htable \
idtree \
ilog \
+ invbloom \
io \
isaac \
iscsi \
--- /dev/null
+../../licenses/BSD-MIT
\ No newline at end of file
--- /dev/null
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+
+/**
+ * invbloom - implementation of invertible bloom lookup tables.
+ *
+ * This code implements a subset of invertible bloom lookup tables
+ * as described in[1].
+ *
+ * [1] Goodrich, Michael T., and Michael Mitzenmacher. "Invertible bloom
+ * lookup tables." Communication, Control, and Computing (Allerton), 2011
+ * 49th Annual Allerton Conference on. IEEE, 2011.
+ * http://arxiv.org/pdf/1101.2245
+ *
+ * License: BSD-MIT
+ *
+ * Example:
+ * #include <ccan/invbloom/invbloom.h>
+ * #include <stdio.h>
+ *
+ * int main(int argc, char *argv[])
+ * {
+ * unsigned int i, n;
+ * struct invbloom *ib = invbloom_new(NULL, char *, 16, 0);
+ *
+ * for (i = 1; i < argc; i++)
+ * invbloom_insert(ib, &argv[i]);
+ *
+ * n = 0;
+ * for (i = 1; i < argc; i++)
+ * n += invbloom_get(ib, &argv[i]);
+ *
+ * printf("%u out of %u are found\n", n, argc);
+ *
+ * n = 0;
+ * for (i = 1; i < argc; i++) {
+ * unsigned int j;
+ * char **p = invbloom_extract(NULL, ib);
+ *
+ * for (j = 1; j < argc; j++) {
+ * if (p == &argv[j])
+ * n++;
+ * }
+ * tal_free(p);
+ * }
+ * printf("%u out of %u were extracted\n", n, argc);
+ * return 0;
+ * }
+ */
+int main(int argc, char *argv[])
+{
+ /* Expect exactly one argument */
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ printf("ccan/endian\n");
+ printf("ccan/hash\n");
+ printf("ccan/short_types\n");
+ printf("ccan/tal\n");
+ return 0;
+ }
+
+ return 1;
+}
--- /dev/null
+/* Licensed under BSD-MIT - see LICENSE file for details */
+#include "invbloom.h"
+#include <ccan/hash/hash.h>
+#include <ccan/endian/endian.h>
+#include <assert.h>
+
+/* "We will show that hash_count values of 3 or 4 work well in practice"
+
+ From:
+
+ Eppstein, David, et al. "What's the difference?: efficient set reconciliation without prior context." ACM SIGCOMM Computer Communication Review. Vol. 41. No. 4. ACM, 2011. http://conferences.sigcomm.org/sigcomm/2011/papers/sigcomm/p218.pdf
+*/
+#define NUM_HASHES 4
+
+struct invbloom *invbloom_new_(const tal_t *ctx,
+ size_t id_size,
+ size_t n_elems,
+ u32 salt)
+{
+ struct invbloom *ib = tal(ctx, struct invbloom);
+
+ if (ib) {
+ ib->n_elems = n_elems;
+ ib->id_size = id_size;
+ ib->salt = salt;
+ ib->count = tal_arrz(ib, s32, n_elems);
+ ib->idsum = tal_arrz(ib, u8, id_size * n_elems);
+ if (!ib->count || !ib->idsum)
+ ib = tal_free(ib);
+ }
+ return ib;
+}
+
+static size_t hash_bucket(const struct invbloom *ib, const void *id, size_t i)
+{
+ return hash((const char *)id, ib->id_size, ib->salt+i*7) % ib->n_elems;
+}
+
+static u8 *idsum_ptr(const struct invbloom *ib, size_t bucket)
+{
+ return (u8 *)ib->idsum + bucket * ib->id_size;
+}
+
+static void add_to_bucket(struct invbloom *ib, size_t n, const u8 *id)
+{
+ size_t i;
+ u8 *idsum = idsum_ptr(ib, n);
+
+ ib->count[n]++;
+
+ for (i = 0; i < ib->id_size; i++)
+ idsum[i] ^= id[i];
+}
+
+static void remove_from_bucket(struct invbloom *ib, size_t n, const u8 *id)
+{
+ size_t i;
+ u8 *idsum = idsum_ptr(ib, n);
+
+ ib->count[n]--;
