Wrapped troublesome updates at StoreInfoDirect in a transaction
[pithos-ms-client] / trunk / Pithos.Core / Agents / StatusAgent.cs
index 67dafb2..89d7e13 100644 (file)
@@ -1,3 +1,44 @@
+#region
+/* -----------------------------------------------------------------------
+ * <copyright file="StatusAgent.cs" company="GRNet">
+ * 
+ * Copyright 2011-2012 GRNET S.A. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above
+ *      copyright notice, this list of conditions and the following
+ *      disclaimer.
+ *
+ *   2. 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.
+ *
+ *
+ * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``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 GRNET S.A OR
+ * 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.
+ *
+ * The views and conclusions contained in the software and
+ * documentation are those of the authors and should not be
+ * interpreted as representing official policies, either expressed
+ * or implied, of GRNET S.A.
+ * </copyright>
+ * -----------------------------------------------------------------------
+ */
+#endregion
 using System;
 using System.Collections.Generic;
 using System.ComponentModel.Composition;
@@ -6,42 +47,109 @@ using System.Diagnostics;
 using System.Diagnostics.Contracts;
 using System.IO;
 using System.Linq;
+using System.Reflection;
+using System.Security.Cryptography;
+using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Castle.ActiveRecord;
+using Castle.ActiveRecord.Framework;
 using Castle.ActiveRecord.Framework.Config;
+using NHibernate.ByteCode.Castle;
+using NHibernate.Cfg;
+using NHibernate.Cfg.Loquacious;
+using NHibernate.Dialect;
 using Pithos.Interfaces;
 using Pithos.Network;
 using log4net;
+using Environment = System.Environment;
 
 namespace Pithos.Core.Agents
 {
     [Export(typeof(IStatusChecker)),Export(typeof(IStatusKeeper))]
     public class StatusAgent:IStatusChecker,IStatusKeeper
     {
+        private static readonly ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
+
         [System.ComponentModel.Composition.Import]
         public IPithosSettings Settings { get; set; }
 
+        [System.ComponentModel.Composition.Import]
+        public IStatusNotification StatusNotification { get; set; }
+
         private Agent<Action> _persistenceAgent;
 
 
-        private static readonly ILog Log = LogManager.GetLogger("StatusAgent");
 
         public StatusAgent()
         {            
             var appDataPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
-            _pithosDataPath = Path.Combine(appDataPath , "Pithos");
 
+            _pithosDataPath = Path.Combine(appDataPath , "GRNET\\PITHOS");
             if (!Directory.Exists(_pithosDataPath))
                 Directory.CreateDirectory(_pithosDataPath);
+
+            var dbPath = Path.Combine(_pithosDataPath, "pithos.db");
+
+            MigrateOldDb(dbPath, appDataPath);
+
+
             var source = GetConfiguration(_pithosDataPath);
             ActiveRecordStarter.Initialize(source,typeof(FileState),typeof(FileTag));
+            
             ActiveRecordStarter.UpdateSchema();
 
-            if (!File.Exists(Path.Combine(_pithosDataPath ,"pithos.db")))
+
+            if (!File.Exists(dbPath))
                 ActiveRecordStarter.CreateSchema();
-        }        
 
