jbitset: new module.
authorRusty Russell <rusty@rustcorp.com.au>
Sat, 30 Oct 2010 10:14:42 +0000 (20:44 +1030)
committerRusty Russell <rusty@rustcorp.com.au>
Sat, 30 Oct 2010 10:14:42 +0000 (20:44 +1030)
ccan/jbitset/_info [new file with mode: 0644]
ccan/jbitset/jbitset.c [new file with mode: 0644]
ccan/jbitset/jbitset.h [new file with mode: 0644]
ccan/jbitset/jbitset_type.h [new file with mode: 0644]
ccan/jbitset/test/run-type.c [new file with mode: 0644]
ccan/jbitset/test/run.c [new file with mode: 0644]

diff --git a/ccan/jbitset/_info b/ccan/jbitset/_info
new file mode 100644 (file)
index 0000000..4fa4dd9
--- /dev/null
@@ -0,0 +1,82 @@
+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * jbitset - variable-length bitset (based on libJudy)
+ *
+ * This provides a convenient wrapper for using Judy bitsets; using
+ * integers or pointers as an index, Judy arrays provide an efficient
+ * bit array or bit map of variable size.
+ *
+ * jbitset.h simply contains wrappers for a size_t-indexed bitset, and
+ * jbitset_type.h contain a wrapper macro for pointer bitsets.
+ *
+ * Example:
+ * // Simple analysis of one-byte mallocs.
+ * #include <stdlib.h>
+ * #include <stdio.h>
+ * #include <err.h>
+ * #include <ccan/jbitset/jbitset_type.h>
+ * 
+ * // Define jbit_char_<op> and jbitset_char, for char * bitset.
+ * JBIT_DEFINE_TYPE(char, char);
+ * 
+ * int main(int argc, char *argv[])
+ * {
+ *     unsigned int i, runs, reuse;
+ *     size_t mindist = -1;
+ *     struct jbitset_char *set = jbit_char_new();
+ *     char *p, *prev;
+ * 
+ *     runs = (argc == 1 ? 1000 : atoi(argv[1]));
+ *     if (!runs)
+ *             errx(1, "Invalid number of allocations '%s'", argv[1]);
+ * 
+ *     for (i = 0; i < runs; i++)
+ *             if (!jbit_char_set(set, malloc(1)))
+ *                     errx(1, "same pointer allocated twice!");
+ * 
+ *     // Calculate minimum distance
+ *     prev = jbit_char_first(set)+1;
+ *     for (p = jbit_char_first(set); p; prev = p, p = jbit_char_next(set,p))
+ *             if (p - prev < mindist)
+ *                     mindist = p - prev;
+ * 
+ *     // Free them all, see how many we reallocate.
+ *     for (p = jbit_char_first(set); p; p = jbit_char_next(set, p))
+ *             free(p);
+ *     for (reuse = 0, i = 0; i < runs; i++)
+ *             reuse += jbit_char_test(set, malloc(1));
+ * 
+ *     printf("Allocation density (bytes): %zu\n"
+ *            "Minimum inter-pointer distance: %zu\n"
+ *            "Reuse rate: %.0f%%\n",
+ *            (jbit_char_last(set) - jbit_char_first(set)) / runs,
+ *            mindist,
+ *            100.0 * reuse / runs);
+ *     return 0;
+ * }
+ *
+ * License: LGPL (2 or any later version)
+ * Author: Rusty Russell <rusty@rustcorp.com.au>
+ */
+int main(int argc, char *argv[])
+{
+       if (argc != 2)
+               return 1;
+
+       if (strcmp(argv[1], "depends") == 0) {
+               printf("ccan/build_assert\n");
+               printf("ccan/compiler\n");
+               printf("Judy\n");
+               return 0;
+       }
+
+       if (strcmp(argv[1], "libs") == 0) {
+               printf("Judy\n");
+               return 0;
+       }
+
+       return 1;
+}
diff --git a/ccan/jbitset/jbitset.c b/ccan/jbitset/jbitset.c
new file mode 100644 (file)
index 0000000..0756e30
--- /dev/null
@@ -0,0 +1,41 @@
+#include <ccan/jbitset/jbitset.h>
+#include <ccan/build_assert/build_assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct jbitset *jbit_new(void)
+{
+       struct jbitset *set;
+