+ for (i = 0; i < ib->id_size; i++)
+ idsum[i] ^= id[i];
+}
+
+void invbloom_insert(struct invbloom *ib, const void *id)
+{
+ unsigned int i;
+
+ for (i = 0; i < NUM_HASHES; i++)
+ add_to_bucket(ib, hash_bucket(ib, id, i), id);
+}
+
+void invbloom_delete(struct invbloom *ib, const void *id)
+{
+ unsigned int i;
+
+ for (i = 0; i < NUM_HASHES; i++)
+ remove_from_bucket(ib, hash_bucket(ib, id, i), id);
+}
+
+static bool all_zero(const u8 *mem, size_t size)
+{
+ unsigned int i;
+
+ for (i = 0; i < size; i++)
+ if (mem[i])
+ return false;
+ return true;
+}
+
+bool invbloom_get(const struct invbloom *ib, const void *id)
+{
+ unsigned int i;
+
+ for (i = 0; i < NUM_HASHES; i++) {
+ size_t h = hash_bucket(ib, id, i);
+ u8 *idsum = idsum_ptr(ib, h);
+
+ if (ib->count[h] == 0 && all_zero(idsum, ib->id_size))
+ return false;
+
+ if (ib->count[h] == 1)
+ return (memcmp(idsum, id, ib->id_size) == 0);
+ }
+ return false;
+}
+
+static void *extract(const tal_t *ctx, struct invbloom *ib, int count)
+{
+ size_t i;
+
+ /* FIXME: this makes full extraction O(n^2). */
+ for (i = 0; i < ib->n_elems; i++) {
+ void *id;
+
+ if (ib->count[i] != count)
+ continue;
+
+ id = tal_dup(ctx, u8, idsum_ptr(ib, i), ib->id_size, 0);
+ return id;
+ }
+ return NULL;
+}
+
+void *invbloom_extract(const tal_t *ctx, struct invbloom *ib)
+{
+ void *id;
+
+ id = extract(ctx, ib, 1);
+ if (id)
+ invbloom_delete(ib, id);
+ return id;
+}
+
+void *invbloom_extract_negative(const tal_t *ctx, struct invbloom *ib)
+{
+ void *id;
+
+ id = extract(ctx, ib, -1);
+ if (id)
+ invbloom_insert(ib, id);
+ return id;
+}
+
+void invbloom_subtract(struct invbloom *ib1, const struct invbloom *ib2)
+{
+ size_t i;
+
+ assert(ib1->n_elems == ib2->n_elems);
+ assert(ib1->id_size == ib2->id_size);
+ assert(ib1->salt == ib2->salt);
+
+ for (i = 0; i < ib1->n_elems; i++)
+ ib1->count[i] -= ib2->count[i];
+
+ for (i = 0; i < ib1->n_elems * ib1->id_size; i++)
+ ib1->idsum[i] ^= ib2->idsum[i];
+}
+
+bool invbloom_empty(const struct invbloom *ib)
+{
+ size_t i;
+
+ for (i = 0; i < ib->n_elems; i++) {
+ if (ib->count[i])
+ return false;
+ if (!all_zero(idsum_ptr(ib, i), ib->id_size))
+ return false;
+ }
+ return true;
+}
--- /dev/null
+/* Licensed under BSD-MIT - see LICENSE file for details */
+#ifndef CCAN_INVBLOOM_H
+#define CCAN_INVBLOOM_H
+#include <ccan/short_types/short_types.h>
+#include <ccan/tal/tal.h>
+
+struct invbloom {
+ size_t n_elems;
+ size_t id_size;
+ u32 hashsum_bytes; /* 0 - 4. */
+ u32 salt;
+ s32 *count; /* [n_elems] */
+ u8 *idsum; /* [n_elems][id_size] */
+};
+
+/**
+ * invbloom_new - create a new invertable bloom lookup table
+ * @ctx: context to tal() from, or NULL.
+ * @type: type to place into the buckets (must not contain padding)
+ * @n_elems: number of entries in table
+ * @salt: 32 bit seed for table
+ *
+ * Returns a new table, which can be freed with tal_free().
+ */
+#define invbloom_new(ctx, type, n_elems, salt) \
+ invbloom_new_((ctx), sizeof(type), (n_elems), (salt))
+struct invbloom *invbloom_new_(const tal_t *ctx,
+ size_t id_size,
+ size_t n_elems, u32 salt);
+
+
+/**
+ * invbloom_insert - add a new element
+ * @ib: the invertable bloom lookup table.
