From d562c8f32deb578e7c4c6ac0e9fa2cd6a367ca10 Mon Sep 17 00:00:00 2001
From: ruti <>
Date: Tue, 17 Jun 2025 17:48:56 +0300
Subject: [PATCH] Move host without copying

(#298)
---
 extend.c | 23 +++++++++++++----------
 main.c   |  4 ++--
 mpool.c  | 53 ++++++++++++++++++++++++++++-------------------------
 mpool.h  | 28 +++++++++++++++++-----------
 4 files changed, 60 insertions(+), 48 deletions(-)

diff --git a/extend.c b/extend.c
index 38c2561..0337378 100644
--- a/extend.c
+++ b/extend.c
@@ -68,7 +68,7 @@ static struct elem_i *cache_get(const union sockaddr_u *dst)
     struct cache_key key = { 0 };
     int len = serialize_addr(dst, &key);
     
-    struct elem_i *val = (struct elem_i *)mem_get(params.mempool, (char *)&key, len);
+    struct elem_i *val = mem_get(params.mempool, (char *)&key, len);
     if (!val) {
         return 0;
     }
@@ -83,29 +83,30 @@ static struct elem_i *cache_get(const union sockaddr_u *dst)
 
 
 static struct elem_i *cache_add(
-        const union sockaddr_u *dst, const char *host, int host_len)
+        const union sockaddr_u *dst, char **host, int host_len)
 {
     struct cache_key key = { 0 };
     int cmp_len = serialize_addr(dst, &key);
     time_t t = time(0);
     
-    size_t total = sizeof(struct cache_data) + host_len;
-    struct cache_data *data = calloc(1, total);
+    struct cache_key *data = calloc(1, cmp_len);
     if (!data) {
         return 0;
     }
     memcpy(data, &key, cmp_len);
     
-    data->host_len = host_len;
-    memcpy(data->host, host, host_len);
-    
-    struct elem_i *val = (struct elem_i *)mem_add(params.mempool, (char *)data, cmp_len, sizeof(struct elem_i));
+    struct elem_i *val = mem_add(params.mempool, (char *)data, cmp_len, sizeof(struct elem_i));
     if (!val) {
         uniperror("mem_add");
         free(data);
         return 0;
     }
     val->time = t;
+    if (!val->extra && *host) {
+        val->extra_len = host_len;
+        val->extra = *host;
+        *host = 0;
+    }
     return val;
 }
 
@@ -276,6 +277,8 @@ static void swop_groups(struct desync_params *dpc, struct desync_params *dpn)
     if (dpc->fail_count <= dpn->fail_count) {
         return;
     }
+    LOG(LOG_S, "swop: %d <-> %d\n", dpc->id, dpn->id);
+    
     struct desync_params dpc_cp = *dpc;
     dpc->next = dpn->next;
     dpc->prev = dpn->prev;
@@ -336,7 +339,7 @@ static int on_trigger(int type, struct poolhd *pool, struct eval *val)
         }
         LOG(LOG_S, "save: ip=%s, id=%d\n", ADDR_STR, dp->id);
         
-        struct elem_i *e = cache_add(&val->addr, val->pair->host, val->pair->host_len);
+        struct elem_i *e = cache_add(&val->addr, &val->pair->host, val->pair->host_len);
         if (e) {
             e->dp = dp;
             e->dp_mask = val->pair->dp_mask;
@@ -348,7 +351,7 @@ static int on_trigger(int type, struct poolhd *pool, struct eval *val)
     }
     LOG(LOG_S, "unreach ip: %s\n", ADDR_STR);
     
-    struct elem_i *e = cache_add(&val->addr, val->pair->host, val->pair->host_len);
+    struct elem_i *e = cache_add(&val->addr, &val->pair->host, val->pair->host_len);
     if (e) {
         e->dp = params.dp;
         e->dp_mask = 0;
diff --git a/main.c b/main.c
index dadeab3..4ec7a1b 100644
--- a/main.c
+++ b/main.c
@@ -309,7 +309,7 @@ static inline int lower_char(char *cl)
 
 struct mphdr *parse_hosts(char *buffer, size_t size)
 {
-    struct mphdr *hdr = mem_pool(1, CMP_HOST);
+    struct mphdr *hdr = mem_pool(MF_STATIC, CMP_HOST);
     if (!hdr) {
         return 0;
     }
@@ -1201,7 +1201,7 @@ int main(int argc, char **argv)
             return -1;
         }
     }
-    params.mempool = mem_pool(0, CMP_BYTES);
+    params.mempool = mem_pool(MF_EXTRA, CMP_BYTES);
     if (!params.mempool) {
         uniperror("mem_pool");
         clear_params();
diff --git a/mpool.c b/mpool.c
index 2b7fffa..42638bc 100644
--- a/mpool.c
+++ b/mpool.c
@@ -67,18 +67,18 @@ static int scmp(const struct elem *p, const struct elem *q)
 KAVL_INIT(my, struct elem, head, scmp)
 
 
-struct mphdr *mem_pool(bool is_static, unsigned char cmp_type)
+struct mphdr *mem_pool(unsigned short flags, unsigned char cmp_type)
 {
     struct mphdr *hdr = calloc(1, sizeof(struct mphdr));
     if (hdr) {
-        hdr->static_data = is_static;
+        hdr->flags = flags;
         hdr->cmp_type = cmp_type;
     }
     return hdr;
 }
 
