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changes in trie_walk_init() - preview

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This commit is contained in:
Vojtech Vilimek 2023-07-06 12:02:42 +02:00
parent b290284769
commit 362081da85
2 changed files with 197 additions and 163 deletions
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344
filter/trie.c
View File

@ -787,6 +787,20 @@ done:
#define NEXT_PREFIX(A,B,X) ((X) ? ip4_compare((A)->v4.addr, net4_prefix(B)) < 0 : ip6_compare((A)->v6.addr, net6_prefix(B)) < 0)
#define MATCH_LOCAL_MASK(A,B,L,X) \
((X) ? (A)->v4.local >= trie_local_mask4(net4_prefix(B), (B)->pxlen, (L)) : (A)->v6.local >= trie_local_mask6(net6_prefix(B), (B)->pxlen, (L)))
#define SELECT_CHILD(pos,step) ((1u << (step)) + (pos))
/*
* We want to select a specific subtrie base on it's index in child array c.
*
* 1
* 2 3
* 4 5 6 7
* 8 9 A B C D E F
* -----------------------------------------------------
* 10 11 12 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F
*
*/
/**
* trie_walk_init
@ -798,14 +812,13 @@ done:
* Initialize walk state for subsequent walk through nodes of the trie @t by
* trie_walk_next(). The argument @net allows to restrict walk to given subnet,
* otherwise full walk over all nodes is used. This is done by finding node at
* or below @net and starting position in it. The argument @include_successors
* removes the restriction for all subnets lexicographically succeeding the
* @net. In case of @net search fail the walk state starting position points to
* the nearest parent node availible. If you use @net and @include_successors,
* beware that the trie_walk_next() could return a net preceding the one
* specified in @net.
* or below @net and starting position in it. The argument @include_successors,
* which requeries specifing the @net argument, removes the restriction for all
* nets lexicographically succeeding the @net. This is done by storing the walken
* nodes on the state's stack.
*
* If desired start position node was found in trie, 1 is returned, 0 otherwise.
* For set @include_successors the return value is 1 if the @net is present in
* the trie @t, in all other cases 0.
*/
int
trie_walk_init(struct f_trie_walk_state *s, const struct f_trie *t, const net_addr *net, u8 include_successors)
@ -819,7 +832,6 @@ trie_walk_init(struct f_trie_walk_state *s, const struct f_trie *t, const net_ad
.stack[0] = &t->root
};
/* Local work copy of @net */
if (!net)
return 0;
@ -842,37 +854,39 @@ trie_walk_init(struct f_trie_walk_state *s, const struct f_trie *t, const net_ad
if (!include_successors)
s->stack[0] = n;
else
{
s->stack[s->stack_pos] = n;
}
s->start_pos = 1;
if (nlen == plen)
{
/* Find proper local_pos, while accept_length is not used */
s->local_pos = 1;
int step = net->pxlen - plen;
s->local_pos = (1u << step) + GET_NET_BITS(net, v4, plen, step);
s->accept_length = plen;
if (include_successors)
if (!include_successors)
{
if (GET_LOCAL(n, v4) != 0 && !MATCH_LOCAL_MASK(n, net, nlen, v4))
goto find_successor;
int pos = 1;
u32 bits = GET_NET_BITS(net, v4, nlen, TRIE_STEP);
for (int i = 0; i < net->pxlen - plen; i++)
{
if (bits & (1u << (TRIE_STEP - i - 1)))
pos = 2 * pos + 1;
else
pos = 2 * pos;
}
s->local_pos = pos;
s->start_pos = s->local_pos;
return 0;
}
if (GET_LOCAL(n, v4) != 0 && !MATCH_LOCAL_MASK(n, net, nlen, v4))
{
s->local_pos = (1u << TRIE_STEP) + GET_NET_BITS(net, v4, nlen, TRIE_STEP);
return 0;
}
int pos = 1;
int bits = GET_NET_BITS(net, v4, nlen, TRIE_STEP);
for (int i = 0; i < net->pxlen - plen; i++)
{
if (bits & (1u << (TRIE_STEP - i - 1)))
pos = 2 * pos + 1;
else
pos = 2 * pos;
}
s->local_pos = pos;
return 0;
}
else
{
@ -893,150 +907,164 @@ trie_walk_init(struct f_trie_walk_state *s, const struct f_trie *t, const net_ad