+       /* Judy uses Word_t, we use size_t. */
+       BUILD_ASSERT(sizeof(size_t) == sizeof(Word_t));
+
+       set = malloc(sizeof(*set));
+       if (set) {
+               set->judy = NULL;
+               memset(&set->err, 0, sizeof(set->err));
+               set->errstr = NULL;
+       }
+       return set;
+}
+
+const char *jbit_error_(struct jbitset *set)
+{
+       char *str;
+       free((char *)set->errstr);
+       set->errstr = str = malloc(100);
+       if (!set->errstr)
+               return "out of memory";
+
+       sprintf(str,
+               "JU_ERRNO_* == %d, ID == %d\n",
+               JU_ERRNO(&set->err), JU_ERRID(&set->err));
+       return str;
+}
+
+void jbit_free(const struct jbitset *set)
+{
+       free((char *)set->errstr);
+       Judy1FreeArray((PPvoid_t)&set->judy, PJE0);
+       free((void *)set);
+}
diff --git a/ccan/jbitset/jbitset.h b/ccan/jbitset/jbitset.h
new file mode 100644 (file)
index 0000000..bbce7eb
--- /dev/null
@@ -0,0 +1,299 @@
+#ifndef CCAN_JBITSET_H
+#define CCAN_JBITSET_H
+#include <Judy.h>
+#include <stdbool.h>
+#include <ccan/compiler/compiler.h>
+#include <assert.h>
+
+/**
+ * jbit_new - create a new, empty jbitset.
+ *
+ * See Also:
+ *     JBIT_DEFINE_TYPE()
+ *
+ * Example:
+ *     struct jbitset *set = jbit_new();
+ *     if (!set)
+ *             errx(1, "Failed to allocate jbitset");
+ */
+struct jbitset *jbit_new(void);
+
+/**
+ * jbit_free - destroy a jbitset.
+ * @set: the set returned from jbit_new.
+ *
+ * Example:
+ *     jbit_free(set);
+ */
+void jbit_free(const struct jbitset *set);
+
+/* This is exposed in the header so we can inline.  Treat it as private! */
+struct jbitset {
+       void *judy;
+       JError_t err;
+       const char *errstr;
+};
+const char *COLD_ATTRIBUTE jbit_error_(struct jbitset *set);
+
+/**
+ * jbit_error - test for an error in the a previous jbit_ operation.
+ * @set: the set to test.
+ *
+ * Under normal circumstances, return NULL to indicate no error has occurred.
+ * Otherwise, it will return a string containing the error.  This string
+ * can only be freed by jbit_free() on the set.
+ *
+ * Other than out-of-memory, errors are caused by memory corruption or
+ * interface misuse.
+ *
+ * Example:
+ *     struct jbitset *set = jbit_new();
+ *     const char *errstr;
+ *
+ *     if (!set)
+ *             err(1, "allocating jbitset");
+ *     errstr = jbit_error(set);
+ *     if (errstr)
+ *             errx(1, "Woah, error on newly created set?! %s", errstr);
+ */
+static inline const char *jbit_error(struct jbitset *set)
+{
+       if (JU_ERRNO(&set->err) <= JU_ERRNO_NFMAX)
+               return NULL;
+       return jbit_error_(set);
+}
+
+/**
+ * jbit_test - test a bit in the bitset.
+ * @set: bitset from jbit_new
+ * @index: the index to test
+ *
+ * Returns true if jbit_set() has been done on this index, false otherwise.
+ *
+ * Example:
+ *     assert(!jbit_test(set, 0));
+ */
+static inline bool jbit_test(const struct jbitset *set, size_t index)
+{
+       return Judy1Test(set->judy, index, (JError_t *)&set->err);
+}
+
+/**
+ * jbit_set - set a bit in the bitset.
+ * @set: bitset from jbit_new
+ * @index: the index to set
+ *
+ * Returns false if it was already set (ie. nothing changed)
+ *
+ * Example:
+ *     if (jbit_set(set, 0))
+ *             err(1, "Bit 0 was already set?!");
+ */
+static inline bool jbit_set(struct jbitset *set, size_t index)
+{
+       return Judy1Set(&set->judy, index, &set->err);
+}
+
+/**
+ * jbit_clear - clear a bit in the bitset.
