This commit adds a new optional region module, JsonStore, that provides structured

storage (dictionaries and arrays of string values) for scripts and region modules.
In addition, there are operations on the storage that enable "real" distributed
computation between scripts through operations similar to those of a tuple space.
Scripts can share task queues, implement shared locks or semaphores, etc.

The structured store is limited to the current region and is not currently
persisted. However, script operations are defined to initialize a store from a notecard
and to serialize the store to a notecard.

Documentation will be posted to the opensim wiki soon.

1 files changed, 498 insertions, 0 deletions

diff --git a/OpenSim/Region/OptionalModules/Scripting/JsonStore/JsonStore.cs b/OpenSim/Region/OptionalModules/Scripting/JsonStore/JsonStore.cs
new file mode 100644
index 0000000..49556b6
--- /dev/null
+++ b/OpenSim/Region/OptionalModules/Scripting/JsonStore/JsonStore.cs
@@ -0,0 +1,498 @@
+/*
+ * Copyright (c) Contributors 
+ * 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 Mono.Addins;
+
+using System;
+using System.Reflection;
+using System.Threading;
+using System.Text;
+using System.Net;
+using System.Net.Sockets;
+using log4net;
+using Nini.Config;
+using OpenMetaverse;
+using OpenMetaverse.StructuredData;
+using OpenSim.Framework;
+using OpenSim.Region.Framework.Interfaces;
+using OpenSim.Region.Framework.Scenes;
+using System.Collections.Generic;
+using System.Text.RegularExpressions;
+
+namespace OpenSim.Region.OptionalModules.Scripting.JsonStore
+{
+    public class JsonStore
+    {
+        private static readonly ILog m_log =
+            LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
+        private OSD m_ValueStore;
+
+        protected class TakeValueCallbackClass
+        {
+            public string Path { get; set; }
+            public bool UseJson { get; set; }
+            public TakeValueCallback Callback { get; set; }
+
+            public TakeValueCallbackClass(string spath, bool usejson, TakeValueCallback cback)
+            {
+                Path = spath;
+                UseJson = usejson;
+                Callback = cback;
+            }
+        }
+
+        protected List<TakeValueCallbackClass> m_TakeStore;
+        protected List<TakeValueCallbackClass> m_ReadStore;
+        
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        public JsonStore(string value = "")
+        {
+            m_TakeStore = new List<TakeValueCallbackClass>();
+            m_ReadStore = new List<TakeValueCallbackClass>();
+           
+            if (String.IsNullOrEmpty(value))
+                m_ValueStore = new OSDMap();
+            else
+                m_ValueStore = OSDParser.DeserializeJson(value);
+        }
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        public bool TestPath(string expr, bool useJson)
+        {
+            Stack<string> path = ParsePathExpression(expr);
+            OSD result = ProcessPathExpression(m_ValueStore,path);
+
+            if (result == null)
+                return false;
+            
+            if (useJson || result.Type == OSDType.String)
+                return true;
+            
+            return false;
+        }
+        
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        public bool GetValue(string expr, out string value, bool useJson)
+        {
+            Stack<string> path = ParsePathExpression(expr);
+            OSD result = ProcessPathExpression(m_ValueStore,path);
+            return ConvertOutputValue(result,out value,useJson); 
+        }
+     
+                
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        public bool RemoveValue(string expr)
+        {
+            return SetValueFromExpression(expr,null);
+        }
+       
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        public bool SetValue(string expr, string value, bool useJson)
+        {
+            OSD ovalue = useJson ? OSDParser.DeserializeJson(value) :  new OSDString(value);
+            return SetValueFromExpression(expr,ovalue);
+        }
+        
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        public bool TakeValue(string expr, bool useJson, TakeValueCallback cback)
+        {
+            Stack<string> path = ParsePathExpression(expr);
+            string pexpr = PathExpressionToKey(path);
+
+            OSD result = ProcessPathExpression(m_ValueStore,path);
+            if (result == null)
+            {
+                m_TakeStore.Add(new TakeValueCallbackClass(pexpr,useJson,cback));
+                return false;
+            }
+            
+            string value = String.Empty;
+            if (! ConvertOutputValue(result,out value,useJson))
+            {
+                // the structure does not match the request so i guess we'll wait
+                m_TakeStore.Add(new TakeValueCallbackClass(pexpr,useJson,cback));
+                return false;
+            }
+
+            SetValueFromExpression(expr,null);
+            cback(value);
+
+            return true;
+        }
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        public bool ReadValue(string expr, bool useJson, TakeValueCallback cback)
+        {
+            Stack<string> path = ParsePathExpression(expr);
+            string pexpr = PathExpressionToKey(path);
