htable: add htable_copy.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/ccan/htable/htable.c b/ccan/htable/htable.c
index 5a773cd8876d2f36b53733c659757213811651ff..e1d13699ea85811fe2f61adbb1ce4eca942406c8 100644 (file)
--- a/ccan/htable/htable.c
+++ b/ccan/htable/htable.c
@@ -5,6 +5,7 @@
 #include <limits.h>
 #include <stdbool.h>
 #include <assert.h>
 #include <limits.h>
 #include <stdbool.h>
 #include <assert.h>

+#include <string.h>

 
 /* We use 0x1 as deleted marker. */
 #define HTABLE_DELETED (0x1)
 
 /* We use 0x1 as deleted marker. */
 #define HTABLE_DELETED (0x1)


@@ -52,6 +53,13 @@ void htable_init(struct htable *ht,
        ht->table = &ht->perfect_bit;
 }
 
        ht->table = &ht->perfect_bit;
 }
 

+/* We've changed ht->bits, update ht->max and ht->max_with_deleted */
+static void htable_adjust_capacity(struct htable *ht)
+{
+       ht->max = ((size_t)3 << ht->bits) / 4;
+       ht->max_with_deleted = ((size_t)9 << ht->bits) / 10;
+}
+

 bool htable_init_sized(struct htable *ht,
                       size_t (*rehash)(const void *, void *),
                       void *priv, size_t expect)
 bool htable_init_sized(struct htable *ht,
                       size_t (*rehash)(const void *, void *),
                       void *priv, size_t expect)


@@ -69,9 +77,7 @@ bool htable_init_sized(struct htable *ht,
                ht->table = &ht->perfect_bit;
                return false;
        }
                ht->table = &ht->perfect_bit;
                return false;
        }

-       ht->max = ((size_t)3 << ht->bits) / 4;
-       ht->max_with_deleted = ((size_t)9 << ht->bits) / 10;
-
+       htable_adjust_capacity(ht);

        return true;
 }
        
        return true;
 }
        


@@ -82,6 +88,19 @@ void htable_clear(struct htable *ht)
        htable_init(ht, ht->rehash, ht->priv);
 }
 
        htable_init(ht, ht->rehash, ht->priv);
 }
 

+bool htable_copy(struct htable *dst, const struct htable *src)
+{
+       uintptr_t *htable = malloc(sizeof(size_t) << src->bits);
+
+       if (!htable)
+               return false;
+
+       *dst = *src;
+       dst->table = htable;
+       memcpy(dst->table, src->table, sizeof(size_t) << src->bits);
+       return true;
+}
+

 static size_t hash_bucket(const struct htable *ht, size_t h)
 {
        return h & ((1 << ht->bits)-1);
 static size_t hash_bucket(const struct htable *ht, size_t h)
 {
        return h & ((1 << ht->bits)-1);


@@ -174,8 +193,7 @@ static COLD bool double_table(struct htable *ht)
                return false;
        }
        ht->bits++;
                return false;
        }
        ht->bits++;

-       ht->max = ((size_t)3 << ht->bits) / 4;
-       ht->max_with_deleted = ((size_t)9 << ht->bits) / 10;
+       htable_adjust_capacity(ht);

 
        /* If we lost our "perfect bit", get it back now. */
        if (!ht->perfect_bit && ht->common_mask) {
 
        /* If we lost our "perfect bit", get it back now. */
        if (!ht->perfect_bit && ht->common_mask) {

diff --git a/ccan/htable/htable.h b/ccan/htable/htable.h
index e150c2ef0958065d3e289482d78dfe8267017a9b..61ed9170fda461779840f63db55295757a9bce8a 100644 (file)
--- a/ccan/htable/htable.h
+++ b/ccan/htable/htable.h
@@ -74,6 +74,25 @@ bool htable_init_sized(struct htable *ht,
  */
 void htable_clear(struct htable *ht);
 
  */
 void htable_clear(struct htable *ht);
 

+/**
+ * htable_copy - duplicate a hash table.
+ * @dst: the hash table to overwrite
+ * @src: the hash table to copy
+ *
+ * Only fails on out-of-memory.
+ *
+ * Equivalent to (but faster than):
+ *    if (!htable_init_sized(dst, src->rehash, src->priv, 1U << src->bits))
+ *        return false;
+ *    v = htable_first(src, &i);
+ *    while (v) {
+ *             htable_add(dst, v);
+ *             v = htable_next(src, i);
+ *    }
+ *    return true;
+ */
+bool htable_copy(struct htable *dst, const struct htable *src);
+

 /**
  * htable_rehash - use a hashtree's rehash function
  * @elem: the argument to rehash()
 /**
  * htable_rehash - use a hashtree's rehash function
  * @elem: the argument to rehash()

diff --git a/ccan/htable/test/run-copy.c b/ccan/htable/test/run-copy.c
new file mode 100644 (file)
index 0000000..02d5bbe
--- /dev/null
+++ b/ccan/htable/test/run-copy.c
@@ -0,0 +1,44 @@
+#include <ccan/htable/htable.h>
+#include <ccan/htable/htable.c>
+#include <ccan/tap/tap.h>
+#include <stdbool.h>
+#include <string.h>
+
+#define NUM_VALS 512
+
+static size_t hash(const void *elem, void *unused)
+{
+       size_t h = *(uint64_t *)elem / 2;
+       return h;
+}
+
+static bool cmp(const void *candidate, void *ptr)
+{
+       return *(const uint64_t *)candidate == *(const uint64_t *)ptr;
+}
+
+int main(int argc, char *argv[])
+{
+       struct htable ht, ht2;
+       uint64_t val[NUM_VALS], i;
+
+       plan_tests((NUM_VALS) * 3);
+       for (i = 0; i < NUM_VALS; i++)
+               val[i] = i;
+
+       htable_init(&ht, hash, NULL);
+       for (i = 0; i < NUM_VALS; i++) {
+               ok1(ht.max >= i);
+               ok1(ht.max <= i * 2);
+               htable_add(&ht, hash(&val[i], NULL), &val[i]);
+       }
+
+       htable_copy(&ht2, &ht);
+       htable_clear(&ht);
+
+       for (i = 0; i < NUM_VALS; i++)
+               ok1(htable_get(&ht2, hash(&i, NULL), cmp, &i) == &val[i]);
+       htable_clear(&ht2);
+
+       return exit_status();
+}