* Introduced common abstract AssetDataBase implementing IAssetProvider

* changed the semantics of SQLiteBase to SQLiteUtils
* Added abstract placeholder files for the other db providers

1 files changed, 269 insertions, 0 deletions

diff --git a/OpenSim/Framework/Data.SQLite/SQLiteUtils.cs b/OpenSim/Framework/Data.SQLite/SQLiteUtils.cs
new file mode 100644
index 0000000..1334e53
--- /dev/null
+++ b/OpenSim/Framework/Data.SQLite/SQLiteUtils.cs
@@ -0,0 +1,269 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSim Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Data;
+using Mono.Data.SqliteClient;
+
+namespace OpenSim.Framework.Data.SQLite
+{
+    /// <summary>
+    /// A base class for methods needed by all SQLite database classes
+    /// </summary>
+    public class SQLiteUtil
+    {
+        /***********************************************************************
+         *
+         *  Database Definition Helper Functions
+         * 
+         *  This should be db agnostic as we define them in ADO.NET terms
+         *
+         **********************************************************************/
+
+        public static void createCol(DataTable dt, string name, Type type)
+        {
+            DataColumn col = new DataColumn(name, type);
+            dt.Columns.Add(col);
+        }
+
+        /***********************************************************************
+         *
+         *  SQL Statement Creation Functions
+         *
+         *  These functions create SQL statements for update, insert, and create.
+         *  They can probably be factored later to have a db independant
+         *  portion and a db specific portion
+         *
+         **********************************************************************/
+
+        public static SqliteCommand createInsertCommand(string table, DataTable dt)
+        {
+            /**
+             *  This is subtle enough to deserve some commentary.
+             *  Instead of doing *lots* and *lots of hardcoded strings
+             *  for database definitions we'll use the fact that
+             *  realistically all insert statements look like "insert
+             *  into A(b, c) values(:b, :c) on the parameterized query
+             *  front.  If we just have a list of b, c, etc... we can
+             *  generate these strings instead of typing them out.
+             */
+            string[] cols = new string[dt.Columns.Count];
+            for (int i = 0; i < dt.Columns.Count; i++)
+            {
+                DataColumn col = dt.Columns[i];
+                cols[i] = col.ColumnName;
+            }
+
+            string sql = "insert into " + table + "(";
+            sql += String.Join(", ", cols);
+            // important, the first ':' needs to be here, the rest get added in the join
+            sql += ") values (:";
+            sql += String.Join(", :", cols);
+            sql += ")";
+            SqliteCommand cmd = new SqliteCommand(sql);
+
+            // this provides the binding for all our parameters, so
+            // much less code than it used to be
+            foreach (DataColumn col in dt.Columns)
+            {
+                cmd.Parameters.Add(createSqliteParameter(col.ColumnName, col.DataType));
+            }
+            return cmd;
+        }
+
+        public static SqliteCommand createUpdateCommand(string table, string pk, DataTable dt)
+        {
+            string sql = "update " + table + " set ";
+            string subsql = String.Empty;
+            foreach (DataColumn col in dt.Columns)
+            {
+                if (subsql.Length > 0)
+                {
+                    // a map function would rock so much here
+                    subsql += ", ";
+                }
+                subsql += col.ColumnName + "= :" + col.ColumnName;
+            }
+            sql += subsql;
+            sql += " where " + pk;
+            SqliteCommand cmd = new SqliteCommand(sql);
+
+            // this provides the binding for all our parameters, so
+            // much less code than it used to be
+
+            foreach (DataColumn col in dt.Columns)
+            {
+                cmd.Parameters.Add(createSqliteParameter(col.ColumnName, col.DataType));
+            }
+            return cmd;
+        }
+
+
+        public static string defineTable(DataTable dt)
+        {
+            string sql = "create table " + dt.TableName + "(";
+            string subsql = String.Empty;
+            foreach (DataColumn col in dt.Columns)
+            {
+                if (subsql.Length > 0)
+                {
+                    // a map function would rock so much here
+                    subsql += ",\n";
+                }
+                subsql += col.ColumnName + " " + sqliteType(col.DataType);
+                if (dt.PrimaryKey.Length > 0)
+                {
+                    if (col == dt.PrimaryKey[0])
+                    {
+                        subsql += " primary key";
+                    }
+                }
+            }
+            sql += subsql;
+            sql += ")";
+            return sql;
+        }
+
+        /***********************************************************************
+         *
+         *  Database Binding functions
+         *
+         *  These will be db specific due to typing, and minor differences
+         *  in databases.
+         *
+         **********************************************************************/
+
+        ///<summary>
+        /// This is a convenience function that collapses 5 repetitive
+        /// lines for defining SqliteParameters to 2 parameters:
+        /// column name and database type.
+        ///        
+        /// It assumes certain conventions like :param as the param
+        /// name to replace in parametrized queries, and that source
+        /// version is always current version, both of which are fine
+        /// for us.
+        ///</summary>
+        ///<returns>a built sqlite parameter</returns>
+        public static SqliteParameter createSqliteParameter(string name, Type type)
+        {
+            SqliteParameter param = new SqliteParameter();
+            param.ParameterName = ":" + name;
+            param.DbType = dbtypeFromType(type);
+            param.SourceColumn = name;
+            param.SourceVersion = DataRowVersion.Current;
+            return param;
+        }
+
+        /***********************************************************************
+         *
+         *  Type conversion functions
+         *
+         **********************************************************************/
+
+        public static DbType dbtypeFromType(Type type)
+        {
+            if (type == typeof (String))
+            {
+                return DbType.String;
+            }
+            else if (type == typeof (Int32))
+            {
+                return DbType.Int32;
+            }
+            else if (type == typeof (UInt32))
+            {
+                return DbType.UInt32;
+            }
+            else if (type == typeof (Int64))
+            {
+                return DbType.Int64;
+            }
+            else if (type == typeof (UInt64))
+            {
+                return DbType.UInt64;
+            }
+            else if (type == typeof (Double))
+            {
+                return DbType.Double;
+            }
+            else if (type == typeof (Boolean))
+            {
+                return DbType.Boolean;
+            }
+            else if (type == typeof (Byte[]))
+            {
+                return DbType.Binary;
+            }
+            else
+            {
+                return DbType.String;
+            }
+        }
+
+        // this is something we'll need to implement for each db
+        // slightly differently.
+        public static string sqliteType(Type type)
+        {
+            if (type == typeof (String))
+            {
+                return "varchar(255)";
+            }
+            else if (type == typeof (Int32))
+            {
+                return "integer";
+            }
+            else if (type == typeof (UInt32))
+            {
+                return "integer";
+            }
+            else if (type == typeof (Int64))
+            {
+                return "varchar(255)";
+            }
+            else if (type == typeof (UInt64))
+            {
+                return "varchar(255)";
+            }
+            else if (type == typeof (Double))
+            {
+                return "float";
+            }
+            else if (type == typeof (Boolean))
+            {
+                return "integer";
+            }
+            else if (type == typeof (Byte[]))
+            {
+                return "blob";
+            }
+            else
+            {
+                return "string";
+            }
+        }
+    }
+}