+            CreateTrigger();
+            
+        }
+
+
+        private static void MigrateOldDb(string dbPath, string appDataPath)
+        {
+            if(String.IsNullOrWhiteSpace(dbPath))
+                throw new ArgumentNullException("dbPath");
+            if(String.IsNullOrWhiteSpace(appDataPath))
+                throw new ArgumentNullException("appDataPath");
+            Contract.EndContractBlock();
+
+            var oldDbPath = Path.Combine(appDataPath, "Pithos", "pithos.db");
+            var oldDbInfo = new FileInfo(oldDbPath);
+            if (oldDbInfo.Exists && !File.Exists(dbPath))
+            {
+                Log.InfoFormat("Moving database from {0} to {1}",oldDbInfo.FullName,dbPath);
+                var oldDirectory = oldDbInfo.Directory;
+                oldDbInfo.MoveTo(dbPath);
+                
+                if (Log.IsDebugEnabled)
+                    Log.DebugFormat("Deleting {0}",oldDirectory.FullName);
+                
+                oldDirectory.Delete(true);
+            }
+        }
+
+        private void CreateTrigger()
+        {
+            using (var connection = GetConnection())
+            using (var triggerCommand = connection.CreateCommand())
+            {
+                var cmdText = new StringBuilder()
+                    .AppendLine("CREATE TRIGGER IF NOT EXISTS update_last_modified UPDATE ON FileState FOR EACH ROW")
+                    .AppendLine("BEGIN")
+                    .AppendLine("UPDATE FileState SET Modified=datetime('now')  WHERE Id=old.Id;")
+                    .AppendLine("END;")
+                    .AppendLine("CREATE TRIGGER IF NOT EXISTS insert_last_modified INSERT ON FileState FOR EACH ROW")
+                    .AppendLine("BEGIN")
+                    .AppendLine("UPDATE FileState SET Modified=datetime('now')  WHERE Id=new.Id;")
+                    .AppendLine("END;")
+                    .ToString();
+                triggerCommand.CommandText = cmdText;                
+                triggerCommand.ExecuteNonQuery();
+            }
+        }
 
 
         private static InPlaceConfigurationSource GetConfiguration(string pithosDbPath)
@@ -95,6 +203,7 @@ namespace Pithos.Core.Agents
                         {
                             Log.ErrorFormat("[ERROR] STATE \n{0}", ex);
                         }
+                        queue.NotifyComplete(action);
 // ReSharper disable AccessToModifiedClosure
                         queue.DoAsync(loop);
 // ReSharper restore AccessToModifiedClosure
@@ -111,69 +220,93 @@ namespace Pithos.Core.Agents
         {
             _persistenceAgent.Stop();            
         }
-       
+
 
         public void ProcessExistingFiles(IEnumerable<FileInfo> existingFiles)
         {
-            if(existingFiles  ==null)
+            if (existingFiles == null)
                 throw new ArgumentNullException("existingFiles");
             Contract.EndContractBlock();
-            
+
             //Find new or matching files with a left join to the stored states
-            var fileStates = FileState.Queryable;
-            var currentFiles=from file in existingFiles
-                      join state in fileStates on file.FullName.ToLower() equals state.FilePath.ToLower() into gs
-                      from substate in gs.DefaultIfEmpty()
-                               select new {File = file, State = substate};
+            var fileStates = FileState.Queryable.ToList();
+            var currentFiles = from file in existingFiles
+                               join state in fileStates on file.FullName.ToLower() equals state.FilePath.ToLower() into
+                                   gs
+                               from substate in gs.DefaultIfEmpty()
+                               select Tuple.Create(file, substate);
 
             //To get the deleted files we must get the states that have no corresponding
             //files. 
             //We can't use the File.Exists method inside a query, so we get all file paths from the states
             var statePaths = (from state in fileStates
-                             select new {state.Id, state.FilePath}).ToList();
+                              select new {state.Id, state.FilePath}).ToList();
             //and check each one
-            var missingStates= (from path in statePaths
-                                where !File.Exists(path.FilePath) && !Directory.Exists(path.FilePath)
-                               select path.Id).ToList();
+            var missingStates = (from path in statePaths
+                                 where !File.Exists(path.FilePath) && !Directory.Exists(path.FilePath)
+                                 select path.Id).ToList();
             //Finally, retrieve the states that correspond to the deleted files            
-            var deletedFiles = from state in fileStates 
-                        where missingStates.Contains(state.Id)
-                        select new { File = default(FileInfo), State = state };
+            var deletedFiles = from state in fileStates
+                               where missingStates.Contains(state.Id)
+                               select Tuple.Create(default(FileInfo), state);
+
+            var pairs = currentFiles.Union(deletedFiles).ToList();
+
+            i = 1;
+            var total = pairs.Count;
+            foreach (var pair in pairs)
+            {
+                ProcessFile(total, pair);
+            }
+        }
 