 
-struct elem *mem_get(const struct mphdr *hdr, const char *str, int len)
+void *mem_get(const struct mphdr *hdr, const char *str, int len)
 {
     struct elem temp = { 
         .cmp_type = hdr->cmp_type,
@@ -88,7 +88,19 @@ struct elem *mem_get(const struct mphdr *hdr, const char *str, int len)
 }
 
 
-struct elem *mem_add(struct mphdr *hdr, char *str, int len, size_t struct_size)
+static void destroy_elem(struct mphdr *hdr, struct elem *e)
+{
+    if (!(hdr->flags & MF_STATIC)) {
+        free(e->data);
+    }
+    if (hdr->flags & MF_EXTRA) {
+        free(((struct elem_ex *)e)->extra);
+    }
+    free(e);
+}
+
+
+void *mem_add(struct mphdr *hdr, char *str, int len, size_t struct_size)
 {
     struct elem *v, *e = calloc(1, struct_size);
     if (!e) {
@@ -104,9 +116,7 @@ struct elem *mem_add(struct mphdr *hdr, char *str, int len, size_t struct_size)
         v = kavl_insert(my, &hdr->root, e, 0);
     }
     if (e != v) {
-        if (!hdr->static_data)
-            free(e->data);
-        free(e);
+        destroy_elem(hdr, e);
     }
     else hdr->count++;
     return v;
@@ -123,11 +133,7 @@ void mem_delete(struct mphdr *hdr, const char *str, int len)
     if (!e) {
         return;
     }
-    if (!hdr->static_data) {
-        free(e->data);
-        e->data = 0;
-    }
-    free(e);
+    destroy_elem(hdr, e);
     hdr->count--;
 }
 
@@ -139,11 +145,7 @@ void mem_destroy(struct mphdr *hdr)
         if (!e) {
             break;
         }
-        if (!hdr->static_data) {
-            free(e->data);
-        }
-        e->data = 0;
-        free(e);
+        destroy_elem(hdr, e);
     }
     free(hdr);
 }
@@ -157,17 +159,18 @@ void dump_cache(struct mphdr *hdr, FILE *out)
     kavl_itr_t(my) itr;
     kavl_itr_first(my, hdr->root, &itr);
     do {
-        const struct elem_i *p = (const struct elem_i *)kavl_at(&itr);
-        struct cache_data *value = (struct cache_data *)p->i.data;
+        struct elem_i *p = (struct elem_i *)kavl_at(&itr);
+        struct cache_key *key = (struct cache_key *)p->main.data;
         
         char ADDR_STR[INET6_ADDRSTRLEN];
-        if (value->key.family == AF_INET)
-            inet_ntop(AF_INET, &value->key.ip.v4, ADDR_STR, sizeof(ADDR_STR));
+        if (key->family == AF_INET)
+            inet_ntop(AF_INET, &key->ip.v4, ADDR_STR, sizeof(ADDR_STR));
         else
-            inet_ntop(AF_INET6, &value->key.ip.v6, ADDR_STR, sizeof(ADDR_STR));
+            inet_ntop(AF_INET6, &key->ip.v6, ADDR_STR, sizeof(ADDR_STR));
         
         fprintf(out, "%s %d %d %jd %.*s\n", 
-            ADDR_STR, ntohs(value->key.port), p->dp->id, 
-            (intmax_t)p->time, value->host_len, value->host);
-    } while (kavl_itr_next(my, &itr));
+            ADDR_STR, ntohs(key->port), p->dp->id, 
+            (intmax_t)p->time, p->extra_len, p->extra ? p->extra : "");
+    } 
+    while (kavl_itr_next(my, &itr));
 }
diff --git a/mpool.h b/mpool.h
index 89db85a..d9bfd2b 100644
--- a/mpool.h
+++ b/mpool.h
@@ -11,6 +11,9 @@
 #define CMP_BITS 1
 #define CMP_HOST 2
 
+#define MF_STATIC 1
+#define MF_EXTRA 2
+
 #pragma pack(push, 1)
 
 struct cache_key {
@@ -22,12 +25,6 @@ struct cache_key {
     } ip;
 };
 
-struct cache_data {
-    struct cache_key key;
-    int host_len;
-    char host[];
-};
-
 #pragma pack(pop)
 
 struct elem {
@@ -37,25 +34,34 @@ struct elem {
     KAVL_HEAD(struct elem) head;
 };
 
+struct elem_ex {
+    struct elem main;
+    unsigned int extra_len;
+    char *extra;
+};
+
 struct elem_i {
-    struct elem i;
+    struct elem main;
+    unsigned int extra_len;
+    char *extra;
+    
     struct desync_params *dp;
     uint64_t dp_mask;
     time_t time;
 };
 
 struct mphdr {
-    bool static_data;
+    unsigned short flags;
     unsigned char cmp_type;
     size_t count;
     struct elem *root;
 };
 
-struct mphdr *mem_pool(bool is_static, unsigned char cmp_type);
+struct mphdr *mem_pool(unsigned short flags, unsigned char cmp_type);
 
-struct elem *mem_get(const struct mphdr *hdr, const char *str, int len);
+void *mem_get(const struct mphdr *hdr, const char *str, int len);
 
-struct elem *mem_add(struct mphdr *hdr, char *str, int len, size_t ssize);
+void *mem_add(struct mphdr *hdr, char *str, int len, size_t ssize);
 
 void mem_delete(struct mphdr *hdr, const char *str, int len);