moor_ffi: Performance improvements for sqlite3 on Android

docs/content/en/docs/Other engines/vm.md

@@ -76,4 +76,29 @@ Note: If you haven't shipped a version with `moor_flutter` to your users yet, yo
 on `sqflite`. Instead, you can use `path_provider` which [works on Desktop](https://github.com/google/flutter-desktop-embedding/tree/master/plugins/flutter_plugins).
 Please be aware that `FlutterQueryExecutor.inDatabaseFolder` might yield a different folder than
 `path_provider` on Android. This can cause data loss if you've already shipped a version using
-`moor_flutter`. In that case, using `getDatabasePath` from sqflite is the suggested solution.
+`moor_flutter`. In that case, using `getDatabasePath` from sqflite is the suggested solution.
+
+## Used compile options on Android
+
+Note: Android is the only platform where moor_ffi will compile sqlite. The sqlite3 library from the system
+is used on all other platforms. The choosen options help reduce binary size by removing features not used by
+moor. Important options are marked in bold.
+
+- We use the `-O3` performance option
+- __SQLITE_DQS=0__: This will make sqlite not accept double-quoted strings (and instead parse them as identifiers). This matches
+  the behavior of moor and compiled queries
+- __SQLITE_THREADSAFE=0__: Since the majority of Flutter apps only use one isolate, thread safety is turned off. Note that you
+  can still use the [isolate api]({{<relref "../Advanced Features/isolates.md">}}) for background operations. As long as all
+  database accesses happen from the same thread, there's no problem.
+- SQLITE_DEFAULT_MEMSTATUS=0: The `sqlite3_status()` interfaces are not exposed by moor_ffi, so there's no point of having them.
+- SQLITE_MAX_EXPR_DEPTH=0: Disables maximum depth when sqlite parses expressions, which can make the parser faster.
+- `SQLITE_OMIT_AUTHORIZATION`, `SQLITE_OMIT_DECLTYPE`, __SQLITE_OMIT_DEPRECATED__, `SQLITE_OMIT_GET_TABLE`, `SQLITE_OMIT_LOAD_EXTENSION`,
+  `SQLITE_OMIT_PROGRESS_CALLBACK`, `SQLITE_OMIT_SHARED_CACHE`, `SQLITE_OMIT_TCL_VARIABLE`, `SQLITE_OMIT_TRACE`: Disables features not supported
+  by moor.
+- `SQLITE_USE_ALLOCA`: Allocate temporary memory on the stack
+- `SQLITE_UNTESTABLE`: Remove util functions that are only required to test sqlite3
+- `SQLITE_HAVE_ISNAN`: Use the `isnan` function from the system instead of the one shipped with sqlite3.
+- `SQLITE_ENABLE_FTS5`: Enable the [fts5](https://www.sqlite.org/fts5.html) engine for full-text search.
+- `SQLITE_ENABLE_JSON1`: Enable the [json1](https://www.sqlite.org/json1.html) extension for json support in sql query.
+
+For more details on sqlite compile options, see [their documentation](https://www.sqlite.org/compile.html).

moor_ffi/CHANGELOG.md

@@ -1,3 +1,7 @@
+## unreleased
+
+- Better setup for compiling sqlite3 on Android
+
 ## 0.2.0
 
 - Remove the `background` flag from the moor apis provided by this package. Use the moor isolate api

moor_ffi/android/.gitignore

@@ -8,5 +8,4 @@
 /captures
 
 .externalNativeBuild/
-cpp/sqlite*
-sqlite_*.zip
+cpp/sqlite*

moor_ffi/android/cpp/CMakeLists.txt

@@ -1,4 +1,31 @@
 cmake_minimum_required(VERSION 3.4.1)
-project(sqlite3)
+project(
+    moor_ffi_android
+    VERSION 3
+    LANGUAGES C
+)
+
+set(CMAKE_C_FLAGS "-O3")
 
 add_library(sqlite3 SHARED sqlite3.c)
+
+target_compile_definitions(sqlite3 PUBLIC
+    SQLITE_DQS=0
+    SQLITE_THREADSAFE=0
+    SQLITE_DEFAULT_MEMSTATUS=0
+    SQLITE_MAX_EXPR_DEPTH=0
+    SQLITE_OMIT_AUTHORIZATION
+    SQLITE_OMIT_DECLTYPE
+    SQLITE_OMIT_DEPRECATED
+    SQLITE_OMIT_GET_TABLE
+    SQLITE_OMIT_LOAD_EXTENSION
+    SQLITE_OMIT_PROGRESS_CALLBACK
+    SQLITE_OMIT_SHARED_CACHE
+    SQLITE_OMIT_TCL_VARIABLE
+    SQLITE_OMIT_TRACE
+    SQLITE_USE_ALLOCA
+    SQLITE_UNTESTABLE
+    SQLITE_HAVE_ISNAN
+    SQLITE_ENABLE_FTS5
+    SQLITE_ENABLE_JSON1
+)

moor_ffi/lib/src/bindings/bindings.dart

@@ -48,9 +48,6 @@ class _SQLiteBindings {
   Pointer<CBlob> Function(Pointer<Statement> statement, int columnIndex)
       sqlite3_column_name;
 
-  Pointer<CBlob> Function(Pointer<Statement> statement, int columnIndex)
-      sqlite3_column_decltype;
-
   int Function(Pointer<Statement> statement, int columnIndex)
       sqlite3_column_type;
 
@@ -158,10 +155,6 @@ class _SQLiteBindings {
         .lookup<NativeFunction<sqlite3_column_name_native_t>>(
             'sqlite3_column_name')
         .asFunction();
-    sqlite3_column_decltype = sqlite
-        .lookup<NativeFunction<sqlite3_column_decltype_native_t>>(
-            'sqlite3_column_decltype')
-        .asFunction();
     sqlite3_column_type = sqlite
         .lookup<NativeFunction<sqlite3_column_type_native_t>>(
             'sqlite3_column_type')

moor_ffi/lib/src/bindings/signatures.dart

@@ -47,9 +47,6 @@ typedef sqlite3_column_count_native_t = Int32 Function(
 typedef sqlite3_column_name_native_t = Pointer<CBlob> Function(
     Pointer<Statement> statement, Int32 columnIndex);
 
-typedef sqlite3_column_decltype_native_t = Pointer<CBlob> Function(
-    Pointer<Statement> statement, Int32 columnIndex);
-
 typedef sqlite3_column_type_native_t = Int32 Function(
     Pointer<Statement> statement, Int32 columnIndex);