Allow clearing raw tables

Author: simolus3

crates/core/src/crud_vtab.rs

@@ -1,7 +1,7 @@
 extern crate alloc;
 
 use alloc::boxed::Box;
-use alloc::sync::Arc;
+use alloc::rc::Rc;
 use const_format::formatcp;
 use core::ffi::{CStr, c_char, c_int, c_void};
 use core::sync::atomic::Ordering;
@@ -42,7 +42,7 @@ struct VirtualTable {
     db: *mut sqlite::sqlite3,
     current_tx: Option<ActiveCrudTransaction>,
     is_simple: bool,
-    state: Arc<DatabaseState>,
+    state: Rc<DatabaseState>,
 }
 
 struct ActiveCrudTransaction {
@@ -301,14 +301,7 @@ extern "C" fn connect(
                 pModule: core::ptr::null(),
                 zErrMsg: core::ptr::null_mut(),
             },
-            state: {
-                // Increase refcount - we can't use from_raw alone because we don't own the aux
-                // data (connect could be called multiple times).
-                let state = Arc::from_raw(aux as *mut DatabaseState);
-                let clone = state.clone();
-                core::mem::forget(state);
-                clone
-            },
+            state: DatabaseState::clone_from(aux),
             db,
             current_tx: None,
             is_simple,
@@ -321,7 +314,7 @@ extern "C" fn connect(
 
 extern "C" fn disconnect(vtab: *mut sqlite::vtab) -> c_int {
     unsafe {
-        drop(Box::from_raw(vtab));
+        drop(Box::from_raw(vtab as *mut VirtualTable));
     }
     ResultCode::OK as c_int
 }
@@ -400,20 +393,20 @@ static MODULE: sqlite_nostd::module = sqlite_nostd::module {
     xIntegrity: None,
 };
 
-pub fn register(db: *mut sqlite::sqlite3, state: Arc<DatabaseState>) -> Result<(), ResultCode> {
+pub fn register(db: *mut sqlite::sqlite3, state: Rc<DatabaseState>) -> Result<(), ResultCode> {
     sqlite::convert_rc(sqlite::create_module_v2(
         db,
         SIMPLE_NAME.as_ptr(),
         &MODULE,
-        Arc::into_raw(state.clone()) as *mut c_void,
-        Some(DatabaseState::destroy_arc),
+        Rc::into_raw(state.clone()) as *mut c_void,
+        Some(DatabaseState::destroy_rc),
     ))?;
     sqlite::convert_rc(sqlite::create_module_v2(
         db,
         MANUAL_NAME.as_ptr(),
         &MODULE,
-        Arc::into_raw(state) as *mut c_void,
-        Some(DatabaseState::destroy_arc),
+        Rc::into_raw(state) as *mut c_void,
+        Some(DatabaseState::destroy_rc),
     ))?;
 
     Ok(())

crates/core/src/lib.rs

@@ -8,7 +8,7 @@ extern crate alloc;
 
 use core::ffi::{c_char, c_int};
 
-use alloc::{ffi::CString, format, sync::Arc};
+use alloc::{ffi::CString, format, rc::Rc};
 use sqlite::ResultCode;
 use sqlite_nostd as sqlite;
 
@@ -66,22 +66,22 @@ pub extern "C" fn sqlite3_powersync_init(
 fn init_extension(db: *mut sqlite::sqlite3) -> Result<(), PowerSyncError> {
     PowerSyncError::check_sqlite3_version()?;
 
-    let state = Arc::new(DatabaseState::new());
+    let state = Rc::new(DatabaseState::new());
 
     crate::version::register(db)?;
     crate::views::register(db)?;
     crate::uuid::register(db)?;
     crate::diff::register(db)?;
     crate::fix_data::register(db)?;
     crate::json_util::register(db)?;
-    crate::view_admin::register(db)?;
+    crate::view_admin::register(db, state.clone())?;
     crate::checkpoint::register(db)?;
     crate::kv::register(db)?;
     crate::state::register(db, state.clone())?;
     sync::register(db, state.clone())?;
     update_hooks::register(db, state.clone())?;
 
-    crate::schema::register(db)?;
+    crate::schema::register(db, state.clone())?;
     crate::operations_vtab::register(db, state.clone())?;
     crate::crud_vtab::register(db, state)?;
 

crates/core/src/migrations.rs

@@ -27,8 +27,9 @@ CREATE TABLE IF NOT EXISTS ps_migration(id INTEGER PRIMARY KEY, down_migrations
     )?;
 
     // language=SQLite
-    let current_version_stmt =
-        local_db.prepare_v2("SELECT ifnull(max(id), 0) as version FROM ps_migration")?;
+    let current_version_stmt = local_db
+        .prepare_v2("SELECT ifnull(max(id), 0) as version FROM ps_migration")
+        .into_db_result(local_db)?;
     let rc = current_version_stmt.step()?;
     if rc != ResultCode::ROW {
         return Err(PowerSyncError::unknown_internal());

crates/core/src/operations_vtab.rs

@@ -1,7 +1,7 @@
 extern crate alloc;
 
 use alloc::boxed::Box;
-use alloc::sync::Arc;
+use alloc::rc::Rc;
 use core::ffi::{c_char, c_int, c_void};
 
 use sqlite::{Connection, ResultCode, Value};
@@ -18,7 +18,7 @@ use crate::vtab_util::*;
 struct VirtualTable {
     base: sqlite::vtab,
     db: *mut sqlite::sqlite3,
-    state: Arc<DatabaseState>,
+    state: Rc<DatabaseState>,
 
