Improve the export process:

 - Exports are now threaded, allowing use of other windows during the export, and can be cancelled (which deletes the partially written export file) including use of the new query cancellation support.
 - Correct the text of XML exports and improve progress feedback for XML exports.
 - Fix .dot export of tables including foreign keys to use the new foreign key formats.

2 files changed, 114 insertions, 47 deletions

diff --git a/Source/TableDump.h b/Source/TableDump.h
index a9831c41..d0f4d336 100644
--- a/Source/TableDump.h
+++ b/Source/TableDump.h
@@ -118,6 +118,7 @@
 - (void)export;
 - (void)exportFile:(int)tag;
 - (void)savePanelDidEnd:(NSSavePanel *)sheet returnCode:(int)returnCode contextInfo:(NSString *)contextInfo;
+- (void)exportBackgroundProcess:(NSDictionary *)exportAction;
 
 // Import methods
 - (void)importFile;
diff --git a/Source/TableDump.m b/Source/TableDump.m
index 90c27a42..222612b5 100644
--- a/Source/TableDump.m
+++ b/Source/TableDump.m
@@ -235,31 +235,54 @@
 					   didEndSelector:@selector(savePanelDidEnd:returnCode:contextInfo:) contextInfo:contextInfo];
 }
 
-/*
- Save the export file; open a file handle, pass it to the appropriate data-writing function for streaming the export, and close the handle.
+/**
+ * When the export "Save" dialog is closed, fire up a background thread to perform
+ * the requested export.
  */
 - (void)savePanelDidEnd:(NSSavePanel *)sheet returnCode:(int)returnCode contextInfo:(NSString *)contextInfo
 {
-	NSFileHandle *fileHandle = nil;
-	BOOL success;
-	
 	[sheet orderOut:self];
 	
 	if ( returnCode != NSOKButton )
 		return;
 	
+	// Save path to preferences
+	[prefs setObject:[sheet directory] forKey:@"savePath"];
+
+	// Set up the details required for the export and pass them into a new worker thread
+	NSDictionary *exportProcessDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
+												contextInfo, @"action",
+												[sheet filename], @"filename",
+												nil];
+	[NSThread detachNewThreadSelector:@selector(exportBackgroundProcess:) toTarget:self withObject:exportProcessDictionary];
+}
+
+/**
+ * Save the export file in a background thread; open a file handle, pass it in to
+ * the appropriate data-writing function for streaming the export data to, and
+ * close the handle.
+ */
+- (void)exportBackgroundProcess:(NSDictionary *)exportAction
+{
+	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+	NSString *exportActionName = [exportAction objectForKey:@"action"];
+	NSString *exportFile = [exportAction objectForKey:@"filename"];
+	NSFileHandle *fileHandle = nil;
+	BOOL success;	
+
 	// Start the notification timer to allow notifications to be shown even if frontmost for long queries
 	[[SPGrowlController sharedGrowlController] setVisibilityForNotificationName:@"Export Finished"];
 
-	// Save path to preferences
-	[prefs setObject:[sheet directory] forKey:@"savePath"];
+	// Reset the progress cancelled boolean
+	progressCancelled = NO;
 	
 	// Error if the file already exists and is not writable, and get a fileHandle to it.
-	if ( [[NSFileManager defaultManager] fileExistsAtPath:[sheet filename]] ) {
-		if ( ![[NSFileManager defaultManager] isWritableFileAtPath:[sheet filename]]
-			|| !(fileHandle = [NSFileHandle fileHandleForWritingAtPath:[sheet filename]]) ) {
+	if ( [[NSFileManager defaultManager] fileExistsAtPath:exportFile] ) {
+		if ( ![[NSFileManager defaultManager] isWritableFileAtPath:exportFile]
+			|| !(fileHandle = [NSFileHandle fileHandleForWritingAtPath:exportFile]) ) {
 			NSBeginAlertSheet(NSLocalizedString(@"Error", @"error"), NSLocalizedString(@"OK", @"OK button"), nil, nil, tableWindow, self, nil, nil, nil,
 							  NSLocalizedString(@"Couldn't replace the file. Be sure that you have the necessary privileges.", @"message of panel when file cannot be replaced"));
+			[pool release];
 			return;
 		}
 		
