Synnefo » Pithos MS Client

using System;

using System.Collections.Generic;

using System.ComponentModel.Composition;

using System.Diagnostics;

using System.Diagnostics.Contracts;

using System.IO;

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

using System.Threading.Tasks.Dataflow;

using Castle.ActiveRecord;

using Castle.ActiveRecord.Framework.Config;

using Pithos.Interfaces;

using Pithos.Network;

using log4net;

using log4net.Appender;

using log4net.Config;

using log4net.Layout;

namespace Pithos.Core.Agents

{

    [Export(typeof(IStatusChecker)),Export(typeof(IStatusKeeper))]

    public class StatusAgent:IStatusChecker,IStatusKeeper

    {

        [System.ComponentModel.Composition.Import]

        public IPithosSettings Settings { get; set; }

        //private Agent<Action> _persistenceAgent;

        private ActionBlock<Action> _persistenceAgent;

        private static readonly ILog Log = LogManager.GetLogger("StatusAgent");

        public StatusAgent()

        {            

            var appDataPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);

            _pithosDataPath = Path.Combine(appDataPath , "Pithos");

            if (!Directory.Exists(_pithosDataPath))

                Directory.CreateDirectory(_pithosDataPath);

            var source = GetConfiguration(_pithosDataPath);

            ActiveRecordStarter.Initialize(source,typeof(FileState),typeof(FileTag));

            ActiveRecordStarter.UpdateSchema();

            if (!File.Exists(Path.Combine(_pithosDataPath ,"pithos.db")))

                ActiveRecordStarter.CreateSchema();

        }        

        private static InPlaceConfigurationSource GetConfiguration(string pithosDbPath)

        {

            if (String.IsNullOrWhiteSpace(pithosDbPath))

                throw new ArgumentNullException("pithosDbPath");

            if (!Path.IsPathRooted(pithosDbPath))

                throw new ArgumentException("path must be a rooted path", "pithosDbPath");

            Contract.EndContractBlock();

            var properties = new Dictionary<string, string>

                                 {

                                     {"connection.driver_class", "NHibernate.Driver.SQLite20Driver"},

                                     {"dialect", "NHibernate.Dialect.SQLiteDialect"},

                                     {"connection.provider", "NHibernate.Connection.DriverConnectionProvider"},

                                     {

                                         "proxyfactory.factory_class",

                                         "NHibernate.ByteCode.Castle.ProxyFactoryFactory, NHibernate.ByteCode.Castle"

                                         },

                                 };

            var connectionString = String.Format(@"Data Source={0}\pithos.db;Version=3", pithosDbPath);

            properties.Add("connection.connection_string", connectionString);

            var source = new InPlaceConfigurationSource();                        

            source.Add(typeof (ActiveRecordBase), properties);

            source.SetDebugFlag(false);            

            return source;

        }

        public void StartProcessing(CancellationToken token)

        {

            _persistenceAgent = new ActionBlock<Action>(async action=>

            {

                    try

                    {

                        await TaskEx.Run(action);

                    }

                    catch (Exception ex)

                    {

                        Log.ErrorFormat("[ERROR] STATE \n{0}",ex);

                    }

            });

        }

        public void Stop()

        {

            _persistenceAgent.Complete();            

        }

        public void ProcessExistingFiles(IEnumerable<FileInfo> existingFiles)

        {

            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};

            //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();

            //and check each one

            var missingStates= (from path in statePaths

                               where !File.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 pairs = currentFiles.Union(deletedFiles);

            Parallel.ForEach(pairs, pair =>

            {

                var fileState = pair.State;

                var file = pair.File;

                if (fileState == null)

                {

                    //This is a new file

                    var fullPath = pair.File.FullName.ToLower();

                    var createState = FileState.CreateForAsync(fullPath, this.BlockSize, this.BlockHash);

                    createState.ContinueWith(state => _persistenceAgent.Post(state.Result.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.

