pfx); if (node == NULL) node = tbm_insert_ext_path (btrie, tbm_node, pfx); pos = end; } } } } static const void * search_trie(const node_t *node, unsigned pos, const btrie_oct_t *prefix, unsigned len) { /* remember last TBM node seen with internal data */ const struct tbm_node *int_node = 0; unsigned int_pfx = 0, int_plen = 0; while (node) { if (is_lc_node (node)) { const struct lc_node *lc_node = &node->lc_node; unsigned end = pos + lc_len (lc_node); if (len < end) break; if (!prefixes_equal (prefix + lc_shift (pos), lc_node->prefix, end - lc_base (pos))) break; if (lc_is_terminal (lc_node)) return lc_node->ptr.data; /* found terminal node */ pos = end; node = lc_node->ptr.child; } else { const struct tbm_node *tbm_node = &node->tbm_node; unsigned end = pos + TBM_STRIDE; if (len < end) { unsigned plen = len - pos; unsigned pfx = extract_bits (prefix, pos, plen); if (has_internal_data (tbm_node, pfx, plen)) { int_node = tbm_node; int_pfx = pfx; int_plen = plen; } break; } else { unsigned pfx = extract_bits (prefix, pos, TBM_STRIDE); if (has_internal_data (tbm_node, pfx >> 1, TBM_STRIDE - 1)) { int_node = tbm_node; int_pfx = pfx >> 1; int_plen = TBM_STRIDE - 1; } pos = end; node = tbm_ext_path (tbm_node, pfx); } } } if (int_node) { const void **data_p = tbm_data_p (int_node, int_pfx, int_plen); while (data_p == NULL) { assert(int_plen > 0); int_pfx >>= 1; int_plen--; data_p = tbm_data_p (int_node, int_pfx, int_plen); } return *data_p; } return NULL; } struct btrie * btrie_init(rspamd_mempool_t *mp) { struct btrie *btrie; if (!(btrie = rspamd_mempool_alloc0 (mp, sizeof(*btrie)))) { return NULL; } btrie->mp = mp; btrie->alloc_total = sizeof(*btrie); /* count the empty root node */ btrie->n_tbm_nodes = 1; return btrie; } enum btrie_result btrie_add_prefix(struct btrie *btrie, const btrie_oct_t *prefix, unsigned len, const void *data) { enum btrie_result rv; if ((rv = setjmp (btrie->exception)) != 0) return rv; /* out of memory */ return add_to_trie (btrie, &btrie->root, 0, prefix, len, data); } const void * btrie_lookup(const struct btrie *btrie, const btrie_oct_t *prefix, unsigned len) { return search_trie (&btrie->root, 0, prefix, len); } /**************************************************************** * * btrie_stats() - statistics reporting */ #ifdef BTRIE_EXTENDED_STATS /* Define BTRIE_EXTENDED_STATS to get extra statistics (including * trie depth). This statistics require a traversal of the entire trie * to compute, and so are disabled by default. */ struct stats { size_t max_depth; size_t total_depth; #ifndef NDEBUG size_t n_lc_nodes; size_t n_tbm_nodes; size_t n_entries; size_t alloc_data; size_t alloc_waste; #endif }; static void node_stats(const node_t *node, size_t depth, struct stats *stats) { if (depth > stats->max_depth) stats->max_depth = depth; stats->total_depth += depth; if (is_lc_node(node)) { #ifndef NDEBUG stats->n_lc_nodes++; #endif if (!lc_is_terminal(&node->lc_node)) node_stats(node->lc_node.ptr.child, depth + 1, stats); #ifndef NDEBUG else stats->n_entries++; #endif } else { unsigned i; unsigned nchildren = count_bits(node->tbm_node.ext_bm); #ifndef NDEBUG unsigned ndata = count_bits(node->tbm_node.int_bm); stats->n_tbm_nodes++; stats->n_entries += ndata; stats->alloc_data += ndata * sizeof(void *); stats->alloc_waste += (ndata % 2) * sizeof(void *); #endif for (i = 0; i < nchildren; i++) node_stats(&node->tbm_node.ptr.children[i], depth + 1, stats); } } #endif /* BTRIE_EXTENDED_STATS */ #ifndef NDEBUG static size_t count_free(const struct btrie *btrie) { size_t total = 0; unsigned sz; for (sz = 1; sz <= MAX_CHILD_ARRAY_LEN; sz++) { const struct free_hunk *free = btrie->free_list[sz - 1]; size_t n; for (n = 0; free; n++) free = free->next; total += sz * n; } return total * sizeof(node_t); } #endif /* not NDEBUG */ const char * btrie_stats(const struct btrie *btrie, guint duplicates) { static char buf[128]; size_t n_nodes = btrie->n_lc_nodes + btrie->n_tbm_nodes; size_t alloc_free = (btrie->alloc_total + sizeof(node_t) /* do not double-count the root node */ - n_nodes * sizeof(node_t) - btrie->alloc_data - btrie->alloc_waste - sizeof(*btrie)); #ifdef BTRIE_EXTENDED_STATS struct stats stats; double average_depth; memset(&stats, 0, sizeof(stats)); node_stats(&btrie->root, 0, &stats); average_depth = (double)stats.total_depth / n_nodes; #ifndef NDEBUG /* check the node counts */ assert(stats.n_lc_nodes == btrie->n_lc_nodes); assert(stats.n_tbm_nodes == btrie->n_tbm_nodes); assert(stats.n_entries == btrie->n_entries); assert(stats.alloc_data == btrie->alloc_data); assert(stats.alloc_waste == btrie->alloc_waste); #endif /* not NDEBUG */ #endif /* BTRIE_EXTENDED_STATS */ #ifndef NDEBUG /* check that we haven't lost any memory */ assert(alloc_free == count_free (btrie)); #endif #ifdef BTRIE_DEBUG_ALLOC dump_alloc_hist(btrie); #endif #ifdef BTRIE_EXTENDED_STATS snprintf(buf, sizeof(buf), "ents=%lu tbm=%lu lc=%lu mem=%.0fk free=%lu waste=%lu" " depth=%.1f/%lu" ,(long unsigned)btrie->n_entries, (long unsigned)btrie->n_tbm_nodes, (long unsigned)btrie->n_lc_nodes, (double)btrie->alloc_total / 1024, (long unsigned)alloc_free, (long unsigned)btrie->alloc_waste , average_depth, (long unsigned)stats.max_depth); #else snprintf(buf, sizeof(buf), "ents=%lu dup=%u tbm=%lu lc=%lu mem=%.0fk free=%lu waste=%lu", (long unsigned)btrie->n_entries, duplicates, (long unsigned)btrie->n_tbm_nodes, (long unsigned)btrie->n_lc_nodes, (double)btrie->alloc_total / 1024, (long unsigned)alloc_free, (long unsigned)btrie->alloc_waste ); #endif buf[sizeof(buf) - 1] = '\0'; return buf; } /****************************************************************/ #ifndef NO_MASTER_DUMP struct walk_context { btrie_walk_cb_t *callback; void *user_data; btrie_oct_t prefix[(BTRIE_MAX_PREFIX + 7) / 8]; }; static void walk_node(const node_t *node, unsigned pos, struct walk_context *ctx); static void walk_tbm_node(const struct tbm_node *node, unsigned pos, unsigned pfx, unsigned plen, struct walk_context *ctx) { btrie_oct_t *prefix = ctx->prefix; int pbyte = pos / 8; btrie_oct_t pbit = 0x80 >> (pos % 8); const void **data_p = tbm_data_p (node, pfx, plen); if (pos >= BTRIE_MAX_PREFIX) { /* This can/should not happen, but don't overwrite buffers if it does. */ return; } if (data_p) ctx->callback (prefix, pos, *data_p, 0, ctx->user_data); /* walk children */ if (plen < TBM_STRIDE - 1) { /* children are internal prefixes in same node */ walk_tbm_node (node, pos + 1, pfx << 1, plen + 1, ctx); prefix[pbyte] |= pbit; walk_tbm_node (node, pos + 1, (pfx << 1) + 1, plen + 1, ctx); prefix[pbyte] &= ~pbit; } else { /* children are extending paths */ const node_t *ext_path; if ((ext_path = tbm_ext_path (node, pfx << 1)) != NULL) walk_node (ext_path, pos + 1, ctx); if ((ext_path = tbm_ext_path (node, (pfx << 1) + 1)) != NULL) { prefix[pbyte] |= pbit; walk_node (ext_path, pos + 1, ctx); prefix[pbyte] &= ~pbit; } } if (data_p) ctx->callback (prefix, pos, *data_p, 1, ctx->user_data); } static void walk_lc_node(const struct lc_node *node, unsigned pos, struct walk_context *ctx) { btrie_oct_t *prefix = ctx->prefix; unsigned end = pos + lc_len (node); btrie_oct_t save_prefix = prefix[lc_shift (pos)]; if (end > BTRIE_MAX_PREFIX) { /* This can/should not happen, but don't overwrite buffers if it does. */ return; } /* construct full prefix to node */ memcpy(&prefix[lc_shift (pos)], node->prefix, lc_bytes (node, pos)); if (end % 8) prefix[end / 8] &= high_bits (end % 8); if (lc_is_terminal (node)) { ctx->callback (prefix, end, node->ptr.data, 0, ctx->user_data); ctx->callback (prefix, end, node->ptr.data, 1, ctx->user_data); } else walk_node (node->ptr.child, end, ctx); prefix[lc_shift (pos)] = save_prefix; /* restore parents prefix */ if (lc_bytes (node, pos) > 1) memset(&prefix[lc_shift (pos) + 1], 0, lc_bytes (node, pos) - 1); } static void walk_node(const node_t *node, unsigned pos, struct walk_context *ctx) { if (is_lc_node (node)) walk_lc_node (&node->lc_node, pos, ctx); else walk_tbm_node (&node->tbm_node, pos, 0, 0, ctx); } /* walk trie in lexicographical order * * calls callback twice (once preorder, once postorder) at each prefix */ void btrie_walk(const struct btrie *btrie, btrie_walk_cb_t *callback, void *user_data) { struct walk_context ctx; memset(&ctx, 0, sizeof(ctx)); ctx.callback = callback; ctx.user_data = user_data; walk_node (&btrie->root, 0, &ctx); } #endif /* not NO_MASTER_DUMP */ #ifdef TEST /***************************************************************** * * Unit tests * */ #include #ifndef UNUSED # define UNUSED __attribute__((unused)) #endif /* bogus replacements mp_alloc for running self-tests */ void * mp_alloc(UNUSED struct mempool *mp, unsigned sz, UNUSED int align) { return malloc(sz); } #if 0 # define PASS(name) puts("OK " name) #else # define PASS(name) fputs(".", stdout); fflush(stdout) #endif const char * pgm_name = "???"; static void test_struct_node_packing() { node_t node; assert(sizeof(struct tbm_node) == 2 * sizeof(void *)); assert(sizeof(struct lc_node) == 2 * sizeof(void *)); assert(sizeof(node_t) == 2 * sizeof(void *)); /* The lc_node bit must be an alias for bit zero of int_bm, since * that is the only unused bit in the TBM node structure. */ memset(&node, 0, sizeof(node)); assert(node.tbm_node.int_bm == 0); lc_init_flags(&node.lc_node, 0, 0); assert(node.tbm_node.int_bm == bit(0)); PASS("test_struct_node_packing"); } static void test_bit() { tbm_bitmap_t ones = ~(tbm_bitmap_t)0; tbm_bitmap_t high_bit = ones ^ (ones >> 1); assert(bit(0) == high_bit); assert(bit(1) == high_bit >> 1); assert(bit(8 * sizeof(tbm_bitmap_t) - 1) == 1); PASS("test_bit"); } static void test_count_bits() { unsigned max_bits = sizeof(tbm_bitmap_t) * 8; tbm_bitmap_t ones = ~(tbm_bitmap_t)0; assert(count_bits(0) == 0); assert(count_bits(1) == 1); assert(count_bits(2) == 1); assert(count_bits(3) == 2); assert(count_bits(ones) == max_bits); assert(count_bits(~1) == max_bits - 1); /* count_bits(0x5555....) */ assert(count_bits(ones / 3) == max_bits / 2); /* count_bits(0x3333...) */ assert(count_bits(ones / 5) == max_bits / 2); /* count_bits(0x0f0f...) */ assert(count_bits(ones / 17) == max_bits / 2); /* count_bits(0x1010...) */ assert(count_bits(ones / 255) == max_bits / 8); PASS("test_count_bits"); } static void test_count_bits_before() { unsigned max_bits = sizeof(tbm_bitmap_t) * 8; tbm_bitmap_t ones = ~(tbm_bitmap_t)0; unsigned i; for (i = 0; i < max_bits; i++) { assert(count_bits_before(0, i) == 0); assert(count_bits_before(ones, i) == i); } PASS("test_count_bits_before"); } static void test_count_bits_from() { unsigned max_bits = sizeof(tbm_bitmap_t) * 8; tbm_bitmap_t ones = ~(tbm_bitmap_t)0; unsigned i; for (i = 0; i < max_bits; i++) { assert(count_bits_from(0, i) == 0); assert(count_bits_from(ones, i) == max_bits - i); } PASS("test_count_bits_from"); } static void test_extract_bits() { static btrie_oct_t prefix[] = {0xff, 0x55, 0xaa, 0x00}; unsigned i; for (i = 0; i < 32; i++) assert(extract_bits(prefix, i, 0) == 0); for (i = 0; i < 8; i++) assert(extract_bits(prefix, i, 1) == 1); for (i = 8; i < 16; i++) assert(extract_bits(prefix, i, 1) == i % 2); for (i = 16; i < 24; i++) assert(extract_bits(prefix, i, 1) == (i + 1) % 2); for (i = 24; i < 32; i++) assert(extract_bits(prefix, i, 1) == 0); assert(extract_bits(prefix, 2, 6) == 0x3f); assert(extract_bits(prefix, 3, 6) == 0x3e); assert(extract_bits(prefix, 4, 6) == 0x3d); assert(extract_bits(prefix, 5, 6) == 0x3a); assert(extract_bits(prefix, 6, 6) == 0x35); assert(extract_bits(prefix, 7, 6) == 0x2a); assert(extract_bits(prefix, 8, 6) == 0x15); PASS("test_extract_bits"); } static void test_high_bits() { assert(high_bits(0) == 0x00); assert(high_bits(1) == 0x80); assert(high_bits(2) == 0xc0); assert(high_bits(3) == 0xe0); assert(high_bits(4) == 0xf0); assert(high_bits(5) == 0xf8); assert(high_bits(6) == 0xfc); assert(high_bits(7) == 0xfe); assert(high_bits(8) == 0xff); PASS("test_high_bits"); } static void test_prefixes_equal() { btrie_oct_t prefix1[LC_BYTES_PER_NODE]; btrie_oct_t prefix2[LC_BYTES_PER_NODE]; unsigned i; memset(prefix1, 0xaa, LC_BYTES_PER_NODE); memset(prefix2, 0xaa, LC_BYTES_PER_NODE); for (i = 0; i < 8 * LC_BYTES_PER_NODE; i++) { assert(prefixes_equal(prefix1, prefix2, i)); prefix1[i / 8] ^= 1 << (7 - i % 8); assert(!prefixes_equal(prefix1, prefix2, 8 * LC_BYTES_PER_NODE)); assert(prefixes_equal(prefix1, prefix2, i)); if (i + 1 < 8 * LC_BYTES_PER_NODE) assert(!prefixes_equal(prefix1, prefix2, i + 1)); prefix1[i / 8] ^= 1 << (7 - i % 8); } PASS("test_prefixes_equal"); } static void test_common_prefix() { btrie_oct_t prefix1[LC_BYTES_PER_NODE]; btrie_oct_t prefix2[LC_BYTES_PER_NODE]; unsigned i; memset(prefix1, 0x55, LC_BYTES_PER_NODE); memset(prefix2, 0x55, LC_BYTES_PER_NODE); for (i = 0; i < 8 * LC_BYTES_PER_NODE; i++) { assert(common_prefix(prefix1, prefix2, i) == i); prefix1[i / 8] ^= 1 << (7 - i % 8); assert(common_prefix(prefix1, prefix2, 8 * LC_BYTES_PER_NODE) == i); if (i + 1 < 8 * LC_BYTES_PER_NODE) assert(common_prefix(prefix1, prefix2, i+1) == i); prefix1[i / 8] ^= 1 << (7 - i % 8); } PASS("test_common_prefix"); } static void test_base_index() { assert(base_index(0,0) == 