--- /dev/null
+/* Based on work Copyright 2002 Christopher Clark */
+/* Copyright 2005-2012 Nick Mathewson */
+/* Copyright 2009-2012 Niels Provos and Nick Mathewson */
+/* See license at end. */
+
+/* Based on ideas by Christopher Clark and interfaces from Niels Provos. */
+
+#ifndef _EVENT_HT_H
+#define _EVENT_HT_H
+
+#define HT_HEAD(name, type) \
+ struct name { \
+ /* The hash table itself. */ \
+ struct type **hth_table; \
+ /* How long is the hash table? */ \
+ unsigned hth_table_length; \
+ /* How many elements does the table contain? */ \
+ unsigned hth_n_entries; \
+ /* How many elements will we allow in the table before resizing it? */ \
+ unsigned hth_load_limit; \
+ /* Position of hth_table_length in the primes table. */ \
+ int hth_prime_idx; \
+ }
+
+#define HT_INITIALIZER() \
+ { NULL, 0, 0, 0, -1 }
+
+#ifdef HT_CACHE_HASH_VALUES
+#define HT_ENTRY(type) \
+ struct { \
+ struct type *hte_next; \
+ unsigned hte_hash; \
+ }
+#else
+#define HT_ENTRY(type) \
+ struct { \
+ struct type *hte_next; \
+ }
+#endif
+
+#define HT_EMPTY(head) \
+ ((head)->hth_n_entries == 0)
+
+/* How many elements in 'head'? */
+#define HT_SIZE(head) \
+ ((head)->hth_n_entries)
+
+#define HT_FIND(name, head, elm) name##_HT_FIND((head), (elm))
+#define HT_INSERT(name, head, elm) name##_HT_INSERT((head), (elm))
+#define HT_REPLACE(name, head, elm) name##_HT_REPLACE((head), (elm))
+#define HT_REMOVE(name, head, elm) name##_HT_REMOVE((head), (elm))
+#define HT_START(name, head) name##_HT_START(head)
+#define HT_NEXT(name, head, elm) name##_HT_NEXT((head), (elm))
+#define HT_NEXT_RMV(name, head, elm) name##_HT_NEXT_RMV((head), (elm))
+#define HT_CLEAR(name, head) name##_HT_CLEAR(head)
+#define HT_INIT(name, head) name##_HT_INIT(head)
+/* Helper: */
+static inline unsigned
+ht_improve_hash(unsigned h)
+{
+ /* Aim to protect against poor hash functions by adding logic here
+ * - logic taken from java 1.4 hashtable source */
+ h += ~(h << 9);
+ h ^= ((h >> 14) | (h << 18)); /* >>> */
+ h += (h << 4);
+ h ^= ((h >> 10) | (h << 22)); /* >>> */
+ return h;
+}
+
+#if 0
+/** Basic string hash function, from Java standard String.hashCode(). */
+static inline unsigned
+ht_string_hash(const char *s)
+{
+ unsigned h = 0;
+ int m = 1;
+ while (*s) {
+ h += ((signed char)*s++)*m;
+ m = (m<<5)-1; /* m *= 31 */
+ }
+ return h;
+}
+#endif
+
+/** Basic string hash function, from Python's str.__hash__() */
+static inline unsigned
+ht_string_hash(const char *s)
+{
+ unsigned h;
+ const unsigned char *cp = (const unsigned char *)s;
+ h = *cp << 7;
+ while (*cp) {
+ h = (1000003*h) ^ *cp++;
+ }
+ /* This conversion truncates the length of the string, but that's ok. */
+ h ^= (unsigned)(cp-(const unsigned char*)s);
+ return h;
+}
+
+#ifdef HT_CACHE_HASH_VALUES
+#define _HT_SET_HASH(elm, field, hashfn) \
+ do { (elm)->field.hte_hash = hashfn(elm); } while (0)
+#define _HT_SET_HASHVAL(elm, field, val) \
+ do { (elm)->field.hte_hash = (val); } while (0)
+#define _HT_ELT_HASH(elm, field, hashfn) \
+ ((elm)->field.hte_hash)
+#else
+#define _HT_SET_HASH(elm, field, hashfn) \
+ ((void)0)
+#define _HT_ELT_HASH(elm, field, hashfn) \
+ (hashfn(elm))
+#define _HT_SET_HASHVAL(elm, field, val) \
+ ((void)0)
+#endif
+
+/* Helper: alias for the bucket containing 'elm'. */
+#define _HT_BUCKET(head, field, elm, hashfn) \
+ ((head)->hth_table[_HT_ELT_HASH(elm,field,hashfn) % head->hth_table_length])
+
+#define HT_FOREACH(x, name, head) \
+ for ((x) = HT_START(name, head); \
+ (x) != NULL; \
+ (x) = HT_NEXT(name, head, x))
+
