Adding upstream version 2.4.56.upstream/2.4.56

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 843 insertions, 0 deletions

diff --git a/modules/lua/lua_dbd.c b/modules/lua/lua_dbd.c
new file mode 100644
index 0000000..1b8d5b7
--- /dev/null
+++ b/modules/lua/lua_dbd.c
@@ -0,0 +1,843 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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.
+ */
+
+
+#include "mod_lua.h"
+#include "lua_dbd.h"
+
+APLOG_USE_MODULE(lua);
+static APR_OPTIONAL_FN_TYPE(ap_dbd_close) *lua_ap_dbd_close = NULL;
+static APR_OPTIONAL_FN_TYPE(ap_dbd_open) *lua_ap_dbd_open = NULL;
+
+
+
+
+static request_rec *ap_lua_check_request_rec(lua_State *L, int index)
+{
+    request_rec *r;
+    luaL_checkudata(L, index, "Apache2.Request");
+    r = lua_unboxpointer(L, index);
+    return r;
+}
+
+static lua_db_handle *lua_get_db_handle(lua_State *L)
+{
+    luaL_checktype(L, 1, LUA_TTABLE);
+    lua_rawgeti(L, 1, 0);
+    luaL_checktype(L, -1, LUA_TUSERDATA);
+    return (lua_db_handle *) lua_topointer(L, -1);
+}
+
+static lua_db_result_set *lua_get_result_set(lua_State *L)
+{
+    luaL_checktype(L, 1, LUA_TTABLE);
+    lua_rawgeti(L, 1, 0);
+    luaL_checktype(L, -1, LUA_TUSERDATA);
+    return (lua_db_result_set *) lua_topointer(L, -1);
+}
+
+
+/*
+   =============================================================================
+    db:close(): Closes an open database connection.
+   =============================================================================
+ */
+int lua_db_close(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_handle   *db;
+    apr_status_t     rc = 0;
+    /*~~~~~~~~~~~~~~~~~~~~*/
+    
+    db = lua_get_db_handle(L);
+    if (db && db->alive) {
+        if (db->type == LUA_DBTYPE_APR_DBD) {
+            rc = apr_dbd_close(db->driver, db->handle);
+            if (db->pool) apr_pool_destroy(db->pool);
+        }
+        else {
+            lua_ap_dbd_close = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_close);
+            if (lua_ap_dbd_close != NULL)
+                if (db->dbdhandle) lua_ap_dbd_close(db->server, db->dbdhandle);
+        }
+
+        db->driver = NULL;
+        db->handle = NULL;
+        db->alive = 0;
+        db->pool = NULL;
+    }
+
+    lua_settop(L, 0);
+    lua_pushnumber(L, rc);
+    return 1;
+} 
+
+/*
+   =============================================================================
+     db:__gc(): Garbage collecting function.
+   =============================================================================
+ */
+int lua_db_gc(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~*/
+    lua_db_handle    *db;
+    /*~~~~~~~~~~~~~~~~~~~~*/
+
+    db = lua_touserdata(L, 1);
+    if (db && db->alive) {
+        if (db->type == LUA_DBTYPE_APR_DBD) {
+            apr_dbd_close(db->driver, db->handle);
+            if (db->pool) apr_pool_destroy(db->pool);
+        }
+        else {
+            lua_ap_dbd_close = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_close);
+            if (lua_ap_dbd_close != NULL)
+                if (db->dbdhandle) lua_ap_dbd_close(db->server, db->dbdhandle);
+        }
+        db->driver = NULL;
+        db->handle = NULL;
+        db->alive = 0;
+        db->pool = NULL;
+    }
+    lua_settop(L, 0);
+    return 0;
+}
+
+/*
+   =============================================================================
+    db:active(): Returns true if the connection to the db is still active.
+   =============================================================================
+ */
+int lua_db_active(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_handle   *db = 0;
+    apr_status_t     rc = 0;
+    /*~~~~~~~~~~~~~~~~~~~~*/
+
+    db = lua_get_db_handle(L);
+    if (db && db->alive) {
+        rc = apr_dbd_check_conn(db->driver, db->pool, db->handle);
+        if (rc == APR_SUCCESS) {
+            lua_pushboolean(L, 1);
+            return 1;
+        }
+    }
+
+    lua_pushboolean(L, 0);
+    return 1;
+}
+
+/*
+   =============================================================================
+    db:query(statement): Executes the given database query and returns the 
+    number of rows affected. If an error is encountered, returns nil as the 
+    first parameter and the error message as the second.
