beagled/FileAttributesStore_Sqlite.cs

   1 //
   2 // FileAttributesStore_Sqlite.cs
   3 //
   4 // Copyright (C) 2004 Novell, Inc.
   5 //
   6
   7 //
   8 // Permission is hereby granted, free of charge, to any person obtaining a copy
   9 // of this software and associated documentation files (the "Software"), to deal
  10 // in the Software without restriction, including without limitation the rights
  11 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 // copies of the Software, and to permit persons to whom the Software is
  13 // furnished to do so, subject to the following conditions:
  14 //
  15 // The above copyright notice and this permission notice shall be included in all
  16 // copies or substantial portions of the Software.
  17 //
  18 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24 // SOFTWARE.
  25 //
  26
  27 using System;
  28 using System.Collections;
  29 using System.IO;
  30 using System.Threading;
  31
  32 using Mono.Data.SqliteClient;
  33
  34 using Beagle.Util;
  35
  36 namespace Beagle.Daemon {
  37
  38         public class FileAttributesStore_Sqlite : IFileAttributesStore {
  39
  40                 // Version history:
  41                 // 1: Original version
  42                 // 2: Replaced LastIndexedTime with LastAttrTime
  43                 const int VERSION = 2;
  44
  45                 private SqliteConnection connection;
  46                 private BitArray path_flags;
  47                 private int transaction_count = 0;
  48
  49                 enum TransactionState {
  50                         None,
  51                         Requested,
  52                         Started
  53                 }
  54                 private TransactionState transaction_state;
  55
  56                 public FileAttributesStore_Sqlite (string directory, string index_fingerprint)
  57                 {
  58                         bool create_new_db = false;
  59                         path_flags = new BitArray (65536);
  60
  61                         if (! File.Exists (GetDbPath (directory))) {
  62                                 create_new_db = true;
  63                         } else {
  64
  65                                 // Funky logic here to deal with sqlite versions.
  66                                 //
  67                                 // When sqlite 3 tries to open an sqlite 2 database,
  68                                 // it will throw an SqliteException with SqliteError
  69                                 // NOTADB when trying to execute a command.
  70                                 //
  71                                 // When sqlite 2 tries to open an sqlite 3 database,
  72                                 // it will throw an ApplicationException when it
  73                                 // tries to open the database.
  74
  75                                 try {
  76                                         connection = Open (directory);
  77                                 } catch (ApplicationException) {
  78                                         Logger.Log.Warn ("Likely sqlite database version mismatch trying to open {0}.  Purging.", GetDbPath (directory));
  79                                         create_new_db = true;
  80                                 }
  81
  82                                 if (! create_new_db) {
  83                                         SqliteCommand command;
  84                                         SqliteDataReader reader = null;
  85                                         int stored_version = 0;
  86                                         string stored_fingerprint = null;
  87
  88
  89                                         command = new SqliteCommand ();
  90                                         command.Connection = connection;
  91                                         command.CommandText =
  92                                                 "SELECT version, fingerprint FROM db_info";
  93                                         try {
  94                                                 reader = ExecuteReaderOrWait (command);
  95                                         } catch (Exception ex) {
  96                                                 Logger.Log.Warn ("Likely sqlite database version mismatch trying to read from {0}.  Purging.", GetDbPath (directory));
  97                                                 create_new_db = true;
  98                                         }
  99                                         if (reader != null && ! create_new_db) {
 100                                                 if (ReadOrWait (reader)) {
 101                                                         stored_version = reader.GetInt32 (0);
 102                                                         stored_fingerprint = reader.GetString (1);
 103                                                 }
 104                                                 reader.Close ();
 105                                         }
 106                                         command.Dispose ();
 107
 108                                         if (VERSION != stored_version
 109                                             || (index_fingerprint != null && index_fingerprint != stored_fingerprint))
 110                                                 create_new_db = true;
 111                                 }
 112                         }
 113
 114                         if (create_new_db) {
 115                                 if (connection != null)
 116                                         connection.Dispose ();
 117                                 File.Delete (GetDbPath (directory));
 118                                 connection = Open (directory);
 119
 120                                 DoNonQuery ("CREATE TABLE db_info (             " +
 121                                             "  version       INTEGER NOT NULL,  " +
 122                                             "  fingerprint   STRING NOT NULL    " +
 123                                             ")");
 124
 125                                 DoNonQuery ("INSERT INTO db_info (version, fingerprint) VALUES ({0}, '{1}')",
 126                                             VERSION, index_fingerprint);
 127
 128                                 DoNonQuery ("CREATE TABLE file_attributes (           " +
 129                                             "  unique_id      STRING UNIQUE,          " +
 130                                             "  directory      STRING NOT NULL,        " +
 131                                             "  filename       STRING NOT NULL,        " +
 132                                             "  last_mtime     STRING NOT NULL,        " +
 133                                             "  last_attrtime  STRING NOT NULL,        " +
 134                                             "  filter_name    STRING NOT NULL,        " +
 135                                             "  filter_version STRING NOT NULL         " +
 136                                             ")");
 137                         } else {
 138                                 SqliteCommand command;
 139                                 SqliteDataReader reader;
 140                                 int count = 0;
 141
 142                                 DateTime dt1 = DateTime.Now;
 143
 144                                 // Select all of the files and use them to populate our bit-vector.