1); assert(base_index(0,1) == 2); assert(base_index(1,1) == 3); assert(base_index(0,2) == 4); assert(base_index(1,2) == 5); assert(base_index(2,2) == 6); assert(base_index(3,2) == 7); PASS("test_base_index"); } static void test_has_internal_data() { struct tbm_node node; unsigned plen, pfx, bi; for (plen = 0; plen < TBM_STRIDE; plen++) { for (pfx = 0; pfx < 1U << plen; pfx++) { tbm_bitmap_t ancestor_mask = 0; for (bi = base_index(pfx, plen); bi; bi >>= 1) { node.int_bm = bit(bi); ancestor_mask |= bit(bi); assert(has_internal_data(&node, pfx, plen)); } node.int_bm = ~ancestor_mask; assert(!has_internal_data(&node, pfx, plen)); } } PASS("test_has_internal_data"); } /****************************************************************/ static const btrie_oct_t numbered_bytes[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, }; static void check_non_terminal_lc_node(struct lc_node *node, unsigned len) { assert(is_lc_node((node_t *)node)); assert(!lc_is_terminal(node)); assert(lc_len(node) == len); } static void check_terminal_lc_node(struct lc_node *node, unsigned len, const void *data) { assert(is_lc_node((node_t *)node)); assert(lc_is_terminal(node)); assert(lc_len(node) == len); assert(node->ptr.data == data); } static void test_init_terminal_node() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; node_t node; struct lc_node *head = &node.lc_node; init_terminal_node(btrie, &node, 0, numbered_bytes, 8 * LC_BYTES_PER_NODE, data); check_terminal_lc_node(head, 8 * LC_BYTES_PER_NODE, data); assert(memcmp(head->prefix, numbered_bytes, LC_BYTES_PER_NODE) == 0); init_terminal_node(btrie, &node, 7, numbered_bytes, 8 * LC_BYTES_PER_NODE, data); check_terminal_lc_node(head, 8 * LC_BYTES_PER_NODE - 7, data); assert(memcmp(head->prefix, numbered_bytes, LC_BYTES_PER_NODE) == 0); init_terminal_node(btrie, &node, 0, numbered_bytes, 2 * 8 * LC_BYTES_PER_NODE, data); check_non_terminal_lc_node(head, 8 * LC_BYTES_PER_NODE); assert(memcmp(head->prefix, numbered_bytes, LC_BYTES_PER_NODE) == 0); { struct lc_node *child = &head->ptr.child->lc_node; check_terminal_lc_node(child, 8 * LC_BYTES_PER_NODE, data); assert(memcmp(child->prefix, &numbered_bytes[LC_BYTES_PER_NODE], LC_BYTES_PER_NODE) == 0); } init_terminal_node(btrie, &node, 15, numbered_bytes, 8 * LC_BYTES_PER_NODE + 15, data); check_non_terminal_lc_node(head, 8 * LC_BYTES_PER_NODE - 7); assert(memcmp(head->prefix, &numbered_bytes[1], LC_BYTES_PER_NODE) == 0); { struct lc_node *child = &head->ptr.child->lc_node; check_terminal_lc_node(child, 7, data); assert(child->prefix[0] == numbered_bytes[LC_BYTES_PER_NODE + 1]); } PASS("test_init_terminal_node"); } static void test_coalesce_lc_node() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; node_t node; struct lc_node *head = &node.lc_node; /* test merging */ init_terminal_node(btrie, &node, 0, numbered_bytes, 8 * (LC_BYTES_PER_NODE + 1), data); check_non_terminal_lc_node(head, LC_BYTES_PER_NODE * 8); lc_add_to_len(head, -8); coalesce_lc_node(btrie, head, 8); check_terminal_lc_node(head, LC_BYTES_PER_NODE * 8, data); assert(head->prefix[LC_BYTES_PER_NODE - 1] == numbered_bytes[LC_BYTES_PER_NODE]); /* test bit stealing */ init_terminal_node(btrie, &node, 0, numbered_bytes, 8 * (2 * LC_BYTES_PER_NODE), data); check_non_terminal_lc_node(head, LC_BYTES_PER_NODE * 8); lc_add_to_len(head, -15); coalesce_lc_node(btrie, head, 15); check_non_terminal_lc_node(head, LC_BYTES_PER_NODE * 8 - 7); assert(memcmp(head->prefix, numbered_bytes, LC_BYTES_PER_NODE - 1) == 0); assert(head->prefix[LC_BYTES_PER_NODE - 1] == numbered_bytes[LC_BYTES_PER_NODE]); { struct lc_node *child = &head->ptr.child->lc_node; check_terminal_lc_node(child, 8 * (LC_BYTES_PER_NODE - 1), data); assert(memcmp(child->prefix, &numbered_bytes[LC_BYTES_PER_NODE + 1], LC_BYTES_PER_NODE - 1) == 0); } PASS("test_coalesce_lc_node"); } static void test_shorten_lc_node() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; node_t node, shorter; /* test shorten without shift */ init_terminal_node(btrie, &node, 0, numbered_bytes, 8 * LC_BYTES_PER_NODE, data); memset(shorter.lc_node.prefix, 0xff, LC_BYTES_PER_NODE); shorten_lc_node(btrie, &shorter, 7, &node.lc_node, 0); check_terminal_lc_node(&shorter.lc_node, LC_BYTES_PER_NODE * 8 - 7, data); assert(memcmp(shorter.lc_node.prefix, numbered_bytes, LC_BYTES_PER_NODE) == 0); /* test shorten with