hashtable: make traverse callback typesafe.
#if HAVE_TYPEOF
#define asearch(key, base, num, cmp) \
((__typeof__(*(base))*)(bsearch((key), (base), (num), sizeof(*(base)), \
- cast_if_type((cmp), \
- int (*)(const __typeof__(*(key)) *, \
- const __typeof__(*(base)) *), \
- int (*)(const void *, const void *)))))
+ cast_if_type(int (*)(const void *, const void *), \
+ (cmp), \
+ int (*)(const __typeof__(*(key)) *, \
+ const __typeof__(*(base)) *)))))
#else
#define asearch(key, base, num, cmp) \
(bsearch((key), (base), (num), sizeof(*(base)), \
* The @cmp function should exactly match the type of the @base and
* @ctx arguments. Otherwise it can take three const void *.
*/
-#if HAVE_TYPEOF
#define asort(base, num, cmp, ctx) \
_asort((base), (num), sizeof(*(base)), \
- cast_if_type((cmp), \
+ cast_if_type(int (*)(const void *, const void *, const void *), \
+ (cmp), \
int (*)(const __typeof__(*(base)) *, \
const __typeof__(*(base)) *, \
- __typeof__(ctx)), \
- int (*)(const void *, const void *, const void *)), (ctx))
-#else
-#define asort(base, num, cmp, ctx) \
- _asort((base), (num), sizeof(*(base)), \
- (int (*)(const void *, const void *, const void *))(cmp), ctx)
-#endif
+ __typeof__(ctx))), (ctx))
void _asort(void *base, size_t nmemb, size_t size,
int(*compar)(const void *, const void *, const void *),
delete_run(ht, i);
return true;
}
-
-
-void hashtable_traverse(struct hashtable *ht, bool (*cb)(void *p, void *cbarg),
- void *cbarg)
+
+void _hashtable_traverse(struct hashtable *ht,
+ bool (*cb)(void *p, void *cbarg),
+ void *cbarg)
{
size_t i;
#define CCAN_HASHTABLE_H
#include "config.h"
#include <stdbool.h>
+#include <ccan/typesafe_cb/typesafe_cb.h>
struct hashtable;
/**
* hashtable_traverse - call a function on every pointer in hash tree
* @ht: the hashtable
+ * @type: the type of the element in the hashtable.
* @cb: the callback: returns true to abort traversal.
* @cbarg: the argument to the callback
*
* Note that your traversal callback may delete any entry (it won't crash),
* but it may make the traverse unreliable.
*/
-void hashtable_traverse(struct hashtable *ht, bool (*cb)(void *p, void *cbarg),
- void *cbarg);
+#define hashtable_traverse(ht, type, cb, cbarg) \
+ _hashtable_traverse(ht, cast_if_type(bool (*)(void *, void *), \
+ cast_if_any(bool (*)(void *, \
+ void *), (cb), \
+ bool (*)(const type *, \
+ const typeof(*cbarg) *), \
+ bool (*)(type *, \
+ const typeof(*cbarg) *), \
+ bool (*)(const type *, \
+ typeof(*cbarg) *)), \
+ bool (*)(type *, \
+ typeof(*cbarg) *)), \
+ cbarg)
+
+void _hashtable_traverse(struct hashtable *ht,
+ bool (*cb)(void *p, void *cbarg), void *cbarg);
#endif /* CCAN_HASHTABLE_H */
uint64_t *val;
};
-static bool count(void *p, void *cbarg)
+static bool count(void *p, struct travarg *travarg)
{
- struct travarg *travarg = cbarg;
travarg->count++;
travarg->touched[*(uint64_t *)p]++;
return false;
}
-static bool delete_self(void *p, void *cbarg)
+static bool delete_self(uint64_t *p, struct travarg *travarg)
{
- struct travarg *travarg = cbarg;
- uint64_t val = *(uint64_t *)p;
-
travarg->count++;
- travarg->touched[val]++;
+ travarg->touched[*p]++;
return !hashtable_del(travarg->ht, hash(p, NULL), p);
}
-static bool delete_next(void *p, void *cbarg)
+static bool delete_next(uint64_t *p, struct travarg *travarg)
{
- struct travarg *travarg = cbarg;
- uint64_t val = *(uint64_t *)p;
- uint64_t *next = &travarg->val[(val + 1) % NUM_VALS];
+ uint64_t *next = &travarg->val[((*p) + 1) % NUM_VALS];
travarg->count++;
- travarg->touched[val]++;
+ travarg->touched[*p]++;