+ * @set: bitset from jbit_new
+ * @index: the index to set
+ *
+ * Returns the old bit value (ie. false if nothing changed).
+ *
+ * Example:
+ *     if (jbit_clear(set, 0))
+ *             err(1, "Bit 0 was already clear?!");
+ */
+static inline bool jbit_clear(struct jbitset *set, size_t index)
+{
+       return Judy1Unset(&set->judy, index, &set->err);
+}
+
+/**
+ * jbit_popcount - get population of (some part of) bitset.
+ * @set: bitset from jbit_new
+ * @start: first index to count
+ * @end_incl: last index to count (use -1 for end).
+ *
+ * Example:
+ *     assert(jbit_popcount(set, 0, 1000) <= jbit_popcount(set, 0, 2000));
+ */
+static inline size_t jbit_popcount(const struct jbitset *set,
+                                  size_t start, size_t end_incl)
+{
+       return Judy1Count(set->judy, start, end_incl, (JError_t *)&set->err);
+}
+
+/**
+ * jbit_nth - return the index of the nth bit which is set.
+ * @set: bitset from jbit_new
+ * @n: which bit we are interested in (0-based)
+ * @invalid: what to return if n >= set population
+ *
+ * This normally returns the nth bit in the set, and often there is a
+ * convenient known-invalid value (ie. something which is never in the
+ * set).  Otherwise, and a wrapper function like this can be used:
+ *
+ *     static bool jbit_nth_index(struct jbitset *set, size_t n, size_t *idx)
+ *     {
+ *             // Zero might be valid, if it's first in set.
+ *             if (n == 0 && jbit_test(set, 0)) {
+ *                     *idx = 0;
+ *                     return true;
+ *             }
+ *             *idx = jbit_nth(set, n, 0);
+ *             return (*idx != 0);
+ *     }
+ *
+ * Example:
+ *     size_t i, val;
+ *
+ *     // We know 0 isn't in set.
+ *     assert(!jbit_test(set, 0));
+ *     for (i = 0; (val = jbit_nth(set, i, 0)) != 0; i++) {
+ *             assert(jbit_popcount(set, 0, val) == i);
+ *             printf("Value %zu = %zu\n", i, val);
+ *     }
+ */
+static inline size_t jbit_nth(const struct jbitset *set,
+                             size_t n, size_t invalid)
+{
+       Word_t index;
+       if (!Judy1ByCount(set->judy, n+1, &index, (JError_t *)&set->err))
+               index = invalid;
+       return index;
+}
+
+/**
+ * jbit_first - return the first bit which is set.
+ * @set: bitset from jbit_new
+ * @invalid: return value if no bits are set at all.
+ *
+ * This is equivalent to jbit_nth(set, 0, invalid).
+ *
+ * Example:
+ *     assert(!jbit_test(set, 0));
+ *     printf("Set contents (increasing order):");
+ *     for (i = jbit_first(set, 0); i; i = jbit_next(set, i, 0))
+ *             printf(" %zu", i);
+ *     printf("\n");
+ */
+static inline size_t jbit_first(const struct jbitset *set, size_t invalid)
+{
+       Word_t index = 0;
+       if (!Judy1First(set->judy, &index, (JError_t *)&set->err))
+               index = invalid;
+       else
+               assert(index != invalid);
+       return index;
+}
+
+/**
+ * jbit_next - return the next bit which is set.
+ * @set: bitset from jbit_new
+ * @prev: previous index
+ * @invalid: return value if no bits are set at all.
+ *
+ * This is usually used to find an adjacent bit which is set, after
+ * jbit_first.
+ */
+static inline size_t jbit_next(const struct jbitset *set, size_t prev,
+                              size_t invalid)
+{
+       if (!Judy1Next(set->judy, (Word_t *)&prev, (JError_t *)&set->err))
+               prev = invalid;
+       else
+               assert(prev != invalid);
+       return prev;
+}
+
+/**
+ * jbit_last - return the last bit which is set.
+ * @set: bitset from jbit_new
+ * @invalid: return value if no bits are set at all.