-            var pairs = currentFiles.Union(deletedFiles);
+        int i = 1;
 
-            foreach(var pair in pairs)
+        private void ProcessFile(int total, Tuple<FileInfo,FileState> pair)
+        {
+            var idx = Interlocked.Increment(ref i);
+            using (StatusNotification.GetNotifier("Indexing file {0} of {1}", "Indexed file {0} of {1} ", idx, total))
             {
-                var fileState = pair.State;
-                var file = pair.File;
+                var fileState = pair.Item2;
+                var file = pair.Item1;
                 if (fileState == null)
                 {
-                    //This is a new file
-                    var fullPath = pair.File.FullName.ToLower();
-                    var createState = FileState.CreateForAsync(fullPath, BlockSize, BlockHash);
-                    createState.ContinueWith(state => _persistenceAgent.Post(state.Result.Create));
-                }                
+                    //This is a new file                        
+                    var createState = FileState.CreateFor(file,StatusNotification);
+                    _persistenceAgent.Post(createState.Create);
+                }
                 else if (file == null)
                 {
                     //This file was deleted while we were down. We should mark it as deleted
                     //We have to go through UpdateStatus here because the state object we are using
                     //was created by a different ORM session.
-                    _persistenceAgent.Post(()=> UpdateStatusDirect(fileState.Id, FileStatus.Deleted));                    
+                    _persistenceAgent.Post(() => UpdateStatusDirect((Guid) fileState.Id, FileStatus.Deleted));
                 }
                 else
                 {
                     //This file has a matching state. Need to check for possible changes
-                    var hashString = file.CalculateHash(BlockSize,BlockHash);
+                    //To check for changes, we use the cheap (in CPU terms) MD5 algorithm
+                    //on the entire file.
+
+                    var hashString = file.ComputeShortHash(StatusNotification);
+                    Debug.Assert(hashString.Length==32);
+
+
+                    //TODO: Need a way to attach the hashes to the filestate so we don't
+                    //recalculate them each time a call to calculate has is made
+                    //We can either store them to the filestate or add them to a 
+                    //dictionary
+
                     //If the hashes don't match the file was changed
-                    if (fileState.Checksum != hashString)
+                    if (fileState.ETag != hashString)
                     {
-                        _persistenceAgent.Post(() => UpdateStatusDirect(fileState.Id, FileStatus.Modified));
-                    }                    
+                        _persistenceAgent.Post(() => UpdateStatusDirect((Guid) fileState.Id, FileStatus.Modified));
+                    }
                 }
-            };            
-         
+            }
         }
 
+
         private int UpdateStatusDirect(Guid id, FileStatus status)
         {
             using (log4net.ThreadContext.Stacks["StatusAgent"].Push("UpdateStatusDirect"))
@@ -217,16 +350,22 @@ namespace Pithos.Core.Agents
                     using (var connection = GetConnection())
                     using (
                         var command =
-                            new SQLiteCommand("update FileState set FileStatus= :fileStatus where FilePath = :path ",
+                            new SQLiteCommand("update FileState set FileStatus= :fileStatus where FilePath = :path COLLATE NOCASE",
                                               connection))
                     {
 
 
                         command.Parameters.AddWithValue("fileStatus", status);
 
-                        command.Parameters.AddWithValue("path", path.ToLower());
+                        command.Parameters.AddWithValue("path", path);
                         
                         var affected = command.ExecuteNonQuery();
+                        if (affected == 0)
+                        {
+                            var createdState = FileState.CreateFor(FileInfoExtensions.FromPath(path), StatusNotification);
+                            createdState.FileStatus = status;
+                            createdState.Create();
+                        }
                         return affected;
                     }
                 }
@@ -238,7 +377,7 @@ namespace Pithos.Core.Agents
             }
         }
 