 145                                 command = new SqliteCommand ();
 146                                 command.Connection = connection;
 147                                 command.CommandText = "SELECT directory, filename FROM file_attributes";
 148
 149                                 reader = ExecuteReaderOrWait (command);
 150
 151                                 while (ReadOrWait (reader)) {
 152
 153                                         string dir = reader.GetString (0);
 154                                         string file = reader.GetString (1);
 155                                         string path = Path.Combine (dir, file);
 156                                         SetPathFlag (path);
 157                                         ++count;
 158                                 }
 159
 160                                 reader.Close ();
 161                                 command.Dispose ();
 162
 163                                 DateTime dt2 = DateTime.Now;
 164
 165                                 Logger.Log.Debug ("Loaded {0} records from {1} in {2:0.000}s",
 166                                                  count, GetDbPath (directory), (dt2 - dt1).TotalSeconds);
 167                         }
 168                 }
 169
 170                 ///////////////////////////////////////////////////////////////////
 171
 172                 private string GetDbPath (string directory)
 173                 {
 174                         return Path.Combine (directory, "FileAttributesStore.db");
 175                 }
 176
 177                 private SqliteConnection Open (string directory)
 178                 {
 179                         SqliteConnection c;
 180                         c = new SqliteConnection ();
 181                         c.ConnectionString = "version=" + ExternalStringsHack.SqliteVersion
 182                                 + ",encoding=UTF-8,URI=file:" + GetDbPath (directory);
 183                         c.Open ();
 184                         return c;
 185                 }
 186
 187                 private void DoNonQuery (string format, params object [] args)
 188                 {
 189                         SqliteCommand command;
 190                         command = new SqliteCommand ();
 191                         command.Connection = connection;
 192                         command.CommandText = String.Format (format, args);
 193
 194                         while (true) {
 195                                 try {
 196                                         command.ExecuteNonQuery ();
 197                                         break;
 198                                 } catch (SqliteBusyException ex) {
 199                                         Thread.Sleep (50);
 200                                 }
 201                         }
 202
 203                         command.Dispose ();
 204                 }
 205
 206                 private SqliteCommand QueryCommand (string where_format, params object [] where_args)
 207                 {
 208                         SqliteCommand command;
 209                         command = new SqliteCommand ();
 210                         command.Connection = connection;
 211                         command.CommandText =
 212                                 "SELECT unique_id, directory, filename, last_mtime, last_attrtime, filter_name, filter_version " +
 213                                 "FROM file_attributes WHERE " +
 214                                 String.Format (where_format, where_args);
 215                         return command;
 216                 }
 217
 218                 static private SqliteDataReader ExecuteReaderOrWait (SqliteCommand command)
 219                 {
 220                         SqliteDataReader reader = null;
 221                         while (reader == null) {
 222                                 try {
 223                                         reader = command.ExecuteReader ();
 224                                 } catch (SqliteBusyException ex) {
 225                                         Thread.Sleep (50);
 226                                 }
 227                         }
 228                         return reader;
 229                 }
 230
 231                 static private bool ReadOrWait (SqliteDataReader reader)
 232                 {
 233                         while (true) {
 234                                 try {
 235                                         return reader.Read ();
 236                                 } catch (SqliteBusyException ex) {
 237                                         Thread.Sleep (50);
 238                                 }
 239                         }
 240                 }
 241
