From 211c374ee27086cf8cd8cc070291a1ad2207aaa1 Mon Sep 17 00:00:00 2001
From: Alice39s <alice39s@xmsl.dev>
Date: Sat, 27 Jun 2026 23:50:19 +0900
Subject: [PATCH] feat(erlang): add xdb header and dual-stack table/pool macros

---
 binding/erlang/include/ip2region.hrl | 30 ++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/binding/erlang/include/ip2region.hrl b/binding/erlang/include/ip2region.hrl
index a0e91e7..2e7ea80 100644
--- a/binding/erlang/include/ip2region.hrl
+++ b/binding/erlang/include/ip2region.hrl
@@ -18,6 +18,36 @@
 
 -define(IP2REGION_POOL, ip2region_pool).
 
+%% xdb header field offsets (bytes)
+-define(XDB_HEADER_VERSION_OFFSET, 0).
+-define(XDB_HEADER_INDEX_POLICY_OFFSET, 2).
+-define(XDB_HEADER_CREATED_AT_OFFSET, 4).
+-define(XDB_HEADER_START_INDEX_PTR_OFFSET, 8).
+-define(XDB_HEADER_END_INDEX_PTR_OFFSET, 12).
+-define(XDB_HEADER_IP_VERSION_OFFSET, 16).
+-define(XDB_HEADER_RUNTIME_PTR_BYTES_OFFSET, 18).
+-define(XDB_HEADER_INFO_LENGTH, 256).
+
+%% IP versions as stored in xdb header
+-define(IP_VERSION_4, 4).
+-define(IP_VERSION_6, 6).
+
+%% Segment index sizes (bytes): start_ip + end_ip + data_len + data_ptr
+-define(XDB_SEGMENT_INDEX_SIZE_V4, 14).  %% 4 + 4 + 2 + 4
+-define(XDB_SEGMENT_INDEX_SIZE_V6, 38).  %% 16 + 16 + 2 + 4
+
+%% Per-version ETS tables
+-define(XDB_VECTOR_INDEX_V4, ets_xdb_vector_index_v4).
+-define(XDB_VECTOR_INDEX_V6, ets_xdb_vector_index_v6).
+-define(XDB_SEGMENT_INDEX_V4, ets_xdb_segment_index_v4).
+-define(XDB_SEGMENT_INDEX_V6, ets_xdb_segment_index_v6).
+-define(IP2REGION_CACHE_V4, ets_ip2region_cache_v4).
+-define(IP2REGION_CACHE_V6, ets_ip2region_cache_v6).
+
+%% Per-version pool names. ?IP2REGION_POOL is kept as the legacy v4 pool name.
+-define(IP2REGION_POOL_V4, ip2region_pool_v4).
+-define(IP2REGION_POOL_V6, ip2region_pool_v6).
+
 -ifndef(IF).
 -define(IF(C, T, F), case (C) of true -> (T); false -> (F) end).
 -define(IF(C, T), ?IF(C, T, skip)).