-        private int UpdateStatusDirect(string absolutePath, FileStatus fileStatus, FileOverlayStatus overlayStatus)
+        private int UpdateStatusDirect(string absolutePath, FileStatus fileStatus, FileOverlayStatus overlayStatus, string conflictReason)
         {
             using (log4net.ThreadContext.Stacks["StatusAgent"].Push("UpdateStatusDirect"))
             {
@@ -251,15 +390,25 @@ namespace Pithos.Core.Agents
                     using (
                         var command =
                             new SQLiteCommand(
-                                "update FileState set OverlayStatus= :overlayStatus, FileStatus= :fileStatus where FilePath = :path  ",
+                                "update FileState set OverlayStatus= :overlayStatus, FileStatus= :fileStatus,ConflictReason= :conflictReason where FilePath = :path COLLATE NOCASE ",
                                 connection))
                     {
 
-                        command.Parameters.AddWithValue("path", absolutePath.ToLower());
+                        command.Parameters.AddWithValue("path", absolutePath);
                         command.Parameters.AddWithValue("fileStatus", fileStatus);
                         command.Parameters.AddWithValue("overlayStatus", overlayStatus);
+                        command.Parameters.AddWithValue("conflictReason", conflictReason);
                         
                         var affected = command.ExecuteNonQuery();
+                        if (affected == 0)
+                        {
+                            var createdState = FileState.CreateFor(FileInfoExtensions.FromPath(absolutePath), StatusNotification);
+                            createdState.FileStatus = fileStatus;
+                            createdState.OverlayStatus = overlayStatus;
+                            createdState.ConflictReason = conflictReason;
+                            createdState.LastMD5 = String.Empty;
+                            createdState.Create();  
+                        }
                         return affected;
                     }
                 }
@@ -292,17 +441,6 @@ namespace Pithos.Core.Agents
 
         }
 
-        private PithosStatus _pithosStatus=PithosStatus.InSynch;       
-
-        public void SetPithosStatus(PithosStatus status)
-        {
-            _pithosStatus = status;
-        }
-
-        public PithosStatus GetPithosStatus()
-        {
-            return _pithosStatus;
-        }
 
 
         private readonly string _pithosDataPath;
@@ -320,10 +458,10 @@ namespace Pithos.Core.Agents
             {
                 
                 using (var connection = GetConnection())
-                using (var command = new SQLiteCommand("select Id, FilePath, OverlayStatus,FileStatus ,Checksum   ,Version    ,VersionTimeStamp,IsShared   ,SharedBy   ,ShareWrite  from FileState where FilePath=:path", connection))
+                using (var command = new SQLiteCommand("select Id, FilePath, OverlayStatus,FileStatus ,Checksum ,ETag,Version    ,VersionTimeStamp,IsShared   ,SharedBy   ,ShareWrite  from FileState where FilePath=:path COLLATE NOCASE", connection))
                 {
                     
-                    command.Parameters.AddWithValue("path", path.ToLower());
+                    command.Parameters.AddWithValue("path", path);
                     
                     using (var reader = command.ExecuteReader())
                     {
@@ -338,11 +476,12 @@ namespace Pithos.Core.Agents
                                                 OverlayStatus =reader.IsDBNull(2)?FileOverlayStatus.Unversioned: (FileOverlayStatus) reader.GetInt64(2),
                                                 FileStatus = reader.IsDBNull(3)?FileStatus.Missing:(FileStatus) reader.GetInt64(3),
                                                 Checksum = reader.IsDBNull(4)?"":reader.GetString(4),
-                                                Version = reader.IsDBNull(5)?default(long):reader.GetInt64(5),
-                                                VersionTimeStamp = reader.IsDBNull(6)?default(DateTime):reader.GetDateTime(6),
-                                                IsShared = !reader.IsDBNull(7) && reader.GetBoolean(7),
-                                                SharedBy = reader.IsDBNull(8)?"":reader.GetString(8),
-                                                ShareWrite = !reader.IsDBNull(9) && reader.GetBoolean(9)
+                                                ETag= reader.IsDBNull(5)?"":reader.GetString(5),
+                                                Version = reader.IsDBNull(6)?default(long):reader.GetInt64(6),
+                                                VersionTimeStamp = reader.IsDBNull(7)?default(DateTime):reader.GetDateTime(7),
+                                                IsShared = !reader.IsDBNull(8) && reader.GetBoolean(8),
+                                                SharedBy = reader.IsDBNull(9)?"":reader.GetString(9),
+                                                ShareWrite = !reader.IsDBNull(10) && reader.GetBoolean(10)
                                             };
 /*
                             var state = new FileState
@@ -388,10 +527,10 @@ namespace Pithos.Core.Agents
             {
                 