+   =============================================================================
+ */
+int lua_db_query(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_handle   *db = 0;
+    apr_status_t     rc = 0;
+    int              x = 0;
+    const char      *statement;
+    /*~~~~~~~~~~~~~~~~~~~~~~~*/
+    luaL_checktype(L, 3, LUA_TSTRING);
+    statement = lua_tostring(L, 3);
+    db = lua_get_db_handle(L);
+    if (db && db->alive)
+        rc = apr_dbd_query(db->driver, db->handle, &x, statement);
+    else {
+        rc = 0;
+        x = -1;
+    }
+
+    if (rc == APR_SUCCESS)
+        lua_pushnumber(L, x);
+    else {
+
+        /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+        const char  *err = apr_dbd_error(db->driver, db->handle, rc);
+        /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+        lua_pushnil(L);
+        if (err) {
+            lua_pushstring(L, err);
+            return 2;
+        }
+    }
+
+    return 1;
+}
+
+/*
+   =============================================================================
+    db:escape(string): Escapes a string for safe use in the given database type.
+   =============================================================================
+ */
+int lua_db_escape(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_handle    *db = 0;
+    const char       *statement;
+    const char       *escaped = 0;
+    request_rec      *r;
+    /*~~~~~~~~~~~~~~~~~~~~~*/
+
+    r = ap_lua_check_request_rec(L, 2);
+    if (r) {
+        luaL_checktype(L, 3, LUA_TSTRING);
+        statement = lua_tostring(L, 3);
+        db = lua_get_db_handle(L);
+        if (db && db->alive) {
+            apr_dbd_init(r->pool);
+            escaped = apr_dbd_escape(db->driver, r->pool, statement,
+                                     db->handle);
+            if (escaped) {
+                lua_pushstring(L, escaped);
+                return 1;
+            }
+        }
+        else {
+            lua_pushnil(L);
+        }
+        return (1);
+    }
+
+    return 0;
+}
+
+/*
+   =============================================================================
+     resultset(N): Fetches one or more rows from a result set.
+   =============================================================================
+ */
+int lua_db_get_row(lua_State *L) 
+{
+    int row_no,x,alpha = 0;
+    const char      *entry, *rowname;
+    apr_dbd_row_t   *row = 0;
+    lua_db_result_set *res = lua_get_result_set(L);
+    
+    row_no = luaL_optinteger(L, 2, 0);
+    if (lua_isboolean(L, 3)) {
+        alpha = lua_toboolean(L, 3);
+    }
+    lua_settop(L,0);
+    
+    /* Fetch all rows at once? */
+    
+    if (row_no == 0) {
+        row_no = 1;
+        lua_newtable(L);
+        while (apr_dbd_get_row(res->driver, res->pool, res->results,
+                            &row, -1) != -1)
+         {
+            lua_pushinteger(L, row_no);
+            lua_newtable(L);
+            for (x = 0; x < res->cols; x++) {
+                entry = apr_dbd_get_entry(res->driver, row, x);
+                if (entry) {
+                    if (alpha == 1) {
+                        rowname = apr_dbd_get_name(res->driver, 
+                                res->results, x);
+                        lua_pushstring(L, rowname ? rowname : "(oob)");
+                    }
+                    else {
+                        lua_pushinteger(L, x + 1);
+                    }
+                    lua_pushstring(L, entry);
+                    lua_rawset(L, -3);
+                }
+            }
+            lua_rawset(L, -3);
+            row_no++;
+        }
+        return 1;
+    }
+    
+    /* Just fetch a single row */
+    if (apr_dbd_get_row(res->driver, res->pool, res->results,
+                            &row, row_no) != -1)
+         {
+        
+        lua_newtable(L);
+        for (x = 0; x < res->cols; x++) {
+            entry = apr_dbd_get_entry(res->driver, row, x);
+            if (entry) {
+                if (alpha == 1) {
+                    rowname = apr_dbd_get_name(res->driver, 
+                            res->results, x);
+                    lua_pushstring(L, rowname ? rowname : "(oob)");
+                }
+                else {
+                    lua_pushinteger(L, x + 1);
+                }
+                lua_pushstring(L, entry);
+                lua_rawset(L, -3);
+            }
+        }
+        return 1;
+    }
+    return 0;
+}
+
+
+/*
+   =============================================================================
+    db:select(statement): Queries the database for the given statement and 
+    returns the rows/columns found as a table. If an error is encountered, 
+    returns nil as the first parameter and the error message as the second.
