Added storing of cursor position so you do not get kicked to the beginning or end of file on join

plugins/Codiad-Collaborative-master/file_db.php

@@ -0,0 +1,307 @@
+<?php
+
+/*
+*  Copyright (c) Luc Verdier & Florent Galland, distributed
+*  as-is and without warranty under the MIT License. See
+*  [root]/license.txt for more. This information must remain intact.
+*/
+
+/*
+ * Suppose a user wants to register as a collaborator of file '/test/test.js'.
+ * He registers to a specific file by creating a marker file
+ * 'data/_test_test.js%%filename%%username%%registered', and he can
+ * unregister by deleting this file. Then his current selection will be in
+ * file 'data/_test_test.js%%username%%selection'.
+ * The collaborative editing algorithm is based on the differential synchronization
+ * algorithm by Neil Fraser. The text shadow and server text are stored
+ * respectively in 'data/_test_test.js%%filename%%username%%shadow' and
+ * 'data/_test_test.js%%filename%%text'.
+ * At regular time intervals, the user send an heartbeat which is stored in
+ * 'data/_test_test.js%%username%%heartbeat' .
+ */
+
+
+/* */
+class file_db {
+    
+    /* They should be the same as those
+     * in the file_db_entry class. */
+    private $separator = '|';
+    private $separator_regex = '\|';
+    private $key_value_separator = ':';
+    private $key_value_separator_regex = '\:';
+    
+    private $index_name = 'index.db';
+    private $base_path;
+    
+    function __construct($base_path) {
+        $this->base_path = $base_path;
+        if(!is_dir($base_path)) {
+            mkdir($base_path);
+        }
+    }
+    
+    /* Create a new entry into the data base. */
+    public function create($query, $group=null) {
+        $query = $this->_normalize_query($query);
+        
+        if(!$this->_is_direct_query($query)) {
+            return null;
+        }
+        
+        $base_path = $this->base_path;
+        if($group != null) {
+            $base_path .= '/' . $group;
+        }
+        $index_file = $base_path . '/' . $this->index_name;
+        
+        if(!is_dir($base_path)) {
+            mkdir($base_path);
+        }
+        
+        $entry_name = $this->_make_entry_name($query);
+        $entry_hash = md5($entry_name);
+        $entry_file = $base_path . '/' . $entry_hash;
+        
+        if(!file_exists($entry_file)) {
+            if(!file_exists($index_file)) {
+                touch($index_file);
+            }
+            
+            $entry = $entry_name . '>' . $entry_hash . '>' . PHP_EOL;
+            file_put_contents($index_file, $entry, FILE_APPEND | LOCK_EX);
+            touch($entry_file);
+        }
+        
+        $entry = new file_db_entry($entry_name, $entry_file, $index_file, $group);
+        $entry->clear();
+        
+        if(file_exists($entry_file)) {
+            return $entry;
+        }
+        return null;
+    }
+
+    /* Get the content for the given query. */
+    public function select($query, $group=null) {
+        $query = $this->_normalize_query($query);
+        
+        $base_path = $this->base_path;
+        if($group != null) {
+            $base_path .= '/' . $group;
+        }
+        $index_file = $base_path . '/' . $this->index_name;
+        
+        if($this->_is_direct_query($query)) {
+            $entry_name = $this->_make_entry_name($query);
+            $entry_hash = md5($entry_name);
+            $entry_file = $base_path . '/' . $entry_hash;
+            
+            if(file_exists($entry_file)) {
+                return new file_db_entry($entry_name, $entry_file, $index_file, $group);
+            }
+            return null;
+        }
+        
+        $entries = array();
+        if(file_exists($index_file)) {
+            $regex = $this->_make_regex($query);
+            $file = fopen($index_file, 'r');
+            while(!feof($file)) { 
+                $line = fgets($file);
+                if (preg_match($regex, $line, $matches)) {
+                    $entry_file = $base_path . '/' . $matches[2];
+                    if(file_exists($entry_file)) {
+                        $entries[] = new file_db_entry($matches[1], $entry_file, $index_file, $group);
+                    }
+                }
+            }
+            fclose($file);
+        }
+        
+        return $entries;
+    }
+    
+    /* Select all entries into the given group. */
+    public function select_group($group) {
+        $entries = array();
+        
+        $base_path = $this->base_path . '/' . $group;
+        $index_file = $base_path . '/' . $this->index_name;
+        
+        if(file_exists($index_file)) {
+            $sep = $this->separator_regex;
+            $regex = '/(' . $sep . '.*?' . $sep . ')\>(.*?)\>/'; 
+            $file = fopen($index_file, 'r');
+            while(!feof($file)) { 
+                $line = fgets($file);