shift */ init_terminal_node(btrie, &node, 7, numbered_bytes, 8 * LC_BYTES_PER_NODE, data); memset(shorter.lc_node.prefix, 0xff, LC_BYTES_PER_NODE); shorten_lc_node(btrie, &shorter, 9, &node.lc_node, 7); check_terminal_lc_node(&shorter.lc_node, LC_BYTES_PER_NODE * 8 - 9, data); assert(memcmp(shorter.lc_node.prefix, &numbered_bytes[1], LC_BYTES_PER_NODE - 1) == 0); { /* test child stealing */ struct lc_node head; node_t tail, shorter; lc_init_flags(&head, 0, 7); head.ptr.child = &tail; init_empty_node(btrie, &tail); shorten_lc_node(btrie, &shorter, 7, &head, 0); assert(is_empty_node(&shorter)); } PASS("test_shorten_lc_node"); } static void test_split_lc_node() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; struct lc_node node; init_terminal_node(btrie, (node_t *)&node, 1, numbered_bytes, 25, data); split_lc_node(btrie, &node, 1, 8); check_non_terminal_lc_node(&node, 8); check_terminal_lc_node(&node.ptr.child->lc_node, 16, data); /* test conversion of terminal to non-terminal */ init_terminal_node(btrie, (node_t *)&node, 7, numbered_bytes, 10, data); split_lc_node(btrie, &node, 7, 3); check_non_terminal_lc_node(&node, 3); check_terminal_lc_node(&node.ptr.child->lc_node, 0, data); PASS("test_split_lc_node"); } static void test_convert_lc_node_1() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; struct lc_node head; /* test tail is left */ lc_init_flags(&head, 0, 1); head.prefix[0] = 0; head.ptr.child = alloc_nodes(btrie, 1, 0); init_terminal_node(btrie, head.ptr.child, 1, numbered_bytes, 1, data); convert_lc_node_1(btrie, &head, 0); { node_t *result = (node_t *)&head; assert(is_tbm_node(result)); assert(result->tbm_node.ext_bm == 0); assert(result->tbm_node.int_bm == bit(base_index(0, 1))); assert(*tbm_data_p(&result->tbm_node, 0, 1) == data); } /* test tail is right */ lc_init_flags(&head, 0, 1); head.prefix[0] = 1; head.ptr.child = alloc_nodes(btrie, 1, 0); init_terminal_node(btrie, head.ptr.child, 8, numbered_bytes, 10, data); convert_lc_node_1(btrie, &head, 7); { node_t *result = (node_t *)&head; assert(is_tbm_node(result)); assert(result->tbm_node.ext_bm == 0); assert(result->tbm_node.int_bm == bit(base_index(4, 3))); assert(*tbm_data_p(&result->tbm_node, 4, 3) == data); } PASS("test_convert_lc_node_1"); } static void test_convert_lc_node() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; node_t node; /* if (len >= TBM_STRIDE) */ init_terminal_node(btrie, &node, 7, numbered_bytes, TBM_STRIDE + 7, data); convert_lc_node(btrie, &node.lc_node, 7); assert(is_tbm_node(&node)); assert(node.tbm_node.ext_bm == bit(0)); assert(node.tbm_node.int_bm == 0); check_terminal_lc_node(&tbm_ext_path(&node.tbm_node, 0)->lc_node, 0, data); /* if (lc_is_terminal(node)) */ init_terminal_node(btrie, &node, 0, numbered_bytes, 0, data); convert_lc_node(btrie, &node.lc_node, 0); assert(is_tbm_node(&node)); assert(node.tbm_node.ext_bm == 0); assert(node.tbm_node.int_bm == bit(base_index(0, 0))); assert(*tbm_data_p(&node.tbm_node, 0, 0) == data); /* else */ lc_init_flags(&node.lc_node, 0, TBM_STRIDE - 1); node.lc_node.prefix[0] = 0; node.lc_node.ptr.child = alloc_nodes(btrie, 1, 0); init_empty_node(btrie, node.lc_node.ptr.child); tbm_insert_data(btrie, &node.lc_node.ptr.child->tbm_node, 0, 0, data); convert_lc_node(btrie, &node.lc_node, 0); assert(is_tbm_node(&node)); assert(node.tbm_node.ext_bm == 0); assert(node.tbm_node.int_bm == bit(base_index(0, TBM_STRIDE - 1))); assert(*tbm_data_p(&node.tbm_node, 0, TBM_STRIDE - 1) == data); PASS("test_convert_lc_node"); } static void test_insert_lc_node() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; node_t node, tail; /* test optimized case, last_bit == 0 */ init_terminal_node(btrie, &tail, 9, numbered_bytes, 17, data); insert_lc_node(btrie, &node, 8, 0, 0, &tail); check_terminal_lc_node(&node.lc_node, 9, data); assert(memcmp(node.lc_node.prefix, &numbered_bytes[1], 2) == 0); /* test optimized case, last_bit == 1 */ init_terminal_node(btrie, &tail, 7, &numbered_bytes[0x12], 15, data); insert_lc_node(btrie, &node, 6, 0x10, 1, &tail); check_terminal_lc_node(&node.lc_node, 9, data); assert(node.lc_node.prefix[0] == 0x12); assert(node.lc_node.prefix[1] == 0x13); /* test with shift */ init_terminal_node(btrie, &tail, 0, numbered_bytes, 8, data); insert_lc_node(btrie, &node, 7, 0x40, 1, &tail); check_terminal_lc_node(&node.lc_node, 9, data); assert(node.lc_node.prefix[0] == 