fix: apply connection compression option

docs/api-reference.md

@@ -137,6 +137,8 @@ dmPython.connect(
 - `packet_size`
 - `port`
 
+`compress_msg` 仅在建连时接受 `DSQL_FALSE` 或 `DSQL_TRUE`，属性读回为协商后的布尔压缩状态。语句句柄缓存尚未实现：`use_stmt_pool=0` 可用，`use_stmt_pool=1` 会报错。
+
 只读：
 
 - `server_code`

docs/test-results/2026-09-26-type-connection-matrix.md

@@ -14,7 +14,7 @@
 | 空值 | 整数、十进制、文本、二进制、日期、时间戳列的 `NULL` 往返 |
 | 连接地址 | `server`、`host`、`dsn=host:port` 均可连接；`host` 与 `server` 同时传入会报错 |
 | 连接行为 | 默认元组与 `DictCursor` 行形状、`schema`、`autoCommit` 开关及开启后无需显式提交的持久化、`txn_isolation` 读回 |
-| 选项基础检查 | 非数字 `port` 报错；`connection_timeout`、`login_timeout`、`compress_msg`、`use_stmt_pool` 可建连并执行查询 |
+| 选项基础检查 | 非数字 `port` 报错；`connection_timeout`、`login_timeout` 可建连并执行查询；消息压缩和语句池行为见下文 |
 
 `DECIMAL`、`FLOAT`、`DOUBLE`、`TIME`、`TIMESTAMP` 在当前默认读取路径通常返回字符串。矩阵断言数值或时间内容，同时保留未来改善 Python 返回类型的空间。
 
@@ -65,3 +65,7 @@
 ## 后续修复：区间子类型
 
 桥接层原先只识别 `DAY TO SECOND` 和 `YEAR TO MONTH` 两种区间列；真实 DM8 中其余 11 种区间限定形式均被读成普通字符串。现在按 DPI 类型码识别全部 13 种形式。`DAY`、`HOUR`、`MINUTE`、`SECOND` 及其组合读为 `datetime.timedelta`，`YEAR`、`MONTH` 和 `YEAR TO MONTH` 保留 `dmPython.YEAR_MONTH_INTERVAL` 描述类型；部分子类型的正负 `timedelta` 写入也验证通过。Python 3.10 在 UTF-8 和 GB18030 官方 ARM DM8 实例上的完整真实库回归各为 **183 passed、0 skipped**，另各有 2 个非真实库用例未选入。
+
+## 后续修复：连接消息压缩
+
+`compress_msg` 原先被静默忽略；现在只接受 `DSQL_FALSE`/`DSQL_TRUE`，将选择传给 Go 驱动并从协商后的连接状态读回。两种取值均已在真实 DM8 上建连和查询成功。底层 Go 驱动只解析 `StmtPoolSize`，没有使用对应缓存大小；因此显式请求 `use_stmt_pool=1` 现在会报不支持，`use_stmt_pool=0` 可用。语句句柄缓存仍待实现。

dpi_bridge/dpi_conn.go

@@ -60,6 +60,7 @@ type connHandle struct {
 	loginTimeout  int
 	connTimeout   int
 	appName       string
+	compressMsg   int
 	svcPath       string
 	mppLogin      int
 	rwSeparate    int
@@ -82,6 +83,7 @@ func newConnHandle(env *envHandle) *connHandle {
 		port:          DSQL_DEAFAULT_TCPIP_PORT,
 		autocommit:    false,
 		loginTimeout:  5000,
+		compressMsg:   -1,
 		mppLogin:      -1,
 		rwSeparate:    -1,
 		rwPercent:     -1,
@@ -227,6 +229,21 @@ func dpi_set_con_attr(hcon C.dhcon, attrID C.sdint4, val C.dpointer, valLen C.sd
 			return DSQL_ERROR
 		}
 		conn.rwPercent = intVal
+	case DSQL_ATTR_COMPRESS_MSG:
+		if conn.conn != nil {
+			conn.lastErr = &diagInfo{errorCode: -1, message: "compress_msg can only be set before login"}
+			return DSQL_ERROR
+		}
+		if intVal != 0 && intVal != 1 {
+			conn.lastErr = &diagInfo{errorCode: -1, message: "compress_msg must be DSQL_FALSE (0) or DSQL_TRUE (1)"}
+			return DSQL_ERROR
+		}
+		conn.compressMsg = intVal
+	case DSQL_ATTR_USE_STMT_POOL:
+		if intVal != 0 {
+			conn.lastErr = &diagInfo{errorCode: -1, message: "use_stmt_pool is not supported by this bridge"}
+			return DSQL_ERROR
+		}
 	case DSQL_ATTR_SSL_PATH, DSQL_ATTR_SSL_PWD, DSQL_ATTR_UKEY_NAME, DSQL_ATTR_UKEY_PIN:
 		if val != nil && C.GoString((*C.char)(val)) != "" {
 			name := map[int32]string{
@@ -236,8 +253,7 @@ func dpi_set_con_attr(hcon C.dhcon, attrID C.sdint4, val C.dpointer, valLen C.sd
 			conn.lastErr = &diagInfo{errorCode: -1, message: name + " is not supported by this bridge"}
 			return DSQL_ERROR
 		}
-	case DSQL_ATTR_COMPRESS_MSG, DSQL_ATTR_USE_STMT_POOL,
-		DSQL_ATTR_CURSOR_ROLLBACK_BEHAVIOR,
+	case DSQL_ATTR_CURSOR_ROLLBACK_BEHAVIOR,
 		DSQL_ATTR_OSAUTH_TYPE, DSQL_ATTR_DDL_AUTOCOMMIT,
 		DSQL_ATTR_COMPATIBLE_MODE, DSQL_ATTR_SHAKE_CRYPTO,
 		DSQL_ATTR_NLS_NUMERIC_CHARACTERS,
@@ -304,6 +320,20 @@ func dpi_get_con_attr(hcon C.dhcon, attrID C.sdint4, val C.dpointer, bufLen C.sd
 		if valLen != nil {
 			*valLen = 4
 		}
+	case DSQL_ATTR_COMPRESS_MSG:
+		value := conn.compressMsg
+		if value < 0 {
+			value = 0
+		}
+		*(*C.sdint4)(val) = C.sdint4(value)
+		if valLen != nil {
+			*valLen = 4
+		}
+	case DSQL_ATTR_USE_STMT_POOL:
+		*(*C.sdint4)(val) = 0
+		if valLen != nil {
+			*valLen = 4
+		}
 	case DSQL_ATTR_AUTOCOMMIT:
 		v := C.udint4(0)
 		if conn.autocommit {
@@ -448,6 +478,9 @@ func dpi_login(hcon C.dhcon, svr *C.sdbyte, user *C.sdbyte, pwd *C.sdbyte) C.DPI
 	if conn.appName != "" {
 		params = append(params, "appName="+url.QueryEscape(conn.appName))
 	}
+	if conn.compressMsg >= 0 {
+		params = append(params, "compress="+strconv.Itoa(conn.compressMsg))
+	}
 	if conn.svcPath != "" {
 		params = append(params, "svcConfPath="+url.QueryEscape(filepath.Join(conn.svcPath, "dm_svc.conf")))
 	}
@@ -512,6 +545,11 @@ func dpi_login(hcon C.dhcon, svr *C.sdbyte, user *C.sdbyte, pwd *C.sdbyte) C.DPI
 