                    UpdateStatus(fileState.Id,state=> state.FileStatus = FileStatus.Deleted);                    

                }

                else

                {

                    //This file has a matching state. Need to check for possible changes

                    var hashString = file.CalculateHash(BlockSize,BlockHash);

                    //If the hashes don't match the file was changed

                    if (fileState.Checksum != hashString)

                    {

                        UpdateStatus(fileState.Id, state => state.FileStatus = FileStatus.Modified);

                    }                    

                }

            });            

        }

        public string BlockHash { get; set; }

        public int BlockSize { get; set; }

        public void ChangeRoots(string oldPath, string newPath)

        {

            if (String.IsNullOrWhiteSpace(oldPath))

                throw new ArgumentNullException("oldPath");

            if (!Path.IsPathRooted(oldPath))

                throw new ArgumentException("oldPath must be an absolute path", "oldPath");

            if (string.IsNullOrWhiteSpace(newPath))

                throw new ArgumentNullException("newPath");

            if (!Path.IsPathRooted(newPath))

                throw new ArgumentException("newPath must be an absolute path", "newPath");

            Contract.EndContractBlock();

            FileState.ChangeRootPath(oldPath,newPath);

        }

        private PithosStatus _pithosStatus=PithosStatus.InSynch;       

        public void SetPithosStatus(PithosStatus status)

        {

            _pithosStatus = status;

        }

        public PithosStatus GetPithosStatus()

        {

            return _pithosStatus;

        }

        private string _pithosDataPath;

        public T GetStatus<T>(string path,Func<FileState,T> getter,T defaultValue )

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("path must be a rooted path", "path");

            if (getter == null)

                throw new ArgumentNullException("getter");

            Contract.EndContractBlock();

            try

            {                

                var state = FileState.FindByFilePath(path);

                return state == null ? defaultValue : getter(state);

            }

            catch (Exception exc)

            {

                Log.ErrorFormat(exc.ToString());

                return defaultValue;

            }

        }

        /// <summary>

        /// Sets the status of a file, creating a new FileState entry if one doesn't already exist.

        /// </summary>

        /// <param name="path"></param>

        /// <param name="setter"></param>

        public void SetStatus(string path,Action<FileState> setter)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path", "path can't be empty");

            if (setter==null)

                throw new ArgumentNullException("setter", "setter can't be empty");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() =>

            {

                using (new SessionScope())

                {

                    var filePath = path.ToLower();

                    var state = FileState.FindByFilePath(filePath);

                    if (state != null)

                    {

                        setter(state);

                        state.Save();

                    }

                    else

                    {

                        state = new FileState {FilePath = filePath};

                        setter(state);

                        state.Save();

                    }                    

                }

            });

        }

        /// <summary>

        /// Sets the status of a file only if the file already exists

        /// </summary>

        /// <param name="path"></param>

        /// <param name="setter"></param>

        private void UpdateStatus(string path, Action<FileState> setter)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            if (setter == null)

                throw new ArgumentNullException("setter");

            Contract.EndContractBlock();

            Debug.Assert(!path.Contains(FolderConstants.CacheFolder));

            Debug.Assert(!path.EndsWith(".ignore"));

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path", "path can't be empty");

            if (setter == null)

                throw new ArgumentNullException("setter", "setter can't be empty");

            _persistenceAgent.Post(() =>

            {

                using (new SessionScope())

                {

                    var filePath = path.ToLower();

                    var state = FileState.FindByFilePath(filePath);

                    if (state == null)

                    {

                        Log.WarnFormat("[NOFILE] Unable to set status for {0}.", filePath);

                        return;

                    }

                    setter(state);

                    state.Save();

                }

            });

        }

        /// <summary>

        /// Sets the status of a specific state

        /// </summary>

        /// <param name="path"></param>

        /// <param name="setter"></param>

        private void UpdateStatus(Guid stateID, Action<FileState> setter)

        {

            if (setter == null)

                throw new ArgumentNullException("setter");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() =>

            {

                using (new SessionScope())

                {

                    var state = FileState.Find(stateID);

                    if (state == null)

                    {

                        Log.WarnFormat("[NOFILE] Unable to set status for {0}.", stateID);

                        return;

                    }

                    setter(state);

                    state.Save();

                }

            });

        }

        public FileOverlayStatus GetFileOverlayStatus(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();

            try

            {

                var state = FileState.FindByFilePath(path);

                return state == null ? FileOverlayStatus.Unversioned : state.OverlayStatus;

            }

            catch (Exception exc)

            {

                Log.ErrorFormat(exc.ToString());

                return FileOverlayStatus.Unversioned;

            }

        }

        public void SetFileOverlayStatus(string path, FileOverlayStatus overlayStatus)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted","path");

            Contract.EndContractBlock();

            SetStatus(path.ToLower(),s=>s.OverlayStatus=overlayStatus);

        }

        /*public void RemoveFileOverlayStatus(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();

            _persistenceAgent.Post(() =>

                InnerRemoveFileOverlayStatus(path));

        }

        private static void InnerRemoveFileOverlayStatus(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();

            FileState.DeleteByFilePath(path);            

