rename open with vfs method, add tests for custom vfs

Tests/FMDatabaseTests.m

@@ -68,6 +68,25 @@ - (void)tearDown
     
 }
 
+- (void)testOpenWithVFS
+{
+    // create custom vfs
+    sqlite3_vfs vfs = *sqlite3_vfs_find(NULL);
+    vfs.zName = "MyCustomVFS";
+    XCTAssertEqual(SQLITE_OK, sqlite3_vfs_register(&vfs, 0));
+    // use custom vfs to open a in memory database
+    FMDatabase *db = [[FMDatabase alloc] initWithPath:@":memory:"];
+    [db openWithFlags:SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE vfs:@"MyCustomVFS"];
+    XCTAssertFalse([db hadError], @"Open with a custom VFS should have succeeded");
+}
+
+- (void)testFailOnOpenWithUnknownVFS
+{
+    FMDatabase *db = [[FMDatabase alloc] initWithPath:@":memory:"];
+    [db openWithFlags:SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE vfs:@"UnknownVFS"];
+    XCTAssertTrue([db hadError], @"Should have failed");    
+}
+
 - (void)testFailOnUnopenedDatabase
 {
     [self.db close];

src/fmdb/FMDatabase.h

@@ -194,7 +194,7 @@ typedef int(^FMDBExecuteStatementsCallbackBlock)(NSDictionary *resultsDictionary
 
 - (BOOL)open;
 
-/** Opening a new database connection with flags
+/** Opening a new database connection with flags and an optional virtual file system (VFS)
 
  @param flags one of the following three values, optionally combined with the `SQLITE_OPEN_NOMUTEX`, `SQLITE_OPEN_FULLMUTEX`, `SQLITE_OPEN_SHAREDCACHE`, `SQLITE_OPEN_PRIVATECACHE`, and/or `SQLITE_OPEN_URI` flags:
 
@@ -210,6 +210,8 @@ typedef int(^FMDBExecuteStatementsCallbackBlock)(NSDictionary *resultsDictionary
  
  The database is opened for reading and writing, and is created if it does not already exist. This is the behavior that is always used for `open` method.
  
+ If vfs is given the value is passed to the vfs parameter of sqlite3_open_v2.
+ 
  @return `YES` if successful, `NO` on error.
 
  @see [sqlite3_open_v2()](http://sqlite.org/c3ref/open.html)
@@ -219,7 +221,7 @@ typedef int(^FMDBExecuteStatementsCallbackBlock)(NSDictionary *resultsDictionary
 
 #if SQLITE_VERSION_NUMBER >= 3005000
 - (BOOL)openWithFlags:(int)flags;
-- (BOOL)openWithFlags:(int)flags andVFS:(const char*)vfs;
+- (BOOL)openWithFlags:(int)flags vfs:(NSString *)vfsName;
 #endif
 
 /** Closing a database connection

src/fmdb/FMDatabase.m

@@ -151,14 +151,14 @@ - (BOOL)open {
 
 #if SQLITE_VERSION_NUMBER >= 3005000
 - (BOOL)openWithFlags:(int)flags {
-    return [self openWithFlags:flags andVFS:NULL];
+    return [self openWithFlags:flags vfs:nil];
 }
-- (BOOL)openWithFlags:(int)flags andVFS:(const char*)vfs {
+- (BOOL)openWithFlags:(int)flags vfs:(NSString *)vfsName; {
     if (_db) {
         return YES;
     }
 
-    int err = sqlite3_open_v2([self sqlitePath], &_db, flags, vfs);
+    int err = sqlite3_open_v2([self sqlitePath], &_db, flags, [vfsName UTF8String]);
     if(err != SQLITE_OK) {
         NSLog(@"error opening!: %d", err);
         return NO;

src/fmdb/FMDatabaseQueue.h

@@ -117,6 +117,17 @@
 
 - (instancetype)initWithPath:(NSString*)aPath flags:(int)openFlags;
 
+/** Create queue using path and specified flags.
+ 
+ @param aPath The file path of the database.
+ @param openFlags Flags passed to the openWithFlags method of the database
+ @param vfsName The name of a custom virtual file system
+ 
+ @return The `FMDatabaseQueue` object. `nil` on error.
+ */
+
+- (instancetype)initWithPath:(NSString*)aPath flags:(int)openFlags vfs:(NSString *)vfsName;
+
 /** Returns the Class of 'FMDatabase' subclass, that will be used to instantiate database object.
  
  Subclasses can override this method to return specified Class of 'FMDatabase' subclass.

src/fmdb/FMDatabaseQueue.m

@@ -51,7 +51,7 @@ + (Class)databaseClass {
     return [FMDatabase class];
 }
 
-- (instancetype)initWithPath:(NSString*)aPath flags:(int)openFlags {
+- (instancetype)initWithPath:(NSString*)aPath flags:(int)openFlags vfs:(NSString *)vfsName {
     
     self = [super init];
     
@@ -61,7 +61,7 @@ - (instancetype)initWithPath:(NSString*)aPath flags:(int)openFlags {
         FMDBRetain(_db);
         
 #if SQLITE_VERSION_NUMBER >= 3005000
-        BOOL success = [_db openWithFlags:openFlags];
+        BOOL success = [_db openWithFlags:openFlags vfs:vfsName];
 #else
         BOOL success = [_db open];
 #endif
@@ -81,10 +81,14 @@ - (instancetype)initWithPath:(NSString*)aPath flags:(int)openFlags {
     return self;
 }
 
+- (instancetype)initWithPath:(NSString*)aPath flags:(int)openFlags {
+    return [self initWithPath:aPath flags:openFlags vfs:nil];
+}
+
 - (instancetype)initWithPath:(NSString*)aPath {
     
     // default flags for sqlite3_open
-    return [self initWithPath:aPath flags:SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE];
+    return [self initWithPath:aPath flags:SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE vfs:nil];
 }
 
 - (instancetype)init {