 	conn.db = db
 	conn.conn = dmConn
+	if dmConn.CompressionMode() != 0 {
+		conn.compressMsg = 1
+	} else {
+		conn.compressMsg = 0
+	}
 
 	// Try to get server version
 	var version string

dpi_bridge/third_party/chunanyong_dm/PATCHES.md

@@ -43,6 +43,15 @@
   against both UTF-8 and GB18030 databases; `clob_encoding_test.go` covers
   ASCII, two-byte, and four-byte boundaries.
 
+## Patch: expose negotiated compression mode
+
+- File: `bridge_options.go`
+- Expose the negotiated compression mode so the DPI bridge can report the
+  effective `compress_msg` setting after login rather than only echoing the
+  requested value.
+- Regression: `test_compress_msg_is_applied` connects with compression both
+  disabled and enabled against a real DM8 instance.
+
 ## Patch: initial connection timeout through endpoint groups
 
 - Files: `a.go`, `n.go`, `x.go`, `y.go`, `m.go`

dpi_bridge/third_party/chunanyong_dm/bridge_options.go

@@ -0,0 +1,9 @@
+package dm
+
+// CompressionMode reports the negotiated wire-compression mode to the DPI bridge.
+func (dc *DmConnection) CompressionMode() int {
+	if dc.dmConnector == nil {
+		return 0
+	}
+	return dc.dmConnector.compress
+}

tests/integration/test_p1_connection_matrix.py

@@ -260,8 +260,7 @@ def test_port_rejects_non_numeric_value(conn_params):
     [
         {"connection_timeout": 5},
         {"login_timeout": 5000},
-        {"compress_msg": 0},
-        {"use_stmt_pool": 1},
+        {"use_stmt_pool": 0},
     ],
 )
 def test_optional_setting_connects_and_queries(conn_params, option):
@@ -271,6 +270,34 @@ def test_optional_setting_connects_and_queries(conn_params, option):
             assert cur.fetchone() == (1,)
 
 
+@pytest.mark.parametrize("enabled", [dmPython.DSQL_FALSE, dmPython.DSQL_TRUE])
+def test_compress_msg_is_applied(conn_params, enabled):
+    with dmPython.connect(**conn_params, compress_msg=enabled) as conn:
+        assert conn.compress_msg == enabled
+        with conn.cursor() as cur:
+            cur.execute("SELECT 1")
+            assert cur.fetchone() == (1,)
+
+
+@pytest.mark.parametrize("value", [-1, 2])
+def test_compress_msg_rejects_invalid_values(conn_params, value):
+    with pytest.raises((dmPython.Error, OverflowError)) as exc:
+        dmPython.connect(**conn_params, compress_msg=value)
+    if isinstance(exc.value, dmPython.Error):
+        assert "compress_msg" in str(exc.value)
+
+
+def test_use_stmt_pool_rejects_unavailable_cache(conn_params):
+    with pytest.raises(dmPython.Error, match="use_stmt_pool.*not supported"):
+        dmPython.connect(**conn_params, use_stmt_pool=1)
+
+
+def test_compress_msg_rejects_post_login_change(conn_params):
+    with dmPython.connect(**conn_params) as conn:
+        with pytest.raises(dmPython.Error, match="before login"):
+            conn.compress_msg = dmPython.DSQL_TRUE
+
+
 def test_connection_timeout_options_are_reported(conn_params):
     with dmPython.connect(
         **conn_params,