Merge pull request #1501 from Nozbe/objc

Objc

native/ios/WatermelonDB/WMDatabase.h

@@ -0,0 +1,29 @@
+#import "FMDB.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface WMDatabase : NSObject
+
+@property (readwrite, strong, nonatomic) FMDatabase *fmdb;
+@property (readwrite, nonatomic) long userVersion;
+
+#pragma mark - Initialization
+
++ (instancetype) databaseWithPath:(NSString *)path;
+
+#pragma mark - Executing queries
+
+- (BOOL) executeQuery:(NSString *)query args:(NSArray *)args error:(NSError **)errorPtr;
+/// Executes multiple queries separated by `;`
+- (BOOL) executeStatements:(NSString *)sql error:(NSError **)errorPtr;
+- (FMResultSet *) queryRaw:(NSString *)query args:(NSArray *)args error:(NSError **)errorPtr;
+- (NSNumber * _Nullable) count:(NSString *)query args:(NSArray *)args error:(NSError **)errorPtr;
+
+#pragma mark - Other database functions
+
+- (BOOL) inTransaction:(BOOL (^)(NSError**))transactionBlock error:(NSError**)errorPtr;
+- (BOOL) unsafeDestroyEverything:(NSError**)errorPtr;
+
+@end
+
+NS_ASSUME_NONNULL_END