+   =============================================================================
+ */
+int lua_db_select(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_handle   *db = 0;
+    apr_status_t     rc = 0;
+    const char      *statement;
+    request_rec     *r;
+    /*~~~~~~~~~~~~~~~~~~~~~~~*/
+    r = ap_lua_check_request_rec(L, 2);
+    if (r) {
+        luaL_checktype(L, 3, LUA_TSTRING);
+        statement = lua_tostring(L, 3);
+        db = lua_get_db_handle(L);
+        if (db && db->alive) {
+
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+            int cols;
+            apr_dbd_results_t   *results = 0;
+            lua_db_result_set* resultset = NULL;
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+            rc = apr_dbd_select(db->driver, db->pool, db->handle,
+                                &results, statement, 0);
+            if (rc == APR_SUCCESS) {
+                
+                cols = apr_dbd_num_cols(db->driver, results);
+                
+                if (cols > 0) {
+                    lua_newtable(L);
+                    resultset = lua_newuserdata(L, sizeof(lua_db_result_set));
+                    resultset->cols = cols;
+                    resultset->driver = db->driver;
+                    resultset->pool = db->pool;
+                    resultset->rows = apr_dbd_num_tuples(db->driver, results);
+                    resultset->results = results;
+                    luaL_newmetatable(L, "lua_apr.dbselect");
+                    lua_pushliteral(L, "__call");
+                    lua_pushcfunction(L, lua_db_get_row);
+                    lua_rawset(L, -3);
+                    lua_setmetatable(L, -3);
+                    lua_rawseti(L, -2, 0);
+                    return 1;
+                }
+                return 0;
+            }
+            else {
+
+                /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+                const char  *err = apr_dbd_error(db->driver, db->handle, rc);
+                /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+                lua_pushnil(L);
+                if (err) {
+                    lua_pushstring(L, err);
+                    return 2;
+                }
+            }
+        }
+
+        lua_pushboolean(L, 0);
+        return 1;
+    }
+
+    return 0;
+}
+
+
+
+/*
+   =============================================================================
+    statement:select(var1, var2, var3...): Injects variables into a prepared 
+    statement and returns the number of rows matching the query.
+   =============================================================================
+ */
+int lua_db_prepared_select(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_prepared_statement  *st = 0;
+    apr_status_t     rc = 0;
+    const char       **vars;
+    int              x, have;
+    /*~~~~~~~~~~~~~~~~~~~~~~~*/
+    
+    /* Fetch the prepared statement and the vars passed */
+    luaL_checktype(L, 1, LUA_TTABLE);
+    lua_rawgeti(L, 1, 0);
+    luaL_checktype(L, -1, LUA_TUSERDATA);
+    st = (lua_db_prepared_statement*) lua_topointer(L, -1);
+    
+    /* Check if we got enough variables passed on to us.
+     * This, of course, only works for prepared statements made through lua. */
+    have = lua_gettop(L) - 2;
+    if (st->variables != -1 && have < st->variables ) {
+        lua_pushboolean(L, 0);
+        lua_pushfstring(L, 
+                "Error in executing prepared statement: Expected %d arguments, got %d.", 
+                st->variables, have);
+        return 2;
+    }
+    vars = apr_pcalloc(st->db->pool, have*sizeof(char *));
+    for (x = 0; x < have; x++) {
+        vars[x] = lua_tostring(L, x + 2);
+    }
+
+    /* Fire off the query */
+    if (st->db && st->db->alive) {
+
+        /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+        int cols;
+        apr_dbd_results_t   *results = 0;
+        /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+        rc = apr_dbd_pselect(st->db->driver, st->db->pool, st->db->handle,
+                                &results, st->statement, 0, have, vars);
+        if (rc == APR_SUCCESS) {
+
+            /*~~~~~~~~~~~~~~~~~~~~~*/
+            lua_db_result_set *resultset;
+            /*~~~~~~~~~~~~~~~~~~~~~*/
+
+            cols = apr_dbd_num_cols(st->db->driver, results);
+            lua_newtable(L);
+            resultset = lua_newuserdata(L, sizeof(lua_db_result_set));
+            resultset->cols = cols;
+            resultset->driver = st->db->driver;
+            resultset->pool = st->db->pool;
+            resultset->rows = apr_dbd_num_tuples(st->db->driver, results);
+            resultset->results = results;
+            luaL_newmetatable(L, "lua_apr.dbselect");
+            lua_pushliteral(L, "__call");
+            lua_pushcfunction(L, lua_db_get_row);
+            lua_rawset(L, -3);
+            lua_setmetatable(L, -3);
+            lua_rawseti(L, -2, 0);
+            return 1;
+            
+        }
+        else {
+
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+            const char  *err = apr_dbd_error(st->db->driver, st->db->handle, rc);
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+            lua_pushnil(L);
+            if (err) {
+                lua_pushstring(L, err);
+                return 2;
+            }
+            return 1;
+        }
+    }
+
+    lua_pushboolean(L, 0);
+    lua_pushliteral(L, 
+            "Database connection seems to be closed, please reacquire it.");
+    return (2);
+}
+
+
+/*
+   =============================================================================
+    statement:query(var1, var2, var3...): Injects variables into a prepared 
+    statement and returns the number of rows affected.