+                if (preg_match($regex, $line, $matches)) {
+                    $entry_file = $base_path . '/' . $matches[2];
+                    $entries[] = new file_db_entry($matches[1], $entry_file, $index_file, $group);
+                }
+            }
+            fclose($file);
+        }
+        
+        return $entries;
+    }
+    
+    /* Make the regex for the given query. */
+    private function _make_regex($query) {
+        $regex = '/(' . $this->separator_regex;
+        foreach($query as $key => $value) {
+            $regex .= $key . $this->key_value_separator_regex;
+            if($value == '%2A') { // %2A=*
+                $regex .= '.*?';
+            }
+            else {
+                $regex .= $value;
+            }
+            $regex .= $this->separator_regex;
+        }
+        $regex .= ')' . '\>(.*?)\>' . '/';
+        return $regex;
+    }
+        
+    /* Make an entry name from the given normalized query. */
+    private function _make_entry_name($query) {
+        $filename = $this->separator;
+        foreach($query as $key => $value) {
+            $filename .= $key . $this->key_value_separator . $value;
+            $filename .= $this->separator;
+        }
+        return $filename;
+    }
+    
+    /* Check if the given query is a direct query. */
+    private function _is_direct_query($query) {
+        foreach($query as $key => $value) {
+            if($value == '%2A'){ // %2A=*
+                return false;
+            }
+        }
+        return true;
+    }
+    
+    /* Normalize the given query. */
+    private function &_normalize_query(&$query) {
+        ksort($query);
+        foreach($query as $key => $value) {
+            $query[$key] = rawurlencode($value);
+        }
+        return $query;
+    }
+    
+}
+
+/* */
+class file_db_entry {
+    
+    /* They should be the same as those
+     * in the file_db class. */
+    private $separator = '|';
+    private $separator_regex = '\|';
+    private $key_value_separator = ':';
+    private $key_value_separator_regex = '\:';
+    
+    private $entry_name;
+    private $entry_hash;
+    private $entry_file;
+    private $index_file;
+    private $group;
+    
+    private $handler;
+    
+    /* Construct the entry with the given filename. */
+    public function __construct($entry_name, $entry_file, $index_file, $group) {
+        $this->entry_name = $entry_name;
+        $this->entry_file = $entry_file;
+        $this->index_file = $index_file;
+        $this->group = $group;
+    }
+    
+    /* Get the value of the field with the given name. */
+    public function get_field($name) {
+        $regex = '/'
+            . $this->separator_regex 
+            . rawurlencode($name)
+            . $this->key_value_separator_regex
+            . '(.*?)' . $this->separator_regex 
+            . '/';
+        if(preg_match($regex, $this->entry_name, $matches)) {
+            return rawurldecode($matches[1]);
+        }
+        return null;
+    }
+    
+    /* Get the group name of the entry. */
+    public function get_group() {
+        return $this->group;
+    }
+    
+    /* Set the value of the entry. */
+    public function put_value($value) {
+        file_put_contents($this->entry_file, serialize($value), LOCK_EX);
+    }
+    
+    /* Get the value of the entry. */
+    public function get_value() {
+        if(file_exists($this->entry_file)) {
+            return unserialize(file_get_contents($this->entry_file));
+        }
+        return null;
+    }
+    
+    /* Remove the entry. */
+    public function remove() {
+        $success = false;
+        if(file_exists($this->index_file)) {
+            $lines = file($this->index_file, FILE_SKIP_EMPTY_LINES);
+            
+            $file = fopen($this->index_file, 'w');
+            flock($file, LOCK_EX);
+            
+            foreach($lines as $line) {
+                if (strpos($line, $this->entry_name) !== 0) {
+                    fwrite($file, $line);
+                }
+                else {
+                    $success = true;
+                }
+            }
+            
+            flock($file, LOCK_UN);
+            fclose($file);  
+        }
+        
+        if($success && file_exists($this->entry_file)) {
+            unlink($this->entry_file);
+            return true;
+        }
+        return false;
+    }
+    
+    /* Clear the value of the entry. */
+    public function clear() {
+        $this->put_value('');
+    }
+    
+    /* Lock the entry. */
+    public function lock() {
+        $lock = $this->entry_file . '.lock';
+        while(file_exists($lock)) {
+            usleep(100);
+        }
+        touch($this->entry_file . '.lock');
+    }
+    
+    /* Unlock the entry. */
+    public function unlock() {
+        $lock = $this->entry_file . '.lock';
+        if(file_exists($lock)) {
+            unlink($lock);
+        }
+    }
+}
+
+?>