return !hashtable_del(travarg->ht, hash(next, NULL), next);
}
-static bool delete_prev(void *p, void *cbarg)
+static bool delete_prev(uint64_t *p, struct travarg *travarg)
{
- struct travarg *travarg = cbarg;
- uint64_t val = *(uint64_t *)p;
- uint64_t *prev = &travarg->val[(val - 1) % NUM_VALS];
+ uint64_t *prev = &travarg->val[((*p) - 1) % NUM_VALS];
travarg->count++;
- travarg->touched[val]++;
+ travarg->touched[*p]++;
return !hashtable_del(travarg->ht, hash(prev, NULL), prev);
}
-static bool stop_halfway(void *p, void *cbarg)
+static bool stop_halfway(void *p, struct travarg *travarg)
{
- struct travarg *travarg = cbarg;
travarg->count++;
travarg->touched[*(uint64_t *)p]++;
travarg.count = 0;
/* Traverse. */
- hashtable_traverse(ht, count, &travarg);
+ hashtable_traverse(ht, void, count, &travarg);
ok1(travarg.count == NUM_VALS);
check_all_touched_once(&travarg);
memset(travarg.touched, 0, sizeof(travarg.touched));
travarg.count = 0;
- hashtable_traverse(ht, stop_halfway, &travarg);
+ hashtable_traverse(ht, void, stop_halfway, &travarg);
ok1(travarg.count == NUM_VALS / 2);
check_only_touched_once(&travarg);
i = 0;
/* Delete until we make no more progress. */
for (;;) {
- hashtable_traverse(ht, delete_self, &travarg);
+ hashtable_traverse(ht, uint64_t, delete_self, &travarg);
if (travarg.count == i || travarg.count > NUM_VALS)
break;
i = travarg.count;
memset(travarg.touched, 0, sizeof(travarg.touched));
travarg.count = 0;
refill_vals(ht, val, NUM_VALS);
- hashtable_traverse(ht, delete_next, &travarg);
+ hashtable_traverse(ht, uint64_t, delete_next, &travarg);
ok1(travarg.count <= NUM_VALS);
check_only_touched_once(&travarg);
memset(travarg.touched, 0, sizeof(travarg.touched));
travarg.count = 0;
refill_vals(ht, val, NUM_VALS);
- hashtable_traverse(ht, delete_prev, &travarg);
+ hashtable_traverse(ht, uint64_t, delete_prev, &travarg);
ok1(travarg.count <= NUM_VALS);
check_only_touched_once(&travarg);
return (double)t->right / t->count;
}
-static bool get_stats(void *elem, void *vinfo)
+static bool get_stats(struct trace *trace, struct get_stats_info *info)
{
- struct trace *trace = elem;
- struct get_stats_info *info = vinfo;
-
if (trace->count < info->min_hits)
return false;
info.worst_ratio = 2;
/* This is O(n), but it's not likely called that often. */
- hashtable_traverse(htable, get_stats, &info);
+ hashtable_traverse(htable, struct trace, get_stats, &info);
if (info.worst_ratio * 100 > percent)
return NULL;
* cast_if_type() and friend become an unconditional cast, so your
* code will compile but you won't get type checking.
*
+ * Example:
+ * #include <ccan/typesafe_cb/typesafe_cb.h>
+ * #include <stdlib.h>
+ * #include <stdio.h>
+ *
+ * // Generic callback infrastructure.
+ * struct callback {
+ * struct callback *next;
+ * int value;
+ * int (*callback)(int value, void *arg);
+ * void *arg;
+ * };
+ * static struct callback *callbacks;
+ *
+ * static void _register_callback(int value, int (*cb)(int, void *),
+ * void *arg)
+ * {
+ * struct callback *new = malloc(sizeof(*new));
+ * new->next = callbacks;
+ * new->value = value;
+ * new->callback = cb;
+ * new->arg = arg;
+ * callbacks = new;
+ * }
+ * #define register_callback(value, cb, arg) \
+ * _register_callback(value, \
+ * typesafe_cb_preargs(int, (cb), (arg), int),\
+ * (arg))
+ *
+ * static struct callback *find_callback(int value)
+ * {
+ * struct callback *i;
+ *
+ * for (i = callbacks; i; i = i->next)
+ * if (i->value == value)
+ * return i;
+ * return NULL;
+ * }
+ *
+ * // Define several silly callbacks. Note they don't use void *!
