Migrate moor_ffi to Dart 2.6

moor_ffi/CHANGELOG.md

@@ -1,3 +1,6 @@
+## 0.1.0-dev.1
+- Support Dart 2.6 (starting from `2.6.0-dev.8.0`)
+
 ## 0.0.1
 
 - Initial release. Contains standalone bindings and a moor implementation.

moor_ffi/lib/src/bindings/types.dart

@@ -15,7 +15,7 @@ import 'dart:ffi';
 /// is its destructor.  There are many other interfaces (such as
 /// [sqlite3_prepare_v2()], [sqlite3_create_function()], and
 /// [sqlite3_busy_timeout()] to name but three) that are methods on an
-class Database extends Struct<Database> {}
+class Database extends Struct {}
 
 /// SQL Statement Object
 ///
@@ -38,7 +38,7 @@ class Database extends Struct<Database> {}
 ///
 /// Refer to documentation on individual methods above for additional
 /// information.
-class Statement extends Struct<Statement> {}
+class Statement extends Struct {}
 
 /// Dynamically Typed Value Object
 ///
@@ -74,4 +74,4 @@ class Statement extends Struct<Statement> {}
 /// [sqlite3_result_value()] and [sqlite3_bind_value()].
 /// The [sqlite3_value_blob | sqlite3_value_type()] family of
 /// interfaces require protected sqlite3_value objects.
-class Value extends Struct<Value> {}
+class Value extends Struct {}

moor_ffi/lib/src/ffi/blob.dart

@@ -7,14 +7,11 @@ import 'package:moor_ffi/src/ffi/utils.dart';
 import 'package:ffi/ffi.dart' as ffi;
 
 /// Pointer to arbitrary blobs in C.
-class CBlob extends Struct<CBlob> {
-  @Uint8()
-  int data;
-
+class CBlob extends Struct {
   static Pointer<CBlob> allocate(Uint8List blob) {
     final str = ffi.allocate<Uint8>(count: blob.length);
 
-    final asList = str.asExternalTypedData(count: blob.length) as Uint8List;
+    final asList = str.asTypedList(blob.length);
     asList.setAll(0, blob);
 
     return str.cast();
@@ -28,37 +25,38 @@ class CBlob extends Struct<CBlob> {
       ..setAll(0, encoded);
     return CBlob.allocate(data);
   }
+}
 
-  /// Reads [bytesToRead] bytes from the current position.
-  Uint8List read(int bytesToRead) {
-    assert(bytesToRead >= 0);
-    final str = addressOf.cast<Uint8>();
-    if (isNullPointer(str)) return null;
-
-    final data = str.asExternalTypedData(count: bytesToRead) as Uint8List;
-    return Uint8List.fromList(data);
-  }
-
-  /// More efficient version of [readString] that doesn't have to find a nil-
-  /// terminator. [length] is the amount of bytes to read. The string will be
-  /// decoded via [utf8].
-  String readAsStringWithLength(int length) {
-    return utf8.decode(read(length));
-  }
-
+extension CBlobPointer on Pointer<CBlob> {
   /// Reads a 0-terminated string, decoded with utf8.
   ///
   /// Warning: This method is very, very slow. If there is any way to know the
   /// length of the string to read, [readAsStringWithLength] will be orders of
   /// magnitude faster.
   String readString() {
-    final str = addressOf;
-    if (isNullPointer(str)) return null;
+    if (isNullPointer) return null;
 
     var len = 0;
-    while (str.elementAt(++len).load<CBlob>().data != 0) {}
+    final asUintPointer = cast<Uint8>();
+    while (asUintPointer[++len] != 0) {}
 
-    final units = read(len);
+    final units = readBytes(len);
     return utf8.decode(units);
   }
+
+  /// More efficient version of [readString] that doesn't have to find a nil-
+  /// terminator. [length] is the amount of bytes to read. The string will be
+  /// decoded via [utf8].
+  String readAsStringWithLength(int length) {
+    return utf8.decode(readBytes(length));
+  }
+
+  /// Reads [length] bytes from this address.
+  Uint8List readBytes(int length) {
+    assert(length >= 0);
+    if (isNullPointer) return null;
+
+    final data = cast<Uint8>().asTypedList(length);
+    return Uint8List.fromList(data);
+  }
 }

moor_ffi/lib/src/ffi/utils.dart

@@ -2,11 +2,10 @@ import 'dart:ffi';
 
 import 'package:ffi/ffi.dart' as ffi;
 
-bool isNullPointer<T extends NativeType>(Pointer<T> ptr) => ptr == nullptr;
+extension FreePointerExtension on Pointer {
+  bool get isNullPointer => this == nullptr;
 
-extension FreePointerExtension<T extends NativeType> on Pointer<T> {
-  // todo rename to "free" after https://github.com/dart-lang/sdk/issues/38860
-  void $free() {
+  void free() {
     ffi.free(this);
   }
 }

moor_ffi/lib/src/impl/database.dart

@@ -37,10 +37,10 @@ class Database implements BaseDatabase {
 
     final resultCode =
         bindings.sqlite3_open_v2(pathC, dbOut, _openingFlags, nullptr.cast());
-    final dbPointer = dbOut.load<Pointer<types.Database>>();
+    final dbPointer = dbOut.value;
 