0x41); assert(node.lc_node.prefix[1] == numbered_bytes[0]); /* test with TBM node */ init_empty_node(btrie, &tail); insert_lc_node(btrie, &node, 6, 0x40, 0, &tail); check_non_terminal_lc_node(&node.lc_node, 1); assert(is_tbm_node(node.lc_node.ptr.child)); PASS("test_insert_lc_node"); } static void test_next_pbyte() { assert(next_pbyte(0xff, 0, 1) == 0x80 >> (TBM_STRIDE - 1)); assert(next_pbyte(0xff, 1, 1) == (0x80 | (0x80 >> TBM_STRIDE))); assert(next_pbyte(0xff, 2, 1) == (0xc0 | (0x80 >> (TBM_STRIDE + 1)))); assert(next_pbyte(0xff, 8 - TBM_STRIDE, 1) == 0); assert(next_pbyte(0xff, 9 - TBM_STRIDE, 1) == 0x80); PASS("test_next_pbyte"); } static void test_init_tbm_node() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; unsigned lr; node_t node; /* test root data */ init_tbm_node(btrie, &node, 0, 0, &data, NULL, NULL); assert(is_tbm_node(&node)); assert(node.tbm_node.ext_bm == 0); assert(node.tbm_node.int_bm == bit(base_index(0, 0))); assert(*tbm_data_p(&node.tbm_node, 0, 0) == data); for (lr = 0; lr < 2; lr++) { node_t child; node_t *left = lr ? NULL : &child; node_t *right = lr ? &child : NULL; unsigned base = lr ? (1U << (TBM_STRIDE - 1)) : 0; unsigned pfx; /* test with long LC node child */ init_terminal_node(btrie, &child, 1, numbered_bytes, TBM_STRIDE + 1, data); init_tbm_node(btrie, &node, 0, 0, NULL, left, right); assert(is_tbm_node(&node)); assert(node.tbm_node.ext_bm == bit(base)); assert(node.tbm_node.int_bm == 0); check_terminal_lc_node(&tbm_ext_path(&node.tbm_node, base)->lc_node, 1, data); /* test with short LC node children */ init_terminal_node(btrie, &child, 1, numbered_bytes, TBM_STRIDE - 1, data); init_tbm_node(btrie, &node, 0, 0, NULL, left, right); assert(is_tbm_node(&node)); assert(node.tbm_node.ext_bm == 0); assert(node.tbm_node.int_bm == bit(base_index(base >> 1, TBM_STRIDE-1))); assert(*tbm_data_p(&node.tbm_node, base >> 1, TBM_STRIDE-1) == data); /* construct TBM node with all eight combinations of having data, * left_ext and/or right_ext in its extending paths */ init_empty_node(btrie, &child); for (pfx = 0; pfx < 8; pfx++) { if (pfx & 1) tbm_insert_data(btrie, &child.tbm_node, pfx, TBM_STRIDE - 1, data); if (pfx & 2) { btrie_oct_t prefix0 = 0; init_terminal_node(btrie, tbm_insert_ext_path(btrie, &child.tbm_node, 2*pfx), TBM_STRIDE + 1, &prefix0, TBM_STRIDE + 2, data); } if (pfx & 4) { btrie_oct_t prefix0 = 0x80 >> TBM_STRIDE; init_terminal_node(btrie, tbm_insert_ext_path(btrie, &child.tbm_node, 2*pfx+1), TBM_STRIDE + 1, &prefix0, TBM_STRIDE + 3, data); } } init_tbm_node(btrie, &node, 0, 0, NULL, left, right); for (pfx = 0; pfx < 8; pfx++) { unsigned base = lr ? (1U << (TBM_STRIDE - 1)) : 0; node_t *ext_path = tbm_ext_path(&node.tbm_node, base + pfx); if (pfx == 0) assert(ext_path == NULL); else if (pfx == 1) check_terminal_lc_node(&ext_path->lc_node, 0, data); else if (pfx == 2) { check_terminal_lc_node(&ext_path->lc_node, 2, data); assert(ext_path->lc_node.prefix[0] == 0); } else if (pfx == 4) { check_terminal_lc_node(&ext_path->lc_node, 3, data); assert(ext_path->lc_node.prefix[0] == (0x80 >> TBM_STRIDE)); } else { tbm_bitmap_t int_bm = 0; assert(is_tbm_node(ext_path)); if (pfx & 1) { int_bm |= bit(base_index(0, 0)); assert(*tbm_data_p(&ext_path->tbm_node, 0, 0) == data); } if (pfx & 2) { int_bm |= bit(base_index(0, 2)); assert(*tbm_data_p(&ext_path->tbm_node, 0, 2) == data); } if (pfx & 4) { int_bm |= bit(base_index(4, 3)); assert(*tbm_data_p(&ext_path->tbm_node, 4, 3) == data); } assert(ext_path->tbm_node.int_bm == int_bm); } } } PASS("test_init_tbm_node"); } static void test_add_to_trie() { struct btrie *btrie = btrie_init(NULL); const void *data = (void *)0xdeadbeef; enum btrie_result result; unsigned pfx, plen; node_t root; /* test initial insertion */ init_empty_node(btrie, &root); result = add_to_trie(btrie, &root, 0, numbered_bytes, 8 * 2 * LC_BYTES_PER_NODE, data); assert(result == BTRIE_OKAY); check_non_terminal_lc_node(&root.lc_node, 8 * LC_BYTES_PER_NODE); check_terminal_lc_node(&root.lc_node.ptr.child->lc_node, 8 * LC_BYTES_PER_NODE, data); /* test can follow LC node to tail, and then detect duplicate prefix */ result = add_to_trie(btrie, &root, 0, numbered_bytes, 8 * 2 * LC_BYTES_PER_NODE, data); assert(result == BTRIE_DUPLICATE_PREFIX); /* test can insert new TBM node within existing LC node */ result = add_to_trie(btrie, &root, 0, &numbered_bytes[1], 