+
+            OSD result = ProcessPathExpression(m_ValueStore,path);
+            if (result == null)
+            {
+                m_ReadStore.Add(new TakeValueCallbackClass(pexpr,useJson,cback));
+                return false;
+            }
+            
+            string value = String.Empty;
+            if (! ConvertOutputValue(result,out value,useJson))
+            {
+                // the structure does not match the request so i guess we'll wait
+                m_ReadStore.Add(new TakeValueCallbackClass(pexpr,useJson,cback));
+                return false;
+            }
+
+            cback(value);
+
+            return true;
+        }
+     
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        protected bool SetValueFromExpression(string expr, OSD ovalue)
+        {
+            Stack<string> path = ParsePathExpression(expr);
+            if (path.Count == 0)
+            {
+                m_ValueStore = ovalue;
+                return true;
+            }
+
+            string pkey = path.Pop();
+            string pexpr = PathExpressionToKey(path);
+            if (pexpr != "")
+                pexpr += ".";
+
+            OSD result = ProcessPathExpression(m_ValueStore,path);
+            if (result == null)
+                return false;
+
+            Regex aPattern = new Regex("\\[([0-9]+|\\+)\\]");
+            MatchCollection amatches = aPattern.Matches(pkey,0);
+            
+            if (amatches.Count > 0)
+            {
+                if (result.Type != OSDType.Array)
+                    return false;
+
+                OSDArray amap = result as OSDArray;
+
+                Match match = amatches[0];
+                GroupCollection groups = match.Groups;
+                string akey = groups[1].Value;
+
+                if (akey == "+")
+                {
+                    string npkey = String.Format("[{0}]",amap.Count);
+
+                    amap.Add(ovalue);
+                    InvokeNextCallback(pexpr + npkey);
+                    return true;
+                }
+
+                int aval = Convert.ToInt32(akey);
+                if (0 <= aval && aval < amap.Count)
+                {
+                    if (ovalue == null)
+                        amap.RemoveAt(aval);
+                    else
+                    {
+                        amap[aval] = ovalue;
+                        InvokeNextCallback(pexpr + pkey);
+                    }
+                    return true;
+                }
+
+                return false;
+            }
+
+            Regex hPattern = new Regex("{([^}]+)}");
+            MatchCollection hmatches = hPattern.Matches(pkey,0);
+            
+            if (hmatches.Count > 0)
+            {
+                Match match = hmatches[0];
+                GroupCollection groups = match.Groups;
+                string hkey = groups[1].Value;
+                
+                if (result is OSDMap)
+                {
+                    OSDMap hmap = result as OSDMap;
+                    if (ovalue != null)
+                    {
+                        hmap[hkey] = ovalue;
+                        InvokeNextCallback(pexpr + pkey);
+                    }
+                    else if (hmap.ContainsKey(hkey))
+                        hmap.Remove(hkey);
+                    
+                    return true;
+                }
+
+                return false;
+            }
+
+            // Shouldn't get here if the path was checked correctly
+            m_log.WarnFormat("[JsonStore] invalid path expression");
+            return false;
+        }
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        protected bool InvokeNextCallback(string pexpr)
+        {
+            // Process all of the reads that match the expression first
+            List<TakeValueCallbackClass> reads = 
+                m_ReadStore.FindAll(delegate(TakeValueCallbackClass tb) { return pexpr.StartsWith(tb.Path); });
+
+            foreach (TakeValueCallbackClass readcb in reads)
+            {
+                m_ReadStore.Remove(readcb);
+                ReadValue(readcb.Path,readcb.UseJson,readcb.Callback);
+            }
+
+            // Process one take next
+            TakeValueCallbackClass takecb =
+                m_TakeStore.Find(delegate(TakeValueCallbackClass tb) { return pexpr.StartsWith(tb.Path); });
+                                                               
+            if (takecb != null)
+            {
+                m_TakeStore.Remove(takecb);
+                TakeValue(takecb.Path,takecb.UseJson,takecb.Callback);
+
+                return true;
+            }
+
+            return false;
+        }
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// Parse the path expression and put the components into a stack. We
+        /// use a stack because we process the path in inverse order later
+        /// </summary>
+        // -----------------------------------------------------------------
+        protected static Stack<string> ParsePathExpression(string path)
+        {
+            Stack<string> m_path = new Stack<string>();
+
+            // add front and rear separators
+            path = "." + path + ".";
+            
+            // add separators for quoted paths
+            Regex pass1 = new Regex("{[^}]+}");