+#define HT_PROTOTYPE(name, type, field, hashfn, eqfn) \
+ int name##_HT_GROW(struct name *ht, unsigned min_capacity); \
+ void name##_HT_CLEAR(struct name *ht); \
+ int _##name##_HT_REP_IS_BAD(const struct name *ht); \
+ static inline void \
+ name##_HT_INIT(struct name *head) { \
+ head->hth_table_length = 0; \
+ head->hth_table = NULL; \
+ head->hth_n_entries = 0; \
+ head->hth_load_limit = 0; \
+ head->hth_prime_idx = -1; \
+ } \
+ /* Helper: returns a pointer to the right location in the table \
+ * 'head' to find or insert the element 'elm'. */ \
+ static inline struct type ** \
+ _##name##_HT_FIND_P(struct name *head, struct type *elm) \
+ { \
+ struct type **p; \
+ if (!head->hth_table) \
+ return NULL; \
+ p = &_HT_BUCKET(head, field, elm, hashfn); \
+ while (*p) { \
+ if (eqfn(*p, elm)) \
+ return p; \
+ p = &(*p)->field.hte_next; \
+ } \
+ return p; \
+ } \
+ /* Return a pointer to the element in the table 'head' matching 'elm', \
+ * or NULL if no such element exists */ \
+ static inline struct type * \
+ name##_HT_FIND(const struct name *head, struct type *elm) \
+ { \
+ struct type **p; \
+ struct name *h = (struct name *) head; \
+ _HT_SET_HASH(elm, field, hashfn); \
+ p = _##name##_HT_FIND_P(h, elm); \
+ return p ? *p : NULL; \
+ } \
+ /* Insert the element 'elm' into the table 'head'. Do not call this \
+ * function if the table might already contain a matching element. */ \
+ static inline void \
+ name##_HT_INSERT(struct name *head, struct type *elm) \
+ { \
+ struct type **p; \
+ if (!head->hth_table || head->hth_n_entries >= head->hth_load_limit) \
+ name##_HT_GROW(head, head->hth_n_entries+1); \
+ ++head->hth_n_entries; \
+ _HT_SET_HASH(elm, field, hashfn); \
+ p = &_HT_BUCKET(head, field, elm, hashfn); \
+ elm->field.hte_next = *p; \
+ *p = elm; \
+ } \
+ /* Insert the element 'elm' into the table 'head'. If there already \
+ * a matching element in the table, replace that element and return \
+ * it. */ \
+ static inline struct type * \
+ name##_HT_REPLACE(struct name *head, struct type *elm) \
+ { \
+ struct type **p, *r; \
+ if (!head->hth_table || head->hth_n_entries >= head->hth_load_limit) \
+ name##_HT_GROW(head, head->hth_n_entries+1); \
+ _HT_SET_HASH(elm, field, hashfn); \
+ p = _##name##_HT_FIND_P(head, elm); \
+ r = *p; \
+ *p = elm; \
+ if (r && (r!=elm)) { \
+ elm->field.hte_next = r->field.hte_next; \
+ r->field.hte_next = NULL; \
+ return r; \
+ } else { \
+ ++head->hth_n_entries; \
+ return NULL; \
+ } \
+ } \
+ /* Remove any element matching 'elm' from the table 'head'. If such \
+ * an element is found, return it; otherwise return NULL. */ \
+ static inline struct type * \
+ name##_HT_REMOVE(struct name *head, struct type *elm) \
+ { \
+ struct type **p, *r; \
+ _HT_SET_HASH(elm, field, hashfn); \
+ p = _##name##_HT_FIND_P(head,elm); \
+ if (!p || !*p) \
+ return NULL; \
+ r = *p; \
+ *p = r->field.hte_next; \
+ r->field.hte_next = NULL; \
+ --head->hth_n_entries; \
+ return r; \
+ } \
+ /* Invoke the function 'fn' on every element of the table 'head', \
+ * using 'data' as its second argument. If the function returns \
+ * nonzero, remove the most recently examined element before invoking \
+ * the function again. */ \
+ static inline void \
+ name##_HT_FOREACH_FN(struct name *head, \
+ int (*fn)(struct type *, void *), \
+ void *data) \
+ { \
+ unsigned idx; \
+ struct type **p, **nextp, *next; \
+ if (!head->hth_table) \
+ return; \
+ for (idx=0; idx < head->hth_table_length; ++idx) { \
+ p = &head->hth_table[idx]; \
+ while (*p) { \
