--- /dev/null
+#include <string.h>
+#include "config.h"
+
+/**
+ * strset - an ordered set of strings
+ *
+ * This code implements an ordered set of string as a critbit tree. See:
+ *
+ * http://cr.yp.to/critbit.html
+ * http://github.com/agl/critbit (which this code is based on)
+ *
+ * Note that ccan/htable is faster and uses less memory, but doesn't provide
+ * ordered or prefix operations.
+ *
+ * Example:
+ * // Print all words in order.
+ * #include <ccan/strset/strset.h>
+ * #include <ccan/grab_file/grab_file.h>
+ * #include <err.h>
+ * #include <string.h>
+ *
+ * static bool dump(const char *member, void *unused)
+ * {
+ * printf("%s ", member);
+ * return false;
+ * }
+ *
+ * int main(void)
+ * {
+ * struct strset words;
+ * char *file, *word;
+ *
+ * strset_init(&words);
+ * file = grab_fd(NULL, 0, NULL);
+ * if (!file)
+ * err(1, "Reading stdin");
+ *
+ * for (word = strtok(file, " \t\r\n");
+ * word;
+ * word = strtok(NULL, " \t\r\n")) {
+ * strset_set(&words, word);
+ * }
+ * strset_iterate(&words, dump, NULL);
+ * printf("\n");
+ * return 0;
+ * }
+ * // Given "foo bar" outputs "bar foo "
+ * // Given "foo foo bar" outputs "bar foo "
+ *
+ * License: Public domain (but some dependencies are LGPL!)
+ * Author: Rusty Russell <rusty@rustcorp.com.au>
+ * Ccanlint:
+ * license_depends_compat FAIL
+ */
+int main(int argc, char *argv[])
+{
+ /* Expect exactly one argument */
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ printf("ccan/ilog\n"
+ "ccan/likely\n"
+ "ccan/short_types\n"
+ "ccan/str\n"
+ "ccan/typesafe_cb\n");
+ return 0;
+ }
+
+ return 1;
+}
--- /dev/null
+/* This code is based on the public domain code at
+ * http://github.com/agl/critbit writtem by Adam Langley
+ * <agl@imperialviolet.org>.
+ *
+ * Here are the main implementation differences:
+ * (1) We don't strdup the string on insert; we use the pointer we're given.
+ * (2) We use a straight bit number rather than a mask; it's simpler.
+ * (3) We don't use the bottom bit of the pointer, but instead use a leading
+ * zero to distinguish nodes from strings.
+ * (4) The empty string (which would look like a node) is handled
+ * using a special "empty node".
+ * (5) Delete returns the string, so you can free it if you want to.
+ * (6) Unions instead of void *, bool instead of int.
+ */
+#include <ccan/strset/strset.h>
+#include <ccan/short_types/short_types.h>
+#include <ccan/likely/likely.h>
+#include <ccan/str/str.h>
+#include <ccan/ilog/ilog.h>
+#include <assert.h>
+#include <stdlib.h>
+
+struct node {
+ /* To differentiate us from strings. */
+ char nul_byte;
+ /* The bit where these children differ. */
+ u8 bit_num;
+ /* The byte number where first bit differs (-1 == empty string node). */
+ size_t byte_num;
+ /* These point to strings or nodes. */
+ struct strset child[2];
+};
+
+/* Closest member to this in a non-empty set. */
+static const char *closest(struct strset n, const char *member)
+{
+ size_t len = strlen(member);
+ const u8 *bytes = (const u8 *)member;
+
+ /* Anything with first byte 0 is a node. */
+ while (!n.u.s[0]) {