plugins/Codiad-Collaborative-master/init.js

@@ -9,20 +9,21 @@
 	var codiad = global.codiad,
 	scripts = document.getElementsByTagName('script'),
 	path = scripts[scripts.length-1].src.split('?')[0],
-	curpath = path.split('/').slice(0, -1).join('/')+'/';
+	curpath = path.split( '/' ).slice( 0, -1 ).join( '/ ') + '/';
 	
-	var site_id = codiad.system.site_id;
-	var session_id = window.session_id;
-	var editor = null;
-	var collaborator = null;
 	var buffer_dumped = false;
-	var last_applied_change = null;
+	var collaborator = null;
-	var just_cleared_buffer = null;
 	var current_editor = codiad.active.getPath();
-	var just_opened = false;
+	var cursor = null;
-	var loaded = false;
+	var editor = null;
 	var initial = false;
+	var just_cleared_buffer = null;
+	var just_opened = false;
+	var last_applied_change = null;
+	var loaded = false;
 	var loading = true;
+	var session_id = codiad.system.session_id;
+	var site_id = codiad.system.site_id;
 	
 	function Collaborator( file_path, session_id ) {
 		
@@ -58,26 +59,45 @@
 			if ( delta.initial === true ) {
 				
 				console.log( 'Setting initial content...' );
-				codiad.editor.setContent( '' );
+				//codiad.editor.setContent( '' );
 				codiad.editor.setContent( delta.content )
 				inital = false;
 			}
+			
+			setTimeout(function(){
+				if( cursor !== null ) {
+					console.log( 'Going to position: '  + cursor.row + ", " + cursor.column );
+					editor.gotoLine( cursor.row, cursor.column, true );
+				}
+			}, 256);
+			
 		}.bind() );
 		
 		this.collaboration_socket.on( "recieve_content", function( ) {
 				
-			console.log( 'Someone is joining...' );
+			console.log( 'Someone is joining ...' );
+			console.log( 'Cursor is at '  + cursor.row + ", " + cursor.column  );
 			
 			// Remove change callback
 			editor.removeEventListener( "change", handle_change );
-			
 			codiad.editor.disableEditing();
 			codiad.editor.setContent( '' );
-			collaborator.dump_buffer();
+			collaborator.dump_buffer()
-			
 			// registering change callback
 			editor.addEventListener( "change", handle_change );
-			setTimeout(function(){codiad.editor.enableEditing();}, 500);
+		}.bind() );
+		
+		this.collaboration_socket.on( "unlock", function( ) {
+				
+			console.log( 'Unlocking editors and going to ' + cursor.row + ", " + cursor.column );
+			
+			codiad.editor.enableEditing();
+			setTimeout(function(){
+				if( cursor !== null ) {
+					console.log( 'Going to position: '  + cursor.row + ", " + cursor.column );
+					editor.gotoLine( cursor.row, cursor.column, true );
+				}
+			}, 256);
 		}.bind() );
 		
 		window.collaboration_socket = this.collaboration_socket;
@@ -107,6 +127,13 @@
 	function handle_change( e ) {
 		
 		// TODO, we could make things more efficient and not likely to conflict by keeping track of change IDs
+		coords = editor.getCursorPosition();
+		if( coords.row !== 0 && coords.column !== 0 ) {
+			cursor = editor.getCursorPosition();
+			cursor.row = cursor.row + 1
+			console.log( 'Cursor at: '  + cursor.row + ", " + cursor.column );
+		}
+		
 		if( last_applied_change!=e && !just_cleared_buffer ) {
 			
 			collaborator.change( JSON.stringify(e) );
@@ -166,6 +193,7 @@
 		
 		collaborator = new Collaborator( session_id );
 		