 242                 private FileAttributes GetFromReader (SqliteDataReader reader)
 243                 {
 244                         FileAttributes attr = new FileAttributes ();
 245
 246                         attr.UniqueId = GuidFu.FromShortString (reader.GetString (0));
 247                         attr.Path = System.IO.Path.Combine (reader.GetString (1), reader.GetString (2));
 248                         attr.LastWriteTime = StringFu.StringToDateTime (reader.GetString (3));
 249                         attr.LastAttrTime = StringFu.StringToDateTime (reader.GetString (4));
 250                         attr.FilterName = reader.GetString (5);
 251                         attr.FilterVersion = int.Parse (reader.GetString (6));
 252
 253                         if (attr.FilterName == "")
 254                                 attr.FilterName = null;
 255
 256                         return attr;
 257                 }
 258
 259                 ///////////////////////////////////////////////////////////////////
 260
 261                 private int GetPathHash (string path)
 262                 {
 263                         uint hash = 0xdeadbeef;
 264                         foreach (char c in path)
 265                                 hash = 17 * hash + (uint) c;
 266                         // Fold the 32 bits in 16.
 267                         return (int) ((hash & 0xffff) ^ (hash >> 16));
 268                 }
 269
 270                 private bool GetPathFlag (string path)
 271                 {
 272                         int hash = GetPathHash (path);
 273                         return path_flags [hash];
 274                 }
 275
 276                 private void SetPathFlag (string path)
 277                 {
 278                         int hash = GetPathHash (path);
 279                         path_flags [hash] = true;
 280                 }
 281
 282                 ///////////////////////////////////////////////////////////////////
 283
 284                 public FileAttributes Read (string path)
 285                 {
 286                         SqliteCommand command;
 287                         SqliteDataReader reader;
 288
 289                         if (! GetPathFlag (path))
 290                                 return null;
 291
 292                         FileAttributes attr = null;
 293                         bool found_too_many = false;
 294
 295                         // We need to quote any 's that appear in the strings
 296                         // (int particular, in the path)
 297                         string directory = FileSystem.GetDirectoryNameRootOk (path).Replace ("'", "''");
 298                         string filename = Path.GetFileName (path).Replace ("'", "''");
 299                         lock (connection) {
 300                                 command = QueryCommand ("directory='{0}' AND filename='{1}'",
 301                                                         directory, filename);
 302                                 reader = ExecuteReaderOrWait (command);
 303
 304                                 if (ReadOrWait (reader)) {
 305                                         attr = GetFromReader (reader);
 306
 307                                         if (ReadOrWait (reader))
 308                                                 found_too_many = true;
 309                                 }
 310                                 reader.Close ();
 311                                 command.Dispose ();
 312
 313                                 // If we found more than one matching record for a given
 314                                 // directory and filename, something has gone wrong.
 315                                 // Since we have no way of knowing which one is correct
 316                                 // and which isn't, we delete them all and return
 317                                 // null.  (Which in most cases will force a re-index.
 318                                 if (found_too_many) {
 319                                         DoNonQuery ("DELETE FROM file_attributes WHERE directory='{0}' AND filename='{1}'",
 320                                                     directory, filename);
 321                                 }
 322                         }
 323
 324                         return attr;
 325                 }
 326
 327                 public bool Write (FileAttributes fa)
 328                 {
 329                         SetPathFlag (fa.Path);
 330
 331                         // We need to quote any 's that appear in the strings
 332                         // (in particular, in the path)
 333                         lock (connection) {
 334
 335                                 // If a transaction has been requested, start it now.