+ u8 direction = 0;
+
+ /* Special node which represents the empty string. */
+ if (unlikely(n.u.n->byte_num == (size_t)-1)) {
+ n = n.u.n->child[0];
+ break;
+ }
+
+ if (n.u.n->byte_num < len) {
+ u8 c = bytes[n.u.n->byte_num];
+ direction = (c >> n.u.n->bit_num) & 1;
+ }
+ n = n.u.n->child[direction];
+ }
+ return n.u.s;
+}
+
+char *strset_test(const struct strset *set, const char *member)
+{
+ const char *str;
+
+ /* Empty set? */
+ if (!set->u.n)
+ return NULL;
+ str = closest(*set, member);
+ if (streq(member, str))
+ return (char *)str;
+ return NULL;
+}
+
+static bool set_string(struct strset *set,
+ struct strset *n, const char *member)
+{
+ /* Substitute magic empty node if this is the empty string */
+ if (unlikely(!member[0])) {
+ n->u.n = malloc(sizeof(*n->u.n));
+ if (unlikely(!n->u.n))
+ return false;
+ n->u.n->nul_byte = '\0';
+ n->u.n->byte_num = (size_t)-1;
+ /* Attach the string to child[0] */
+ n = &n->u.n->child[0];
+ }
+ n->u.s = member;
+ return true;
+}
+
+bool strset_set(struct strset *set, const char *member)
+{
+ size_t len = strlen(member);
+ const u8 *bytes = (const u8 *)member;
+ struct strset *np;
+ const char *str;
+ struct node *newn;
+ size_t byte_num;
+ u8 bit_num, new_dir;
+
+ /* Empty set? */
+ if (!set->u.n) {
+ return set_string(set, set, member);
+ }
+
+ /* Find closest existing member. */
+ str = closest(*set, member);
+
+ /* Find where they differ. */
+ for (byte_num = 0; str[byte_num] == member[byte_num]; byte_num++) {
+ if (member[byte_num] == '\0') {
+ /* All identical! */
+ return false;
+ }
+ }
+
+ /* Find which bit differs (if we had ilog8, we'd use it) */
+ bit_num = ilog32_nz((u8)str[byte_num] ^ bytes[byte_num]) - 1;
+ assert(bit_num < CHAR_BIT);
+
+ /* Which direction do we go at this bit? */
+ new_dir = ((bytes[byte_num]) >> bit_num) & 1;
+
+ /* Allocate new node. */
+ newn = malloc(sizeof(*newn));
+ if (!newn) {
+ /* FIXME */
+ return false;
+ }
+ newn->nul_byte = '\0';
+ newn->byte_num = byte_num;
+ newn->bit_num = bit_num;
+ if (unlikely(!set_string(set, &newn->child[new_dir], member))) {
+ free(newn);
+ return false;
+ }
+
+ /* Find where to insert: not closest, but first which differs! */
+ np = set;
+ while (!np->u.s[0]) {
+ u8 direction = 0;
+
+ /* Special node which represents the empty string will
+ * break here too! */
+ if (np->u.n->byte_num > byte_num)
+ break;
+ /* Subtle: bit numbers are "backwards" for comparison */
+ if (np->u.n->byte_num == byte_num && np->u.n->bit_num < bit_num)
+ break;
+
+ if (np->u.n->byte_num < len) {
+ u8 c = bytes[np->u.n->byte_num];
+ direction = (c >> np->u.n->bit_num) & 1;
+ }
+ np = &np->u.n->child[direction];
+ }
+
+ newn->child[!new_dir]= *np;
+ np->u.n = newn;
+ return true;
+}
+
+char *strset_clear(struct strset *set, const char *member)
+{
+ size_t len = strlen(member);
+ const u8 *bytes = (const u8 *)member;
+ struct strset *parent = NULL, *n;
+ const char *ret = NULL;
+ u8 direction = 0; /* prevent bogus gcc warning. */
+
+ /* Empty set? */
+ if (!set->u.n)
+ return NULL;
+
+ /* Find closest, but keep track of parent. */