+ nextp = &(*p)->field.hte_next; \
+ next = *nextp; \
+ if (fn(*p, data)) { \
+ --head->hth_n_entries; \
+ *p = next; \
+ } else { \
+ p = nextp; \
+ } \
+ } \
+ } \
+ } \
+ /* Return a pointer to the first element in the table 'head', under \
+ * an arbitrary order. This order is stable under remove operations, \
+ * but not under others. If the table is empty, return NULL. */ \
+ static inline struct type ** \
+ name##_HT_START(struct name *head) \
+ { \
+ unsigned b = 0; \
+ while (b < head->hth_table_length) { \
+ if (head->hth_table[b]) \
+ return &head->hth_table[b]; \
+ ++b; \
+ } \
+ return NULL; \
+ } \
+ /* Return the next element in 'head' after 'elm', under the arbitrary \
+ * order used by HT_START. If there are no more elements, return \
+ * NULL. If 'elm' is to be removed from the table, you must call \
+ * this function for the next value before you remove it. \
+ */ \
+ static inline struct type ** \
+ name##_HT_NEXT(struct name *head, struct type **elm) \
+ { \
+ if ((*elm)->field.hte_next) { \
+ return &(*elm)->field.hte_next; \
+ } else { \
+ unsigned b = (_HT_ELT_HASH(*elm, field, hashfn) % head->hth_table_length)+1; \
+ while (b < head->hth_table_length) { \
+ if (head->hth_table[b]) \
+ return &head->hth_table[b]; \
+ ++b; \
+ } \
+ return NULL; \
+ } \
+ } \
+ static inline struct type ** \
+ name##_HT_NEXT_RMV(struct name *head, struct type **elm) \
+ { \
+ unsigned h = _HT_ELT_HASH(*elm, field, hashfn); \
+ *elm = (*elm)->field.hte_next; \
+ --head->hth_n_entries; \
+ if (*elm) { \
+ return elm; \
+ } else { \
+ unsigned b = (h % head->hth_table_length)+1; \
+ while (b < head->hth_table_length) { \
+ if (head->hth_table[b]) \
+ return &head->hth_table[b]; \
+ ++b; \
+ } \
+ return NULL; \
+ } \
+ }
+
+#define HT_GENERATE(name, type, field, hashfn, eqfn, load, mallocfn, \
+ reallocfn, freefn) \
+ static unsigned name##_PRIMES[] = { \
+ 53, 97, 193, 389, \
+ 769, 1543, 3079, 6151, \
+ 12289, 24593, 49157, 98317, \
+ 196613, 393241, 786433, 1572869, \
+ 3145739, 6291469, 12582917, 25165843, \
+ 50331653, 100663319, 201326611, 402653189, \
+ 805306457, 1610612741 \
+ }; \
+ static unsigned name##_N_PRIMES = \
+ (unsigned)(sizeof(name##_PRIMES)/sizeof(name##_PRIMES[0])); \
+ /* Expand the internal table of 'head' until it is large enough to \
+ * hold 'size' elements. Return 0 on success, -1 on allocation \
+ * failure. */ \
+ int \
+ name##_HT_GROW(struct name *head, unsigned size) \
+ { \
+ unsigned new_len, new_load_limit; \
+ int prime_idx; \
+ struct type **new_table; \
+ if (head->hth_prime_idx == (int)name##_N_PRIMES - 1) \
+ return 0; \
+ if (head->hth_load_limit > size) \
+ return 0; \
+ prime_idx = head->hth_prime_idx; \
+ do { \
+ new_len = name##_PRIMES[++prime_idx]; \
+ new_load_limit = (unsigned)(load*new_len); \
+ } while (new_load_limit <= size && \
+ prime_idx < (int)name##_N_PRIMES); \
+ if ((new_table = mallocfn(new_len*sizeof(struct type*)))) { \
+ unsigned b; \
+ memset(new_table, 0, new_len*sizeof(struct type*)); \
+ for (b = 0; b < head->hth_table_length; ++b) { \
+ struct type *elm, *next; \
+ unsigned b2; \
+ elm = head->hth_table[b]; \
+ while (elm) { \
+ next = elm->field.hte_next; \
+ b2 = _HT_ELT_HASH(elm, field, hashfn) % new_len; \
+ elm->field.hte_next = new_table[b2]; \
+ new_table[b2] = elm; \
+ elm = next; \
+ } \
+ } \
+ if (head->hth_table) \
+ freefn(head->hth_table); \
+ head->hth_table = new_table; \
+ } else { \
+ unsigned b, b2; \
+ new_table = reallocfn(head->hth_table, new_len*sizeof(struct type*)); \
+ if (!new_table) return -1; \