                 using (var connection = GetConnection())
-                using (var command = new SQLiteCommand("select OverlayStatus from FileState where FilePath=:path", connection))
+                using (var command = new SQLiteCommand("select OverlayStatus from FileState where FilePath=:path  COLLATE NOCASE", connection))
                 {
                     
-                    command.Parameters.AddWithValue("path", path.ToLower());
+                    command.Parameters.AddWithValue("path", path);
                     
                     var s = command.ExecuteScalar();
                     return (FileOverlayStatus) Convert.ToInt32(s);
@@ -423,7 +562,7 @@ namespace Pithos.Core.Agents
             return connection;
         }
 
-        public void SetFileOverlayStatus(string path, FileOverlayStatus overlayStatus)
+       /* public void SetFileOverlayStatus(string path, FileOverlayStatus overlayStatus)
         {
             if (String.IsNullOrWhiteSpace(path))
                 throw new ArgumentNullException("path");
@@ -431,7 +570,18 @@ namespace Pithos.Core.Agents
                 throw new ArgumentException("The path must be rooted","path");
             Contract.EndContractBlock();
 
-            _persistenceAgent.Post(() => FileState.StoreOverlayStatus(path.ToLower(),overlayStatus));
+            _persistenceAgent.Post(() => FileState.StoreOverlayStatus(path,overlayStatus));
+        }*/
+
+        public Task SetFileOverlayStatus(string path, FileOverlayStatus overlayStatus, string etag = null)
+        {
+            if (String.IsNullOrWhiteSpace(path))
+                throw new ArgumentNullException("path");
+            if (!Path.IsPathRooted(path))
+                throw new ArgumentException("The path must be rooted","path");
+            Contract.EndContractBlock();
+
+            return _persistenceAgent.PostAndAwait(() => FileState.StoreOverlayStatus(path,overlayStatus,etag));
         }
 
        /* public void RenameFileOverlayStatus(string oldPath, string newPath)
@@ -449,7 +599,7 @@ namespace Pithos.Core.Agents
             _persistenceAgent.Post(() =>FileState.RenameState(oldPath, newPath));
         }*/
 
-        public void SetFileState(string path, FileStatus fileStatus, FileOverlayStatus overlayStatus)
+        public void SetFileState(string path, FileStatus fileStatus, FileOverlayStatus overlayStatus, string conflictReason)
         {
             if (String.IsNullOrWhiteSpace(path))
                 throw new ArgumentNullException("path");
@@ -460,7 +610,7 @@ namespace Pithos.Core.Agents
             Debug.Assert(!path.Contains(FolderConstants.CacheFolder));
             Debug.Assert(!path.EndsWith(".ignore"));
 
-            _persistenceAgent.Post(() => UpdateStatusDirect(path.ToLower(), fileStatus, overlayStatus));
+            _persistenceAgent.Post(() => UpdateStatusDirect(path, fileStatus, overlayStatus, conflictReason));
         }
 