+ *
+ * Example:
+ *     assert(!jbit_test(set, 0));
+ *     printf("Set contents (decreasing order):");
+ *     for (i = jbit_last(set, 0); i; i = jbit_prev(set, i, 0))
+ *             printf(" %zu", i);
+ *     printf("\n");
+ */
+static inline size_t jbit_last(const struct jbitset *set, size_t invalid)
+{
+       Word_t index = -1;
+       if (!Judy1Last(set->judy, &index, (JError_t *)&set->err))
+               index = invalid;
+       else
+               assert(index != invalid);
+       return index;
+}
+
+/**
+ * jbit_prev - return the previous bit which is set.
+ * @set: bitset from jbit_new
+ * @prev: previous index
+ * @invalid: return value if no bits are set at all.
+ *
+ * This is usually used to find an adjacent bit which is set, after
+ * jbit_last.
+ */
+static inline size_t jbit_prev(const struct jbitset *set, size_t prev,
+                              size_t invalid)
+{
+       if (!Judy1Prev(set->judy, (Word_t *)&prev, (JError_t *)&set->err))
+               prev = invalid;
+       else
+               assert(prev != invalid);
+       return prev;
+}
+
+/**
+ * jbit_first_clear - return the first bit which is unset.
+ * @set: bitset from jbit_new
+ * @invalid: return value if no bits are clear at all.
+ *
+ * This allows for iterating the inverse of the bitmap.
+ */
+static inline size_t jbit_first_clear(const struct jbitset *set,
+                                     size_t invalid)
+{
+       Word_t index = 0;
+       if (!Judy1FirstEmpty(set->judy, &index, (JError_t *)&set->err))
+               index = invalid;
+       else
+               assert(index != invalid);
+       return index;
+}
+
+static inline size_t jbit_next_clear(const struct jbitset *set, size_t prev,
+                                    size_t invalid)
+{
+       if (!Judy1NextEmpty(set->judy, (Word_t *)&prev, (JError_t *)&set->err))
+               prev = invalid;
+       else
+               assert(prev != invalid);
+       return prev;
+}
+
+static inline size_t jbit_last_clear(const struct jbitset *set, size_t invalid)
+{
+       Word_t index = -1;
+       if (!Judy1LastEmpty(set->judy, &index, (JError_t *)&set->err))
+               index = invalid;
+       else
+               assert(index != invalid);
+       return index;
+}
+
+static inline size_t jbit_prev_clear(const struct jbitset *set, size_t prev,
+                                    size_t invalid)
+{
+       if (!Judy1PrevEmpty(set->judy, (Word_t *)&prev, (JError_t *)&set->err))
+               prev = invalid;
+       else
+               assert(prev != invalid);
+       return prev;
+}
+#endif /* CCAN_JBITSET_H */
diff --git a/ccan/jbitset/jbitset_type.h b/ccan/jbitset/jbitset_type.h
new file mode 100644 (file)
index 0000000..abd8c2b
--- /dev/null
@@ -0,0 +1,84 @@
+#ifndef CCAN_JBITSET_TYPE_H
+#define CCAN_JBITSET_TYPE_H
+#include <ccan/jbitset/jbitset.h>
+
+/**
+ * JBIT_DEFINE_TYPE - create a set of jbit ops for a given pointer type
+ * @type: a type whose pointers will go into the bitset.
+ * @name: a name for all the functions to define (of form jbit_<name>_*)
+ *
+ * This macro defines a set of inline functions for typesafe and convenient
+ * usage of a Judy bitset for pointers.  It is assumed that a NULL pointer
+ * is never set in the bitset.
+ *
+ * Example:
+ *     JBIT_DEFINE_TYPE(char, char);
+ *     JBIT_DEFINE_TYPE(struct foo, foo);
+ *
+ *     static struct jbitset_char *jc;
+ *     struct jbitset_foo *jf;
+ *
+ *     static void add_to_bitsets(const char *p, const struct foo *f)
+ *     {
+ *             // Note, this adds the pointer, not the string!