+   =============================================================================
+ */
+int lua_db_prepared_query(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_prepared_statement  *st = 0;
+    apr_status_t     rc = 0;
+    const char       **vars;
+    int              x, have;
+    /*~~~~~~~~~~~~~~~~~~~~~~~*/
+    
+    /* Fetch the prepared statement and the vars passed */
+    luaL_checktype(L, 1, LUA_TTABLE);
+    lua_rawgeti(L, 1, 0);
+    luaL_checktype(L, -1, LUA_TUSERDATA);
+    st = (lua_db_prepared_statement*) lua_topointer(L, -1);
+    
+    /* Check if we got enough variables passed on to us.
+     * This, of course, only works for prepared statements made through lua. */
+    have = lua_gettop(L) - 2;
+    if (st->variables != -1 && have < st->variables ) {
+        lua_pushboolean(L, 0);
+        lua_pushfstring(L, 
+                "Error in executing prepared statement: Expected %d arguments, got %d.", 
+                st->variables, have);
+        return 2;
+    }
+    vars = apr_pcalloc(st->db->pool, have*sizeof(char *));
+    for (x = 0; x < have; x++) {
+        vars[x] = lua_tostring(L, x + 2);
+    }
+
+    /* Fire off the query */
+    if (st->db && st->db->alive) {
+
+        /*~~~~~~~~~~~~~~*/
+        int affected = 0;
+        /*~~~~~~~~~~~~~~*/
+
+        rc = apr_dbd_pquery(st->db->driver, st->db->pool, st->db->handle,
+                                &affected, st->statement, have, vars);
+        if (rc == APR_SUCCESS) {
+            lua_pushinteger(L, affected);
+            return 1;
+        }
+        else {
+
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+            const char  *err = apr_dbd_error(st->db->driver, st->db->handle, rc);
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+            lua_pushnil(L);
+            if (err) {
+                lua_pushstring(L, err);
+                return 2;
+            }
+            return 1;
+        }
+    }
+
+    lua_pushboolean(L, 0);
+    lua_pushliteral(L, 
+            "Database connection seems to be closed, please reacquire it.");
+    return (2);
+}
+
+/*
+   =============================================================================
+    db:prepare(statement): Prepares a statement for later query/select.
+    Returns a table with a :query and :select function, same as the db funcs.
+   =============================================================================
+ */
+int lua_db_prepare(lua_State* L) 
+{
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_handle   *db = 0;
+    apr_status_t     rc = 0;
+    const char      *statement, *at;
+    request_rec     *r;
+    lua_db_prepared_statement* st;
+    int need = 0;
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+    
+    r = ap_lua_check_request_rec(L, 2);
+    if (r) {
+        apr_dbd_prepared_t *pstatement = NULL;
+        luaL_checktype(L, 3, LUA_TSTRING);
+        statement = lua_tostring(L, 3);
+        
+        /* Count number of variables in statement */
+        at = ap_strchr_c(statement,'%');
+        while (at != NULL) {
+            if (at[1] == '%') {
+                at++;
+            }
+            else {
+                need++;
+            }
+            at = ap_strchr_c(at+1,'%');
+        }
+        
+        
+        db = lua_get_db_handle(L);
+        rc = apr_dbd_prepare(db->driver, r->pool, db->handle, statement, 
+                    NULL, &pstatement);
+        if (rc != APR_SUCCESS) {
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+            const char  *err = apr_dbd_error(db->driver, db->handle, rc);
+            /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+            lua_pushnil(L);
+            if (err) {
+                lua_pushstring(L, err);
+                return 2;
+            }
+            return 1;
+        }
+        
+        /* Push the prepared statement table */
+        lua_newtable(L);
+        st = lua_newuserdata(L, sizeof(lua_db_prepared_statement));
+        st->statement = pstatement;
+        st->variables = need;
+        st->db = db;
+        
+        lua_pushliteral(L, "select");
+        lua_pushcfunction(L, lua_db_prepared_select);
+        lua_rawset(L, -4);
+        lua_pushliteral(L, "query");
+        lua_pushcfunction(L, lua_db_prepared_query);
+        lua_rawset(L, -4);
+        lua_rawseti(L, -2, 0);
+        return 1;
+    }
+    return 0;
+}
+
+
+
+/*
+   =============================================================================
+    db:prepared(statement): Fetches a prepared statement made through 
+    DBDPrepareSQL.
