1 files changed, 143 insertions, 0 deletions
diff --git a/src/rgw/rgw_lua_data_filter.cc b/src/rgw/rgw_lua_data_filter.cc
new file mode 100644
index 000000000..9ebaf3453
--- /dev/null
+++ b/src/rgw/rgw_lua_data_filter.cc
@@ -0,0 +1,143 @@
+#include "rgw_lua_data_filter.h"
+#include "rgw_lua_utils.h"
+#include "rgw_lua_request.h"
+#include "rgw_lua_background.h"
+#include "rgw_process_env.h"
+#include <lua.hpp>
+
+namespace rgw::lua {
+
+void push_bufferlist_byte(lua_State* L, bufferlist::iterator& it) {
+    char byte[1];
+    it.copy(1, byte);
+    lua_pushlstring(L, byte, 1);
+}
+
+struct BufferlistMetaTable : public EmptyMetaTable {
+
+  static std::string TableName() {return "Data";}
+  static std::string Name() {return TableName() + "Meta";}
+  
+  static int IndexClosure(lua_State* L) {
+    auto bl = reinterpret_cast<bufferlist*>(lua_touserdata(L, lua_upvalueindex(1)));
+    const auto index = luaL_checkinteger(L, 2);
+    if (index <= 0 || index > bl->length()) {
+      // lua arrays start from 1
+      lua_pushnil(L);
+      return ONE_RETURNVAL;
+    }
+    auto it = bl->begin(index-1);
+    if (it != bl->end()) {
+      push_bufferlist_byte(L, it);
+    } else {
+      lua_pushnil(L);
+    }
+    
+    return ONE_RETURNVAL;
+  }
+
+  static int PairsClosure(lua_State* L) {
+    auto bl = reinterpret_cast<bufferlist*>(lua_touserdata(L, lua_upvalueindex(1)));
+    ceph_assert(bl);
+    lua_pushlightuserdata(L, bl);
+    lua_pushcclosure(L, stateless_iter, ONE_UPVAL); // push the stateless iterator function
+    lua_pushnil(L);                                 // indicate this is the first call
+    // return stateless_iter, nil
+
+    return TWO_RETURNVALS;
+  }
+  
+  static int stateless_iter(lua_State* L) {
+    // based on: http://lua-users.org/wiki/GeneralizedPairsAndIpairs
+    auto bl = reinterpret_cast<bufferlist*>(lua_touserdata(L, lua_upvalueindex(1)));
+    lua_Integer index;
+    if (lua_isnil(L, -1)) {
+      index = 1;
+    } else {
+      index = luaL_checkinteger(L, -1) + 1;
+    }
+
+    // lua arrays start from 1
+    auto it = bl->begin(index-1);
+
+    if (index > bl->length()) {
+      // index of the last element was provided
+      lua_pushnil(L);
+      lua_pushnil(L);
+      // return nil, nil
+    } else {
+      lua_pushinteger(L, index);
+      push_bufferlist_byte(L, it);
+      // return key, value
+    }
+
+    return TWO_RETURNVALS;
+  }
+  
+  static int LenClosure(lua_State* L) {
+    const auto bl = reinterpret_cast<bufferlist*>(lua_touserdata(L, lua_upvalueindex(1)));
+
+    lua_pushinteger(L, bl->length());
+
+    return ONE_RETURNVAL;
+  }
+};
+
+int RGWObjFilter::execute(bufferlist& bl, off_t offset, const char* op_name) const {
+  auto L = luaL_newstate();
+  lua_state_guard lguard(L);
+
+  open_standard_libs(L);
+
+  create_debug_action(L, s->cct);  
+
+  // create the "Data" table
+  create_metatable<BufferlistMetaTable>(L, true, &bl);
+  lua_getglobal(L, BufferlistMetaTable::TableName().c_str());
+  ceph_assert(lua_istable(L, -1));
+
+  // create the "Request" table
+  request::create_top_metatable(L, s, op_name);
+
+  // create the "Offset" variable
+  lua_pushinteger(L, offset);
+  lua_setglobal(L, "Offset");
+
+  if (s->penv.lua.background) {
+    // create the "RGW" table
+    s->penv.lua.background->create_background_metatable(L);
+    lua_getglobal(L, rgw::lua::RGWTable::TableName().c_str());
+    ceph_assert(lua_istable(L, -1));
+  }
+
+  try {
+    // execute the lua script
+    if (luaL_dostring(L, script.c_str()) != LUA_OK) {
+      const std::string err(lua_tostring(L, -1));
+      ldpp_dout(s, 1) << "Lua ERROR: " << err << dendl;
+      return -EINVAL;
+    }
+  } catch (const std::runtime_error& e) {
+    ldpp_dout(s, 1) << "Lua ERROR: " << e.what() << dendl;
+    return -EINVAL;
+  }
+
+  return 0;
+}
+
+int RGWGetObjFilter::handle_data(bufferlist& bl,
+                  off_t bl_ofs,
+                  off_t bl_len) {
+  filter.execute(bl, bl_ofs, "get_obj");
+  // return value is ignored since we don't want to fail execution if lua script fails
+  return RGWGetObj_Filter::handle_data(bl, bl_ofs, bl_len);
+}
+
+int RGWPutObjFilter::process(bufferlist&& data, uint64_t logical_offset) {
+  filter.execute(data, logical_offset, "put_obj");
+  // return value is ignored since we don't want to fail execution if lua script fails
+  return rgw::putobj::Pipe::process(std::move(data), logical_offset); 
+}
+
+} // namespace rgw::lua
+