Added LUA parser for the mapping of external data query results.

1 files changed, 134 insertions, 0 deletions

diff --git a/server/src/luaquerymapper.cc b/server/src/luaquerymapper.cc
new file mode 100644
index 0000000..f4f6f20
--- /dev/null
+++ b/server/src/luaquerymapper.cc
@@ -0,0 +1,134 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            luaquerymapper.cc
+ *
+ *  Mon May  5 15:43:52 CEST 2008
+ *  Copyright 2008 Bent Bisballe Nyeng, Lars Bisballe Jensen and Peter Skaarup
+ *  deva@aasimon.org, elsenator@gmail.com and piparum@piparum.dk
+ ****************************************************************************/
+
+/*
+ *  This file is part of Pracro.
+ *
+ *  Pracro is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  Pracro is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with Pracro; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#include "luaquerymapper.h"
+
+static std::string loadresultstring(QueryResult &res, std::string group = "")
+{
+  std::string s;
+
+  std::map< std::string, std::string >::iterator v = res.values.begin();
+  while(v != res.values.end()) {
+    s += group + (*v).first + " = \"" + (*v).second + "\"\n";
+    v++;
+  }
+
+  std::map< std::string, QueryResult >::iterator g = res.groups.begin();
+  while(g != res.groups.end()) {
+    s += group + (*g).first + " = {}\n";
+    s += loadresultstring((*g).second, group + (*g).first + ".");
+    g++;
+  }
+
+  return s;
+}
+
+LUAQueryMapper::LUAQueryMapper(QueryResult &res)
+{
+  L = luaL_newstate();
+  if(L == NULL) {
+    //    throw LUADataParserException("Could not create LUA state.");
+  }
+
+  luaL_openlibs(L);
+
+  // FIXME: Insert these variables directly into the LUA stack instead of parsing them.
+  std::string preload = loadresultstring(res);
+
+  int s = luaL_loadbuffer(L, preload.c_str(), preload.size(), "preload");
+  switch(s) {
+  case 0: //no errors;
+    break;
+  case LUA_ERRSYNTAX: //syntax error during pre-compilation;
+  case LUA_ERRMEM: //memory allocation error.
+  case LUA_ERRFILE: //cannot open/read the file.
+    //throw LUADataParserException(lua_tostring(L, lua_gettop(L)));
+    break;
+  default:
+    //throw LUADataParserException("Unknown return value of luaL_loadfile.");
+    break;
+  }
+
+  // Run program (init)
+  lua_pcall(L, 0, LUA_MULTRET, 0);
+}
+
+LUAQueryMapper::~LUAQueryMapper()
+{
+  lua_close(L);
+}
+
+std::string LUAQueryMapper::map(const std::string &mapper)
+{
+  int s = luaL_loadbuffer(L, mapper.c_str(), mapper.size(), "mapper");
+  switch(s) {
+  case 0: //no errors;
+    break;
+  case LUA_ERRSYNTAX: //syntax error during pre-compilation;
+  case LUA_ERRMEM: //memory allocation error.
+  case LUA_ERRFILE: //cannot open/read the file.
+    //throw LUADataParserException(lua_tostring(L, lua_gettop(L)));
+    break;
+  default:
+    //throw LUADataParserException("Unknown return value of luaL_loadfile.");
+    break;
+  }
+
+  // Run the loaded code
+  lua_pcall(L, 0, LUA_MULTRET, 0);
+
+  return lua_tostring(L, lua_gettop(L));
+}
+
+#ifdef TEST_LUAQUERYMAPPER
+
+int main()
+{
+  QueryResult res;
+
+  QueryResult group1;
+  group1.values["dims"] = "42";
+
+  QueryResult group2;
+  group2.values["foo"] = "bar";
+  group2.values["bar"] = "foo";
+  group2.groups["fnuller"] = group1;
+
+  res.values["dims"] = "42";
+  res.groups["dimmer"] = group2;
+
+  LUAQueryMapper mapper(res);
+
+  std::string luamap = "return dimmer.fnuller.dims * 2 + dims";
+  printf("%s\n", mapper.map(luamap).c_str());
+
+  luamap = "return math.sin(dimmer.fnuller.dims * 2 + dims)";
+  printf("%s\n", mapper.map(luamap).c_str());
+
+  return 0;
+}
+
+#endif/*TEST_LUAQUERYMAPPER*/