-    dbOut.$free();
-    pathC.$free();
+    dbOut.free();
+    pathC.free();
 
     if (resultCode == Errors.SQLITE_OK) {
       return Database._(dbPointer);
@@ -94,14 +94,14 @@ class Database implements BaseDatabase {
     final result =
         bindings.sqlite3_exec(_db, sqlPtr, nullptr, nullptr, errorOut);
 
-    sqlPtr.$free();
+    sqlPtr.free();
 
-    final errorPtr = errorOut.load<Pointer<CBlob>>();
-    errorOut.$free();
+    final errorPtr = errorOut.value;
+    errorOut.free();
 
     String errorMsg;
-    if (!isNullPointer(errorPtr)) {
-      errorMsg = errorPtr.load<CBlob>().readString();
+    if (!errorPtr.isNullPointer) {
+      errorMsg = errorPtr.readString();
       // the message was allocated from sqlite, we need to free it
       bindings.sqlite3_free(errorPtr.cast());
     }
@@ -120,10 +120,10 @@ class Database implements BaseDatabase {
 
     final resultCode =
         bindings.sqlite3_prepare_v2(_db, sqlPtr, -1, stmtOut, nullptr.cast());
-    sqlPtr.$free();
+    sqlPtr.free();
 
-    final stmt = stmtOut.load<Pointer<types.Statement>>();
-    stmtOut.$free();
+    final stmt = stmtOut.value;
+    stmtOut.free();
 
     if (resultCode != Errors.SQLITE_OK) {
       // we don't need to worry about freeing the statement. If preparing the

moor_ffi/lib/src/impl/errors.dart

@@ -12,11 +12,11 @@ class SqliteException implements Exception {
     // hold the error message string is managed internally. The application does
     // not need to worry about freeing the result."
     // https://www.sqlite.org/c3ref/errcode.html
-    final dbMessage = bindings.sqlite3_errmsg(db).load<CBlob>().readString();
+    final dbMessage = bindings.sqlite3_errmsg(db).readString();
 
     String explanation;
     if (code != null) {
-      explanation = bindings.sqlite3_errstr(code).load<CBlob>().readString();
+      explanation = bindings.sqlite3_errstr(code).readString();
     }
 
     return SqliteException(dbMessage, explanation);

moor_ffi/lib/src/impl/prepared_statement.dart

@@ -40,8 +40,7 @@ class PreparedStatement implements BasePreparedStatement {
 
     for (var i = 0; i < columnCount; i++) {
       // name pointer doesn't need to be disposed, that happens when we finalize
-      names[i] =
-          bindings.sqlite3_column_name(_stmt, i).load<CBlob>().readString();
+      names[i] = bindings.sqlite3_column_name(_stmt, i).readString();
     }
 
     while (_step() == Errors.SQLITE_ROW) {
@@ -62,14 +61,10 @@ class PreparedStatement implements BasePreparedStatement {
         final length = bindings.sqlite3_column_bytes(_stmt, index);
         return bindings
             .sqlite3_column_text(_stmt, index)
-            .load<CBlob>()
             .readAsStringWithLength(length);
       case Types.SQLITE_BLOB:
         final length = bindings.sqlite3_column_bytes(_stmt, index);
-        return bindings
-            .sqlite3_column_blob(_stmt, index)
-            .load<CBlob>()
-            .read(length);
+        return bindings.sqlite3_column_blob(_stmt, index).readBytes(length);
       case Types.SQLITE_NULL:
       default:
         return null;
@@ -95,7 +90,7 @@ class PreparedStatement implements BasePreparedStatement {
       _bound = false;
     }
     for (var pointer in _allocatedWhileBinding) {
-      pointer.$free();
+      pointer.free();
     }
     _allocatedWhileBinding.clear();
   }

moor_ffi/pubspec.yaml

@@ -1,16 +1,16 @@
 name: moor_ffi
 description: "Provides sqlite bindings using dart:ffi, including a moor executor"
-version: 0.1.0-dev
+version: 0.1.0-dev.1
 author: Simon Binder <oss@simonbinder.eu>
 homepage: https://github.com/simolus3/moor/tree/develop/moor_ffi
 issue_tracker: https://github.com/simolus3/moor/issues
 
 environment:
-  sdk: ">=2.6.0-dev <3.0.0"
+  sdk: ">=2.6.0-dev.8.0 <3.0.0"
 
 dependencies:
   moor: ">=1.7.0 <3.0.0"
-  ffi: 0.1.3-dev.1 # todo replace with carret after the next dev release, then non-dev version once Dart 2.6 is out
+  ffi: ^0.1.3-dev.3 # todo non-dev version once Dart 2.6 is out
   collection: ^1.0.0
 
 dev_dependencies:

moor_ffi/test/ffi/blob_test.dart

@@ -1,5 +1,6 @@
 import 'package:moor/moor.dart';
 import 'package:moor_ffi/src/ffi/blob.dart';
+import 'package:moor_ffi/src/ffi/utils.dart';
 import 'package:test/test.dart';
 
 void main() {
@@ -7,7 +8,7 @@ void main() {
     final content = 'Hasta Mañana';
     final blob = CBlob.allocateString(content);
 
-    expect(blob.load<CBlob>().readString(), content);
+    expect(blob.readString(), content);
     blob.free();
   });
 
@@ -15,7 +16,7 @@ void main() {
     final data = List.generate(256, (x) => x);
     final blob = CBlob.allocate(Uint8List.fromList(data));
 
-    expect(blob.load<CBlob>().read(256), data);
+    expect(blob.readBytes(256), data);
     blob.free();
   });
 }