+   =============================================================================
+ */
+int lua_db_prepared(lua_State* L) 
+{
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+    lua_db_handle   *db = 0;
+    const char      *tag;
+    request_rec     *r;
+    lua_db_prepared_statement* st;
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+    
+    r = ap_lua_check_request_rec(L, 2);
+    if (r) {
+        apr_dbd_prepared_t *pstatement = NULL;
+        db = lua_get_db_handle(L);
+        luaL_checktype(L, 3, LUA_TSTRING);
+        tag = lua_tostring(L, 3);
+        
+        /* Look for the statement */
+        pstatement = apr_hash_get(db->dbdhandle->prepared, tag, 
+                APR_HASH_KEY_STRING);
+        
+        if (pstatement == NULL) {
+            lua_pushnil(L);
+            lua_pushfstring(L, 
+                    "Could not find any prepared statement called %s!", tag);
+            return 2;
+        }
+        
+        
+        /* Push the prepared statement table */
+        lua_newtable(L);
+        st = lua_newuserdata(L, sizeof(lua_db_prepared_statement));
+        st->statement = pstatement;
+        st->variables = -1; /* we don't know :( */
+        st->db = db;
+        lua_pushliteral(L, "select");
+        lua_pushcfunction(L, lua_db_prepared_select);
+        lua_rawset(L, -4);
+        lua_pushliteral(L, "query");
+        lua_pushcfunction(L, lua_db_prepared_query);
+        lua_rawset(L, -4);
+        lua_rawseti(L, -2, 0);
+        return 1;
+    }
+    return 0;
+}
+
+
+
+/* lua_push_db_handle: Creates a database table object with database functions 
+   and a userdata at index 0, which will call lua_dbgc when garbage collected.
+ */
+static lua_db_handle* lua_push_db_handle(lua_State *L, request_rec* r, int type,
+        apr_pool_t* pool) 
+{
+    lua_db_handle* db;
+    lua_newtable(L);
+    db = lua_newuserdata(L, sizeof(lua_db_handle));
+    db->alive = 1;
+    db->pool = pool;
+    db->type = type;
+    db->dbdhandle = 0;
+    db->server = r->server;
+    luaL_newmetatable(L, "lua_apr.dbacquire");
+    lua_pushliteral(L, "__gc");
+    lua_pushcfunction(L, lua_db_gc);
+    lua_rawset(L, -3);
+    lua_setmetatable(L, -2);
+    lua_rawseti(L, -2, 0);
+    
+    lua_pushliteral(L, "escape");
+    lua_pushcfunction(L, lua_db_escape);
+    lua_rawset(L, -3);
+    
+    lua_pushliteral(L, "close");
+    lua_pushcfunction(L, lua_db_close);
+    lua_rawset(L, -3);
+    
+    lua_pushliteral(L, "select");
+    lua_pushcfunction(L, lua_db_select);
+    lua_rawset(L, -3);
+    
+    lua_pushliteral(L, "query");
+    lua_pushcfunction(L, lua_db_query);
+    lua_rawset(L, -3);
+    
+    lua_pushliteral(L, "active");
+    lua_pushcfunction(L, lua_db_active);
+    lua_rawset(L, -3);
+    
+    lua_pushliteral(L, "prepare");
+    lua_pushcfunction(L, lua_db_prepare);
+    lua_rawset(L, -3);
+    
+    lua_pushliteral(L, "prepared");
+    lua_pushcfunction(L, lua_db_prepared);
+    lua_rawset(L, -3);
+    return db;
+}
+
+/*
+   =============================================================================
+    dbacquire(dbType, dbString): Opens a new connection to a database of type 
+    _dbType_ and with the connection parameters _dbString_. If successful, 
+    returns a table with functions for using the database handle. If an error 
+    occurs, returns nil as the first parameter and the error message as the 
+    second. See the APR_DBD for a list of database types and connection strings 
+    supported.