+ * @elem: the element
+ *
+ * This is guaranteed to be the inverse of invbloom_delete.
+ */
+void invbloom_insert(struct invbloom *ib, const void *elem);
+
+/**
+ * invbloom_delete - remove an element
+ * @ib: the invertable bloom lookup table.
+ * @elem: the element
+ *
+ * Note that this doesn't check the element was previously added (as
+ * that can not be done in general anyway).
+ *
+ * This is guaranteed to be the inverse of invbloom_delete.
+ */
+void invbloom_delete(struct invbloom *ib, const void *elem);
+
+/**
+ * invbloom_get - check if an element is (probably) in the table.
+ * @ib: the invertable bloom lookup table.
+ * @elem: the element
+ *
+ * This may return a false negative if the table is too full.
+ *
+ * It will only return a false positive if deletions and insertions
+ * don't match, and have managed to produce a result which matches the
+ * element. This is much less likely.
+ */
+bool invbloom_get(const struct invbloom *ib, const void *elem);
+
+/**
+ * invbloom_extract - try to recover an entry added to a bloom lookup table.
+ * @ctx: the context to tal() the return value from.
+ * @ib: the invertable bloom lookup table.
+ *
+ * This may be able to recover (and delete) an element which was
+ * invbloom_insert()ed into the table (and not deleted). This will
+ * not work if the table is too full.
+ *
+ * It may return a bogus element if deletions and insertions don't
+ * match.
+ */
+void *invbloom_extract(const tal_t *ctx, struct invbloom *ib);
+
+/**
+ * invbloom_extract_negative - try to recover an entry deleted from a bloom lookup table.
+ * @ctx: the context to tal() the return value from.
+ * @ib: the invertable bloom lookup table.
+ *
+ * This may be able to recover (and insert/undo) an element which was
+ * invbloom_delete()ed from the table (and not inserted). This will
+ * not work if the table is too full.
+ *
+ * It may return a bogus element if deletions and insertions don't
+ * match.
+ */
+void *invbloom_extract_negative(const tal_t *ctx, struct invbloom *ib);
+
+/**
+ * invbloom_subtract - return the differences of two IBLTs.
+ * @ib1: the invertable bloom lookup table to alter
+ * @ib2: the invertable bloom lookup table to subtract.
+ *
+ * This produces exactly the same result as if a new table had all the
+ * elements only in @ib1 inserted, then all the elements onlt in @ib2
+ * deleted.
+ *
+ * ie. if @ib1 and @ib2 are similar, the result may be a usable by
+ * invbloom_extract and invbloom_extract_negative.
+ */
+void invbloom_subtract(struct invbloom *ib1, const struct invbloom *ib2);
+
+/**
+ * invbloom_empty - is an invertable bloom lookup table completely clean?
+ * @ib: the invertable bloom lookup table
+ *
+ * This is always true if @ib has had the same elements inserted and
+ * deleted. It is far less likely to be true if different ones were
+ * deleted than inserted.
+ */
+bool invbloom_empty(const struct invbloom *ib);
+#endif /* CCAN_INVBLOOM_H */
--- /dev/null
+#include <ccan/invbloom/invbloom.h>
+/* Include the C files directly. */
+#include <ccan/invbloom/invbloom.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+ struct invbloom *ib1, *ib2;
+ const tal_t *ctx = tal(NULL, char);
+ int val = 1, val2 = 2, *ip;
+
+ /* This is how many tests you plan to run */
+ plan_tests(8);