+ n = set;
+ /* Anything with first byte 0 is a node. */
+ while (!n->u.s[0]) {
+ u8 c = 0;
+
+ /* Special node which represents the empty string. */
+ if (unlikely(n->u.n->byte_num == (size_t)-1)) {
+ const char *empty_str = n->u.n->child[0].u.s;
+
+ if (member[0])
+ return NULL;
+
+ /* Sew empty string back so remaining logic works */
+ free(n->u.n);
+ n->u.s = empty_str;
+ break;
+ }
+
+ parent = n;
+ if (n->u.n->byte_num < len) {
+ c = bytes[n->u.n->byte_num];
+ direction = (c >> n->u.n->bit_num) & 1;
+ } else
+ direction = 0;
+ n = &n->u.n->child[direction];
+ }
+
+ /* Did we find it? */
+ if (!streq(member, n->u.s))
+ return NULL;
+
+ ret = n->u.s;
+
+ if (!parent) {
+ /* We deleted last node. */
+ set->u.n = NULL;
+ } else {
+ struct node *old = parent->u.n;
+ /* Raise other node to parent. */
+ *parent = old->child[!direction];
+ free(old);
+ }
+
+ return (char *)ret;
+}
+
+static bool iterate(struct strset n,
+ bool (*handle)(const char *, void *), void *data)
+{
+ if (n.u.s[0])
+ return handle(n.u.s, data);
+ if (unlikely(n.u.n->byte_num == (size_t)-1))
+ return handle(n.u.n->child[0].u.s, data);
+
+ return iterate(n.u.n->child[0], handle, data)
+ || iterate(n.u.n->child[1], handle, data);
+}
+
+void strset_iterate_(const struct strset *set,
+ bool (*handle)(const char *, void *), void *data)
+{
+ /* Empty set? */
+ if (!set->u.n)
+ return;
+
+ iterate(*set, handle, data);
+}
+
+const struct strset *strset_prefix(const struct strset *set, const char *prefix)
+{
+ const struct strset *n, *top;
+ size_t len = strlen(prefix);
+ const u8 *bytes = (const u8 *)prefix;
+
+ /* Empty set -> return empty set. */
+ if (!set->u.n)
+ return set;
+
+ top = n = set;
+
+ /* We walk to find the top, but keep going to check prefix matches. */
+ while (!n->u.s[0]) {
+ u8 c = 0, direction;
+
+ /* Special node which represents the empty string. */
+ if (unlikely(n->u.n->byte_num == (size_t)-1)) {
+ n = &n->u.n->child[0];
+ break;
+ }
+
+ if (n->u.n->byte_num < len)
+ c = bytes[n->u.n->byte_num];
+
+ direction = (c >> n->u.n->bit_num) & 1;
+ n = &n->u.n->child[direction];
+ if (c)
+ top = n;
+ }
+
+ if (!strstarts(n->u.s, prefix)) {
+ /* Convenient return for prefixes which do not appear in set. */
+ static const struct strset empty_set;
+ return &empty_set;
+ }
+
+ return top;
+}
+
+static void destroy(struct strset n)
+{
+ if (!n.u.s[0]) {
+ if (likely(n.u.n->byte_num != (size_t)-1)) {
+ destroy(n.u.n->child[0]);
+ destroy(n.u.n->child[1]);
+ }
+ free(n.u.n);
+ }
+}
+
+void strset_destroy(struct strset *set)
+{
+ if (set->u.n)
+ destroy(*set);
+ set->u.n = NULL;
+}
--- /dev/null
+#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 */
--- /dev/null
+/* Test high bit handling. */
+#include <ccan/strset/strset.h>
+#include <ccan/strset/strset.c>
+#include <ccan/tap/tap.h>
+
+#define NUM 1000
+
+static void encode(char template[3], unsigned int val)
+{
+ assert(val < 255 * 255);
+ template[0] = (val / 255) + 1;
+ template[1] = (val % 255) + 1;
+ template[2] = '\0';
+}
+
+static bool in_order(const char *value, unsigned int *count)