+ memset(new_table + head->hth_table_length, 0, \
+ (new_len - head->hth_table_length)*sizeof(struct type*)); \
+ for (b=0; b < head->hth_table_length; ++b) { \
+ struct type *e, **pE; \
+ for (pE = &new_table[b], e = *pE; e != NULL; e = *pE) { \
+ b2 = _HT_ELT_HASH(e, field, hashfn) % new_len; \
+ if (b2 == b) { \
+ pE = &e->field.hte_next; \
+ } else { \
+ *pE = e->field.hte_next; \
+ e->field.hte_next = new_table[b2]; \
+ new_table[b2] = e; \
+ } \
+ } \
+ } \
+ head->hth_table = new_table; \
+ } \
+ head->hth_table_length = new_len; \
+ head->hth_prime_idx = prime_idx; \
+ head->hth_load_limit = new_load_limit; \
+ return 0; \
+ } \
+ /* Free all storage held by 'head'. Does not free 'head' itself, or \
+ * individual elements. */ \
+ void \
+ name##_HT_CLEAR(struct name *head) \
+ { \
+ if (head->hth_table) \
+ freefn(head->hth_table); \
+ head->hth_table_length = 0; \
+ name##_HT_INIT(head); \
+ } \
+ /* Debugging helper: return false iff the representation of 'head' is \
+ * internally consistent. */ \
+ int \
+ _##name##_HT_REP_IS_BAD(const struct name *head) \
+ { \
+ unsigned n, i; \
+ struct type *elm; \
+ if (!head->hth_table_length) { \
+ if (!head->hth_table && !head->hth_n_entries && \
+ !head->hth_load_limit && head->hth_prime_idx == -1) \
+ return 0; \
+ else \
+ return 1; \
+ } \
+ if (!head->hth_table || head->hth_prime_idx < 0 || \
+ !head->hth_load_limit) \
+ return 2; \
+ if (head->hth_n_entries > head->hth_load_limit) \
+ return 3; \
+ if (head->hth_table_length != name##_PRIMES[head->hth_prime_idx]) \
+ return 4; \
+ if (head->hth_load_limit != (unsigned)(load*head->hth_table_length)) \
+ return 5; \
+ for (n = i = 0; i < head->hth_table_length; ++i) { \
+ for (elm = head->hth_table[i]; elm; elm = elm->field.hte_next) { \
+ if (_HT_ELT_HASH(elm, field, hashfn) != hashfn(elm)) \
+ return 1000 + i; \
+ if ((_HT_ELT_HASH(elm, field, hashfn) % head->hth_table_length) != i) \
+ return 10000 + i; \
+ ++n; \
+ } \
+ } \
+ if (n != head->hth_n_entries) \
+ return 6; \
+ return 0; \
+ }
+
+/** Implements an over-optimized "find and insert if absent" block;
+ * not meant for direct usage by typical code, or usage outside the critical
+ * path.*/
+#define _HT_FIND_OR_INSERT(name, field, hashfn, head, eltype, elm, var, y, n) \
+ { \
+ struct name *_##var##_head = head; \
+ struct eltype **var; \
+ if (!_##var##_head->hth_table || \
+ _##var##_head->hth_n_entries >= _##var##_head->hth_load_limit) \
+ name##_HT_GROW(_##var##_head, _##var##_head->hth_n_entries+1); \
+ _HT_SET_HASH((elm), field, hashfn); \
+ var = _##name##_HT_FIND_P(_##var##_head, (elm)); \
+ if (*var) { \
+ y; \
+ } else { \
+ n; \
+ } \
+ }
+#define _HT_FOI_INSERT(field, head, elm, newent, var) \
+ { \
+ _HT_SET_HASHVAL(newent, field, (elm)->field.hte_hash); \
+ newent->field.hte_next = NULL; \
+ *var = newent; \
+ ++((head)->hth_n_entries); \
+ }
+
+/*
+ * Copyright 2005, Nick Mathewson. Implementation logic is adapted from code
+ * by Cristopher Clark, retrofit to allow drop-in memory management, and to
+ * use the same interface as Niels Provos's tree.h. This is probably still
+ * a derived work, so the original license below still applies.
+ *
+ * Copyright (c) 2002, Christopher Clark
+ * 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 the original author; nor the names of any 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 THE COPYRIGHT OWNER
+ * OR CONTRIBUTORS 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.
+*/
+
+#endif
+
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