16, data); assert(result == BTRIE_OKAY); check_non_terminal_lc_node(&root.lc_node, 7); assert(is_tbm_node(root.lc_node.ptr.child)); /* test can convert terminal LC node to TBM node */ init_terminal_node(btrie, &root, 0, numbered_bytes, 12, data); result = add_to_trie(btrie, &root, 0, numbered_bytes, 24, data); assert(result == BTRIE_OKAY); check_non_terminal_lc_node(&root.lc_node, 12); assert(is_tbm_node(root.lc_node.ptr.child)); /* test can insert internal prefix data in TBM node */ for (plen = 0; plen < TBM_STRIDE; plen++) { for (pfx = 0; pfx < (1U << plen); pfx++) { btrie_oct_t prefix0 = plen ? pfx << (8 - plen) : 0; init_empty_node(btrie, &root); init_terminal_node(btrie, tbm_insert_ext_path(btrie, &root.tbm_node, 0), TBM_STRIDE, numbered_bytes, 8, data); result = add_to_trie(btrie, &root, 0, &prefix0, plen, data); assert(result == BTRIE_OKAY); assert(is_tbm_node(&root)); assert(root.tbm_node.ext_bm == bit(0)); assert(root.tbm_node.int_bm == bit(base_index(pfx, plen))); assert(*tbm_data_p(&root.tbm_node, pfx, plen) == data); result = add_to_trie(btrie, &root, 0, &prefix0, plen, data); assert(result == BTRIE_DUPLICATE_PREFIX); } } /* test can add extending paths to TBM node */ for (pfx = 0; pfx < (1U << TBM_STRIDE); pfx++) { btrie_oct_t prefix0 = pfx << (8 - TBM_STRIDE); init_empty_node(btrie, &root); tbm_insert_data(btrie, &root.tbm_node, 0, 0, data); result = add_to_trie(btrie, &root, 0, &prefix0, 8, data); assert(result == BTRIE_OKAY); assert(is_tbm_node(&root)); assert(root.tbm_node.ext_bm == bit(pfx)); assert(root.tbm_node.int_bm == bit(base_index(0, 0))); check_terminal_lc_node(&tbm_ext_path(&root.tbm_node, pfx)->lc_node, 8 - TBM_STRIDE, data); result = add_to_trie(btrie, &root, 0, &prefix0, 8, data); assert(result == BTRIE_DUPLICATE_PREFIX); } /* test can follow extending path */ init_empty_node(btrie, &root); init_terminal_node(btrie, tbm_insert_ext_path(btrie, &root.tbm_node, 0), TBM_STRIDE, numbered_bytes, 8, data); result = add_to_trie(btrie, &root, 0, numbered_bytes, 7, data); assert(result == BTRIE_OKAY); assert(root.tbm_node.ext_bm == bit(0)); assert(root.tbm_node.int_bm == 0); check_non_terminal_lc_node(&root.tbm_node.ptr.children[0].lc_node, 7 - TBM_STRIDE); PASS("test_add_to_trie"); } static void test_search_trie() { struct btrie *btrie = btrie_init(NULL); const void *data01 = (void *)0xdead0001; const void *data11 = (void *)0xdead0101; const void *data = (void *)0xdeadbeef; unsigned plen, pfx; node_t root; /* test can follow chain of LC nodes to an exact match */ init_empty_node(btrie, &root); add_to_trie(btrie, &root, 0, numbered_bytes, 8 * 2 * LC_BYTES_PER_NODE, data); assert(search_trie(&root, 0, numbered_bytes, 8 * 2 * LC_BYTES_PER_NODE) == data); assert(search_trie(&root, 0, numbered_bytes, 8 * 2 * LC_BYTES_PER_NODE + 1) == data); assert(search_trie(&root, 0, numbered_bytes, 8 * 2 * LC_BYTES_PER_NODE - 1) == NULL); assert(search_trie(&root, 0, &numbered_bytes[1], 8 * 2 * LC_BYTES_PER_NODE) == NULL); /* test can follow extending path to an exact match */ for (pfx = 0; pfx < (1U << TBM_STRIDE); pfx++) { btrie_oct_t prefix0 = pfx << (8 - TBM_STRIDE); init_empty_node(btrie, &root); tbm_insert_data(btrie, &root.tbm_node, 0, 1, data01); tbm_insert_data(btrie, &root.tbm_node, 1, 1, data11); add_to_trie(btrie, &root, 0, &prefix0, 8, data); assert(search_trie(&root, 0, &prefix0, 8) == data); /* test that last matching TBM internal prefix gets picked up */ if (prefix0 & 0x80) assert(search_trie(&root, 0, &prefix0, 7) == data11); else assert(search_trie(&root, 0, &prefix0, 7) == data01); prefix0 ^= 1 << (8 - TBM_STRIDE); if (prefix0 & 0x80) assert(search_trie(&root, 0, &prefix0, 8) == data11); else assert(search_trie(&root, 0, &prefix0, 8) == data01); } /* test finding of TBM internal prefixes */ init_empty_node(btrie, &root); tbm_insert_data(btrie, &root.tbm_node, 0, 1, data01); tbm_insert_data(btrie, &root.tbm_node, 1, 1, data11); assert(search_trie(&root, 0, numbered_bytes, 0) == NULL); for (plen = 1; plen < TBM_STRIDE; plen++) { for (pfx = 0; pfx < (1U << TBM_STRIDE); pfx++) { btrie_oct_t prefix0 = pfx << (8 - plen); if (prefix0 & 0x80) assert(search_trie(&root, 0, &prefix0, plen) == data11); else assert(search_trie(&root, 0, &prefix0, plen) == data01); } } PASS("test_search_trie"); } static int unit_tests() { test_struct_node_packing(); test_bit(); test_count_bits(); test_count_bits_before(); test_count_bits_from(); test_extract_bits(); test_high_bits(); test_prefixes_equal(); test_common_prefix(); test_base_index(); test_has_internal_data(); test_init_terminal_node(); test_coalesce_lc_node(); test_shorten_lc_node(); test_split_lc_node(); test_convert_lc_node_1(); test_convert_lc_node(); test_insert_lc_node(); test_next_pbyte(); test_init_tbm_node(); test_add_to_trie(); test_search_trie(); puts("\nOK"); return 0; } /***************************************************************** * * btrie_dump: print out the trie structure (for testing) * */ #define INDENT_FILL "....:....