@@ -268,37 +291,39 @@
 		
 		// Otherwise attempt to create a file
 	} else {
-		if ( ![[NSFileManager defaultManager] createFileAtPath:[sheet filename] contents:[NSData data] attributes:nil] ) {
+		if ( ![[NSFileManager defaultManager] createFileAtPath:exportFile contents:[NSData data] attributes:nil] ) {
 			NSBeginAlertSheet(NSLocalizedString(@"Error", @"error"), NSLocalizedString(@"OK", @"OK button"), nil, nil, tableWindow, self, nil, nil, nil,
 							  NSLocalizedString(@"Couldn't write to file. Be sure that you have the necessary privileges.", @"message of panel when file cannot be written"));
+			[pool release];
 			return;
 		}
 		
 		// Retrieve a filehandle for the file, attempting to delete it on failure.
-		fileHandle = [NSFileHandle fileHandleForWritingAtPath:[sheet filename]];
+		fileHandle = [NSFileHandle fileHandleForWritingAtPath:exportFile];
 		if ( !fileHandle ) {
-			[[NSFileManager defaultManager] removeFileAtPath:[sheet filename] handler:nil];
+			[[NSFileManager defaultManager] removeFileAtPath:exportFile handler:nil];
 			NSBeginAlertSheet(NSLocalizedString(@"Error", @"error"), NSLocalizedString(@"OK", @"OK button"), nil, nil, tableWindow, self, nil, nil, nil,
 							  NSLocalizedString(@"Couldn't write to file. Be sure that you have the necessary privileges.", @"message of panel when file cannot be written"));
+			[pool release];
 			return;
 		}
 	}
 	
 	// Export the tables selected in the MySQL export sheet to a file
-	if ( [contextInfo isEqualToString:@"exportDump"] ) {
+	if ( [exportActionName isEqualToString:@"exportDump"] ) {
 		success = [self dumpSelectedTablesAsSqlToFileHandle:fileHandle];
 		
 		// Export the full resultset for the currently selected table to a file in CSV format
-	} else if ( [contextInfo isEqualToString:@"exportTableContentAsCSV"] ) {
+	} else if ( [exportActionName isEqualToString:@"exportTableContentAsCSV"] ) {
 		success = [self exportTables:[NSArray arrayWithObject:[tableDocumentInstance table]] toFileHandle:fileHandle usingFormat:@"csv" usingMulti:NO];
 		
 		// Export the full resultset for the currently selected table to a file in XML format
-	} else if ( [contextInfo isEqualToString:@"exportTableContentAsXML"] ) {
+	} else if ( [exportActionName isEqualToString:@"exportTableContentAsXML"] ) {
 		success = [self exportTables:[NSArray arrayWithObject:[tableDocumentInstance table]] toFileHandle:fileHandle usingFormat:@"xml" usingMulti:NO];
 		
 	// Export the current "browse" view to a file in CSV or XML format
-	} else if ( [contextInfo isEqualToString:@"exportBrowseViewAsCSV"]
-				|| [contextInfo isEqualToString:@"exportBrowseViewAsXML"] )
+	} else if ( [exportActionName isEqualToString:@"exportBrowseViewAsCSV"]
+				|| [exportActionName isEqualToString:@"exportBrowseViewAsXML"] )
 	{
 
 		// Start an indeterminate progress sheet, as getting the current result set can take a significant period of time
@@ -307,11 +332,12 @@
 		[singleProgressBar setUsesThreadedAnimation:YES];
 		[singleProgressBar setIndeterminate:YES];
 		[NSApp beginSheet:singleProgressSheet modalForWindow:tableWindow modalDelegate:self didEndSelector:nil contextInfo:nil];
+		[singleProgressSheet makeKeyWindow];
 
 		[singleProgressBar startAnimation:self];		
 		NSArray *contentViewArray = [tableContentInstance currentResult];
 
-		if ( [contextInfo isEqualToString:@"exportBrowseViewAsCSV"] ) {
+		if ( [exportActionName isEqualToString:@"exportBrowseViewAsCSV"] ) {
 			success = [self writeCsvForArray:contentViewArray orStreamingResult:nil
 								toFileHandle:fileHandle
 							outputFieldNames:[exportFieldNamesSwitch state]
@@ -335,21 +361,26 @@
 		[self closeAndStopProgressSheet];
 		
