From 931fb9e67b8647e1ce4467e22ebe3496e26a3bf2 Mon Sep 17 00:00:00 2001
From: lion <chenxin619315@gmail.com>
Date: Tue, 23 Sep 2025 18:15:46 +0800
Subject: [PATCH] use the local stack region_buffer instead of heap allocation

---
 binding/c/xdb_api.h      |  3 ++-
 binding/c/xdb_searcher.c | 27 ++++++---------------------
 binding/c/xdb_util.c     |  4 ++--
 3 files changed, 10 insertions(+), 24 deletions(-)

diff --git a/binding/c/xdb_api.h b/binding/c/xdb_api.h
index 2db43cf..6d69995 100644
--- a/binding/c/xdb_api.h
+++ b/binding/c/xdb_api.h
@@ -41,7 +41,8 @@
 #define xdb_vector_index_rows  256
 #define xdb_vector_index_cols  256
 #define xdb_vector_index_size  8
-#define xdb_segment_index_size 14
+#define xdb_v4_index_size 14    // 4 + 4 + 2 + 4
+#define xdb_v6_index_size 38    // 16 + 16 + 2 + 4
 
 // --- ip version info
 #define xdb_ipv4_id 4
diff --git a/binding/c/xdb_searcher.c b/binding/c/xdb_searcher.c
index 8eba674..b2b5c04 100644
--- a/binding/c/xdb_searcher.c
+++ b/binding/c/xdb_searcher.c
@@ -132,7 +132,7 @@ XDB_PUBLIC(int) xdb_search(xdb_searcher_t *xdb, const bytes_ip_t *ip_bytes, int
     register int seg_index_size, l, h, m, p;
     unsigned int s_ptr, e_ptr, data_ptr, data_len;
     char vector_buffer[xdb_vector_index_size];
-    char *segment_buffer = NULL;
+    char segment_buffer[xdb_v6_index_size];
 
     // ip version check
     if (ip_len != xdb->version->bytes) {
@@ -168,12 +168,8 @@ XDB_PUBLIC(int) xdb_search(xdb_searcher_t *xdb, const bytes_ip_t *ip_bytes, int
 
     // printf("s_ptr=%u, e_ptr=%u\n", s_ptr, e_ptr);
     // binary search to get the final region info
+    // segment_buffer = xdb_malloc(seg_index_size);
     seg_index_size = xdb->version->segment_index_size;
-    segment_buffer = xdb_malloc(seg_index_size);
-    if (segment_buffer == NULL) {
-        return -2;
-    }
-
     data_len = 0, data_ptr = 0;
     l = 0, h = ((int) (e_ptr - s_ptr)) / seg_index_size;
     while (l <= h) {
@@ -183,8 +179,7 @@ XDB_PUBLIC(int) xdb_search(xdb_searcher_t *xdb, const bytes_ip_t *ip_bytes, int
         // read the segment index item
         err = read(xdb, p, segment_buffer, seg_index_size);
         if (err != 0) {
-            err += 20;
-            goto defer;
+            return 20 + err;
         }
 
         // decode the data fields as needed
@@ -201,28 +196,18 @@ XDB_PUBLIC(int) xdb_search(xdb_searcher_t *xdb, const bytes_ip_t *ip_bytes, int
 
     // printf("data_len=%u, data_ptr=%u\n", data_len, data_ptr);
     if (data_len == 0) {
-        err = 100;
-        goto defer;
+        return 100;
     }
 
     // buffer alloc checking
     err = xdb_region_buffer_alloc(region, data_len);
     if (err != 0) {
-        err += 100;
-        goto defer;
+        return 100 + err;
     }
 
     err = read(xdb, data_ptr, region->value, data_len);
     if (err != 0) {
-        err += 30;
-        goto defer;
-    }
-
-defer:
-    // checn and free the segment buffer
-    if (segment_buffer != NULL) {
-        xdb_free(segment_buffer);
-        segment_buffer = NULL;
+        return 30 + err;
     }
 
     return err;
diff --git a/binding/c/xdb_util.c b/binding/c/xdb_util.c
index c2e8ef9..1f21630 100644
--- a/binding/c/xdb_util.c
+++ b/binding/c/xdb_util.c
@@ -305,10 +305,10 @@ XDB_PRIVATE(int) _ipv4_sub_compare(const bytes_ip_t *ip_bytes, int bytes, const
 
 static xdb_version_t _ip_version_list[] = {
     // 14 = 4 + 4 + 2 + 4
-    {xdb_ipv4_id, "IPv4", xdb_ipv4_bytes, 14, _ipv4_sub_compare},
+    {xdb_ipv4_id, "IPv4", xdb_ipv4_bytes, xdb_v4_index_size, _ipv4_sub_compare},
 
     // 38 = 16 + 16 + 2 + 4
-    {xdb_ipv6_id, "IPv6", xdb_ipv6_bytes, 38, xdb_ip_sub_compare},
+    {xdb_ipv6_id, "IPv6", xdb_ipv6_bytes, xdb_v6_index_size, xdb_ip_sub_compare},
 
     // END
     {0, NULL, 0, 0, NULL}