bludgeon/DirectoryObject.cs

   1
   2 using System;
   3 using System.Collections;
   4 using System.IO;
   5
   6 using Mono.Unix.Native;
   7
   8 using Beagle.Util;
   9 using Beagle;
  10
  11 namespace Bludgeon {
  12
  13         public class DirectoryObject : FileSystemObject {
  14
  15                 private bool is_root = false;
  16                 private string root_path = null;
  17
  18                 int n_files_below = 0;
  19                 int n_dirs_below = 0;
  20
  21                 public DirectoryObject ()
  22                 {
  23                         timestamp = FileSystemObject.PickTimestamp ();
  24                         AllowChildren ();
  25                 }
  26
  27                 public DirectoryObject (string root_path)
  28                 {
  29                         ClearName ();
  30
  31                         this.is_root = true;
  32                         this.root_path = Path.GetFullPath (root_path);
  33
  34                         AllowChildren ();
  35                         AddOnDisk (null);
  36                 }
  37
  38                 override public bool IsRoot {
  39                         get { return is_root; }
  40                 }
  41
  42                 override public string Name {
  43                         get {
  44                                 if (is_root)
  45                                         return root_path;
  46                                 return base.Name;
  47                         }
  48                 }
  49
  50                 override protected string GetChildUri (FileSystemObject child)
  51                 {
  52                         return Path.Combine (this.Uri, child.Name);
  53                 }
  54
  55                 override public string Uri {
  56                         get {
  57                                 if (is_root)
  58                                         return "file://" + root_path;
  59                                 return base.Uri;
  60                         }
  61                 }
  62
  63                 override public string Extension {
  64                         get { return is_root ? null : ".dir"; }
  65                 }
  66
  67                 override public string MimeType {
  68                         get { return "inode/directory"; }
  69                 }
  70
  71                 ///////////////////////////////////////////////////////////////////////
  72
  73                 static private void GetCountDeltas (FileSystemObject fso, out int d_files, out int d_dirs)
  74                 {
  75                         if (fso is DirectoryObject) {
  76                                 DirectoryObject dir = (DirectoryObject) fso;
  77                                 d_files = dir.n_files_below;
  78                                 d_dirs = dir.n_dirs_below + 1; // add one for ourself
  79                         } else if (fso is FileObject) {
  80                                 d_files = 1; // just ourself
  81                                 d_dirs = 0;
  82                         } else {
  83                                 throw new Exception ("Unknown type " + fso);
  84                         }
  85                 }
  86
  87                 public override void AddChild (FileSystemObject child, EventTracker tracker)
  88                 {
  89                         // Every time we add a child, we walk up the tree
  90                         // and adjust the n_*_below counts for every node
  91                         // above us.
  92
  93                         int d_files, d_dirs;
  94                         GetCountDeltas (child, out d_files, out d_dirs);
  95
  96                         DirectoryObject curr;
  97                         curr = this;
  98                         while (curr != null) {
  99                                 curr.n_files_below += d_files;
 100                                 curr.n_dirs_below += d_dirs;
 101                                 curr = (DirectoryObject) curr.Parent;
 102                         }
 103
 104                         base.AddChild (child, tracker);
 105                 }
 106
 107                 public override void RemoveChild (FileSystemObject child, EventTracker tracker)
 108                 {
 109                         // Likewise, we have to walk up the tree and adjust
 110                         // the n_*_below counts when we remove a child.
 111
 112                         int d_files, d_dirs;
 113                         GetCountDeltas (child, out d_files, out d_dirs);
 114
 115                         DirectoryObject curr;
 116                         curr = this;
 117                         while (curr != null) {
 118                                 curr.n_files_below -= d_files;
 119                                 curr.n_dirs_below -= d_dirs;
 120                                 curr = (DirectoryObject) curr.Parent;
 121                         }
 122
 123                         base.RemoveChild (child, tracker);
 124                 }
 125
 126                 public override void MoveChild (FileSystemObject child, FileSystemObject new_parent, EventTracker tracker)
 127                 {
 128                         int d_files, d_dirs;
 129                         GetCountDeltas (child, out d_files, out d_dirs);
 130
 131                         DirectoryObject curr;
 132                         curr = this;
 133                         while (curr != null) {
 134                                 curr.n_files_below -= d_files;
 135                                 curr.n_dirs_below -= d_dirs;
 136                                 curr = (DirectoryObject) curr.Parent;
 137                         }
 138                         curr = (DirectoryObject) new_parent;
 139                         while (curr != null) {
 140                                 curr.n_files_below += d_files;
 141                                 curr.n_dirs_below += d_dirs;
 142                                 curr = (DirectoryObject) curr.Parent;
 143                         }
 144
 145                         base.MoveChild (child, new_parent, tracker);
 146                 }
 147
 148                 ///////////////////////////////////////////////////////////////////////
 149
 150                 override public void AddOnDisk (EventTracker tracker)
 151                 {
 152                         string full_name;
 153                         full_name = FullName;
 154                         if (full_name == null)
 155                                 throw new Exception ("Attempt to instantiate something other than a real file: " + Uri);
 156
 157                         if (is_root) {
 158                                 // Root directories must already exist.