/* We do not override the trie root in case of inclusive search */
if (!include_successors)
s->stack[0] = NULL;
/* We are out of path, find nearest successor */
else
{
if (s->stack_pos == 0)
return 0;
/*
* If we end up on node that has compressed path, we need to step up node
* for better decision making
*/
s->stack[0] = NULL;
return 0;
}
s->stack_pos--;
n = s->stack[s->stack_pos];
/* We are out of path, find nearest successor */
if (s->stack_pos == 0)
return 0;
ASSERT(n != NULL);
/*
* If we end up on node that has compressed path, we need to step up node
* for better decision making
*/
s->stack_pos--;
n = s->stack[s->stack_pos];
ASSERT(n != NULL);
int nlen = v4 ? n->v4.plen : n->v6.plen;
s->accept_length = nlen;
/* We find the nearest successor in subsequent trie_walk_next() */
int nlen = v4 ? n->v4.plen : n->v6.plen;
u32 bits = GET_NET_BITS(net, v4, nlen, TRIE_STEP);
const struct f_trie_node *child = GET_CHILD(n, v4, bits);
if (child != NULL)
struct net_addr_ip4 *net4 = NULL;
struct net_addr_ip6 *net6 = NULL;
if (v4) net4 = (net_addr_ip4 *) net;
else net6 = (net_addr_ip6 *) net;
/* We known for sure that the searched prefix is not in the trie */
int cmp;
int bits = GET_NET_BITS(net, v4, nlen, TRIE_STEP);
const struct f_trie_node *child = GET_CHILD(n, v4, bits);
while (child)
{
cmp = v4 ? ip4_compare(child->v4.addr, net4->prefix)
: ip6_compare(child->v6.addr, net6->prefix);
if (cmp == 0)
{
s->accept_length = nlen;
/* Performs basically more granular net_comapre_ip{4,6}() */
struct net_addr_ip4 *net4 = NULL;
struct net_addr_ip6 *net6 = NULL;
if (v4) net4 = (struct net_addr_ip4 *) net;
else net6 = (struct net_addr_ip6 *) net;
int cmp = v4 ? ip4_compare(child->v4.addr, net4->prefix)
: ip6_compare(child->v6.addr, net6->prefix);
if (cmp < 0)
{
s->stack_pos++;
s->stack[s->stack_pos] = child;
s->local_pos = 0x1f;
}
else if (cmp > 0)
{
/* We continue in child node */
if (bits % 2 == 0)
s->local_pos = 0x08 + (bits >> 1);
else
s->local_pos = MIN(0x10 + bits, 0x1f);
}
if (v4 ? child->v4.plen <= net4->pxlen : child->v6.plen <= net6->pxlen)
bits = 0;
else
{
if (v4 ? child->v4.plen <= net4->pxlen : child->v6.plen < net6->pxlen)
{
/* We continue in child node */
if (bits % 2 == 0)
s->local_pos = 0x08 + (bits >> 1);
else
s->local_pos = MIN(0x10 + bits, 0x1f);
}
else
{
s->stack_pos++;
s->stack[s->stack_pos] = child;
s->local_pos = 0x01;
}
}
return 0;
// TODO handle properly search with short prefix length
int clen =0;
/* We are dealing with a compressed child */
if (clen > nlen + TRIE_STEP)
{
int len = nlen;
while (GET_NODE_BITS(child, v4, len, TRIE_STEP) == bits && len < MIN(clen, plen))
{
len += TRIE_STEP;
bits = GET_NET_BITS(net, v4, len, TRIE_STEP);
}
if (len > nlen)
{
s->stack_pos++;
s->stack[s->stack_pos] = child;
}
else
die("hidden");
/* successive siblings walk */
const struct f_trie_node *ns = NULL;
for (u32 i = bits + 1; i < (1u << TRIE_STEP); i++)
{
/* The node n is parent and the node ns is older sibling of the node child */
if ((ns = v4 ? (struct f_trie_node *) n->v4.c[i] : (struct f_trie_node *) n->v6.c[i]) == NULL)
continue;
// TODO
if (!SAME_PREFIX(ns, net, v4, len - TRIE_STEP))
break;
if (bits < GET_NODE_BITS(ns, v4, len, TRIE_STEP))
//if (GET_NET_BITS(net, v4, len, TRIE_STEP) < bits)
break;
s->stack[s->stack_pos] = ns;
}
s->accept_length = len + TRIE_STEP;
// if (ns && !SAME_PREFIX(ns, net, v4, len))
// {
// //s->local_pos = 0x10 + (bits - 1);
// s->local_pos = 0x1f;
// return 0;
// }
if (GET_NET_BITS(net, v4, len, TRIE_STEP) > GET_NODE_BITS(child, v4, len, TRIE_STEP))
s->local_pos = 0x1f; // + GET_NET_BITS(net, v4, nlen, TRIE_STEP);
else
s->local_pos = 0x01; //0x10 + GET_NET_BITS(net, v4, nlen, TRIE_STEP);
return 0;
}
else
s->local_pos = 0x10 + bits;
bits = 15;
}
else
else if (cmp < 0)
{
s->local_pos = 0x10 + bits;
for (int i = bits; i < (1 << TRIE_STEP); i++)