+		//codiad.editor.disableEditing();
 		//collaborator.open_file(  )
 		content = codiad.editor.getContent()
 		codiad.editor.setContent( '' )
@@ -201,9 +229,29 @@
 	});
 	
 	$(window).blur(function() {
+		
+		if( editor !== null ) {
+			coords = editor.getCursorPosition();
+			if( coords.row !== 0 && coords.column !== 0 ) {
+				cursor = editor.getCursorPosition();
+				cursor.row = cursor.row + 1
+				console.log( 'Cursor at: '  + cursor.row + ", " + cursor.column );
+			}
+		}
 		close();
 	});
 	
+	/* When the window is clicked get the cursor position. 
+	$(window).click(function () {
+		
+		coords = editor.getCursorPosition();
+		if( coords.row !== 0 && coords.column !== 0 ) {
+			//cursor = editor.getCursorPosition();
+			//cursor.row = cursor.row + 1
+			//console.log( 'Cursor at: '  + cursor.row + ", " + cursor.column );
+		}
+	});*/
+	
 	/* Subscribe to know when a file become active. */
 	amplify.subscribe('active.onFocus', function (path) {
 		
@@ -211,7 +259,8 @@
 		
 		if( current_editor !== codiad.active.getPath() && current_editor !== null ) {
 		
-			console.log( 'Closing Socket' );+
+			cursor = null;
+			console.log( 'Closing Socket' );
 			close();
 		}
 		console.log( 'Last Editor: ' + current_editor );
@@ -222,6 +271,13 @@
 			body_loaded();
 		}
 		console.log( 'Focused Editor: ' + codiad.active.getPath() );
+		
+		coords = editor.getCursorPosition();
+		if( coords.row !== 0 && coords.column !== 0 ) {
+			cursor = editor.getCursorPosition();
+			cursor.row = cursor.row + 1
+			console.log( 'Cursor at: '  + cursor.row + ", " + cursor.column );
+		}
 	});
 	
 	//////////////////////////////////////////////////////////////////
@@ -234,6 +290,8 @@
 	//////////////////////////////////////////////////////////////////
 	
 	codiad.collaborative = {
+		
+		
 	};
 	
 })(this, jQuery);

plugins/Codiad-Collaborative-master/server.js

@@ -1,19 +1,19 @@
 // config variables
 verbose = false ;
-session_directory = "./sessions" ; // it has to exist
+session_directory = "./sessions"; // it has to exist
 
 /* https specific */
-var https = require('https'),
+var https = require( 'https' ),
-fs =    require('fs');
+fs = require( 'fs' );
 
 var options = {
-key:    fs.readFileSync('/etc/letsencrypt/live/local.telaaedifex.com/privkey.pem'),
+	key:    fs.readFileSync( '/etc/letsencrypt/live/local.telaaedifex.com/privkey.pem' ),
-cert:   fs.readFileSync('/etc/letsencrypt/live/local.telaaedifex.com/fullchain.pem'),
+	cert:   fs.readFileSync( '/etc/letsencrypt/live/local.telaaedifex.com/fullchain.pem' ),
-ca:     fs.readFileSync('/etc/letsencrypt/live/local.telaaedifex.com/chain.pem')
+	ca:     fs.readFileSync( '/etc/letsencrypt/live/local.telaaedifex.com/chain.pem' )
 };
-var app = https.createServer(options);
+var app = https.createServer( options );
-io = require('socket.io').listen(app);     //socket.io server listens to https connections
+io = require( 'socket.io' ).listen( app );     //socket.io server listens to https connections
-app.listen(1337, "0.0.0.0");
+app.listen( 1337, "0.0.0.0" );
 
