diff options
Diffstat (limited to 'Source/CMMCPConnection.m')
| -rw-r--r-- | Source/CMMCPConnection.m | 330 |
1 files changed, 312 insertions, 18 deletions
diff --git a/Source/CMMCPConnection.m b/Source/CMMCPConnection.m index 8d4e2673..20f5ba11 100644 --- a/Source/CMMCPConnection.m +++ b/Source/CMMCPConnection.m @@ -23,10 +23,191 @@ // Or mail to <lorenz@textor.ch> #import "CMMCPConnection.h" +#include <unistd.h> +#include <setjmp.h> +static jmp_buf pingTimeoutJumpLocation; +static void forcePingTimeout(int signalNumber); @implementation CMMCPConnection + +/* + * Override the normal init methods, extending them to also init additional details. + */ +- (id) init +{ + [self initSPExtensions]; + self = [super init]; + return self; +} +- (id) initToHost:(NSString *) host withLogin:(NSString *) login password:(NSString *) pass usingPort:(int) port +{ + [self initSPExtensions]; + self = [super initToHost:host withLogin:login password:pass usingPort:port]; + return self; +} +- (id) initToSocket:(NSString *) socket withLogin:(NSString *) login password:(NSString *) pass +{ + [self initSPExtensions]; + self = [super initToSocket:socket withLogin:login password:pass]; + return self; +} + + +/* + * Instantiate extra variables and load the connection error dialog for potential use. + */ +- (void) initSPExtensions +{ + parentWindow = nil; + connectionLogin = nil; + connectionPassword = nil; + connectionHost = nil; + connectionPort = 0; + connectionSocket = nil; + [NSBundle loadNibNamed:@"ConnectionErrorDialog" owner:self]; +} + + +/* + * Override the normal connection method, extending it to also store details of the + * current connection to allow reconnection as necessary. This also sets the connection timeout + * - used for pings, not for long-running commands. + */ +- (BOOL) connectWithLogin:(NSString *) login password:(NSString *) pass host:(NSString *) host port:(int) port socket:(NSString *) socket +{ + if (connectionLogin) [connectionLogin release]; + if (login) connectionLogin = [[NSString alloc] initWithString:login]; + if (connectionPassword) [connectionPassword release]; + if (pass) connectionPassword = [[NSString alloc] initWithString:pass]; + if (connectionHost) [connectionHost release]; + if (host) connectionHost = [[NSString alloc] initWithString:host]; + connectionPort = port; + if (connectionSocket) [connectionSocket release]; + if (socket) connectionSocket = [[NSString alloc] initWithString:socket]; + + if (mConnection != NULL) { + unsigned int connectionTimeout = SP_CONNECTION_TIMEOUT; + mysql_options(mConnection, MYSQL_OPT_CONNECT_TIMEOUT, (const void *)&connectionTimeout); + } + + return [super connectWithLogin:login password:pass host:host port:port socket:socket]; +} + + +/* + * Override the stored disconnection method to ensure that disconnecting clears stored details. + */ +- (void) disconnect +{ + [super disconnect]; + + if (connectionLogin) [connectionLogin release]; + connectionLogin = nil; + if (connectionPassword) [connectionPassword release]; + connectionPassword = nil; + if (connectionHost) [connectionHost release]; + connectionHost = nil; + connectionPort = 0; + if (connectionSocket) [connectionSocket release]; + connectionSocket = nil; +} + + +/* + * Reconnect to the currently "active" - but possibly disconnected - connection, using the + * stored details. + * Error checks extensively - if this method fails, it will ask how to proceed and loop depending + * on the status, not returning control until either a connection has been established or + * the connection and document have been closed. + */ +- (BOOL) reconnect +{ + NSString *currentEncoding = nil; + NSString *currentDatabase = nil; + + // Store the current database and encoding so they can be re-set if reconnection was successful + if (delegate && [delegate valueForKey:@"selectedDatabase"]) { + currentDatabase = [NSString stringWithString:[delegate valueForKey:@"selectedDatabase"]]; + } + if (delegate && [delegate valueForKey:@"_encoding"]) { + currentEncoding = [NSString stringWithString:[delegate valueForKey:@"_encoding"]]; + } + + // Close the connection if it exists. + if (mConnected) { + mysql_close(mConnection); + mConnection = NULL; + } + mConnected = NO; + + // Attempt to reinitialise the connection - if this fails, it will still be set to NULL. + if (mConnection == NULL) { + mConnection = mysql_init(NULL); + } + + if (mConnection != NULL) { + + // Set a connection timeout for the new connection + unsigned int connectionTimeout = SP_CONNECTION_TIMEOUT; + mysql_options(mConnection, MYSQL_OPT_CONNECT_TIMEOUT, (const void *)&connectionTimeout); + + // Attempt to reestablish the connection - using own method so