 336                                 MaybeStartTransaction ();
 337
 338                                 string filter_name;
 339                                 filter_name = fa.FilterName;
 340                                 if (filter_name == null)
 341                                         filter_name = "";
 342                                 filter_name = filter_name.Replace ("'", "''");
 343
 344                                 DoNonQuery ("INSERT OR REPLACE INTO file_attributes " +
 345                                             " (unique_id, directory, filename, last_mtime, last_attrtime, filter_name, filter_version) " +
 346                                             " VALUES ('{0}', '{1}', '{2}', '{3}', '{4}', '{5}', '{6}')",
 347                                             GuidFu.ToShortString (fa.UniqueId),
 348                                             fa.Directory.Replace ("'", "''"), fa.Filename.Replace ("'", "''"),
 349                                             StringFu.DateTimeToString (fa.LastWriteTime),
 350                                             StringFu.DateTimeToString (fa.LastAttrTime),
 351                                             filter_name,
 352                                             fa.FilterVersion);
 353                         }
 354                         return true;
 355                 }
 356
 357                 public void Drop (string path)
 358                 {
 359                         // We don't want to "UnSetPathFlag" here, since we have no way of knowing
 360                         // if another path hashes to the same value as this one.
 361
 362                         // We need to quote any 's that appear in the strings
 363                         // (in particular, in the path)
 364                         string directory = FileSystem.GetDirectoryNameRootOk (path).Replace ("'", "''");
 365                         string filename = Path.GetFileName (path).Replace ("'", "''");
 366                         lock (connection) {
 367
 368                                 // If a transaction has been requested, start it now.
 369                                 MaybeStartTransaction ();
 370
 371                                 DoNonQuery ("DELETE FROM file_attributes WHERE directory='{0}' AND filename='{1}'",
 372                                             directory, filename);
 373                         }
 374                 }
 375
 376                 private void MaybeStartTransaction ()
 377                 {
 378                         if (transaction_state == TransactionState.Requested) {
 379                                 DoNonQuery ("BEGIN");
 380                                 transaction_state = TransactionState.Started;
 381                         }
 382                 }
 383
 384                 public void BeginTransaction ()
 385                 {
 386                         if (transaction_state == TransactionState.None)
 387                                 transaction_state = TransactionState.Requested;
 388                 }
 389
 390                 public void CommitTransaction ()
 391                 {
 392                         if (transaction_state == TransactionState.Started) {
 393                                 lock (connection)
 394                                         DoNonQuery ("COMMIT");
 395                         }
 396                         transaction_state = TransactionState.None;
 397                 }
 398
 399                 public void Flush ()
 400                 {
 401                         lock (connection) {
 402                                 if (transaction_count > 0) {
 403                                         Logger.Log.Debug ("Flushing requested -- committing sqlite transaction");
 404                                         DoNonQuery ("COMMIT");
 405                                         transaction_count = 0;
 406                                 }
 407                         }
 408                 }
 409
 410                 ///////////////////////////////////////////////////////////////////
 411
 412                 // Return all attributes in the attributes database, used for merging
 413
 414                 private ICollection ReadAllAttributes ()
 415                 {
 416                         ArrayList attributes = new ArrayList ();
 417
 418                         SqliteCommand command;
 419                         SqliteDataReader reader;
 420
 421                         lock (connection) {
 422                                 command = new SqliteCommand ();
 423                                 command.Connection = connection;
 424                                 command.CommandText =
 425                                         "SELECT unique_id, directory, filename, last_mtime, last_attrtime, filter_name, filter_version " +
 426                                         "FROM file_attributes";
 427
 428                                 reader = ExecuteReaderOrWait (command);
 429
 430                                 while (ReadOrWait (reader)) {
 431                                         attributes.Add (GetFromReader (reader));
 432                                 }
 433                                 reader.Close ();
 434                                 command.Dispose ();
 435                         }
 436
 437                         return attributes;
 438                 }
 439
 440                 // FIXME: Might wanna do this a bit more intelligently
 441
 442                 public void Merge (FileAttributesStore_Sqlite fa_sqlite_store_to_merge)
 443                 {
 444                         ICollection attributes = fa_sqlite_store_to_merge.ReadAllAttributes ();
 445
 446                         BeginTransaction ();
 447
 448                         foreach (FileAttributes attribute in attributes)
 449                                 Write (attribute);
 450
 451                         CommitTransaction ();
 452                 }
 453         }
 454 }