 /*
@@ -524,43 +674,60 @@ namespace Pithos.Core.Agents
             {
                 
                 using (var connection = GetConnection())
+                using(var tx=connection.BeginTransaction())
                 using (var command = new SQLiteCommand(connection))
                 {
-                    if (StateExists(path, connection))
+                    //If the ID exists, update the status
+                    command.CommandText ="update FileState set FilePath=:path,FileStatus= :fileStatus, Checksum=:checksum, ETag=:etag,LastMD5=:etag,Version=:version,VersionTimeStamp=:versionTimeStamp where ObjectID = :objectID  ";                        
+                    command.Parameters.AddWithValue("path", path);
+                    command.Parameters.AddWithValue("checksum", objectInfo.X_Object_Hash);
+                    command.Parameters.AddWithValue("etag", objectInfo.ETag);
+                    command.Parameters.AddWithValue("version", objectInfo.Version);
+                    command.Parameters.AddWithValue("versionTimeStamp", objectInfo.VersionTimestamp);
+                    command.Parameters.AddWithValue("fileStatus", FileStatus.Unchanged);
+                    command.Parameters.AddWithValue("overlayStatus", FileOverlayStatus.Normal);
+                    command.Parameters.AddWithValue("objectID",objectInfo.UUID);
+                    var affected = command.ExecuteNonQuery();
+                    if (affected == 0)
+                    {
+                        //If the ID doesn't exist, try to update using the path, and store the ID as well.
                         command.CommandText =
-                            "update FileState set FileStatus= :fileStatus where FilePath = :path  ";
-                    else
+                            "update FileState set FileStatus= :fileStatus, ObjectID=:objectID, Checksum=:checksum, ETag=:etag,LastMD5=:etag,Version=:version,VersionTimeStamp=:versionTimeStamp where FilePath = :path  COLLATE NOCASE ";
+                        affected = command.ExecuteNonQuery();
+                    }
+                    if (affected==0)
                     {
                         command.CommandText =
-                            "INSERT INTO FileState (Id,FilePath,Checksum,Version,VersionTimeStamp,FileStatus,OverlayStatus) VALUES (:id,:path,:checksum,:version,:versionTimeStamp,:fileStatus,:overlayStatus)";
+                            "INSERT INTO FileState (Id,FilePath,Checksum,Version,VersionTimeStamp,ETag,LastMD5,FileStatus,OverlayStatus,ObjectID) VALUES (:id,:path,:checksum,:version,:versionTimeStamp,:etag,:etag,:fileStatus,:overlayStatus,:objectID)";
                         command.Parameters.AddWithValue("id", Guid.NewGuid());
+                        affected = command.ExecuteNonQuery();
                     }
 
-                    command.Parameters.AddWithValue("path", path.ToLower());
-                    command.Parameters.AddWithValue("checksum", objectInfo.Hash);
-                    command.Parameters.AddWithValue("version", objectInfo.Version);
-                    command.Parameters.AddWithValue("versionTimeStamp",
-                                                    objectInfo.VersionTimestamp);
-                    command.Parameters.AddWithValue("fileStatus", FileStatus.Unchanged);
-                    command.Parameters.AddWithValue("overlayStatus",
-                                                    FileOverlayStatus.Normal);
-
-                    var affected = command.ExecuteNonQuery();
-                    return;
                 }
             }
             catch (Exception exc)
             {
-                Log.Error(exc.ToString());
+                Log.ErrorFormat("Failed to update [{0}]:[{1}]\r\n{2}",path,objectInfo.UUID, exc);
                 throw;
             }
         }
 
         private bool StateExists(string filePath,SQLiteConnection connection)
         {
-            using (var command = new SQLiteCommand("Select count(*) from FileState where FilePath=:path", connection))
+            using (var command = new SQLiteCommand("Select count(*) from FileState where FilePath=:path  COLLATE NOCASE", connection))
             {
-                command.Parameters.AddWithValue("path", filePath.ToLower());
+                command.Parameters.AddWithValue("path", filePath);
+                var result = command.ExecuteScalar();
+                return ((long)result >= 1);
+            }
+
+        }
+
+        private bool StateExistsByID(string objectId,SQLiteConnection connection)
+        {
+            using (var command = new SQLiteCommand("Select count(*) from FileState where ObjectId=:id", connection))
+            {
+                command.Parameters.AddWithValue("id", objectId);
                 var result = command.ExecuteScalar();
                 return ((long)result >= 1);
             }
@@ -575,7 +742,7 @@ namespace Pithos.Core.Agents
                 throw new ArgumentException("The path must be rooted", "path");
             Contract.EndContractBlock();
             