 // will use the following for file IO
 var fs = require( "fs" ) ;
@@ -27,10 +27,10 @@ socket_id_to_session_id = [] ;
 
 io.sockets.on('connection', function(socket) {
 	
+	init = false
 	var file = socket.handshake.query.file;
 	//var session_id = socket.handshake.query.session_id;
 	var session_id = socket.handshake.query.file;
-	
 	socket_id_to_session_id[socket.id] = session_id ;
 	
 	if( verbose ) { console.log( session_id + "connected on socket" + socket.id ) ; }
@@ -42,7 +42,7 @@ io.sockets.on('connection', function(socket) {
 			if( verbose ) { console.log( "session terminated previously, pulling back from filesystem" ); }
 			
 			var data = read_file( session_directory + "/" + session_id );
-			if( data!==false ) {
+			if( data !== false ) {
 				
 				init = false;
 				collaborations[session_id] = {'cached_instructions':JSON.parse(data), 'participants':[]};
@@ -59,23 +59,31 @@ io.sockets.on('connection', function(socket) {
 		}
 	}
 	
-	for( var i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
+	var i = 0;
+	
+	for( i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
 		if( socket.id!=collaborations[session_id]['participants'][i] ) {
 			io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "recieve_content" );
 		}
 	}
+	
 	collaborations[session_id]['participants'].push( socket.id );
 	
+	for( i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
+		if( socket.id!=collaborations[session_id]['participants'][i] ) {
+			io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "unlock" );
+		}
+	}
 	
 	socket.on('change', function( delta ) {
 		if( verbose ) { console.log( "change " + socket_id_to_session_id[socket.id] + " " + delta ) ; }
 		if( socket_id_to_session_id[socket.id] in collaborations ) {
-		collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'].push( ["change", delta, Date.now()] ) ;
+			collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'].push( ["change", delta, Date.now()] ) ;
-		for( var i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
+			for( var i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
-		if( socket.id!=collaborations[session_id]['participants'][i] ) {
+				if( socket.id!=collaborations[session_id]['participants'][i] ) {
-		io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "change", delta ) ;
+					io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "change", delta ) ;
-		}
+				}
-		}
+			}
 		} else {
 		if( verbose ) { console.log( "WARNING: could not tie socket_id to any collaboration" ) ; }
 		}
@@ -85,13 +93,13 @@ io.sockets.on('connection', function(socket) {
 	socket.on('change_selection', function( selections ) {
 		if( verbose ) { console.log( "change_selection " + socket_id_to_session_id[socket.id] + " " + selections ) ; }
 		if( socket_id_to_session_id[socket.id] in collaborations ) {
-		for( var i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
+			for( var i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
-		if( socket.id!=collaborations[session_id]['participants'][i] ) {
+				if( socket.id!=collaborations[session_id]['participants'][i] ) {
-		io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "change_selection", selections ) ;
+					io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "change_selection", selections ) ;
-		}
+				}
-		}
+			}
 		} else {
-		if( verbose ) { console.log( "WARNING: could not tie socket_id to any collaboration" ) ; }
+			if( verbose ) { console.log( "WARNING: could not tie socket_id to any collaboration" ) ; }
 		}
 	});
 	
@@ -99,26 +107,27 @@ io.sockets.on('connection', function(socket) {
 	socket.on('clear_buffer', function() {
 		if( verbose ) { console.log( "clear_buffer " + socket_id_to_session_id[socket.id] ) ; }
 		if( socket_id_to_session_id[socket.id] in collaborations ) {
-		collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'] = [] ;
+			collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'] = [] ;
-		for( var i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
+			for( var i=0 ; i<collaborations[session_id]['participants'].length ; i++ ) {
-		if( socket.id!=collaborations[session_id]['participants'][i] ) {
+				if( socket.id!=collaborations[session_id]['participants'][i] ) {
-		io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "clear_buffer" ) ;
+					io.sockets.connected[collaborations[session_id]['participants'][i]].emit( "clear_buffer" ) ;
-		}
+				}
-		}
+			}
 		} else {
-		if( verbose ) { console.log( "WARNING: could not tie socket_id to any collaboration" ) ; }
+			if( verbose ) { console.log( "WARNING: could not tie socket_id to any collaboration" ) ; }
 		}
 	});
 	
