objset: new module.

[ccan] / ccan / objset / objset.h

diff --git a/ccan/objset/objset.h b/ccan/objset/objset.h
new file mode 100644 (file)
index 0000000..2492a52
--- /dev/null
+++ b/ccan/objset/objset.h
@@ -0,0 +1,173 @@
+/* Licensed under LGPLv2+ - see LICENSE file for details */
+#ifndef CCAN_OBJSET_H
+#define CCAN_OBJSET_H
+#include "config.h"
+#include <ccan/htable/htable_type.h>
+#include <ccan/hash/hash.h>
+#include <ccan/tcon/tcon.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+static inline const void *objset_key_(const void *elem)
+{
+       return elem;
+}
+static inline size_t objset_hashfn_(const void *elem)
+{
+       return hash_pointer(elem, 0);
+}
+static inline bool objset_eqfn_(const void *e1, const void *e2)
+{
+       return e1 == e2;
+}
+HTABLE_DEFINE_TYPE(void, objset_key_, objset_hashfn_, objset_eqfn_, objset_h);
+
+/**
+ * OBJSET_MEMBERS - declare members for a type-specific unordered objset.
+ * @type: type for this set's values, or void * for any pointer.
+ *
+ * You use this to create your own typed objset for a particular type.
+ * You can use an integer type, *but* remember you can't use "0" as a
+ * value!
+ *
+ * Example:
+ *     struct objset_int {
+ *             OBJSET_MEMBERS(int *);
+ *     };
+ */
+#define OBJSET_MEMBERS(type)                   \
+       struct objset_h raw;                    \
+       TCON(type canary)
+
+/**
+ * objset_init - initialize an empty objset
+ * @set: the typed objset to initialize.
+ *
+ * Example:
+ *     struct objset_int set;
+ *
+ *     objset_init(&set);
+ */
+#define objset_init(set) objset_h_init(&(set)->raw)
+
+/**
+ * objset_empty - is this set empty?
+ * @set: the typed objset to check.
+ *
+ * Example:
+ *     if (!objset_empty(&set))
+ *             abort();
+ */
+#define objset_empty(set) objset_empty_(&(set)->raw)
+
+static inline bool objset_empty_(const struct objset_h *set)
+{
+       struct objset_h_iter i;
+       return objset_h_first(set, &i) == NULL;
+}
+
+/**
+ * objset_add - place a member into the set.
+ * @set: the typed objset to add to.
+ * @value: the (non-NULL) object to place in the set.
+ *
+ * This returns false if we run out of memory (errno = ENOMEM), or
+ * (more normally) if that pointer already appears in the set (EEXIST).
+ *
+ * Example:
+ *     int *val;
+ *
+ *     val = malloc(sizeof *val);
+ *     *val = 17;
+ *     if (!objset_add(&set, val))
+ *             printf("Impossible: value was already in the set?\n");
+ */
+#define objset_add(set, value)                                         \
+       objset_h_add(&tcon_check((set), canary, (value))->raw, (void *)(value))
+
+/**
+ * objset_get - get a value from a set
+ * @set: the typed objset to search.
+ * @value: the value to search for.
+ *
+ * Returns the value, or NULL if it isn't in the set (and sets errno = ENOENT).
+ *
+ * Example:
+ *     if (objset_get(&set, val));
+ *             printf("hello => %i\n", *val);
+ */
+#define objset_get(set, member) \
+       tcon_cast((set), canary, objset_h_get(&(set)->raw, (member)))
+
+/**
+ * objset_del - remove a member from the set.
+ * @set: the typed objset to delete from.
+ * @value: the value (non-NULL) to remove from the set
+ *
+ * This returns false NULL if @value was not in the set (and sets
+ * errno = ENOENT).
+ *
+ * Example:
+ *     if (!objset_del(&set, val))
+ *             printf("val was not in the set?\n");
+ */
+#define objset_del(set, value)                                         \
+       objset_h_del(&tcon_check((set), canary, value)->raw,            \
+                    (const void *)value)
+
+/**
+ * objset_clear - remove every member from the set.
+ * @set: the typed objset to clear.
+ *
+ * The set will be empty after this.
+ *
+ * Example:
+ *     objset_clear(&set);
+ */
+#define objset_clear(set) objset_h_clear(&(set)->raw)
+
+/**
+ * objset_iter - iterator reference.
+ *
+ * This is valid for a particular set as long as the contents remain unchaged,
+ * otherwise the effect is undefined.
+ */
+struct objset_iter {
+       struct objset_h_iter iter;
+};
+
+/**
+ * objset_first - get an element in the set
+ * @set: the typed objset to iterate through.
+ * @i: a struct objset_iter to use as an iterator.
+ *
+ * Example:
+ *     struct objset_iter i;
+ *     int *v;
+ *
+ *     v = objset_first(&set, &i);
+ *     if (v)
+ *             printf("One value is %i\n", *v);
+ */
+#define objset_first(set, i) \
+       tcon_cast((set), canary, objset_h_first(&(set)->raw, &(i)->iter))
+
+/**
+ * objset_next - get the another element in the set
+ * @set: the typed objset to iterate through.
+ * @i: a struct objset_iter to use as an iterator.
+ *
+ * @i must have been set by a successful objset_first() or
+ * objset_next() call.
+ *
+ * Example:
+ *     while (v) {
+ *             v = objset_next(&set, &i);
+ *             if (v)
+ *                     printf("Another value is %i\n", *v);
+ *     }
+ */
+#define objset_next(set, i) \
+       tcon_cast((set), canary, objset_h_next(&(set)->raw, &(i)->iter))
+
+#endif /* CCAN_OBJSET_H */