-            _persistenceAgent.Post(() => UpdateStatusDirect(path.ToLower(), status));
+            _persistenceAgent.Post(() => UpdateStatusDirect(path, status));
         }
 
         public FileStatus GetFileStatus(string path)
@@ -589,14 +756,20 @@ namespace Pithos.Core.Agents
             
             using (var connection = GetConnection())
             {
-                var command = new SQLiteCommand("select FileStatus from FileState where FilePath=:path", connection);
-                command.Parameters.AddWithValue("path", path.ToLower());
+                var command = new SQLiteCommand("select FileStatus from FileState where FilePath=:path  COLLATE NOCASE", connection);
+                command.Parameters.AddWithValue("path", path);
                 
-                var s = command.ExecuteScalar();
-                return (FileStatus)Convert.ToInt32(s);
+                var statusValue = command.ExecuteScalar();
+                if (statusValue==null)
+                    return FileStatus.Missing;
+                return (FileStatus)Convert.ToInt32(statusValue);
             }
         }
 
+        /// <summary>
+        /// Deletes the status of the specified file
+        /// </summary>
+        /// <param name="path"></param>
         public void ClearFileStatus(string path)
         {
             if (String.IsNullOrWhiteSpace(path))
@@ -608,6 +781,48 @@ namespace Pithos.Core.Agents
             _persistenceAgent.Post(() => DeleteDirect(path));   
         }
 
+        /// <summary>
+        /// Deletes the status of the specified folder and all its contents
+        /// </summary>
+        /// <param name="path"></param>
+        public void ClearFolderStatus(string path)
+        {
+            if (String.IsNullOrWhiteSpace(path))
+                throw new ArgumentNullException("path");
+            if (!Path.IsPathRooted(path))
+                throw new ArgumentException("The path must be rooted", "path");
+            Contract.EndContractBlock();
+            //TODO: May throw if the agent is cleared for some reason. Should never happen
+            _persistenceAgent.Post(() => DeleteFolderDirect(path));   
+        }
+
+        public IEnumerable<FileState> GetChildren(FileState fileState)
+        {
+            if (fileState == null)
+                throw new ArgumentNullException("fileState");
+            Contract.EndContractBlock();
+
+            var children = from state in FileState.Queryable
+                           where state.FilePath.StartsWith(fileState.FilePath + "\\")
+                           select state;
+            return children;
+        }
+
+        public void EnsureFileState(string path)
+        {
+            var existingState = GetStateByFilePath(path);
+            if (existingState != null)
+                return;
+            var fileInfo = FileInfoExtensions.FromPath(path);
+            using (new SessionScope())
+            {
+                var newState = FileState.CreateFor(fileInfo,StatusNotification);
+                newState.FileStatus=FileStatus.Missing;
+                _persistenceAgent.PostAndAwait(newState.CreateAndFlush).Wait();
+            }
+
+        }
+
         private int DeleteDirect(string filePath)
         {
             using (log4net.ThreadContext.Stacks["StatusAgent"].Push("DeleteDirect"))
@@ -619,10 +834,38 @@ namespace Pithos.Core.Agents
                     
