marcoarment
diff --git a/‎FCModel/FCModel.h‎
Lines changed: 74 additions & 140 deletions b/‎FCModel/FCModel.h‎
Lines changed: 74 additions & 140 deletions
diff --git a/‎FCModel/FCModel.m‎
Lines changed: 505 additions & 901 deletions b/‎FCModel/FCModel.m‎
Lines changed: 505 additions & 901 deletions
diff --git a/‎FCModel/FCModelCachedObject.m‎
Lines changed: 6 additions & 3 deletions b/‎FCModel/FCModelCachedObject.m‎
Lines changed: 6 additions & 3 deletions
diff --git a/‎FCModel/FCModelDatabase.h‎
Lines changed: 28 additions & 0 deletions b/‎FCModel/FCModelDatabase.h‎
Lines changed: 28 additions & 0 deletions
diff --git a/‎FCModel/FCModelDatabase.m‎
Lines changed: 151 additions & 0 deletions b/‎FCModel/FCModelDatabase.m‎
Lines changed: 151 additions & 0 deletions
diff --git a/‎FCModel/FCModelDatabaseQueue.h‎
Lines changed: 0 additions & 32 deletions b/‎FCModel/FCModelDatabaseQueue.h‎
Lines changed: 0 additions & 32 deletions
diff --git a/‎FCModel/FCModelDatabaseQueue.m‎
Lines changed: 0 additions & 144 deletions b/‎FCModel/FCModelDatabaseQueue.m‎
Lines changed: 0 additions & 144 deletions
@@ -8,9 +8,13 @@
 #import "FCModelCachedObject.h"
 #import "FCModel.h"
 
+#if TARGET_OS_IPHONE
+#import <UIKit/UIKit.h>
+#endif
+
 // FCModelCachedObject has its own notification that runs BEFORE the other FCModel change notifications
 //  so it can remove stale data before any application actions fetch new data in response to the change.
-extern NSString * const FCModelWillSendAnyChangeNotification;
+extern NSString * const FCModelWillSendChangeNotification;
 
 #pragma mark - Global cache
 
@@ -123,8 +127,7 @@ + (instancetype)objectWithModelClass:(Class)fcModelClass cacheIdentifier:(id)ide
         obj.generator = generatorBlock;
         obj.ignoredFieldsForInvalidation = ignoredFields;
 
-        [NSNotificationCenter.defaultCenter addObserver:obj selector:@selector(dataSourceChanged:) name:FCModelWillReloadNotification object:fcModelClass];
-        [NSNotificationCenter.defaultCenter addObserver:obj selector:@selector(dataSourceChanged:) name:FCModelWillSendAnyChangeNotification object:fcModelClass];
+        [NSNotificationCenter.defaultCenter addObserver:obj selector:@selector(dataSourceChanged:) name:FCModelWillSendChangeNotification object:fcModelClass];
 
 #if TARGET_OS_IPHONE
         [NSNotificationCenter.defaultCenter addObserver:obj selector:@selector(flush:) name:UIApplicationDidReceiveMemoryWarningNotification object:nil];
 