+{
+ char template[3];
+ encode(template, *count);
+ ok1(streq(value, template));
+ (*count)++;
+ return false;
+}
+
+static bool in_order_by_2(const char *value, unsigned int *count)
+{
+ char template[3];
+ encode(template, *count);
+ ok1(streq(value, template));
+ (*count) += 2;
+ return false;
+}
+
+static bool dump(const char *value, void *unused)
+{
+ diag("%s", value);
+ return false;
+}
+
+int main(void)
+{
+ struct strset set;
+ unsigned int i;
+ char *str[NUM];
+
+ plan_tests(NUM + 3 * NUM / 2);
+ strset_init(&set);
+
+ for (i = 0; i < NUM; i++) {
+ char template[3];
+ encode(template, i);
+ str[i] = strdup(template);
+ }
+
+ for (i = 0; i < NUM; i++)
+ strset_set(&set, str[i]);
+
+ strset_iterate(&set, dump, NULL);
+
+ /* Iterate. */
+ i = 0;
+ strset_iterate(&set, in_order, &i);
+
+ /* Preserve order after deletion. */
+ for (i = 0; i < NUM; i += 2)
+ ok1(strset_clear(&set, str[i]) == str[i]);
+
+ i = 1;
+ strset_iterate(&set, in_order_by_2, &i);
+
+ for (i = 1; i < NUM; i += 2)
+ ok1(strset_clear(&set, str[i]) == str[i]);
+
+ /* empty traverse. */
+ strset_iterate(&set, in_order_by_2, (unsigned int *)NULL);
+
+ for (i = 0; i < NUM; i++)
+ free(str[i]);
+
+ /* This exits depending on whether all tests passed */
+ return exit_status();
+}
--- /dev/null
+#include <ccan/strset/strset.h>
+#include <ccan/strset/strset.c>
+#include <ccan/tap/tap.h>
+#include <stdio.h>
+
+#define NUM 1000
+
+static bool in_order(const char *value, unsigned int *count)
+{
+ int i = atoi(value);
+ ok1(*count == i);
+ (*count)++;
+ return false;
+}
+
+static bool in_order_by_2(const char *value, unsigned int *count)
+{
+ int i = atoi(value);
+ ok1(*count == i);
+ (*count) += 2;
+ return false;
+}
+
+static bool dump(const char *value, void *unused)
+{
+ diag("%s", value);
+ return false;
+}
+
+int main(void)
+{
+ struct strset set;
+ unsigned int i;
+ char *str[NUM];
+
+ plan_tests(NUM * 2 + 3 * NUM / 2);
+ strset_init(&set);
+
+ for (i = 0; i < NUM; i++) {
+ char template[10];
+ sprintf(template, "%08u", i);
+ str[i] = strdup(template);
+ }
+
+ for (i = 0; i < NUM; i++)
+ strset_set(&set, str[i]);
+
+ strset_iterate(&set, dump, NULL);
+
+ /* Iterate. */
+ i = 0;
+ strset_iterate(&set, in_order, &i);
+
+ /* Preserve order after deletion. */
+ for (i = 0; i < NUM; i += 2)
+ ok1(strset_clear(&set, str[i]) == str[i]);
+
+ i = 1;
+ strset_iterate(&set, in_order_by_2, &i);
+
+ for (i = 1; i < NUM; i += 2)
+ ok1(strset_clear(&set, str[i]) == str[i]);
+
+ /* empty traverse. */
+ strset_iterate(&set, in_order_by_2, (unsigned int *)NULL);
+
+ /* insert backwards, should be fine. */
+ for (i = 0; i < NUM; i++)
+ strset_set(&set, str[NUM-1-i]);
+
+ i = 0;
+ strset_iterate(&set, in_order, &i);
+
+ strset_destroy(&set);
+
+ for (i = 0; i < NUM; i++)
+ free(str[i]);
+
+ /* This exits depending on whether all tests passed */
+ return exit_status();
+}
--- /dev/null
+#include <ccan/strset/strset.h>
+#include <ccan/strset/strset.c>
+#include <ccan/tap/tap.h>
+#include <stdio.h>
+
+/* Must be > 100, see below. */
+#define NUM 200