|....:....|....:....|....:....|" static void dump_node(const node_t *node, unsigned pos, btrie_oct_t *prefix, int indent); static void dump_prefix(btrie_oct_t *prefix, unsigned len, int indent, const char *tail) { unsigned i; printf("%*.*s0x", indent, indent, INDENT_FILL); for (i = 0; i < len / 8; i++) printf("%02x", prefix[i]); if (len % 8) printf("%02x", prefix[len / 8] & high_bits(len % 8)); printf("/%u%s", len, tail); } /* the opposite of extract_bits, sets a short string of bits from integer */ static void insert_bits(btrie_oct_t *prefix, unsigned pos, btrie_oct_t pfx, unsigned nbits) { if (nbits != 0) { unsigned v = (prefix[pos / 8] << 8) + prefix[pos / 8 + 1]; unsigned mask = (1U << nbits) - 1; unsigned shift = 16 - (pos % 8) - nbits; v = (v & ~(mask << shift)) | (pfx << shift); prefix[pos / 8] = v >> 8; prefix[pos / 8 + 1] = (btrie_oct_t)v; } } static void dump_tbm_node(const struct tbm_node *node, unsigned pos, btrie_oct_t *prefix, int indent) { unsigned pfx = 0, plen = 0; dump_prefix(prefix, pos, indent, " [tbm]\n"); for (;;) { if (plen < TBM_STRIDE) { const void **data_p = tbm_data_p(node, pfx, plen); if (data_p) { insert_bits(prefix, pos, pfx, plen); dump_prefix(prefix, pos + plen, indent, ""); printf(" [%u/%u] (%s)\n", pfx, plen, (const char *)*data_p); } plen++; pfx <<= 1; } else { const node_t *ext_path = tbm_ext_path(node, pfx); if (ext_path) { insert_bits(prefix, pos, pfx, TBM_STRIDE); dump_node(ext_path, pos + TBM_STRIDE, prefix, indent + 1); } while (pfx & 1) { if (--plen == 0) return; pfx >>= 1; } pfx++; } } } static void dump_lc_node(const struct lc_node *node, unsigned pos, btrie_oct_t *prefix, int indent) { unsigned end = pos + lc_len(node); btrie_oct_t save_prefix = prefix[lc_shift(pos)]; memcpy(&prefix[lc_shift(pos)], node->prefix, lc_bytes(node, pos)); if (lc_is_terminal(node)) { dump_prefix(prefix, end, indent, ""); printf(" (%s)\n", (const char *)node->ptr.data); } else { dump_prefix(prefix, end, indent, "\n"); dump_node(node->ptr.child, end, prefix, indent + 1); } prefix[lc_shift(pos)] = save_prefix; if (lc_bytes(node, pos) > 1) memset(&prefix[lc_shift(pos) + 1], 0, lc_bytes(node, pos) - 1); } static void dump_node(const node_t *node, unsigned pos, btrie_oct_t *prefix, int indent) { if (is_lc_node(node)) dump_lc_node(&node->lc_node, pos, prefix, indent); else dump_tbm_node(&node->tbm_node, pos, prefix, indent); } static void btrie_dump(struct btrie *btrie) { btrie_oct_t prefix[(BTRIE_MAX_PREFIX + 7) / 8]; memset(prefix, 0, sizeof(prefix)); dump_node(&btrie->root, 0, prefix, 0); puts(btrie_stats(btrie)); } /**************************************************************** * * test program - just enough to construct a trie and preform a lookup * */ #include static int parse_prefix(const char *arg, btrie_oct_t prefix[16], unsigned *len) { char addrbuf[128]; return sscanf(arg, "%127[0-9a-fA-F:]/%u", addrbuf, len) == 2 && inet_pton(AF_INET6, addrbuf, prefix) == 1; } static int test_btrie(int argc, char *argv[]) { struct btrie *btrie = btrie_init(NULL); int i; btrie_oct_t prefix[16]; unsigned len; for (i = 1; i < argc-1; i++) { if (!parse_prefix(argv[i], prefix, &len)) { fprintf(stderr, "Can not parse arg '%s'\n", argv[i]); return 1; } btrie_add_prefix(btrie, prefix, len, argv[i]); } btrie_dump(btrie); if (argc > 1) { const void *data; if (!parse_prefix(argv[argc-1], prefix, &len)) { fprintf(stderr, "Can not parse arg '%s'\n", argv[argc-1]); return 1; } data = btrie_lookup(btrie, prefix, 128); printf("lookup(%s) => %s\n", argv[argc-1], (const char *)data); } return 0; } int main(int argc, char *argv[]) { if ((pgm_name = strrchr(argv[0], '/')) != NULL) pgm_name++; else pgm_name = argv[0]; if (argc > 1) return test_btrie(argc, argv); else return unit_tests(); } #endif /* TEST */