 	// Export the current custom query result set to a file in CSV or XML format
-	} else if ( [contextInfo isEqualToString:@"exportCustomResultAsCSV"]
-				|| [contextInfo isEqualToString:@"exportCustomResultAsXML"] )
+	} else if ( [exportActionName isEqualToString:@"exportCustomResultAsCSV"]
+				|| [exportActionName isEqualToString:@"exportCustomResultAsXML"] )
 	{
 
 		// Start an indeterminate progress sheet, as getting the current result set can take a significant period of time
-		[singleProgressTitle setStringValue:[NSString stringWithFormat:NSLocalizedString(@"Exporting custom query view to CSV", @"title showing that application is saving custom query view as CSV")]];
+		if ([exportActionName isEqualToString:@"exportCustomResultAsCSV"]) {
+			[singleProgressTitle setStringValue:[NSString stringWithFormat:NSLocalizedString(@"Exporting custom query view to CSV", @"title showing that application is saving custom query view as CSV")]];
+		} else {
+			[singleProgressTitle setStringValue:[NSString stringWithFormat:NSLocalizedString(@"Exporting custom query view to XML", @"title showing that application is saving custom query view as XML")]];
+		}
 		[singleProgressText setStringValue:NSLocalizedString(@"Exporting data...", @"text showing that app is preparing data")];
 		[singleProgressBar setUsesThreadedAnimation:YES];
 		[singleProgressBar setIndeterminate:YES];
 		[NSApp beginSheet:singleProgressSheet modalForWindow:tableWindow modalDelegate:self didEndSelector:nil contextInfo:nil];
+		[singleProgressSheet makeKeyWindow];
 
 		[singleProgressBar startAnimation:self];
 		NSArray *customQueryViewArray = [customQueryInstance currentResult];
 
-		if ( [contextInfo isEqualToString:@"exportCustomResultAsCSV"] ) {
+		if ( [exportActionName isEqualToString:@"exportCustomResultAsCSV"] ) {
 			success = [self writeCsvForArray:customQueryViewArray orStreamingResult:nil
 								toFileHandle:fileHandle
 							outputFieldNames:[exportFieldNamesSwitch state]
@@ -373,39 +404,44 @@
 		[self closeAndStopProgressSheet];
 
 		// Export multiple tables to a file in CSV format
-	} else if ( [contextInfo isEqualToString:@"exportMultipleTablesAsCSV"] ) {
+	} else if ( [exportActionName isEqualToString:@"exportMultipleTablesAsCSV"] ) {
 		success = [self exportSelectedTablesToFileHandle:fileHandle usingFormat:@"csv"];
 		
 		// Export multiple tables to a file in XML format
-	} else if ( [contextInfo isEqualToString:@"exportMultipleTablesAsXML"] ) {
+	} else if ( [exportActionName isEqualToString:@"exportMultipleTablesAsXML"] ) {
 		success = [self exportSelectedTablesToFileHandle:fileHandle usingFormat:@"xml"];
 		
 		// Export the tables selected in the MySQL export sheet to a file
-	} else if ( [contextInfo isEqualToString:@"exportDot"] ) {
+	} else if ( [exportActionName isEqualToString:@"exportDot"] ) {
 			success = [self dumpSchemaAsDotToFileHandle:fileHandle];
 			
 		// Unknown operation
 	} else {
-		ALog(@"Unknown export operation: %@", [contextInfo description]);
+		ALog(@"Unknown export operation: %@", [exportActionName description]);
+		[pool release];
 		return;
 	}
 	
 	// Close the file handle
 	[fileHandle closeFile];
-	
-	if ( !success ) {
+
+	// If progress was cancelled, remove the file
+	if (progressCancelled) {
+		[[NSFileManager defaultManager] removeItemAtPath:exportFile error:nil];
+	}
+
+	// Display error message on problems
+	if ( !progressCancelled && !success ) {
 		NSBeginAlertSheet(NSLocalizedString(@"Error", @"error"), NSLocalizedString(@"OK", @"OK button"), nil, nil, tableWindow, self, nil, nil, nil,
 						  NSLocalizedString(@"Couldn't write to file. Be sure that you have the necessary privileges.", @"message of panel when file cannot be written"));
 	}
-    if (progressCancelled)
-	{
-		progressCancelled = NO;
-	}
+
     // Export finished Growl notification
     [[SPGrowlController sharedGrowlController] notifyWithTitle:@"Export Finished" 
-                                                   description:[NSString stringWithFormat:NSLocalizedString(@"Finished exporting to %@",@"description for finished exporting growl notification"), [[sheet filename] lastPathComponent]] 
+                                                   description:[NSString stringWithFormat:NSLocalizedString(@"Finished exporting to %@",@"description for finished exporting growl notification"), [exportFile lastPathComponent]] 
 														window:tableWindow
                                               notificationName:@"Export Finished"];
+	[pool release];
 }
 