+
+static bool in_order(const char *value, unsigned int *count)
+{
+ int i = atoi(value);
+ ok1(*count == i);
+ (*count)++;
+ return false;
+}
+
+static bool find_empty(const char *value, char *empty)
+{
+ if (value == empty)
+ pass("Found empty entry!");
+ return false;
+}
+
+int main(void)
+{
+ struct strset set;
+ const struct strset *sub;
+ unsigned int i;
+ char *str[NUM], *empty;
+
+ plan_tests(7 + 1 + 10 + 100);
+ strset_init(&set);
+
+ for (i = 0; i < NUM; i++) {
+ char template[10];
+ sprintf(template, "%08u", i);
+ str[i] = strdup(template);
+ }
+
+ for (i = 0; i < NUM; i++)
+ strset_set(&set, str[i]);
+
+ /* Nothing */
+ sub = strset_prefix(&set, "a");
+ ok1(strset_empty(sub));
+
+ /* Everything */
+ sub = strset_prefix(&set, "0");
+ ok1(sub->u.n == set.u.n);
+ sub = strset_prefix(&set, "");
+ ok1(sub->u.n == set.u.n);
+
+ /* Singleton. */
+ sub = strset_prefix(&set, "00000000");
+ i = 0;
+ strset_iterate(sub, in_order, &i);
+ ok1(i == 1);
+
+ /* First 10. */
+ sub = strset_prefix(&set, "0000000");
+ i = 0;
+ strset_iterate(sub, in_order, &i);
+ ok1(i == 10);
+
+ /* First 100. */
+ sub = strset_prefix(&set, "000000");
+ i = 0;
+ strset_iterate(sub, in_order, &i);
+ ok1(i == 100);
+
+ /* Everything, *plus* empty string. */
+ empty = strdup("");
+ strset_set(&set, empty);
+
+ sub = strset_prefix(&set, "");
+ /* Check we get *our* empty string back! */
+ strset_iterate(sub, find_empty, empty);
+
+ strset_destroy(&set);
+
+ for (i = 0; i < NUM; i++)
+ free(str[i]);
+ free(empty);
+
+ /* This exits depending on whether all tests passed */
+ return exit_status();
+}
--- /dev/null
+#include <ccan/strset/strset.h>
+#include <ccan/strset/strset.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+ struct strset set;
+ const char str[] = "hello";
+ const char none[] = "";
+ char *dup = strdup(str);
+
+ /* This is how many tests you plan to run */
+ plan_tests(24);
+
+ strset_init(&set);
+
+ ok1(!strset_test(&set, str));
+ ok1(!strset_test(&set, none));
+ ok1(!strset_clear(&set, str));
+ ok1(!strset_clear(&set, none));
+
+ ok1(strset_set(&set, str));
+ ok1(strset_test(&set, str));
+ /* We compare the string, not the pointer. */
+ ok1(strset_test(&set, dup));
+ ok1(!strset_test(&set, none));
+
+ /* Delete should return original string. */
+ ok1(strset_clear(&set, dup) == str);
+ ok1(!strset_test(&set, str));
+ ok1(!strset_test(&set, none));
+
+ /* Try insert and delete of empty string. */
+ ok1(strset_set(&set, none));
+ ok1(strset_test(&set, none));
+ ok1(!strset_test(&set, str));
+
+ /* Delete should return original string. */
+ ok1(strset_clear(&set, "") == none);
+ ok1(!strset_test(&set, str));
+ ok1(!strset_test(&set, none));
+
+ /* Both at once... */
+ ok1(strset_set(&set, none));
+ ok1(strset_set(&set, str));
+ ok1(strset_test(&set, str));
+ ok1(strset_test(&set, none));
+ ok1(strset_clear(&set, "") == none);
+ ok1(strset_clear(&set, dup) == str);
+
+ ok1(set.u.n == NULL);
+ free(dup);
+
+ /* This exits depending on whether all tests passed */
+ return exit_status();
+}
projects / ccan / commitdiff