 	
 	socket.on('dump_buffer', function() {
 		if( verbose ) { console.log( "dump_buffer " + socket_id_to_session_id[socket.id] ) ; }
+		
 		if( socket_id_to_session_id[socket.id] in collaborations ) {
-		for( var i=0 ; i<collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'].length ; i++ ) {
+			for( var i=0 ; i<collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'].length ; i++ ) {
-		socket.emit( collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'][i][0], collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'][i][1] ) ;
+				socket.emit( collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'][i][0], collaborations[socket_id_to_session_id[socket.id]]['cached_instructions'][i][1] ) ;
-		}
+			}
 		} else {
-		if( verbose ) { console.log( "WARNING: could not tie socket_id to any collaboration" ) ; }
+			if( verbose ) { console.log( "WARNING: could not tie socket_id to any collaboration" ) ; }
 		}
 		socket.emit( "buffer_dumped" ) ;
 	});
@@ -128,20 +137,20 @@ io.sockets.on('connection', function(socket) {
 		console.log( socket_id_to_session_id[socket.id] + " disconnected" ) ;
 		var found_and_removed = false ;
 		if( socket_id_to_session_id[socket.id] in collaborations ) {
-		//var index = collaborations[socket_id_to_session_id[socket.id]].participants.indexOf( socket.id ) ;
+			//var index = collaborations[socket_id_to_session_id[socket.id]].participants.indexOf( socket.id ) ;
-		var index = collaborations[socket_id_to_session_id[socket.id]]['participants'].indexOf( socket.id ) ;
+			var index = collaborations[socket_id_to_session_id[socket.id]]['participants'].indexOf( socket.id ) ;
-		if( index>-1 ) {
+			if( index>-1 ) {
-		//collaborations[socket_id_to_session_id[socket.id]].participants.splice( index, 1 ) ;
+				//collaborations[socket_id_to_session_id[socket.id]].participants.splice( index, 1 ) ;
-		collaborations[socket_id_to_session_id[socket.id]]['participants'].splice( index, 1 ) ;
+				collaborations[socket_id_to_session_id[socket.id]]['participants'].splice( index, 1 ) ;
-		found_and_removed = true ;
+				found_and_removed = true ;
-		//if( collaborations[socket_id_to_session_id[socket.id]].participants.length==0 ) {
+				//if( collaborations[socket_id_to_session_id[socket.id]].participants.length==0 ) {
-		if( collaborations[socket_id_to_session_id[socket.id]]['participants'].length==0 ) {
+				if( collaborations[socket_id_to_session_id[socket.id]]['participants'].length==0 ) {
-		if( verbose ) { console.log( "last participant in collaboration, committing to disk & removing from memory" ) ; }
+					if( verbose ) { console.log( "last participant in collaboration, committing to disk & removing from memory" ) ; }
-		// no one is left in this session, we commit it to disk & remove it from memory
+						// no one is left in this session, we commit it to disk & remove it from memory
-		write_file( session_directory + "/" + socket_id_to_session_id[socket.id], JSON.stringify(collaborations[socket_id_to_session_id[socket.id]]['cached_instructions']) ) ;
+						write_file( session_directory + "/" + socket_id_to_session_id[socket.id], JSON.stringify(collaborations[socket_id_to_session_id[socket.id]]['cached_instructions']) ) ;
-		delete collaborations[socket_id_to_session_id[socket.id]] ;
+						delete collaborations[socket_id_to_session_id[socket.id]] ;
-		}
+					}
-		}
+			}
 		}
 		if( !found_and_removed ) {
 		console.log( "WARNING: could not tie socket_id to any collaboration" ) ;
@@ -163,34 +172,34 @@ io.sockets.on('connection', function(socket) {
 
 
 function write_file( path, data ) {
-try {
+	try {
-fs.writeFileSync( path, data ) ;
+		fs.writeFileSync( path, data ) ;
-return true ;
+		return true ;
-} catch( e ) {
+	} catch( e ) {
-return false ;
+		return false ;
-}
+	}
 }
 
 
 function read_file( path ) {
-try {
+	try {
-var data = fs.readFileSync( path ) ;
+		var data = fs.readFileSync( path ) ;
-return data ;
+		return data ;
-} catch( e ) {
+	} catch( e ) {
-return false
+		return false
-}
+	}
 }
 
 
 function file_exists( path ) {
-try {
+	try {
-stats = fs.lstatSync( path ) ;
+		stats = fs.lstatSync( path ) ;
-if (stats.isFile()) {
+		if (stats.isFile()) {
-return true ;
+			return true ;
-}
+		}
-} catch( e ) {
+	} catch( e ) {
-return false ;
+		return false ;
-}
+	}
-// we should not reach that point
+	// we should not reach that point
-return false ;
+	return false ;
 }