everything gets set up as standard. + // Will store the supplied details again, which isn't a problem. + [self connectWithLogin:connectionLogin password:connectionPassword host:connectionHost port:connectionPort socket:connectionSocket]; + } + + // If the connection was successfully established, reselect the old database and encoding if appropriate. + if (mConnected) { + if (currentDatabase) { + [self selectDB:currentDatabase]; + } + if (currentEncoding) { + [self queryString:[NSString stringWithFormat:@"SET NAMES '%@'", currentEncoding]]; + [self setEncoding:[CMMCPConnection encodingForMySQLEncoding:[currentEncoding UTF8String]]]; + } + } else if (parentWindow) { + + // If the connection was not successfully established, ask how to proceed. + [NSApp beginSheet:connectionErrorDialog modalForWindow:parentWindow modalDelegate:self didEndSelector:nil contextInfo:nil]; + int connectionErrorCode = [NSApp runModalForWindow:connectionErrorDialog]; + [NSApp endSheet:connectionErrorDialog]; + [connectionErrorDialog orderOut:nil]; + + switch (connectionErrorCode) { + + // Should disconnect + case 2: + [parentWindow close]; + return NO; + + // Should retry + default: + return [self reconnect]; + } + } + + return mConnected; +} + + +/* + * Set the parent window of the connection for use with dialogs. + */ +- (void)setParentWindow:(NSWindow *)theWindow { + parentWindow = theWindow; +} + + +/* + * Ends and existing modal session + */ +- (IBAction) closeSheet:(id)sender +{ + [NSApp stopModalWithCode:[sender tag]]; +} + /* Gets a proper NSStringEncoding according to the given MySQL charset. @@ -92,7 +273,7 @@ WARNING : incomplete implementation. Please, send your fixes. if (!strncmp(mysqlEncoding, "sjis", 4)) { return NSShiftJISStringEncoding; } - + // default to iso latin 1, even if it is not exact (throw an exception?) NSLog(@"warning: unknown encoding %s! falling back to latin1.", mysqlEncoding); return NSISOLatin1StringEncoding; @@ -101,7 +282,10 @@ WARNING : incomplete implementation. Please, send your fixes. /* - modified version of queryString to be used in sequel-pro + * Modified version of queryString to be used in Sequel Pro. + * Error checks extensively - if this method fails, it will ask how to proceed and loop depending + * on the status, not returning control until either the query has been executed and the result can + * be returned or the connection and document have been closed. */ - (CMMCPResult *)queryString:(NSString *) query { @@ -109,30 +293,29 @@ WARNING : incomplete implementation. Please, send your fixes. const char *theCQuery = [self cStringFromString:query]; int theQueryCode; - // check connection - if (![self checkConnection]) { - NSLog(@"Connection was gone, but should be reestablished now!"); - } + // If no connection is present, return nil. + if (!mConnected) return nil; + + // Check the connection. This triggers reconnects as necessary, and should only return false if a disconnection + // has been requested - in which case return nil + if (![self checkConnection]) return nil; - // inform the delegate about the query + // Inform the delegate about the query if (delegate && [delegate respondsToSelector:@selector(willQueryString:)]) { [delegate willQueryString:query]; } if (0 == (theQueryCode = mysql_query(mConnection, theCQuery))) { if (mysql_field_count(mConnection) != 0) { - // use CMMCPResult instad of MCPResult + + // Use CMMCPResult instad of MCPResult theResult = [[CMMCPResult alloc] initWithMySQLPtr:mConnection encoding:mEncoding timeZone:mTimeZone]; } else { return nil; } } else { -// NSLog (@"Problem in queryString error code is : %d, query is : %s -in ObjC : %@-\n", theQueryCode, theCQuery, query); -// NSLog(@"Error message is : %@\n", [self getLastErrorMessage]); -// theResult = [theResult init]; // Old version... -// theResult = nil; - - // inform the delegate about errors + + // Inform the delegate about errors if (delegate && [delegate respondsToSelector:@selector(queryGaveError:)]) { [delegate queryGaveError:[self getLastErrorMessage]]; } @@ -142,6 +325,50 @@ WARNING : incomplete implementation. Please, send your fixes. return [theResult autorelease]; } +static void sigalarm(int segnum) { + NSLog(@"BOOOOYAAAAA"); +} +/* + * Checks whether the connection to the server is still active. If not, prompts for what approach to take, + * offering to retry, reconnect or disconnect the connection. + */ +- (BOOL)checkConnection +{ + if (!mConnected) return NO; + + BOOL connectionVerified = FALSE; + + // Check whether the connection is still operational via a wrapped version of MySQL ping. + connectionVerified = [self pingConnection]; + + // If the connection doesn't appear to be