From 0bf9268453d3af82bbd1257da547b1dd8f225ba2 Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Sat, 19 Apr 2014 23:54:10 +0200 Subject: Keep peers in a hash table to allow fast address lookups --- src/peer_hashtable.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) create mode 100644 src/peer_hashtable.c (limited to 'src/peer_hashtable.c') diff --git a/src/peer_hashtable.c b/src/peer_hashtable.c new file mode 100644 index 0000000..f6cc11e --- /dev/null +++ b/src/peer_hashtable.c @@ -0,0 +1,107 @@ +/* + Copyright (c) 2012-2014, Matthias Schiffer + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions are met: + + 1. Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + 2. Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + + THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE + FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER + CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. +*/ + + +#include "peer_hashtable.h" +#include "fastd.h" +#include "hash.h" +#include "peer.h" + + +#define PEER_ADDR_HT_SIZE 64 + + +void fastd_peer_hashtable_init(fastd_context_t *ctx) { + fastd_random_bytes(ctx, &ctx->peer_addr_ht_seed, sizeof(ctx->peer_addr_ht_seed), false); + + ctx->peer_addr_ht = malloc(sizeof(*ctx->peer_addr_ht) * PEER_ADDR_HT_SIZE); + + size_t i; + for (i = 0; i < PEER_ADDR_HT_SIZE; i++) + VECTOR_ALLOC(ctx->peer_addr_ht[i], 0); +} + +void fastd_peer_hashtable_free(fastd_context_t *ctx) { + size_t i; + for (i = 0; i < PEER_ADDR_HT_SIZE; i++) + VECTOR_FREE(ctx->peer_addr_ht[i]); + + free(ctx->peer_addr_ht); +} + +static size_t peer_address_bucket(fastd_context_t *ctx, const fastd_peer_address_t *addr) { + uint32_t hash = ctx->peer_addr_ht_seed; + + switch(addr->sa.sa_family) { + case AF_INET: + fastd_hash(&hash, &addr->in, sizeof(addr->in)); + break; + + case AF_INET6: + fastd_hash(&hash, &addr->in6, sizeof(addr->in6)); + break; + + default: + exit_bug(ctx, "peer_address_bucket: unknown address family"); + } + + fastd_hash_final(&hash); + + return hash % PEER_ADDR_HT_SIZE; +} + +void fastd_peer_hashtable_insert(fastd_context_t *ctx, fastd_peer_t *peer) { + size_t b = peer_address_bucket(ctx, &peer->address); + VECTOR_ADD(ctx->peer_addr_ht[b], peer); +} + +void fastd_peer_hashtable_remove(fastd_context_t *ctx, fastd_peer_t *peer) { + if (!peer->address.sa.sa_family) + return; + + size_t b = peer_address_bucket(ctx, &peer->address); + + size_t i; + for (i = 0; i < VECTOR_LEN(ctx->peer_addr_ht[b]); i++) { + if (VECTOR_INDEX(ctx->peer_addr_ht[b], i) == peer) { + VECTOR_DELETE(ctx->peer_addr_ht[b], i); + break; + } + } +} + +fastd_peer_t *fastd_peer_hashtable_lookup(fastd_context_t *ctx, const fastd_peer_address_t *addr) { + size_t b = peer_address_bucket(ctx, addr); + + size_t i; + for (i = 0; i < VECTOR_LEN(ctx->peer_addr_ht[b]); i++) { + fastd_peer_t *peer = VECTOR_INDEX(ctx->peer_addr_ht[b], i); + + if (fastd_peer_address_equal(&peer->address, addr)) + return peer; + } + + return NULL; +} -- cgit v1.2.3