 159                                 if (! Directory.Exists (full_name))
 160                                         throw new Exception ("Missing root directory " + full_name);
 161                         } else {
 162                                 Directory.CreateDirectory (full_name);
 163                                 timestamp = Directory.GetLastWriteTime (full_name);
 164                         }
 165
 166                         if (tracker != null)
 167                                 tracker.ExpectingAdded (this.Uri);
 168
 169                         // Recursively add the children
 170                         foreach (FileSystemObject fso in children.Values)
 171                                 fso.AddOnDisk (tracker);
 172                 }
 173
 174                 override public void DeleteOnDisk (EventTracker tracker)
 175                 {
 176                         // Recursively delete the children
 177                         foreach (FileSystemObject fso in children.Values)
 178                                 fso.DeleteOnDisk (tracker);
 179
 180                         // Then delete ourselves
 181                         Syscall.rmdir (FullName);
 182                 }
 183
 184                 override public void MoveOnDisk (string old_full_name, EventTracker tracker)
 185                 {
 186                         Syscall.rename (old_full_name, FullName);
 187                 }
 188
 189                 override public bool VerifyOnDisk ()
 190                 {
 191                         // Make sure the directory exists.
 192                         if (! Directory.Exists (FullName)) {
 193                                 Log.Failure ("Missing directory '{0}'", FullName);
 194                                 return false;
 195                         }
 196
 197                         // Make sure all of the children exist.
 198                         Hashtable name_hash = new Hashtable ();
 199                         foreach (FileSystemObject fso in children.Values) {
 200                                 name_hash [fso.FullName] = fso;
 201                                 if (! fso.VerifyOnDisk ())
 202                                         return false;
 203                         }
 204
 205                         // Make sure there is nothing in the directory that shouldn't be there.
 206                         foreach (string name in Directory.GetFileSystemEntries (FullName)) {
 207                                 name_hash.Remove (name);
 208                         }
 209                         if (name_hash.Count > 0) {
 210                                 Log.Failure ("Extra items in directory '{0}'", FullName);
 211                                 foreach (string name in name_hash.Keys)
 212                                         Log.Failure ("   extra item: '{0}'", name);
 213                                 return false;
 214                         }
 215
 216                         return true;
 217                 }
 218
 219                 ///////////////////////////////////////////////////////////////////////
 220
 221                 // All of the query parts than can possibly match a directory are handled
 222                 // in FileSystemObject.MatchesQuery.
 223                 override protected bool MatchesQueryPart (QueryPart abstract_part)
 224                 {
 225                         return false;
 226                 }
 227
 228                 ///////////////////////////////////////////////////////////////////////
 229
 230                 static Random random = new Random ();
 231
 232                 public FileObject PickChildFile ()
 233                 {
 234                         if (n_files_below == 0)
 235                                 return null;
 236
 237                         int i;
 238                         i = random.Next (n_files_below);
 239
 240                         foreach (FileSystemObject fso in Children) {
 241                                 if (fso is FileObject) {
 242                                         if (i == 0)
 243                                                 return (FileObject) fso;
 244                                         --i;
 245                                 } else if (fso is DirectoryObject) {
 246                                         int nfb;
 247                                         nfb = ((DirectoryObject) fso).n_files_below;
 248                                         if (i < nfb)
 249                                                 return ((DirectoryObject) fso).PickChildFile ();
 250                                         i -= nfb;
 251                                 }
 252                         }
 253
 254                         throw new Exception ("This shouldn't happen!");
 255                 }
 256
 257                 public DirectoryObject PickChildDirectory ()
 258                 {
 259                         if (n_dirs_below == 0)
 260                                 return null;
 261
 262                         int i;
 263                         i = random.Next (n_dirs_below);
 264
 265                         foreach (FileSystemObject fso in Children) {
 266
 267                                 DirectoryObject dir = fso as DirectoryObject;
 268                                 if (dir == null)
 269                                         continue;
 270
 271                                 if (i == 0)
 272                                         return dir;
 273                                 --i;
 274
 275                                 if (i < dir.n_dirs_below)
 276                                         return dir.PickChildDirectory ();
 277                                 i -= dir.n_dirs_below;
 278                         }
 279
 280                         throw new Exception ("This also shouldn't happen!");
 281                 }
 282
 283                 // Returns a directory, either a child directory or itself.
 284                 public DirectoryObject PickDirectory ()
 285                 {
 286                         int i;
 287                         i = random.Next (n_dirs_below + 1);
 288                         if (i == 0)
 289                                 return this;
 290                         return PickChildDirectory ();
 291                 }
 292         }
 293 }