 #pragma mark -
@@ -1310,6 +1346,7 @@
 	[NSApp beginSheet:singleProgressSheet
 	   modalForWindow:tableWindow modalDelegate:self
 	   didEndSelector:nil contextInfo:nil];
+	[singleProgressSheet makeKeyWindow];
 
 	[tableDocumentInstance setQueryMode:SPImportExportQueryMode];
 
@@ -1360,6 +1397,7 @@
 	
 	// Loop through the selected tables
 	for ( i = 0 ; i < [selectedTables count] ; i++ ) {
+		if (progressCancelled) break;
 		lastProgressValue = 0;
 		
 		// Update the progress text and reset the progress bar to indeterminate status while fetching data
@@ -1461,6 +1499,11 @@
 				j = 0;
 				exportAutoReleasePool = [[NSAutoreleasePool alloc] init];
 				while (theRow = [streamingResult fetchNextRowAsArray]) {
+					if (progressCancelled) {
+						[mySQLConnection cancelCurrentQuery];
+						[streamingResult cancelResultLoad];
+						break;
+					}
 					j++;
 					[sqlString setString:@""];
 					
@@ -1533,7 +1576,7 @@
 					// Write this row to the file
 					[fileHandle writeData:[sqlString dataUsingEncoding:NSUTF8StringEncoding]];
 				}
-				
+
 				// Complete the command
 				[fileHandle writeData:[[NSString stringWithString:@";\n\n"] dataUsingEncoding:NSUTF8StringEncoding]];
 
@@ -1542,7 +1585,7 @@
 				[metaString appendString:[NSString stringWithFormat:@"/*!40000 ALTER TABLE %@ ENABLE KEYS */;\n", [tableName backtickQuotedString]]];
 				[metaString appendString:@"UNLOCK TABLES;\n"];
 				[fileHandle writeData:[metaString dataUsingEncoding:NSUTF8StringEncoding]];
-				
+
 				if ( ![[mySQLConnection getLastErrorMessage] isEqualToString:@""] ) {
 					[errors appendString:[NSString stringWithFormat:@"%@\n", [mySQLConnection getLastErrorMessage]]];
 					if ( [addErrorsSwitch state] == NSOnState ) {
@@ -1558,11 +1601,11 @@
 			// Release the result set
 			[streamingResult release];
 		}
-		
+
 		// Add an additional separator between tables
 		[fileHandle writeData:[[NSString stringWithString:@"\n\n"] dataUsingEncoding:NSUTF8StringEncoding]];
 	}
-	
+
 	// Process any deferred views, adding commands to delete the placeholder tables and add the actual views
 	viewSyntaxEnumerator = [viewSyntaxes keyEnumerator];
 	while (tableName = [viewSyntaxEnumerator nextObject]) {
@@ -1593,7 +1636,7 @@
 	 setConnectionEncoding:[NSString stringWithFormat:@"%@%@", previousConnectionEncoding, previousConnectionEncodingViaLatin1?@"-":@""]
 	 reloadingViews:NO];
 	[previousConnectionEncoding release];
-	
+
 	// Close the progress sheet
 	[self closeAndStopProgressSheet];
 
@@ -1638,6 +1681,7 @@
 	[NSApp beginSheet:singleProgressSheet
 	   modalForWindow:tableWindow modalDelegate:self
 	   didEndSelector:nil contextInfo:nil];
+	[singleProgressSheet makeKeyWindow];
 		
 	[metaString setString:@"// Generated by: Sequel Pro\n"];
 	[metaString appendString:[NSString stringWithFormat:@"// Version %@\n",
@@ -1670,6 +1714,7 @@
 	
 	// tables here
 	for ( int i = 0 ; i < [tables count] ; i++ ) {
+		if (progressCancelled) break;
 