                     using (var connection = GetConnection())
                     {
-                        var command = new SQLiteCommand("delete from FileState where FilePath = :path",
+                        var command = new SQLiteCommand("delete from FileState where FilePath = :path  COLLATE NOCASE",
+                                                        connection);
+
+                        command.Parameters.AddWithValue("path", filePath);
+                        
+                        var affected = command.ExecuteNonQuery();
+                        return affected;
+                    }
+                }
+                catch (Exception exc)
+                {
+                    Log.Error(exc.ToString());
+                    throw;
+                }
+            }
+        }
+
+        private int DeleteFolderDirect(string filePath)
+        {
+            using (log4net.ThreadContext.Stacks["StatusAgent"].Push("DeleteDirect"))
+            {
+
+                try
+                {
+
+                    
+                    using (var connection = GetConnection())
+                    {
+                        var command = new SQLiteCommand(@"delete from FileState where FilePath = :path or FilePath like :path || '\%'  COLLATE NOCASE",
                                                         connection);
 
-                        command.Parameters.AddWithValue("path", filePath.ToLower());
+                        command.Parameters.AddWithValue("path", filePath);
                         
                         var affected = command.ExecuteNonQuery();
                         return affected;
@@ -636,7 +879,7 @@ namespace Pithos.Core.Agents
             }
         }
 
-        public void UpdateFileChecksum(string path, string checksum)
+        public void UpdateFileChecksum(string path, string etag, string checksum)
         {
             if (String.IsNullOrWhiteSpace(path))
                 throw new ArgumentNullException("path");
@@ -644,9 +887,79 @@ namespace Pithos.Core.Agents
                 throw new ArgumentException("The path must be rooted", "path");            
             Contract.EndContractBlock();
 
-            _persistenceAgent.Post(() => FileState.UpdateChecksum(path.ToLower(), checksum));
+            _persistenceAgent.Post(() => FileState.UpdateChecksum(path, etag,checksum));
+        }
+
+        public void UpdateLastMD5(FileInfo file, string etag)
+        {
+            if (file==null)
+                throw new ArgumentNullException("file");
+            if (String.IsNullOrWhiteSpace(etag))
+                throw new ArgumentNullException("etag");
+            Contract.EndContractBlock();
+
+            _persistenceAgent.Post(() => FileState.UpdateLastMD5(file, etag));
         }
 
+
+        public void CleanupOrphanStates()
+        {
+            //Orphan states are those that do not correspond to an account, ie. their paths
+            //do not start with the root path of any registered account
+
+            var roots=(from account in Settings.Accounts
+                      select account.RootPath).ToList();
+            
+            var allStates = from state in FileState.Queryable
+                select state.FilePath;
+
+            foreach (var statePath in allStates)
+            {
+                if (!roots.Any(root=>statePath.StartsWith(root,StringComparison.InvariantCultureIgnoreCase)))
+                    this.DeleteDirect(statePath);
+            }
+        }
+
+        public void CleanupStaleStates(AccountInfo accountInfo, List<ObjectInfo> objectInfos)
+        {
+            if (accountInfo == null)
+                throw new ArgumentNullException("accountInfo");
+            if (objectInfos == null)
+                throw new ArgumentNullException("objectInfos");
+            Contract.EndContractBlock();
+            
+
+
+            //Stale states are those that have no corresponding local or server file
+            
+
+            var agent=FileAgent.GetFileAgent(accountInfo);
+
+            var localFiles=agent.EnumerateFiles();
+            var localSet = new HashSet<string>(localFiles);
+
+            //RelativeUrlToFilePath will fail for
+            //infos of accounts, containers which have no Name
+
+            var serverFiles = from info in objectInfos
+                              where info.Name != null
+                              select Path.Combine(accountInfo.AccountPath,info.RelativeUrlToFilePath(accountInfo.UserName));
+            var serverSet = new HashSet<string>(serverFiles);
+
+            var allStates = from state in FileState.Queryable
+                            where state.FilePath.StartsWith(agent.RootPath)
+                            select state.FilePath;
+            var stateSet = new HashSet<string>(allStates);
+            stateSet.ExceptWith(serverSet);
+            stateSet.ExceptWith(localSet);
+
+            foreach (var remainder in stateSet)
+            {
+                DeleteDirect(remainder);
+            }
+
+            
+        }
     }