native/ios/WatermelonDB/WMDatabase.m

@@ -0,0 +1,192 @@
+#import "WMDatabase.h"
+#import <sqlite3.h>
+
+@implementation WMDatabase {
+    NSString *_path;
+}
+
+- (instancetype) initWithPath:(NSString *)path
+{
+    if (self = [super init]) {
+        _path = path;
+        _fmdb = [FMDatabase databaseWithPath:path];
+        [self open];
+    }
+
+    return self;
+}
+
++ (instancetype) databaseWithPath:(NSString *)path
+{
+    return [[self alloc] initWithPath:path];
+}
+
+- (void) open
+{
+    if (![_fmdb open]) {
+        [NSException raise:@"OpenFailed" format:@"Failed to open the database: %@", _fmdb.lastErrorMessage];
+    }
+
+    // TODO: Experiment with WAL
+    //     // must be queryRaw - returns value
+    //     _ = try queryRaw("pragma journal_mode=wal")
+
+    // TODO: Configurable logger
+    NSLog(@"Opened database at %@", _path);
+}
+
+#pragma mark - Executing queries
+
+- (BOOL) executeQuery:(NSString *)query args:(NSArray *)args error:(NSError **)errorPtr
+{
+    return [_fmdb executeUpdate:query values:args error:errorPtr];
+}
+
+- (BOOL) executeStatements:(NSString *)sql error:(NSError **)errorPtr
+{
+    if (![_fmdb executeStatements:sql]) {
+        *errorPtr = _fmdb.lastError;
+        return NO;
+    }
+
+    return YES;
+}
+
+- (FMResultSet *) queryRaw:(NSString *)query args:(NSArray *)args error:(NSError **)errorPtr
+{
+    return [_fmdb executeQuery:query values:args error:errorPtr];
+}
+
+- (NSNumber * _Nullable) count:(NSString *)query args:(NSArray *)args error:(NSError **)errorPtr
+{
+    FMResultSet *result = [_fmdb executeQuery:query values:args error:errorPtr];
+
+    if (!result) {
+        *errorPtr = _fmdb.lastError;
+        return nil;
+    }
+
+    if (![result next]) {
+        *errorPtr = [NSError errorWithDomain:@"WMDatabase" code:0 userInfo:@{
+            NSLocalizedDescriptionKey: @"Invalid count query, can't find next() on the result"
+        }];
+        return nil;
+    }
+
+    if ([result columnIndexForName:@"count"] != 1) {
+        *errorPtr = [NSError errorWithDomain:@"WMDatabase" code:0 userInfo:@{
+            NSLocalizedDescriptionKey: @"Invalid count query, can't find `count` column"
+        }];
+        return nil;
+    }
+
+    return @([result intForColumn:@"count"]);
+}
+
+#pragma mark - Other database functions
+
+- (BOOL) inTransaction:(BOOL (^)(NSError**))transactionBlock error:(NSError**)errorPtr
+{
+    if (![_fmdb beginTransaction]) {
+        *errorPtr = _fmdb.lastError;
+        return NO;
+    }
+
+    BOOL txnResult = transactionBlock(errorPtr);
+
+    if (txnResult) {
+        if (![_fmdb commit]) {
+            *errorPtr = _fmdb.lastError;
+            return NO;
+        }
+        return YES;
+    } else {
+        if (![_fmdb rollback]) {
+            *errorPtr = _fmdb.lastError;
+        }
+        return NO;
+    }
+}
+
+- (long) userVersion
+{
+    FMResultSet *result = [_fmdb executeQuery:@"pragma user_version"];
+    [result next];
+    return [result longForColumnIndex:0];
+}
+
+- (void) setUserVersion:(long)userVersion
+{
+    BOOL result = [_fmdb executeUpdateWithFormat:@"pragma user_version = %li", userVersion];
+    if (!result) {
+        [NSException raise:@"SetUserVersionFailed" format:@"Failed to set user version: %@", _fmdb.lastErrorMessage];
+    }
+}
+
+- (BOOL) unsafeDestroyEverything:(NSError**)errorPtr
+{
+    // NOTE: Deleting files by default because it seems simpler, more reliable
+    // But sadly this won't work for in-memory (shared) databases
+    if ([self isInMemoryDatabase]) {
+        // NOTE: As of iOS 14, selecting tables from sqlite_master and deleting them does not work
+        // They seem to be enabling "defensive" config. So we use another obscure method to clear the database
+        // https://www.sqlite.org/c3ref/c_dbconfig_defensive.html#sqlitedbconfigresetdatabase
+
+        if (sqlite3_db_config(_fmdb.sqliteHandle, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0) != SQLITE_OK) {
+            *errorPtr = [NSError errorWithDomain:@"WMDatabase" code:0 userInfo:@{
+                NSLocalizedDescriptionKey: @"Failed to enable reset database mode",
+                @"FMDBError": _fmdb.lastError
+            }];
+            return NO;
+        }
+
+        if (![self executeStatements:@"vacuum" error:errorPtr]) {
+            return NO;
+        }
+
+        if (sqlite3_db_config(_fmdb.sqliteHandle, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0) != SQLITE_OK) {
+            *errorPtr = [NSError errorWithDomain:@"WMDatabase" code:0 userInfo:@{
+                NSLocalizedDescriptionKey: @"Failed to disable reset database mode",
+                @"FMDBError": _fmdb.lastError
+            }];
+            return NO;
+        }
+
+        return YES;
+    } else {
+        if (![_fmdb close]) {
+            *errorPtr = [NSError errorWithDomain:@"WMDatabase" code:0 userInfo:@{
+                NSLocalizedDescriptionKey: @"Could not close database",
+                @"FMDBError": _fmdb.lastError
+            }];
+            return NO;
+        }
+
+        NSFileManager *manager = [NSFileManager defaultManager];
+
+        // remove database
+        if (![manager removeItemAtPath:_path error:errorPtr]) {
+            return NO;
+        }
+
+        // try removing database WAL files (ignore errors)
+        [manager removeItemAtPath:[NSString stringWithFormat:@"%@-wal", _path] error:nil];
+        [manager removeItemAtPath:[NSString stringWithFormat:@"%@-shm", _path] error:nil];
+
+        // reopen database
+        [self open];
+        return YES;
+    }
+}
+
+# pragma mark - Private helpers
+
+- (BOOL) isInMemoryDatabase
+{
+    return [_path isEqualToString:@":memory:"]
+        || [_path isEqualToString:@"file::memory:"]
+        || [_path containsString:@"?mode=memory"];
+}
+
+@end
+

native/ios/WatermelonDB/WMDatabaseDriver.h

@@ -0,0 +1,12 @@
+#import "WMDatabase.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface WMDatabaseDriver : NSObject
+
+@property (readwrite, strong, nonatomic) WMDatabase *db;
+@property (readonly, strong, nonatomic) NSMutableDictionary<NSString *, NSMutableSet<NSString *> *> *cachedRecords;
+
+@end
+
+NS_ASSUME_NONNULL_END