{
const struct f_trie_node *tmp = GET_CHILD(n, v4, i);
if (!tmp) continue;
if (v4 ? ip4_compare(tmp->v4.addr, net4->prefix) > 0
: ip6_compare(tmp->v6.addr, net6->prefix) > 0)
break;
child = tmp;
}
bits = 15;
}
else /* cmp > 0 */
bits = 0;
s->stack_pos++;
s->stack[s->stack_pos] = n = child;
child = GET_CHILD(child, v4, bits);
}
nlen = (v4) ? n->v4.plen : n->v6.plen;
cmp = v4 ? ip4_compare(n->v4.addr, net4->prefix)
: ip6_compare(n->v6.addr, net6->prefix);
if (cmp == 0)
{
bits = GET_NET_BITS(net, v4, nlen, TRIE_STEP);
if (plen - nlen >= TRIE_STEP)
{
s->local_pos = SELECT_CHILD(bits, TRIE_STEP);
return 0;
}
nlen = v4 ? n->v4.plen : n->v6.plen;
int pos = 1;
for (int i = 0; i < net->pxlen - plen; i++)
{
if (bits & (1u << (TRIE_STEP - i - 1)))
pos = 2 * pos + 1;
else
pos = 2 * pos;
}
s->local_pos = pos;
}
else if (cmp < 0)
{
s->local_pos = SELECT_CHILD(bits, TRIE_STEP);
s->accept_length = nlen;
}
return 0;
find_successor:;
ASSERT(n != NULL);
u32 nlen = v4 ? n->v4.plen : n->v6.plen;
u32 bits = GET_NET_BITS(net, v4, nlen, TRIE_STEP);
s->local_pos = 0x10 + bits;
else /* cmp > 0 */
{
}
return 0;
// if (child)
//
// {
// /* Performs basically more granular net_comapre_ip{4,6}() */
// if (v4) net4 = (struct net_addr_ip4 *) net;
// else net6 = (struct net_addr_ip6 *) net;
//
// int cmp = v4 ? ip4_compare(child->v4.addr, net4->prefix)
// : ip6_compare(child->v6.addr, net6->prefix);
// if (cmp < 0)
// {
// while ()
// {
// }
// /* We continue as we've just finished walk in a child node */
// s->local_pos = before_pos(bits + 1, TRIE_STEP);
// s->stack_pos++;
// s->stack[s->stack_pos] = child;
// s->local_pos = last_pos(TRIE_STEP);
// }
// else if (cmp > 0)
// {
// /* We continue in child node */
// if (bits % 2 == 0)
// {
// s->stack_pos++;
// s->stack[s->stack_pos] = child;
// s->local_pos = 1; //last_pos(TRIE_STEP);
// }
// //s->local_pos = 0x08 + (bits >> 1);
// //s->local_pos = before_pos(bits, TRIE_STEP);
// //s->local_pos = MAX(0, after_pos(bits - 1, TRIE_STEP)); //s->local_pos = before_pos(bits >> 1, TRIE_STEP);
// else
// //s->local_pos = MIN((1u << TRIE_STEP) + bits, (1u << TRIE_STEP) + 15);
// s->local_pos = after_pos(bits, TRIE_STEP);
// }
// else
// {
// if (v4 ? child->v4.plen <= net4->pxlen : child->v6.plen < net6->pxlen)
// {
// /* We continue in child node */
// if (bits % 2 == 0)
// s->local_pos = before_pos(bits >> 1, TRIE_STEP);
// //s->local_pos = 0x08 + (bits >> 1);
// else
// //s->local_pos = MIN((1u << TRIE_STEP) + bits, (1u << TRIE_STEP) + 15);
// s->local_pos = after_pos(bits, TRIE_STEP);
// }
// else
// {
// /* We continue in current node from first position */
// s->stack_pos++;
// s->stack[s->stack_pos] = child;
// s->local_pos = 1;
// }
// }
// return 0;
// }
//
// s->local_pos = 0x10 + bits;
// return 0;
}
#define GET_ACCEPT_BIT(N,X,B) ((X) ? ip4_getbit((N)->v4.accept, (B)) : ip6_getbit((N)->v6.accept, (B)))

16
filter/trie_test.c
View File

@ -655,6 +655,11 @@ t_trie_walk(void)
{
bt_bird_init();
bt_config_parse(BT_CONFIG_SIMPLE);
unsigned int r = rand();
printf("random seed t_trie_walk %u\n", r);
srandom(r);
//srandom(732437807);
//srandom(1182332329);
for (int round = 0; round < TESTS_NUM*8; round++)
{
@ -886,10 +891,12 @@ t_trie_walk_inclusive(void)
{
bt_bird_init();
bt_config_parse(BT_CONFIG_SIMPLE);
//unsigned int r = rand();
//printf("random seed %u\n", r);
//srandom(r);
//srandom(1985510202);
//srandom(25273275);
//srandom(1959294931);
//srandom(1182332329);
unsigned int r = rand();
printf("random seed t_trie_walk_inclusive %u\n", r);
srandom(r);
for (int round = 0; round < TESTS_NUM*8; round++)
{
@ -909,7 +916,6 @@ t_trie_walk_inclusive(void)
qsort(pxset, num, sizeof(struct f_prefix), compare_prefixes);
/* Prepare net for subnet walk - start with random prefix from trie */
if (num)
pos = bt_random() % num;