+ *             jbit_char_set(jc, p);
+ *             jbit_foo_set(jf, f);
+ *     }
+ */
+#define JBIT_DEFINE_TYPE(type, name)                                   \
+struct jbitset_##name;                                                 \
+static inline struct jbitset_##name *jbit_##name##_new(void)           \
+{                                                                      \
+       return (struct jbitset_##name *)jbit_new();                     \
+}                                                                      \
+static inline void jbit_##name##_free(const struct jbitset_##name *set)        \
+{                                                                      \
+       jbit_free((const struct jbitset *)set);                         \
+}                                                                      \
+static inline const char *jbit_##name##_error(struct jbitset_##name *set) \
+{                                                                      \
+       return jbit_error((struct jbitset *)set);                       \
+}                                                                      \
+static inline bool jbit_##name##_test(const struct jbitset_##name *set,        \
+                                     const type *index)                \
+{                                                                      \
+       return jbit_test((const struct jbitset *)set, (size_t)index);   \
+}                                                                      \
+static inline bool jbit_##name##_set(struct jbitset_##name *set,       \
+                                    const type *index)                 \
+{                                                                      \
+       return jbit_set((struct jbitset *)set, (size_t)index);          \
+}                                                                      \
+static inline bool jbit_##name##_clear(struct jbitset_##name *set,     \
+                                      const type *index)               \
+{                                                                      \
+       return jbit_clear((struct jbitset *)set, (size_t)index);        \
+}                                                                      \
+static inline size_t jbit_##name##_count(struct jbitset_##name *set)   \
+{                                                                      \
+       return jbit_popcount((const struct jbitset *)set, 0, -1);       \
+}                                                                      \
+static inline type *jbit_##name##_nth(const struct jbitset_##name *set,        \
+                                           size_t n)                   \
+{                                                                      \
+       return (type *)jbit_nth((const struct jbitset *)set, n, 0);     \
+}                                                                      \
+static inline type *jbit_##name##_first(const struct jbitset_##name *set) \
+{                                                                      \
+       return (type *)jbit_first((const struct jbitset *)set, 0);      \
+}                                                                      \
+static inline type *jbit_##name##_next(struct jbitset_##name *set,     \
+                                      const type *prev)                \
+{                                                                      \
+       return (type *)jbit_next((const struct jbitset *)set, (size_t)prev, 0); \
+}                                                                      \
+static inline type *jbit_##name##_last(struct jbitset_##name *set)     \
+{                                                                      \
+       return (type *)jbit_last((const struct jbitset *)set, 0);       \
+}                                                                      \
+static inline type *jbit_##name##_prev(struct jbitset_##name *set,     \
+                                      const type *prev)                \
+{                                                                      \
+       return (type *)jbit_prev((const struct jbitset *)set, (size_t)prev, 0); \
+}
+#endif /* CCAN_JBITSET_TYPE_H */
