X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fstrset%2Fstrset.h;fp=ccan%2Fstrset%2Fstrset.h;h=8d0d307e34c483d2b21351defe68d0ba0baab3c1;hp=0000000000000000000000000000000000000000;hb=ab83de953730f5e5e571dbf69ffb3cc685a102dc;hpb=0845e79650c9257aa0ddef8ff99fd815b5edffac

diff --git a/ccan/strset/strset.h b/ccan/strset/strset.h
new file mode 100644
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+++ b/ccan/strset/strset.h
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+#ifndef CCAN_STRSET_H
+#define CCAN_STRSET_H
+#include "config.h"
+#include <ccan/typesafe_cb/typesafe_cb.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+/**
+ * struct strset - representation of a string set
+ *
+ * It's exposed here to allow you to embed it and so we can inline the
+ * trivial functions.
+ */
+struct strset {
+	union {
+		struct node *n;
+		const char *s;
+	} u;
+};
+
+/**
+ * strset_init - initialize a string set (empty)
+ *
+ * For completeness; if you've arranged for it to be NULL already you don't
+ * need this.
+ *
+ * Example:
+ *	struct strset set;
+ *
+ *	strset_init(&set);
+ */
+static inline void strset_init(struct strset *set)
+{
+	set->u.n = NULL;
+}
+
+/**
+ * strset_empty - is this string set empty?
+ * @set: the set.
+ *
+ * Example:
+ *	if (!strset_empty(&set))
+ *		abort();
+ */
+static inline bool strset_empty(const struct strset *set)
+{
+	return set->u.n == NULL;
+}
+
+/**
+ * strset_test - is this a member of this string set?
+ * @set: the set.
+ * @member: the string to search for.
+ *
+ * Returns the member, or NULL if it isn't in the set.
+ *
+ * Example:
+ *	if (strset_test(&set, "hello"))
+ *		printf("hello is in the set\n");
+ */
+char *strset_test(const struct strset *set, const char *member);
+
+/**
+ * strset_set - place a member in the string set.
+ * @set: the set.
+ * @member: the string to place in the set.
+ *
+ * This returns false if we run out of memory, or (more normally) if that
+ * string already appears in the set.
+ *
+ * Note that the pointer is placed in the set, the string is not copied.  If
+ * you want a copy in the set, use strdup().
+ *
+ * Example:
+ *	if (!strset_set(&set, "goodbye"))
+ *		printf("goodbye was already in the set\n");
+ */
+bool strset_set(struct strset *set, const char *member);
+
+/**
+ * strset_clear - remove a member from the string set.
+ * @set: the set.
+ * @member: the string to remove from the set.
+ *
+ * This returns the string which was passed to strset_set(), or NULL.
+ * This means that if you allocated a string (eg. using strdup()), you can
+ * free it here.
+ *
+ * Example:
+ *	if (!strset_clear(&set, "goodbye"))
+ *		printf("goodbye was not in the set?\n");
+ */
+char *strset_clear(struct strset *set, const char *member);
+
+/**
+ * strset_destroy - remove every member from the set.
+ * @set: the set.
+ *
+ * The set will be empty after this.
+ *
+ * Example:
+ *	strset_destroy(&set);
+ */
+void strset_destroy(struct strset *set);
+
+/**
+ * strset_iterate - ordered iteration over a set
+ * @set: the set.
+ * @handle: the function to call.
+ * @arg: the argument for the function (types should match).
+ *
+ * You should not alter the set within the @handle function!  If it returns
+ * true, the iteration will stop.
+ *
+ * Example:
+ *	static bool dump_some(const char *member, int *num)
+ *	{
+ *		// Only dump out num nodes.
+ *		if (*(num--) == 0)
+ *			return true;
+ *		printf("%s\n", member);
+ *		return false;
+ *	}
+ *
+ *	static void dump_set(const struct strset *set)
+ *	{
+ *		int max = 100;
+ *		strset_iterate(set, dump_some, &max);
+ *		if (max < 0)
+ *			printf("... (truncated to 100 entries)\n");
+ *	}
+ */
+#define strset_iterate(set, handle, arg)				\
+	strset_iterate_((set), typesafe_cb_preargs(bool, void *,	\
+						   (handle), (arg),	\
+						   const char *),	\
+			(arg))
+void strset_iterate_(const struct strset *set,
+		     bool (*handle)(const char *, void *), void *data);
+
+
+/**
+ * strset_prefix - return a subset matching a prefix
+ * @set: the set.
+ * @prefix: the prefix.
+ *
+ * This returns a pointer into @set, so don't alter @set while using
+ * the return value.  You can use strset_iterate(), strset_test() or
+ * strset_empty() on the returned pointer.
+ *
+ * Example:
+ *	static void dump_prefix(const struct strset *set, const char *prefix)
+ *	{
+ *		int max = 100;
+ *		printf("Nodes with prefix %s:\n", prefix);
+ *		strset_iterate(strset_prefix(set, prefix), dump_some, &max);
+ *		if (max < 0)
+ *			printf("... (truncated to 100 entries)\n");
+ *	}
+ */
+const struct strset *strset_prefix(const struct strset *set,
+				   const char *prefix);
+
+#endif /* CCAN_STRSET_H */