*************************** SDStoreDirectory.h **************************



@interface SDStoreDirectory:NSObject



{

    NSMutableDictionary *entries;

    SDStore *storeFile;

    BOOL dirty;

    int blockNumber;

}



- initInStore:(SDStore *)aStoreFile;

- (id) initFromBlock: (unsigned int) blockNo inStore: (SDStore *) aStoreFile ;

- (id) openEntryNamed: (NSString *)aName ;

- (BOOL) hasEntryNamed: (NSString *)aName ;

- (id) addEntryNamed: (NSString *)aName ofClass:(Class)aClass ;

- (void) freeEntryNamed: (NSString *)aName;

- (NSArray *) entries;

- (void) getBlock:(unsigned int *)aBlock andStore:(SDStore **)aStore;



- (void) commitTransaction;



@end





*************************** SDStoreDirectory.m **************************



#import "ixCover.h"



@interface SDStoreDirectory(PrivateMethods)



- (void)setStore:(SDStore *)aStore;



@end



@implementation SDStoreDirectory:NSObject



///////////////////////////////////////////////////////////////////////////

//

//      Utilities and private methods

//

///////////////////////////////////////////////////////////////////////////





- (BOOL) isDirty

{

    return dirty;

}



- (void) setDirty:(BOOL)flag

{

    dirty = flag;

}





///////////////////////////////////////////////////////////////////////////

//

//      Implementation:

//            NSDictionary to hold NSString (name) / NSEntry pairs

//            NSEntry holds information necessary to create or read in

//            an object

//

///////////////////////////////////////////////////////////////////////////



- initInStore:(SDStore *)aStore

{

    [super init];

    [self setStore:aStore];

    

    entries = [[NSMutableDictionary allocWithZone:[self zone]] initWithCapacity:1];

    [storeFile createBlock:&blockNumber withSize:0];

    

    return self;



}



- initFromBlock: (unsigned int)blockNo inStore: (SDStore *) aStoreFile 

{

    NSData *blockData;

    NSEnumerator *enumerator;

    SDEntry *anEntry;

    

    [super init];

    

    [self setStore:aStoreFile];

    blockNumber = blockNo;

    blockData = [storeFile readBlock:blockNumber];



    entries = [[NSUnarchiver unarchiveObjectWithData:blockData]retain];

    

    enumerator = [entries objectEnumerator];

    while ((anEntry = [enumerator nextObject])) {

        [anEntry setStoreFile:storeFile];

    }

    [self setDirty:NO];

    return self;

}



- (id) openEntryNamed: (NSString *)aName 

{

    SDEntry *theEntry = [entries objectForKey:aName];

    if (!theEntry) return nil;

    return [theEntry theObject];

}



- (BOOL) hasEntryNamed: (NSString *)aName 

{

    SDEntry *theEntry = [entries objectForKey:aName];

    return theEntry?YES:NO;

}



- (id) addEntryNamed: (NSString *)aName ofClass:(Class)aClass 

{

    SDEntry *theEntry;

    theEntry = [[SDEntry alloc] initWithName:aName class:aClass forStoreFile:storeFile];

    [entries setObject:theEntry forKey:aName];

    [self setDirty:YES];

    return [theEntry theObject];

}



- (void) freeEntryNamed: (NSString *)aName

{

    SDEntry *theEntry = [[entries objectForKey:aName] retain];

    // remove the entry

    [entries removeObjectForKey:aName];

    // remove the "block"

    [theEntry freeObjectFromBlock];

    [theEntry release];

    [self setDirty:YES];

}



- (void) commitTransaction

{

    NSData *data;



    if ([self isDirty]) {

        data = [NSArchiver archivedDataWithRootObject:entries];

        [storeFile writeData:data toBlock:blockNumber];

        [self setDirty:NO];

    }

}



- (NSArray *) entries

{

    return [entries allKeys];

}



- (void) getBlock:(unsigned int *)aBlock andStore:(SDStore **)aStore

{

    *aBlock = blockNumber;

    *aStore = storeFile;

}



+ (void) freeFromBlock:(unsigned int) aBlockNumber inStore:(SDStore *)aStoreFile

{

    [aStoreFile freeBlock:aBlockNumber];

}





- (void) freeFromStore

{

    [storeFile freeBlock:blockNumber];

}



- (void) commitTransaction:(NSNotification *)aNotification

{

    if ([aNotification object] == storeFile)

        [self commitTransaction];

}



- (void)registerForTransactions

{

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(commitTransaction:) name: SDStoreTransactionWasCommitted object:storeFile];

}



- (void) unregisterForTransactions

{

    [[NSNotificationCenter defaultCenter]removeObserver:self name:SDStoreTransactionWasCommitted object:storeFile];

}



- (void)setStore:(SDStore *)aStore

{

    storeFile = aStore;

    [self registerForTransactions];

}



- (void) dealloc

{

    [self unregisterForTransactions];

    [entries release];

    [super dealloc];

}



@end