        }*/

        public void RenameFileOverlayStatus(string oldPath, string newPath)

        {

            if (String.IsNullOrWhiteSpace(oldPath))

                throw new ArgumentNullException("oldPath");

            if (!Path.IsPathRooted(oldPath))

                throw new ArgumentException("The oldPath must be rooted", "oldPath");

            if (String.IsNullOrWhiteSpace(newPath))

                throw new ArgumentNullException("newPath");

            if (!Path.IsPathRooted(newPath))

                throw new ArgumentException("The newPath must be rooted", "newPath");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() =>

                InnerRenameFileOverlayStatus(oldPath, newPath));

        }

        private static void InnerRenameFileOverlayStatus(string oldPath, string newPath)

        {

            if (String.IsNullOrWhiteSpace(oldPath))

                throw new ArgumentNullException("oldPath");

            if (!Path.IsPathRooted(oldPath))

                throw new ArgumentException("The oldPath must be rooted", "oldPath");

            if (String.IsNullOrWhiteSpace(newPath))

                throw new ArgumentNullException("newPath");

            if (!Path.IsPathRooted(newPath))

                throw new ArgumentException("The newPath must be rooted", "newPath");

            Contract.EndContractBlock();

            var state = FileState.FindByFilePath(oldPath);

            if (state == null)

            {

                Log.WarnFormat("[NOFILE] Unable to set status for {0}.", oldPath);

                return;

            }

            //NOTE: This will cause problems if path is used as a key in relationships

            state.FilePath = newPath;

            state.Update();

        }

        public void SetFileState(string path, FileStatus fileStatus, FileOverlayStatus overlayStatus)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");

            Contract.EndContractBlock();

            UpdateStatus(path.ToLower(),state=>

                                  {

                                      state.FileStatus = fileStatus;

                                      state.OverlayStatus = overlayStatus;

                                  });            

        }

        public void StoreInfo(string path,ObjectInfo objectInfo)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");            

            if (objectInfo == null)

                throw new ArgumentNullException("objectInfo", "objectInfo can't be empty");

            Contract.EndContractBlock();

            _persistenceAgent.Post(() =>

            {

                var filePath = path.ToLower();

                //Load the existing files state and set its properties in one session            

                using (new SessionScope())

                {

                    //Forgetting to use a sessionscope results in two sessions being created, one by 

                    //FirstOrDefault and one by Save()

                    var state =FileState.FindByFilePath(filePath);

                    //Create a new empty state object if this is a new file

                    state = state ?? new FileState();

                    state.FilePath = filePath;

                    state.Checksum = objectInfo.Hash;

                    state.Version = objectInfo.Version;

                    state.VersionTimeStamp = objectInfo.VersionTimestamp;

                    state.FileStatus = FileStatus.Unchanged;

                    state.OverlayStatus = FileOverlayStatus.Normal;

                    //Create a list of tags from the ObjectInfo's tag dictionary

                    //Make sure to bind each tag to its parent state so we don't have to save each tag separately

                    //state.Tags = (from pair in objectInfo.Tags

                    //                select

                    //                    new FileTag

                    //                        {

                    //                            FileState = state,

                    //                            Name = pair.Key,

                    //                            Value = pair.Value

                    //                        }

                    //            ).ToList();

                    //Do the save

                    state.Save();

                }

            });

        }

        public void SetFileStatus(string path, FileStatus status)

        {            

            UpdateStatus(path.ToLower(), state=>state.FileStatus = status);

        }

        public FileStatus GetFileStatus(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();

            var state = FileState.FindByFilePath(path);

            return (state==null)?FileStatus.Missing:state.FileStatus ;

        }

        public void ClearFileStatus(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:SHOULDN'T need both clear file status and remove overlay status

            _persistenceAgent.Post(() =>

            {

                using (new SessionScope())

                {

                    FileState.DeleteByFilePath(path);

                }

            });   

        }

        public void UpdateFileChecksum(string path, string checksum)

        {

            if (String.IsNullOrWhiteSpace(path))

                throw new ArgumentNullException("path");

            if (!Path.IsPathRooted(path))

                throw new ArgumentException("The path must be rooted", "path");            

            Contract.EndContractBlock();

            _persistenceAgent.Post(() =>

            {

                using (new SessionScope())

                {

                    var state = FileState.FindByFilePath(path);

                    if (state == null)

                    {

                        Log.WarnFormat("[NOFILE] Unable to set checkesum for {0}.", path);

                        return;

                    }

                    state.Checksum = checksum;

                    state.Update();

                }

            });

        }

    }

}