@@ -0,0 +1,28 @@
+//
+//  FCModelDatabase.h
+//
+//  Created by Marco Arment on 3/12/14.
+//  Copyright (c) 2014 Marco Arment. See included LICENSE file.
+//
+
+#import <Foundation/Foundation.h>
+
+#ifdef COCOAPODS
+#import <FMDB/FMDatabase.h>
+#else
+#import "FMDatabase.h"
+#endif
+
+@interface FCModelDatabase : NSObject
+
+- (instancetype)initWithDatabasePath:(NSString *)filename;
+- (void)startMonitoringForExternalChanges;
+- (void)close;
+- (void)inDatabase:(void (^)(FMDatabase *db))block;
+
+@property (nonatomic, readonly) FMDatabase *database;
+@property (nonatomic, readonly) NSMutableDictionary *enqueuedChangedFieldsByClass;
+@property (nonatomic) BOOL isQueuingNotifications;
+@property (nonatomic) BOOL isInInternalWrite;
+
+@end
@@ -0,0 +1,151 @@
+//
+//  FCModelDatabase.m
+//
+//  Created by Marco Arment on 3/12/14.
+//  Copyright (c) 2014 Marco Arment. See included LICENSE file.
+//
+
+#import "FCModelDatabase.h"
+#import "FCModel.h"
+#import <sqlite3.h>
+
+@interface FCModel ()
++ (void)postChangeNotificationWithChangedFields:(NSSet *)changedFields;
++ (void)dataChangedExternally;
+@end
+
+@interface FCModelDatabase ()
+- (uint32_t)sqliteChangeCount;
+- (BOOL)sqliteChangeTrackingIsActive;
+@property (nonatomic) int32_t expectedChangeCount;
+@end
+
+#define kSQLiteFileChangeCounterOffset 24
+
+static void _sqlite3_update_hook(void *context, int sqlite_operation, char const *db_name, char const *table_name, sqlite3_int64 rowid)
+{
+    Class class = NSClassFromString([NSString stringWithCString:table_name encoding:NSUTF8StringEncoding]);
+    if (! class || ! [class isSubclassOfClass:FCModel.class]) return;
+
+    FCModelDatabase *queue = (__bridge FCModelDatabase *) context;
+    if (! queue.sqliteChangeTrackingIsActive) return;
+    queue.expectedChangeCount = [queue sqliteChangeCount] + 1;
+    if (queue.isInInternalWrite) return;
+
+    // Can't run synchronously since SQLite requires that no other database queries are executed before this function returns,
+    //  and queries are likely to be executed by any notification listeners.
+    if (queue.isQueuingNotifications) [class postChangeNotificationWithChangedFields:nil];
+    else dispatch_async(dispatch_get_main_queue(), ^{ [class postChangeNotificationWithChangedFields:nil]; });
+}
+
+@interface FCModelDatabase () {
+    int changeCounterReadFileDescriptor;
+    int dispatchEventFileDescriptor;
+    dispatch_source_t dispatchFileWriteSource;
+}
+@property (nonatomic) FMDatabase *openDatabase;
+@property (nonatomic) NSString *path;
+@property (nonatomic) NSMutableDictionary *enqueuedChangedFieldsByClass;
+@property (nonatomic) BOOL inExpectedWrite;
+@end
+
+@implementation FCModelDatabase
+
+- (instancetype)initWithDatabasePath:(NSString *)path
+{
+    if ( (self = [super init]) ) {
+        self.path = path;
+        self.enqueuedChangedFieldsByClass = [NSMutableDictionary dictionary];
+    }
+    return self;
+}
+
+- (FMDatabase *)database
+{
+    if (! _openDatabase) fcm_onMainThread(^{
+        self.openDatabase = [[FMDatabase alloc] initWithPath:_path];
+        if (! [_openDatabase open]) {
+            [[NSException exceptionWithName:NSGenericException reason:[NSString stringWithFormat:@"Cannot open or create database at path: %@", self.path] userInfo:nil] raise];
+        }
+
+        sqlite3_update_hook(_openDatabase.sqliteHandle, &_sqlite3_update_hook, (__bridge void *) self);
+    });
+    return _openDatabase;
+}
+
+- (BOOL)sqliteChangeTrackingIsActive { return changeCounterReadFileDescriptor > 0; }
+
+- (uint32_t)sqliteChangeCount
+{
+    if (! changeCounterReadFileDescriptor) return 0;
+    
+    uint32_t changeCounter = 0;
+    lseek(changeCounterReadFileDescriptor, kSQLiteFileChangeCounterOffset, SEEK_SET);
+    read(changeCounterReadFileDescriptor, &changeCounter, sizeof(uint32_t));
+    return CFSwapInt32BigToHost(changeCounter);
+}
+
+- (void)startMonitoringForExternalChanges
+{
+    if (! self.openDatabase) [[NSException exceptionWithName:NSGenericException reason:@"Database must be open" userInfo:nil] raise];
+    
+    const char *fsp = _path.fileSystemRepresentation;
+    changeCounterReadFileDescriptor = open(fsp, O_RDONLY);
+    dispatchEventFileDescriptor = open(fsp, O_EVTONLY);
+    dispatchFileWriteSource = dispatch_source_create(DISPATCH_SOURCE_TYPE_VNODE, dispatchEventFileDescriptor, DISPATCH_VNODE_WRITE, dispatch_get_main_queue());
+    
+    int rfdCopy = changeCounterReadFileDescriptor;
+    int efdCopy = dispatchEventFileDescriptor;
+    dispatch_source_set_cancel_handler(dispatchFileWriteSource, ^{
+        close(rfdCopy);
+        close(efdCopy);
+    });
+
+    __weak typeof(self) weakSelf = self;
+    dispatch_source_set_event_handler(dispatchFileWriteSource, ^{
+        __strong typeof(self) strongSelf = weakSelf;
+        if (strongSelf && strongSelf.expectedChangeCount != strongSelf.sqliteChangeCount) [FCModel dataChangedExternally];
+    });
+
+    dispatch_resume(dispatchFileWriteSource);
+}
+
+- (void)close
+{
+    dispatchEventFileDescriptor = 0;
+    changeCounterReadFileDescriptor = 0;
+    dispatch_source_cancel(dispatchFileWriteSource);
+    dispatchFileWriteSource = NULL;
+
+    [self.openDatabase close];
+    self.openDatabase = nil;
+}
+
+- (void)dealloc
+{
+    [_openDatabase close];
+    self.openDatabase = nil;
+}
+
+- (void)inDatabase:(void (^)(FMDatabase *db))block
+{
+    NSParameterAssert(NSThread.isMainThread);
+    
+    FMDatabase *db = self.database;
+    BOOL hadOpenResultSetsBefore = db.hasOpenResultSets;
+    uint32_t changeCounterBeforeBlock = [self sqliteChangeCount];
+
+    block(db);
+
+    if (changeCounterReadFileDescriptor) {
+        // if more than 1 change during this expected write, either there's 2 queries in it (unexpected) or another process changed it
+        uint32_t changeCounterAfterBlock = [self sqliteChangeCount];
+        if (changeCounterAfterBlock - changeCounterBeforeBlock > 1) [FCModel dataChangedExternally];
+    }
+
+    if (db.hasOpenResultSets != hadOpenResultSetsBefore) {
+        [[NSException exceptionWithName:NSGenericException reason:@"FCModelDatabase has an open FMResultSet after inDatabase:" userInfo:nil] raise];
+    }
+}
+
+@end