 		NSString *tableName = [[tables objectAtIndex:i] objectAtIndex:1];
 		NSDictionary *tinfo = [tableDataInstance informationForTable:tableName];
@@ -1705,15 +1750,18 @@
 		// see about relations
 		cinfo = [tinfo objectForKey:@"constraints"];
 		for( int j = 0; j < [cinfo count]; j++ ) {
-			// get the column refs. these can be comma separated.
-			NSString *ccol = [NSArrayObjectAtIndex(cinfo, j) objectForKey:@"columns"];
+			if (progressCancelled) break;
+
+			// Get the column references.  Currently the columns themselves are an array,
+			// while reference columns and tables are comma separated if there are more than
+			// one.  Only use the first of each for the time being.
+			NSArray *ccols = [NSArrayObjectAtIndex(cinfo, j) objectForKey:@"columns"];
+			NSString *ccol = NSArrayObjectAtIndex(ccols, 0);
 			NSString *rcol = [NSArrayObjectAtIndex(cinfo, j) objectForKey:@"ref_columns"];
 			NSString *extra = @"";
-			NSArray *tc = [ccol componentsSeparatedByString:@","];
-			if( [tc count] > 1 ) {
+			if( [ccols count] > 1 ) {
 				extra = @" [ arrowhead=crow, arrowtail=odiamond ]";
-				ccol = NSArrayObjectAtIndex(tc, 0);
-				rcol = NSArrayObjectAtIndex([ccol componentsSeparatedByString:@","], 0);
+				rcol = NSArrayObjectAtIndex([rcol componentsSeparatedByString:@","], 0);
 			}
 			[fkInfo addObject:[NSString stringWithFormat:@"%@:%@ -> %@:%@ %@",
 							   tableName,
@@ -1842,6 +1890,7 @@
 		[NSApp beginSheet:singleProgressSheet
 		   modalForWindow:tableWindow modalDelegate:self
 		   didEndSelector:nil contextInfo:nil];
+		[singleProgressSheet makeKeyWindow];
 	}
 	
 	// Set up escaped versions of strings for substitution within the loop
@@ -1861,6 +1910,13 @@
 	csvExportPool = [[NSAutoreleasePool alloc] init];
 	currentPoolDataLength = 0;
 	while (1) {
+		if (progressCancelled) {
+			if (streamingResult) {
+				[mySQLConnection cancelCurrentQuery];
+				[streamingResult cancelResultLoad];
+			}
+			break;
+		}
 
 		// Retrieve the next row from the supplied data, either directly from the array...
 		if (array) {
@@ -2037,6 +2093,7 @@
 	// Updating the progress bar can take >20% of processing time - store details to only update when required
 	progressBarWidth = (int)[singleProgressBar bounds].size.width;
 	lastProgressValue = 0;
+	[singleProgressBar setIndeterminate:NO];
 	[singleProgressBar setMaxValue:progressBarWidth];
 	[singleProgressBar setDoubleValue:0];
 	[singleProgressBar displayIfNeeded];
@@ -2065,6 +2122,7 @@
 		[NSApp beginSheet:singleProgressSheet
 		   modalForWindow:tableWindow modalDelegate:self
 		   didEndSelector:nil contextInfo:nil];
+		[singleProgressSheet makeKeyWindow];
 	}
 	
 	// Output the XML header if required
@@ -2097,6 +2155,13 @@
 	xmlExportPool = [[NSAutoreleasePool alloc] init];
 	currentPoolDataLength = 0;
 	while (1) {
+		if (progressCancelled) {
+			if (streamingResult) {
+				[mySQLConnection cancelCurrentQuery];
+				[streamingResult cancelResultLoad];
+			}
+			break;
+		}
 
 		// Retrieve the next row from the supplied data, either directly from the array...
 		if (array) {
@@ -2229,8 +2294,8 @@
 	[NSApp beginSheet:singleProgressSheet
 	   modalForWindow:tableWindow modalDelegate:self
 	   didEndSelector:nil contextInfo:nil];
-	
-	
+	[singleProgressSheet makeKeyWindow];	
+
 	// Add a dump header to the dump file, dependant on export type.
 	if ( [type isEqualToString:@"csv"] ) {
 		csvLineEnd = [NSMutableString stringWithString:[exportMultipleLinesTerminatedField stringValue]]; 
@@ -2266,6 +2331,7 @@
 	
 	// Loop through the selected tables
 	for ( i = 0 ; i < [selectedTables count] && !progressCancelled; i++ ) {
+		if (progressCancelled) break;
 		
 		// Update the progress text and reset the progress bar to indeterminate status
 		tableName = [selectedTables objectAtIndex:i];