diff --git a/ccan/jbitset/test/run-type.c b/ccan/jbitset/test/run-type.c
new file mode 100644 (file)
index 0000000..1eefb42
--- /dev/null
@@ -0,0 +1,57 @@
+#include <ccan/tap/tap.h>
+#include <ccan/jbitset/jbitset_type.h>
+#include <ccan/jbitset/jbitset.c>
+
+struct foo;
+
+JBIT_DEFINE_TYPE(struct foo, foo);
+
+static int cmp_ptr(const void *a, const void *b)
+{
+       return *(char **)a - *(char **)b;
+}
+
+#define NUM 100
+
+int main(int argc, char *argv[])
+{
+       struct jbitset_foo *set;
+       struct foo *foo[NUM];
+       unsigned int i;
+
+       plan_tests(20);
+       for (i = 0; i < NUM; i++)
+               foo[i] = malloc(20);
+
+       set = jbit_foo_new();
+       ok1(jbit_foo_error(set) == NULL);
+
+       ok1(jbit_foo_set(set, foo[0]) == true);
+       ok1(jbit_foo_set(set, foo[0]) == false);
+       ok1(jbit_foo_clear(set, foo[0]) == true);
+       ok1(jbit_foo_clear(set, foo[0]) == false);
+       ok1(jbit_foo_count(set) == 0);
+       ok1(jbit_foo_nth(set, 0) == (struct foo *)NULL);
+       ok1(jbit_foo_first(set) == (struct foo *)NULL);
+       ok1(jbit_foo_last(set) == (struct foo *)NULL);
+
+       for (i = 0; i < NUM; i++)
+               jbit_foo_set(set, foo[i]);
+
+       qsort(foo, NUM, sizeof(foo[0]), cmp_ptr);
+
+       ok1(jbit_foo_count(set) == NUM);
+       ok1(jbit_foo_nth(set, 0) == foo[0]);
+       ok1(jbit_foo_nth(set, NUM-1) == foo[NUM-1]);
+       ok1(jbit_foo_nth(set, NUM) == (struct foo *)NULL);
+       ok1(jbit_foo_first(set) == foo[0]);
+       ok1(jbit_foo_last(set) == foo[NUM-1]);
+       ok1(jbit_foo_next(set, foo[0]) == foo[1]);
+       ok1(jbit_foo_next(set, foo[NUM-1]) == (struct foo *)NULL);
+       ok1(jbit_foo_prev(set, foo[1]) == foo[0]);
+       ok1(jbit_foo_prev(set, foo[0]) == (struct foo *)NULL);
+       ok1(jbit_foo_error(set) == NULL);
+       jbit_foo_free(set);
+
+       return exit_status();
+}
diff --git a/ccan/jbitset/test/run.c b/ccan/jbitset/test/run.c
new file mode 100644 (file)
index 0000000..09f00bd
--- /dev/null
@@ -0,0 +1,66 @@
+#include <ccan/tap/tap.h>
+#include <ccan/jbitset/jbitset.c>
+
+int main(int argc, char *argv[])
+{
+       struct jbitset *set;
+       size_t i;
+       const char *err;
+
+       plan_tests(36);
+
+       set = jbit_new();
+       ok1(jbit_error(set) == NULL);
+
+       ok1(jbit_set(set, 0) == true);
+       ok1(jbit_set(set, 0) == false);
+       ok1(jbit_clear(set, 0) == true);
+       ok1(jbit_clear(set, 0) == false);
+       ok1(jbit_popcount(set, 0, -1) == 0);
+       ok1(jbit_nth(set, 0, 0) == 0);
+       ok1(jbit_nth(set, 0, -1) == (size_t)-1);
+       ok1(jbit_first(set, 0) == 0);
+       ok1(jbit_first(set, -1) == (size_t)-1);
+       ok1(jbit_last(set, 0) == 0);
+       ok1(jbit_last(set, -1) == (size_t)-1);
+       ok1(jbit_first_clear(set, -1) == 0);
+       ok1(jbit_first_clear(set, -2) == 0);
+       ok1(jbit_last_clear(set, 0) == (size_t)-1);
+       ok1(jbit_prev_clear(set, 1, -1) == 0);
+       ok1(jbit_next_clear(set, 0, -1) == 1);
+       ok1(jbit_next_clear(set, -1, -1) == -1);
+
+       /* Set a million bits, 16 bits apart. */
+       for (i = 0; i < 1000000; i++)
+               jbit_set(set, i << 4);
+
+       /* This only take 1.7MB on my 32-bit system. */
+       diag("%u bytes memory used\n", (unsigned)Judy1MemUsed(set->judy));
+       
+       ok1(jbit_popcount(set, 0, -1) == 1000000);
+       ok1(jbit_nth(set, 0, -1) == 0);
+       ok1(jbit_nth(set, 999999, -1) == 999999 << 4);
+       ok1(jbit_nth(set, 1000000, -1) == (size_t)-1);
+       ok1(jbit_first(set, -1) == 0);
+       ok1(jbit_last(set, -1) == 999999 << 4);
+       ok1(jbit_first_clear(set, -1) == 1);
+       ok1(jbit_last_clear(set, 0) == (size_t)-1);
+       ok1(jbit_prev_clear(set, 1, -1) == (size_t)-1);
+       ok1(jbit_next(set, 0, -1) == 1 << 4);
+       ok1(jbit_next(set, 999999 << 4, -1) == (size_t)-1);
+       ok1(jbit_prev(set, 1, -1) == 0);
+       ok1(jbit_prev(set, 0, -1) == (size_t)-1);
+       ok1(jbit_error(set) == NULL);
+
+       /* Test error handling */
+       JU_ERRNO(&set->err) = 100;
+       JU_ERRID(&set->err) = 991;
+       err = jbit_error(set);
+       ok1(err);
+       ok1(strstr(err, "100"));
+       ok1(strstr(err, "991"));
+       ok1(err == set->errstr);
+       jbit_free(set);
+
+       return exit_status();
+}