fix(erlang): unify v4 pool name and stop caching errors

binding/erlang/README.md

@@ -133,6 +133,10 @@ Finished in 0.150 seconds
 
 Both IPv4 and IPv6 benchmarks share the same script. Run it with the desired IP version:
 
+> `cold` = first pass over the source file: each IP triggers a real search and the
+> result is written into the ETS cache. `warm` = second pass over the same list,
+> where every lookup is served directly from the ETS cache.
+
 ```
 $ cd benchmarks/
 $ sh xdb-benchmark.sh ipv4

binding/erlang/README_zh.md

@@ -110,6 +110,9 @@ Finished in 0.074 seconds
 
 IPv4 与 IPv6 共用一个脚本，通过参数指定版本：
 
+> `cold` = 第一次遍历源文件：每个 IP 都会触发真实查询，并把结果写入 ETS 缓存。
+> `warm` = 第二次遍历同一列表，所有查询都直接命中 ETS 缓存。
+
 ```
 $ cd benchmarks/
 $ sh xdb-benchmark.sh ipv4

binding/erlang/include/ip2region.hrl

@@ -9,15 +9,6 @@
 -define(XDB_VECTOR_INDEX_SIZE, 8).
 -define(XDB_VECTOR_INDEX_COUNT, (16#10000)). %% 256*256
 
-%% 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).
-
 %% IP versions as stored in xdb header
 -define(IP_VERSION_4, 4).
 -define(IP_VERSION_6, 6).
@@ -34,9 +25,18 @@
 -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, ip2region_pool).
+%% Per-version pool names.
 -define(IP2REGION_POOL_V4, ip2region_pool_v4).
 -define(IP2REGION_POOL_V6, ip2region_pool_v6).
 
+-record(xdb_header, {
+    version :: non_neg_integer(),
+    index_policy :: non_neg_integer(),
+    created_at :: non_neg_integer(),
+    start_index_ptr :: non_neg_integer(),
+    end_index_ptr :: non_neg_integer(),
+    ip_version :: non_neg_integer(),
+    runtime_ptr_bytes :: non_neg_integer()
+}).
+
 -endif.

binding/erlang/src/ip2region_sup.erl

@@ -58,16 +58,9 @@ ensure_table(Name, Opts) ->
 pool_child_specs() ->
     {ok, DbConfig} = application:get_env(db),
     {ok, PoolArgsCfg} = application:get_env(poolargs),
-    Versions = [Version || {Version, _File} <- DbConfig],
-    UseLegacyName = (Versions == [ipv4]),
-    V4PoolName = case UseLegacyName of
-                     true -> ?IP2REGION_POOL;
-                     false -> ?IP2REGION_POOL_V4
-                 end,
-    ok = application:set_env(?APP_NAME, v4_pool_name, V4PoolName),
     lists:foldl(
         fun({ipv4, File}, Acc) ->
-                [make_pool_spec(V4PoolName, ipv4, File, PoolArgsCfg) | Acc];
+                [make_pool_spec(?IP2REGION_POOL_V4, ipv4, File, PoolArgsCfg) | Acc];
            ({ipv6, File}, Acc) ->
                 [make_pool_spec(?IP2REGION_POOL_V6, ipv6, File, PoolArgsCfg) | Acc];
            (_, Acc) ->

binding/erlang/src/ip2region_worker.erl

@@ -134,6 +134,7 @@ do_info(Info, State) ->
     error_logger:error_report(io:format("unknown info: ~p", [Info])),
     {noreply, State}.
 
+-spec resolve_version(#xdb_header{}) -> {ok, ipv4 | ipv6} | {error, term()}.
 resolve_version(Header) ->
     case ip2region_xdb:header_version(Header) of
         2 -> {ok, ipv4};
@@ -147,6 +148,10 @@ resolve_version(Header) ->
     end.
 
 load_vector_index(IoDevice, Version) ->
+    %% The vector index ETS table is global and shared by all pool workers.
+    %% Only the first worker (or the first worker after a restart) populates it.
+    %% Subsequent workers skip the file:read here; search_ip/2 uses file:pread/3,
+    %% so the current file pointer position does not affect correctness.
     Table = ip2region_xdb:vector_index_table(Version),
     case ets:info(Table, size) of
         undefined ->

binding/erlang/src/ip2region_xdb.erl

@@ -18,16 +18,6 @@
 
 -include("ip2region.hrl").
 