+   =============================================================================
+ */
+int lua_db_acquire(lua_State *L)
+{
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+    const char      *type;
+    const char      *arguments;
+    const char      *error = 0;
+    request_rec     *r;
+    lua_db_handle   *db = 0;
+    apr_status_t     rc = 0;
+    ap_dbd_t        *dbdhandle = NULL;
+    apr_pool_t      *pool = NULL;
+    /*~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
+
+    r = ap_lua_check_request_rec(L, 1);
+    if (r) {
+        type = luaL_optstring(L, 2, "mod_dbd"); /* Defaults to mod_dbd */
+        
+        if (!strcmp(type, "mod_dbd")) {
+
+            lua_settop(L, 0);
+            lua_ap_dbd_open = APR_RETRIEVE_OPTIONAL_FN(ap_dbd_open);
+            if (lua_ap_dbd_open)
+                dbdhandle = (ap_dbd_t *) lua_ap_dbd_open(
+                        r->server->process->pool, r->server);
+
+            if (dbdhandle) {
+                db = lua_push_db_handle(L, r, LUA_DBTYPE_MOD_DBD, dbdhandle->pool);
+                db->driver = dbdhandle->driver;
+                db->handle = dbdhandle->handle;
+                db->dbdhandle = dbdhandle;
+                return 1;
+            }
+            else {
+                lua_pushnil(L);
+                if ( lua_ap_dbd_open == NULL )
+                    lua_pushliteral(L,
+                                    "mod_dbd doesn't seem to have been loaded.");
+                else
+                    lua_pushliteral(
+                        L,
+                        "Could not acquire connection from mod_dbd. If your database is running, this may indicate a permission problem.");
+                return 2;
+            }
+        }
+        else {
+            rc = apr_pool_create(&pool, NULL);
+            if (rc != APR_SUCCESS) {
+                lua_pushnil(L);
+                lua_pushliteral(L, "Could not allocate memory for database!");
+                return 2;
+            }
+            apr_pool_tag(pool, "lua_dbd_pool");
+            apr_dbd_init(pool);
+            dbdhandle = apr_pcalloc(pool, sizeof(ap_dbd_t));
+            rc = apr_dbd_get_driver(pool, type, &dbdhandle->driver);
+            if (rc == APR_SUCCESS) {
+                luaL_checktype(L, 3, LUA_TSTRING);
+                arguments = lua_tostring(L, 3);
+                lua_settop(L, 0);
+                
+                if (*arguments) {
+                    rc = apr_dbd_open_ex(dbdhandle->driver, pool, 
+                            arguments, &dbdhandle->handle, &error);
+                    if (rc == APR_SUCCESS) {
+                        db = lua_push_db_handle(L, r, LUA_DBTYPE_APR_DBD, pool);
+                        db->driver = dbdhandle->driver;
+                        db->handle = dbdhandle->handle;
+                        db->dbdhandle = dbdhandle;
+                        return 1;
+                    }
+                    else {
+                        lua_pushnil(L);
+                        if (error) {
+                            lua_pushstring(L, error);
+                            return 2;
+                        }
+
+                        return 1;
+                    }
+                }
+
+                lua_pushnil(L);
+                lua_pushliteral(L,
+                                "No database connection string was specified.");
+                apr_pool_destroy(pool);
+                return (2);
+            }
+            else {
+                lua_pushnil(L);
+                if (APR_STATUS_IS_ENOTIMPL(rc)) {
+                    lua_pushfstring(L, 
+                         "driver for %s not available", type);
+                }
+                else if (APR_STATUS_IS_EDSOOPEN(rc)) {
+                    lua_pushfstring(L, 
+                                "can't find driver for %s", type);
+                }
+                else if (APR_STATUS_IS_ESYMNOTFOUND(rc)) {
+                    lua_pushfstring(L, 
+                                "driver for %s is invalid or corrupted",
+                                type);
+                }
+                else {
+                    lua_pushliteral(L, 
+                                "mod_lua not compatible with APR in get_driver");
+                }
+                lua_pushinteger(L, rc);
+                apr_pool_destroy(pool);
+                return 3;
+            }
+        }
+
+        lua_pushnil(L);
+        return 1;
+    }
+
+    return 0;
+}
+