+            path = pass1.Replace(path,".$0.",-1,0);
+                
+            // add separators for array references
+            Regex pass2 = new Regex("(\\[[0-9]+\\]|\\[\\+\\])");
+            path = pass2.Replace(path,".$0.",-1,0);
+                
+            // add quotes to bare identifier
+            Regex pass3 = new Regex("\\.([a-zA-Z]+)");
+            path = pass3.Replace(path,".{$1}",-1,0);
+                
+            // remove extra separators
+            Regex pass4 = new Regex("\\.+");
+            path = pass4.Replace(path,".",-1,0);
+
+            Regex validate = new Regex("^\\.(({[^}]+}|\\[[0-9]+\\]|\\[\\+\\])\\.)+$");
+            if (validate.IsMatch(path))
+            {
+                Regex parser = new Regex("\\.({[^}]+}|\\[[0-9]+\\]|\\[\\+\\]+)");
+                MatchCollection matches = parser.Matches(path,0);
+                foreach (Match match in matches)
+                    m_path.Push(match.Groups[1].Value);
+            }
+
+            return m_path;
+        }
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <param>path is a stack where the top level of the path is at the bottom of the stack</param>
+        // -----------------------------------------------------------------
+        protected static OSD ProcessPathExpression(OSD map, Stack<string> path)
+        {
+            if (path.Count == 0)
+                return map;
+            
+            string pkey = path.Pop();
+
+            OSD rmap = ProcessPathExpression(map,path);
+            if (rmap == null)
+                return null;
+            
+            // ---------- Check for an array index ----------
+            Regex aPattern = new Regex("\\[([0-9]+)\\]");
+            MatchCollection amatches = aPattern.Matches(pkey,0);
+            
+            if (amatches.Count > 0)
+            {
+                if (rmap.Type != OSDType.Array)
+                {
+                    m_log.WarnFormat("[JsonStore] wrong type for key {2}, expecting {0}, got {1}",OSDType.Array,rmap.Type,pkey);
+                    return null;
+                }
+
+                OSDArray amap = rmap as OSDArray;
+
+                Match match = amatches[0];
+                GroupCollection groups = match.Groups;
+                string akey = groups[1].Value;
+                int aval = Convert.ToInt32(akey);
+                
+                if (aval < amap.Count)
+                    return (OSD) amap[aval];
+
+                return null;
+            }
+
+            // ---------- Check for a hash index ----------
+            Regex hPattern = new Regex("{([^}]+)}");
+            MatchCollection hmatches = hPattern.Matches(pkey,0);
+            
+            if (hmatches.Count > 0)
+            {
+                if (rmap.Type != OSDType.Map)
+                {
+                    m_log.WarnFormat("[JsonStore] wrong type for key {2}, expecting {0}, got {1}",OSDType.Map,rmap.Type,pkey);
+                    return null;
+                }
+                
+                OSDMap hmap = rmap as OSDMap;
+
+                Match match = hmatches[0];
+                GroupCollection groups = match.Groups;
+                string hkey = groups[1].Value;
+                
+                if (hmap.ContainsKey(hkey))
+                    return (OSD) hmap[hkey];
+
+                return null;
+            }
+
+            // Shouldn't get here if the path was checked correctly
+            m_log.WarnFormat("[JsonStore] Path type (unknown) does not match the structure");
+            return null;
+        }
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        protected static bool ConvertOutputValue(OSD result, out string value, bool useJson)
+        {
+            value = String.Empty;
+            
+            // If we couldn't process the path
+            if (result == null)
+                return false;
+
+            if (useJson)
+            {
+                // The path pointed to an intermediate hash structure
+                if (result.Type == OSDType.Map)
+                {
+                    value = OSDParser.SerializeJsonString(result as OSDMap);
+                    return true;
+                }
+
+                // The path pointed to an intermediate hash structure
+                if (result.Type == OSDType.Array)
+                {
+                    value = OSDParser.SerializeJsonString(result as OSDArray);
+                    return true;
+                }
+
+                value = "'" + result.AsString() + "'"; 
+                return true;
+            }
+
+            if (result.Type == OSDType.String)
+            {
+                value = result.AsString(); 
+                return true;
+            }
+
+            return false;
+        }
+
+        // -----------------------------------------------------------------
+        /// <summary>
+        /// 
+        /// </summary>
+        // -----------------------------------------------------------------
+        protected static string PathExpressionToKey(Stack<string> path)
+        {
+            if (path.Count == 0)
+                return "";
+                
+            string pkey = "";
+            foreach (string k in path)
+                pkey = (pkey == "") ? k : (k + "." + pkey);
+            
+            return pkey;
+        }
+    }
+}