responding, show a dialog asking how to proceed + if (!connectionVerified) { + [NSApp beginSheet:connectionErrorDialog modalForWindow:parentWindow modalDelegate:self didEndSelector:nil contextInfo:nil]; + int responseCode = [NSApp runModalForWindow:connectionErrorDialog]; + [NSApp endSheet:connectionErrorDialog]; + [connectionErrorDialog orderOut:nil]; + + switch (responseCode) { + + // "Reconnect" has been selected. Request a reconnect, and retry. + case 1: + [self reconnect]; + return [self checkConnection]; + + // "Disconnect" has been selected. Close the parent window, which will handle disconnections, and return false. + case 2: + [parentWindow close]; + return FALSE; + + // "Retry" has been selected - return a recursive call. + default: + return [self checkConnection]; + } + } + + return connectionVerified; +} + - (void)setDelegate:(id)object { delegate = object; @@ -156,7 +383,7 @@ WARNING : incomplete implementation. Please, send your fixes. NSArray *theRow; id theTZName; NSTimeZone *theTZ; - + [theSessionTZ dataSeek:1ULL]; theRow = [theSessionTZ fetchRowAsArray]; theTZName = [theRow objectAtIndex:1]; @@ -176,7 +403,7 @@ WARNING : incomplete implementation. Please, send your fixes. theTZName = [self stringWithText:theTZName]; } } - + if (theTZName) { // Old versions of the server does not support there own time zone ? theTZ = [NSTimeZone timeZoneWithName:theTZName]; } else { @@ -195,7 +422,7 @@ WARNING : incomplete implementation. Please, send your fixes. NSLog(@"The time zone is not defined on the server, set it to the default one : %@", theTZ); } } - + if (theTZ != mTimeZone) { [mTimeZone release]; mTimeZone = [theTZ retain]; @@ -204,4 +431,71 @@ WARNING : incomplete implementation. Please, send your fixes. return mTimeZone; } -@end + +/* + * The current versions of MCPKit (and up to and including 3.0.1) use MySQL 4.1.12; this has an issue with + * mysql_ping where a connection which is terminated will cause mysql_ping never to respond, even when + * connection timeouts are set. Full details of this issue are available at http://bugs.mysql.com/bug.php?id=9678 ; + * this bug was fixed in 4.1.22 and later versions. + * This issue can be replicated by connecting to a remote host, and then configuring a firewall on that host + * to drop all packets on the connected port - mysql_ping and so Sequel Pro will hang. + * Until the client libraries are updated, this provides a drop-in wrapper for mysql_ping, which calls mysql_ping + * while running a SIGALRM to enforce the specified connection time. This is low-level but effective. + * Unlike mysql_ping, this function returns FALSE on failure and TRUE on success. + */ +- (BOOL) pingConnection +{ + struct sigaction timeoutAction; + NSDate *startDate = [NSDate date]; + BOOL pingSuccess = FALSE; + + // Construct the SIGALRM to fire after the connection timeout if it isn't cleared, calling the forcePingTimeout function. + timeoutAction.sa_handler = forcePingTimeout; + sigemptyset(&timeoutAction.sa_mask); + timeoutAction.sa_flags = 0; + sigaction(SIGALRM, &timeoutAction, NULL); + alarm(SP_CONNECTION_TIMEOUT+1); + + // Set up a "restore point", returning 0; if longjmp is used later with this reference, execution + // jumps back to this point and returns a nonzero value, so this function evaluates to false when initially + // set and true if it's called again. + if (setjmp(pingTimeoutJumpLocation)) { + + // The connection timed out - we want to return false. + pingSuccess = FALSE; + + // On direct execution: + } else { + + // Run mysql_ping, which returns 0 on success, and otherwise an error. + pingSuccess = (BOOL)(! mysql_ping(mConnection)); + + // If the ping failed within a second, try another one; this is because a terminated-but-then + // restored connection is at times restored or functional after a ping, but the ping still returns + // an error. This additional check ensures the returned status is correct with minimal other effect. + if (!pingSuccess && ([[NSDate date] timeIntervalSinceDate:startDate] < 1)) { + pingSuccess = (BOOL)(! mysql_ping(mConnection)); + } + } + + // Reset and clear the SIGALRM used to check connection timeouts. + alarm(0); + timeoutAction.sa_handler = SIG_IGN; + sigemptyset(&timeoutAction.sa_mask); + timeoutAction.sa_flags = 0; + sigaction(SIGALRM, &timeoutAction, NULL); + + + return pingSuccess; +} + +/* + * This function is paired with pingConnection, and provides a method of enforcing the connection + * timeout when mysql_ping does not respect the specified limits. + */ +static void forcePingTimeout(int signalNumber) +{ + longjmp(pingTimeoutJumpLocation, 1); +} + +@end
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