     target_applied: bool,
     target_validated: bool,
@@ -46,14 +46,7 @@ extern "C" fn connect(
                 zErrMsg: core::ptr::null_mut(),
             },
             db,
-            state: {
-                // Increase refcount - we can't use from_raw alone because we don't own the aux
-                // data (connect could be called multiple times).
-                let state = Arc::from_raw(aux as *mut DatabaseState);
-                let clone = state.clone();
-                core::mem::forget(state);
-                clone
-            },
+            state: DatabaseState::clone_from(aux),
             target_validated: false,
             target_applied: false,
         }));
@@ -65,7 +58,7 @@ extern "C" fn connect(
 
 extern "C" fn disconnect(vtab: *mut sqlite::vtab) -> c_int {
     unsafe {
-        drop(Box::from_raw(vtab));
+        drop(Box::from_raw(vtab as *mut VirtualTable));
     }
     ResultCode::OK as c_int
 }
@@ -150,12 +143,12 @@ static MODULE: sqlite_nostd::module = sqlite_nostd::module {
     xIntegrity: None,
 };
 
-pub fn register(db: *mut sqlite::sqlite3, state: Arc<DatabaseState>) -> Result<(), ResultCode> {
+pub fn register(db: *mut sqlite::sqlite3, state: Rc<DatabaseState>) -> Result<(), ResultCode> {
     db.create_module_v2(
         "powersync_operations",
         &MODULE,
-        Some(Arc::into_raw(state) as *mut c_void),
-        Some(DatabaseState::destroy_arc),
+        Some(Rc::into_raw(state) as *mut c_void),
+        Some(DatabaseState::destroy_rc),
     )?;
 
     Ok(())

crates/core/src/schema/management.rs

@@ -1,5 +1,6 @@
 extern crate alloc;
 
+use alloc::rc::Rc;
 use alloc::string::String;
 use alloc::vec::Vec;
 use alloc::{format, vec};
@@ -11,6 +12,7 @@ use sqlite_nostd::Context;
 
 use crate::error::{PSResult, PowerSyncError};
 use crate::ext::ExtendedDatabase;
+use crate::state::DatabaseState;
 use crate::util::{quote_identifier, quote_json_path};
 use crate::{create_auto_tx_function, create_sqlite_text_fn};
 
@@ -138,10 +140,8 @@ SELECT name, internal_name, local_only FROM powersync_tables WHERE name NOT IN (
     Ok(())
 }
 
-fn update_indexes(db: *mut sqlite::sqlite3, schema: &str) -> Result<(), PowerSyncError> {
+fn update_indexes(db: *mut sqlite::sqlite3, schema: &Schema) -> Result<(), PowerSyncError> {
     let mut statements: Vec<String> = alloc::vec![];
-    let schema =
-        serde_json::from_str::<Schema>(schema).map_err(PowerSyncError::as_argument_error)?;
     let mut expected_index_names: Vec<String> = vec![];
 
     {
@@ -298,15 +298,20 @@ fn powersync_replace_schema_impl(
     args: &[*mut sqlite::value],
 ) -> Result<String, PowerSyncError> {
     let schema = args[0].text();
+    let state = unsafe { DatabaseState::from_context(&ctx) };
+    let parsed_schema =
+        serde_json::from_str::<Schema>(schema).map_err(PowerSyncError::as_argument_error)?;
+
     let db = ctx.db_handle();
 
     // language=SQLite
     db.exec_safe("SELECT powersync_init()").into_db_result(db)?;
 
     update_tables(db, schema)?;
-    update_indexes(db, schema)?;
+    update_indexes(db, &parsed_schema)?;
     update_views(db, schema)?;
 
+    state.set_schema(parsed_schema);
     Ok(String::from(""))
 }
 
@@ -317,16 +322,16 @@ create_sqlite_text_fn!(
     "powersync_replace_schema"
 );
 
-pub fn register(db: *mut sqlite::sqlite3) -> Result<(), ResultCode> {
+pub fn register(db: *mut sqlite::sqlite3, state: Rc<DatabaseState>) -> Result<(), ResultCode> {
     db.create_function_v2(
         "powersync_replace_schema",
         1,
         sqlite::UTF8,
-        None,
+        Some(Rc::into_raw(state) as *mut _),
         Some(powersync_replace_schema),
         None,
         None,
-        None,
+        Some(DatabaseState::destroy_rc),
     )?;
 
     Ok(())

crates/core/src/schema/mod.rs

@@ -1,7 +1,7 @@
 mod management;
 mod table_info;
 
-use alloc::vec::Vec;
+use alloc::{rc::Rc, vec::Vec};
 use serde::Deserialize;
 use sqlite::ResultCode;
 use sqlite_nostd as sqlite;
@@ -10,13 +10,15 @@ pub use table_info::{
     TableInfoFlags,
 };
 
+use crate::state::DatabaseState;
+
 #[derive(Deserialize, Default)]
 pub struct Schema {
     pub tables: Vec<table_info::Table>,
     #[serde(default)]
     pub raw_tables: Vec<table_info::RawTable>,
 }
 
-pub fn register(db: *mut sqlite::sqlite3) -> Result<(), ResultCode> {
-    management::register(db)
+pub fn register(db: *mut sqlite::sqlite3, state: Rc<DatabaseState>) -> Result<(), ResultCode> {
+    management::register(db, state)
 }

crates/core/src/schema/table_info.rs

@@ -24,6 +24,8 @@ pub struct RawTable {
     pub name: String,
     pub put: PendingStatement,
     pub delete: PendingStatement,
+    #[serde(default)]
+    pub clear: Option<String>,
 }
 
 impl Table {