--record(xdb_header, {
-    version :: non_neg_integer(),
-    index_policy :: non_neg_integer(),
-    created_at :: non_neg_integer(),
-    start_index_ptr :: non_neg_integer(),
-    end_index_ptr :: non_neg_integer(),
-    ip_version :: non_neg_integer(),
-    runtime_ptr_bytes :: non_neg_integer()
-}).
-
 -spec parse_header(binary()) -> {ok, #xdb_header{}} | {error, invalid_header}.
 parse_header(Bin) when is_binary(Bin), byte_size(Bin) >= 20 ->
     <<Version:16/little, IndexPolicy:16/little, CreatedAt:32/little,
@@ -57,11 +47,14 @@ header_runtime_ptr_bytes(#xdb_header{runtime_ptr_bytes = B}) -> B.
 segment_index_size(ipv4) -> ?XDB_SEGMENT_INDEX_SIZE_V4;
 segment_index_size(ipv6) -> ?XDB_SEGMENT_INDEX_SIZE_V6.
 
+-spec vector_index_table(ipv4 | ipv6) -> atom().
 vector_index_table(ipv4) -> ?XDB_VECTOR_INDEX_V4;
 vector_index_table(ipv6) -> ?XDB_VECTOR_INDEX_V6.
 
+-spec segment_index_table(ipv4 | ipv6) -> atom().
 segment_index_table(ipv4) -> ?XDB_SEGMENT_INDEX_V4;
 segment_index_table(ipv6) -> ?XDB_SEGMENT_INDEX_V6.
 
+-spec cache_table(ipv4 | ipv6) -> atom().
 cache_table(ipv4) -> ?IP2REGION_CACHE_V4;
 cache_table(ipv6) -> ?IP2REGION_CACHE_V6.

binding/erlang/src/xdb.erl

@@ -17,7 +17,7 @@
 search(Ip) ->
     case ip2region_util:ip_to_bytes(Ip) of
         {ok, ipv4, IpBin} ->
-            do_search(v4_pool(), ipv4, IpBin);
+            do_search(?IP2REGION_POOL_V4, ipv4, IpBin);
         {ok, ipv6, IpBin} ->
             do_search(?IP2REGION_POOL_V6, ipv6, IpBin);
         Ret ->
@@ -31,16 +31,13 @@ do_search(PoolName, Version, IpBin) ->
         _ ->
             Worker = poolboy:checkout(PoolName, true, infinity),
             try
-                Region = ip2region_worker:search(Worker, IpBin),
+                case ip2region_worker:search(Worker, IpBin) of
+                    {error, _} = Err -> Err;
+                    Region ->
                         ets:insert(CacheTable, {IpBin, Region}),
                         Region
+                end
             after
                 poolboy:checkin(PoolName, Worker)
             end
     end.
-
-v4_pool() ->
-    case application:get_env(?APP_NAME, v4_pool_name) of
-        {ok, PoolName} -> PoolName;
-        undefined -> ?IP2REGION_POOL
-    end.

binding/erlang/test/ip2region_sup_test.erl

@@ -6,6 +6,10 @@ pools_started_test() ->
     application:stop(ip2region),
     application:unload(ip2region),
     ok = application:load(ip2region),
+    %% NOTE: rebar3 compiles tests under _build/test/lib/ip2region via a
+    %% symlink back to the source tree, so ?FILE resolves to the original
+    %% binding/erlang/test/... path. If rebar3 is configured to copy
+    %% instead of symlink, this path traversal must be adjusted.
     TestDir = filename:dirname(?FILE),
     ErlangDir = filename:dirname(TestDir),
     BindingDir = filename:dirname(ErlangDir),