+
+ ib1 = invbloom_new(ctx, int, 1024, 0);
+ ib2 = invbloom_new(ctx, int, 1024, 0);
+ invbloom_insert(ib1, &val);
+ invbloom_insert(ib2, &val2);
+
+ invbloom_subtract(ib1, ib2);
+
+ ip = invbloom_extract(ctx, ib1);
+ ok1(ip);
+ ok1(tal_parent(ip) == ctx);
+ ok1(*ip == val);
+
+ ip = invbloom_extract(ctx, ib1);
+ ok1(!ip);
+
+ ip = invbloom_extract_negative(ctx, ib1);
+ ok1(ip);
+ ok1(tal_parent(ip) == ctx);
+ ok1(*ip == val2);
+
+ ip = invbloom_extract_negative(ctx, ib1);
+ ok1(!ip);
+
+ tal_free(ctx);
+
+ /* This exits depending on whether all tests passed */
+ return exit_status();
+}
--- /dev/null
+#include <ccan/invbloom/invbloom.h>
+/* Include the C files directly. */
+#include <ccan/invbloom/invbloom.c>
+#include <ccan/tap/tap.h>
+
+int main(void)
+{
+ struct invbloom *ib;
+ const tal_t *ctx = tal(NULL, char);
+ int val, val2, *ip, *ip2, i;
+
+ /* This is how many tests you plan to run */
+ plan_tests(127);
+
+ ib = invbloom_new(ctx, int, 1, 100);
+ ok1(tal_parent(ib) == ctx);
+ ok1(ib->id_size == sizeof(int));
+ ok1(ib->salt == 100);
+ ok1(ib->n_elems == 1);
+ ok1(invbloom_empty(ib));
+
+ val = 0;
+ invbloom_insert(ib, &val);
+ ok1(ib->count[0] == NUM_HASHES);
+ ok1(!invbloom_empty(ib));
+ invbloom_delete(ib, &val);
+ ok1(invbloom_empty(ib));
+
+ val2 = 2;
+ invbloom_insert(ib, &val);
+ invbloom_insert(ib, &val2);
+ ok1(!invbloom_empty(ib));
+ invbloom_delete(ib, &val);
+ ok1(!invbloom_empty(ib));
+ invbloom_delete(ib, &val2);
+ ok1(invbloom_empty(ib));
+
+ tal_free(ib);
+
+ ib = invbloom_new(ctx, int, 1, 100);
+ ok1(tal_parent(ib) == ctx);
+ ok1(ib->id_size == sizeof(int));
+ ok1(ib->salt == 100);
+ ok1(ib->n_elems == 1);
+ ok1(invbloom_empty(ib));
+
+ val = 0;
+ invbloom_insert(ib, &val);
+ ok1(ib->count[0] == NUM_HASHES);
+ ok1(!invbloom_empty(ib));
+ invbloom_delete(ib, &val);
+ ok1(invbloom_empty(ib));
+
+ val2 = 2;
+ invbloom_insert(ib, &val);
+ invbloom_insert(ib, &val2);
+ ok1(!invbloom_empty(ib));
+ invbloom_delete(ib, &val);
+ ok1(!invbloom_empty(ib));
+ invbloom_delete(ib, &val2);
+ ok1(invbloom_empty(ib));
+
+ tal_free(ib);
+
+ /* Now, a more realistic test. */
+ for (i = 0; i < 5; i++) {
+ ib = invbloom_new(ctx, int, 1024, i);
+ invbloom_insert(ib, &val);
+ invbloom_insert(ib, &val2);
+ ok1(invbloom_get(ib, &val));
+ ok1(invbloom_get(ib, &val2));
+
+ ip = invbloom_extract_negative(ctx, ib);
+ ok1(!ip);
+
+ ip = invbloom_extract(ctx, ib);
+ ok1(ip);
+ ok1(tal_parent(ip) == ctx);
+ ok1(*ip == val || *ip == val2);
+
+ ip2 = invbloom_extract(ctx, ib);
+ ok1(ip2);
+ ok1(tal_parent(ip2) == ctx);
+ ok1(*ip2 == val || *ip2 == val2);
+ ok1(*ip2 != *ip);
+
+ ok1(invbloom_extract(ctx, ib) == NULL);
+
+ invbloom_delete(ib, &val);
+ invbloom_delete(ib, &val2);
+ ip = invbloom_extract(ctx, ib);
+ ok1(!ip);
+
+ ip = invbloom_extract_negative(ctx, ib);
+ ok1(ip);
+ ok1(tal_parent(ip) == ctx);
+ ok1(*ip == val || *ip == val2);
+
+ ip2 = invbloom_extract_negative(ctx, ib);
+ ok1(ip2);
+ ok1(tal_parent(ip2) == ctx);
+ ok1(*ip2 == val || *ip2 == val2);
+ ok1(*ip2 != *ip);
+
+ ok1(invbloom_extract_negative(ctx, ib) == NULL);
+ ok1(invbloom_empty(ib));
+
+ tal_free(ib);
+ }
+
+ tal_free(ctx);
+
+ /* This exits depending on whether all tests passed */
+ return exit_status();
+}
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