add byteof

6 files changed, 73 insertions, 4 deletions

diff --git a/core/src/xmake/engine.c b/core/src/xmake/engine.c
index f7d5a1c20..e4ac9f0f5 100644
--- a/core/src/xmake/engine.c
+++ b/core/src/xmake/engine.c
@@ -230,6 +230,7 @@ tb_int_t xm_libc_strndup(lua_State* lua);
 tb_int_t xm_libc_dataptr(lua_State* lua);
 tb_int_t xm_libc_ptraddr(lua_State* lua);
 tb_int_t xm_libc_diffptr(lua_State* lua);
+tb_int_t xm_libc_byteof(lua_State* lua);
 
 #ifdef XM_CONFIG_API_HAVE_CURSES
 // register curses
@@ -433,6 +434,7 @@ static luaL_Reg const g_libc_functions[] =
 ,   { "dataptr",        xm_libc_dataptr     }
 ,   { "ptraddr",        xm_libc_ptraddr     }
 ,   { "diffptr",        xm_libc_diffptr     }
+,   { "byteof",         xm_libc_byteof      }
 ,   { tb_null,          tb_null             }
 };
 
diff --git a/core/src/xmake/libc/byteof.c b/core/src/xmake/libc/byteof.c
new file mode 100644
index 000000000..9d0031559
--- /dev/null
+++ b/core/src/xmake/libc/byteof.c
@@ -0,0 +1,58 @@
+/*!A cross-platform build utility based on Lua
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Copyright (C) 2015-present, TBOOX Open Source Group.
+ *
+ * @author      ruki
+ * @file        byteof.c
+ *
+ */
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * trace
+ */
+#define TB_TRACE_MODULE_NAME    "byteof"
+#define TB_TRACE_MODULE_DEBUG   (0)
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * includes
+ */
+#include "prefix.h"
+
+/* //////////////////////////////////////////////////////////////////////////////////////
+ * implementation
+ */
+tb_int_t xm_libc_byteof(lua_State* lua)
+{
+    // check
+    tb_assert_and_check_return_val(lua, 0);
+
+    // get data
+    tb_pointer_t data = tb_null;
+    if (xm_lua_ispointer(lua, 1))
+        data = (tb_pointer_t)xm_lua_topointer(lua, 1);
+    else if (lua_isstring(lua, 1))
+        data = (tb_pointer_t)luaL_checkstring(lua, 1);
+    else xm_libc_return_error(lua, "libc.byteof(invalid data)!");
+
+    // get offset
+    tb_int_t offset = 0;
+    if (lua_isnumber(lua, 2))
+        offset = (tb_int_t)lua_tonumber(lua, 2);
+    else xm_libc_return_error(lua, "libc.byteof(invalid offset)!");
+    lua_pushinteger(lua, ((tb_byte_t const*)data)[offset]);
+    return 1;
+}
+
+
diff --git a/core/src/xmake/makefile b/core/src/xmake/makefile
index b766b272d..a37003b37 100644
--- a/core/src/xmake/makefile
+++ b/core/src/xmake/makefile
@@ -123,6 +123,7 @@ xmake_C_FILES 			+= \
 						libc/dataptr \
 						libc/ptraddr \
 						libc/diffptr \
+						libc/byteof \
 						libc/strndup
 
 iswin =
diff --git a/tests/modules/bytes/test.lua b/tests/modules/bytes/test.lua
index ac12db29c..4cb272c94 100644
--- a/tests/modules/bytes/test.lua
+++ b/tests/modules/bytes/test.lua
@@ -10,7 +10,6 @@ function test_ctor(t)
     t:are_equal(bytes({bytes("123"), bytes("456"), bytes("789")}):str(), "123456789")
 end
 
---[[
 function test_clone(t)
     t:are_equal(bytes(10):clone():size(), 10)
     t:are_equal(bytes("123456789"):clone():str(), "123456789")
@@ -36,4 +35,4 @@ end
 function test_concat(t)
     t:are_equal((bytes("123") .. bytes("456")):str(), "123456")
     t:are_equal(bytes(bytes("123"), bytes("456")):str(), "123456")
-end]]
+end
diff --git a/xmake/core/base/bytes.lua b/xmake/core/base/bytes.lua
index f35f20790..0486f0178 100644
--- a/xmake/core/base/bytes.lua
+++ b/xmake/core/base/bytes.lua
@@ -138,7 +138,7 @@ function _instance.new(...)
                 os.raise("incorrect bounds(%d-%d)!", start, last)
             end
             instance._SIZE     = last - start + 1
-            instance._CDATA    = b:cdata() - 1 + start
+            instance._CDATA    = libc.diffptr(b:cdata(), -1 + start)
             instance._REF      = b -- keep lua ref for GC
             instance._MANAGED  = false
             instance._READONLY = b:readonly()
@@ -390,7 +390,7 @@ function _instance:__index(key)
         if key < 1 or key > self:size() then
             os.raise("%s: index(%d/%d) out of bounds!", self, key, self:size())
         end
-        return self._CDATA[key - 1]
+        return libc.byteof(self._CDATA, key - 1)
     elseif type(key) == "table" then
         local start, last = key[1], key[2]
         return self:slice(start, last)
diff --git a/xmake/core/base/libc.lua b/xmake/core/base/libc.lua
index 18c14a669..d3f02d7f5 100644
--- a/xmake/core/base/libc.lua
+++ b/xmake/core/base/libc.lua
@@ -30,6 +30,7 @@ libc._strndup = libc._strndup or libc.strndup
 libc._dataptr = libc._dataptr or libc.dataptr
 libc._ptraddr = libc._ptraddr or libc.ptraddr
 libc._diffptr = libc._diffptr or libc.diffptr
+libc._byteof  = libc._byteof or libc.byteof
 
 -- load modules
 local ffi = xmake._LUAJIT and require("ffi")
@@ -94,6 +95,14 @@ function libc.strndup(s, n)
     end
 end
 
+function libc.byteof(data, offset)
+    if ffi then
+        return data[offset]
+    else
+        return libc._byteof(data, offset)
+    end
+end
+
 function libc.diffptr(data, offset)
     if ffi then
         return data + offset