+ * #define DEF_CALLBACK(name, op) \
+ * static int name(int val, const int *arg)\
+ * { \
+ * printf("%s", #op); \
+ * return val op *arg; \
+ * }
+ * DEF_CALLBACK(multiply, *);
+ * DEF_CALLBACK(add, +);
+ * DEF_CALLBACK(divide, /);
+ * DEF_CALLBACK(sub, -);
+ * DEF_CALLBACK(or, |);
+ * DEF_CALLBACK(and, &);
+ * DEF_CALLBACK(xor, ^);
+ * DEF_CALLBACK(assign, =);
+ *
+ * // Silly game to find the longest chain of values.
+ * int main(int argc, char *argv[])
+ * {
+ * int i, run = 1, num = argv[1] ? atoi(argv[1]) : 0;
+ *
+ * for (i = 1; i < 1024;) {
+ * // Since run is an int, compiler checks "add" does too.
+ * register_callback(i++, add, &run);
+ * register_callback(i++, divide, &run);
+ * register_callback(i++, sub, &run);
+ * register_callback(i++, multiply, &run);
+ * register_callback(i++, or, &run);
+ * register_callback(i++, and, &run);
+ * register_callback(i++, xor, &run);
+ * register_callback(i++, assign, &run);
+ * }
+ *
+ * printf("%i ", num);
+ * while (run < 56) {
+ * struct callback *cb = find_callback(num % i);
+ * if (!cb) {
+ * printf("-> STOP\n");
+ * return 1;
+ * }
+ * num = cb->callback(num, cb->arg);
+ * printf("->%i ", num);
+ * run++;
+ * }
+ * printf("-> Winner!\n");
+ * return 0;
+ * }
+ *
* Licence: LGPL (2 or any later version)
*/
int main(int argc, char *argv[])
}
#define set_some_value(expr) \
- _set_some_value(cast_if_type((expr), unsigned long, void *))
+ _set_some_value(cast_if_type(void *, (expr), unsigned long))
int main(int argc, char *argv[])
{
}
#define set_some_value(expr) \
- _set_some_value(cast_if_type((expr), unsigned long, void *))
+ _set_some_value(cast_if_type(void *, (expr), unsigned long))
static void _callback_onearg(void (*fn)(void *arg), void *arg)
{
#if HAVE_TYPEOF && HAVE_BUILTIN_CHOOSE_EXPR && HAVE_BUILTIN_TYPES_COMPATIBLE_P
/**
* cast_if_type - only cast an expression if it is of a given type
+ * @desttype: the type to cast to
* @expr: the expression to cast
* @oktype: the type we allow
- * @desttype: the type to cast to
*
* This macro is used to create functions which allow multiple types.
* The result of this macro is used somewhere that a @desttype type is
* // We can take either an unsigned long or a void *.
* void _set_some_value(void *val);
* #define set_some_value(expr) \
- * _set_some_value(cast_if_type((expr), unsigned long, void *))
+ * _set_some_value(cast_if_type(void *, (expr), unsigned long))
*/
-#define cast_if_type(expr, oktype, desttype) \
+#define cast_if_type(desttype, expr, oktype) \
__builtin_choose_expr(__builtin_types_compatible_p(typeof(1?(expr):0), oktype), \
(desttype)(expr), (expr))
#else
#define cast_if_type(expr, oktype, desttype) ((desttype)(expr))
#endif
+/**
+ * cast_if_any - only cast an expression if it is one of the three given types
+ * @desttype: the type to cast to
+ * @expr: the expression to cast
+ * @ok1: the first type we allow
+ * @ok2: the second type we allow
+ * @ok3: the third type we allow
+ *
+ * This is a convenient wrapper for multiple cast_if_type() calls. You can
+ * chain them inside each other (ie. use cast_if_any() for expr) if you need
+ * more than 3 arguments.
+ *
+ * Example:
+ * // We can take either a long, unsigned long, void * or a const void *.
+ * void _set_some_value(void *val);
+ * #define set_some_value(expr) \
+ * _set_some_value(cast_if_any(void *, (expr), \
+ * long, unsigned long, const void *))
+ */
+#define cast_if_any(desttype, expr, ok1, ok2, ok3) \
+ cast_if_type(desttype, \
+ cast_if_type(desttype, \
+ cast_if_type(desttype, (expr), ok1), \
+ ok2), \
+ ok3)
+
/**
* typesafe_cb - cast a callback function if it matches the arg
* @rtype: the return type of the callback function
* #define register_callback(fn, arg) \
* _register_callback(typesafe_cb(void, (fn), (arg)), (arg))
*/
-#define typesafe_cb(rtype, fn, arg) \
- cast_if_type(cast_if_type(cast_if_type((fn), \
- rtype (*)(const typeof(*arg)*), \
- rtype (*)(void *)), \
- rtype (*)(volatile typeof(*arg) *), \
- rtype (*)(void *)), \
- rtype (*)(typeof(arg)), \
- rtype (*)(void *))
+#define typesafe_cb(rtype, fn, arg) \
+ cast_if_any(rtype (*)(void *), (fn), \
+ rtype (*)(typeof(*arg)*), \
+ rtype (*)(const typeof(*arg)*), \
+ rtype (*)(volatile typeof(*arg)*))
/**
* typesafe_cb_const - cast a const callback function if it matches the arg
* _register_callback(typesafe_cb_const(void, (fn), (arg)), (arg))
*/
#define typesafe_cb_const(rtype, fn, arg) \
- cast_if_type((fn), \
- rtype (*)(const typeof(*arg)*), rtype (*)(const void *))
+ cast_if_type(rtype (*)(const void *), (fn), \
+ rtype (*)(const typeof(*arg)*))
/**
* typesafe_cb_preargs - cast a callback function if it matches the arg
* (arg))
*/
#define typesafe_cb_preargs(rtype, fn, arg, ...) \
- cast_if_type(cast_if_type(cast_if_type((fn), \
- rtype (*)(__VA_ARGS__, \
- const typeof(*arg) *),\
- rtype (*)(__VA_ARGS__, \
- void *)), \
- rtype (*)(__VA_ARGS__, \
- volatile typeof(*arg) *), \
- rtype (*)(__VA_ARGS__, void *)), \
- rtype (*)(__VA_ARGS__, typeof(arg)), \
- rtype (*)(__VA_ARGS__, void *))
+ cast_if_any(rtype (*)(__VA_ARGS__, void *), (fn), \
+ rtype (*)(__VA_ARGS__, typeof(arg)), \
+ rtype (*)(__VA_ARGS__, const typeof(*arg) *), \
+ rtype (*)(__VA_ARGS__, volatile typeof(*arg) *))
/**
* typesafe_cb_postargs - cast a callback function if it matches the arg
* Example:
* void _register_callback(void (*fn)(void *arg, int), void *arg);
* #define register_callback(fn, arg) \
- * _register_callback(typesafe_cb_preargs(void, (fn), (arg), int),\
+ * _register_callback(typesafe_cb_postargs(void, (fn), (arg), int),\
* (arg))
*/
#define typesafe_cb_postargs(rtype, fn, arg, ...) \
- cast_if_type(cast_if_type(cast_if_type((fn), \
- rtype (*)(const typeof(*arg) *, \
- __VA_ARGS__), \
- rtype (*)(void *, \
- __VA_ARGS__)), \
- rtype (*)(volatile typeof(*arg) *, \
- __VA_ARGS__), \
- rtype (*)(void *, __VA_ARGS__)), \
- rtype (*)(typeof(arg), __VA_ARGS__), \
- rtype (*)(void *, __VA_ARGS__))
+ cast_if_any(rtype (*)(void *, __VA_ARGS__), (fn), \
+ rtype (*)(typeof(arg), __VA_ARGS__), \
+ rtype (*)(const typeof(*arg) *, __VA_ARGS__), \
+ rtype (*)(volatile typeof(*arg) *, __VA_ARGS__))
/**
* typesafe_cb_cmp - cast a compare function if it matches the arg
* typesafe_cb_cmp(int, (cmpfn), (base)), (arg))
*/
#define typesafe_cb_cmp(rtype, cmpfn, arg) \
- cast_if_type((cmpfn), \
- rtype (*)(const typeof(*arg)*, const typeof(*arg)*), \
- rtype (*)(const void *, const void *))
+ cast_if_type(rtype (*)(const void *, const void *), (cmpfn), \
+ rtype (*)(const typeof(*arg)*, const typeof(*arg)*))
+
#endif /* CCAN_CAST_IF_TYPE_H */
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