Add option to compare site_id when values are equal to determine ultimate winner

core/rs/core/src/c.rs

@@ -46,8 +46,8 @@ pub enum ChangeRowType {
 }
 
 #[repr(C)]
-#[derive(Debug, Copy, Clone)]
 #[allow(non_snake_case, non_camel_case_types)]
+#[derive(Debug, Copy, Clone)]
 pub struct crsql_ExtData {
     pub pPragmaSchemaVersionStmt: *mut sqlite::stmt,
     pub pPragmaDataVersionStmt: *mut sqlite::stmt,
@@ -67,6 +67,7 @@ pub struct crsql_ExtData {
     pub pSetSiteIdOrdinalStmt: *mut sqlite::stmt,
     pub pSelectSiteIdOrdinalStmt: *mut sqlite::stmt,
     pub pSelectClockTablesStmt: *mut sqlite::stmt,
+    pub mergeEqualValues: ::core::ffi::c_int,
 }
 
 #[repr(C)]
@@ -258,20 +259,20 @@ fn bindgen_test_layout_crsql_Changes_cursor() {
 #[test]
 #[allow(non_snake_case)]
 fn bindgen_test_layout_crsql_ExtData() {
-    const UNINIT: ::core::mem::MaybeUninit<crsql_ExtData> = ::core::mem::MaybeUninit::uninit();
+    const UNINIT: ::std::mem::MaybeUninit<crsql_ExtData> = ::std::mem::MaybeUninit::uninit();
     let ptr = UNINIT.as_ptr();
     assert_eq!(
-        ::core::mem::size_of::<crsql_ExtData>(),
-        128usize,
+        ::std::mem::size_of::<crsql_ExtData>(),
+        136usize,
         concat!("Size of: ", stringify!(crsql_ExtData))
     );
     assert_eq!(
-        ::core::mem::align_of::<crsql_ExtData>(),
+        ::std::mem::align_of::<crsql_ExtData>(),
         8usize,
         concat!("Alignment of ", stringify!(crsql_ExtData))
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pPragmaSchemaVersionStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pPragmaSchemaVersionStmt) as usize - ptr as usize },
         0usize,
         concat!(
             "Offset of field: ",
@@ -281,7 +282,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pPragmaDataVersionStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pPragmaDataVersionStmt) as usize - ptr as usize },
         8usize,
         concat!(
             "Offset of field: ",
@@ -291,7 +292,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pragmaDataVersion) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pragmaDataVersion) as usize - ptr as usize },
         16usize,
         concat!(
             "Offset of field: ",
@@ -301,7 +302,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).dbVersion) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).dbVersion) as usize - ptr as usize },
         24usize,
         concat!(
             "Offset of field: ",
@@ -311,7 +312,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pendingDbVersion) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pendingDbVersion) as usize - ptr as usize },
         32usize,
         concat!(
             "Offset of field: ",
@@ -321,7 +322,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pragmaSchemaVersion) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pragmaSchemaVersion) as usize - ptr as usize },
         40usize,
         concat!(
             "Offset of field: ",
@@ -331,7 +332,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).updatedTableInfosThisTx) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).updatedTableInfosThisTx) as usize - ptr as usize },
         44usize,
         concat!(
             "Offset of field: ",
@@ -342,7 +343,7 @@ fn bindgen_test_layout_crsql_ExtData() {
     );
     assert_eq!(
         unsafe {
-            ::core::ptr::addr_of!((*ptr).pragmaSchemaVersionForTableInfos) as usize - ptr as usize
+            ::std::ptr::addr_of!((*ptr).pragmaSchemaVersionForTableInfos) as usize - ptr as usize
         },
         48usize,
         concat!(
@@ -353,7 +354,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).siteId) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).siteId) as usize - ptr as usize },
         56usize,
         concat!(
             "Offset of field: ",
@@ -363,7 +364,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pDbVersionStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pDbVersionStmt) as usize - ptr as usize },
         64usize,
         concat!(
             "Offset of field: ",
@@ -373,7 +374,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).tableInfos) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).tableInfos) as usize - ptr as usize },
         72usize,
         concat!(
             "Offset of field: ",
@@ -383,7 +384,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).rowsImpacted) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).rowsImpacted) as usize - ptr as usize },
         80usize,
         concat!(
             "Offset of field: ",
@@ -393,7 +394,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).seq) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).seq) as usize - ptr as usize },
         84usize,
         concat!(
             "Offset of field: ",
@@ -403,7 +404,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pSetSyncBitStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pSetSyncBitStmt) as usize - ptr as usize },
         88usize,
         concat!(
             "Offset of field: ",
@@ -413,7 +414,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pClearSyncBitStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pClearSyncBitStmt) as usize - ptr as usize },
         96usize,
         concat!(
             "Offset of field: ",
@@ -423,7 +424,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pSetSiteIdOrdinalStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pSetSiteIdOrdinalStmt) as usize - ptr as usize },
         104usize,
         concat!(
             "Offset of field: ",
@@ -433,7 +434,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pSelectSiteIdOrdinalStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pSelectSiteIdOrdinalStmt) as usize - ptr as usize },
         112usize,
         concat!(
             "Offset of field: ",
@@ -443,7 +444,7 @@ fn bindgen_test_layout_crsql_ExtData() {
         )
     );
     assert_eq!(
-        unsafe { ::core::ptr::addr_of!((*ptr).pSelectClockTablesStmt) as usize - ptr as usize },
+        unsafe { ::std::ptr::addr_of!((*ptr).pSelectClockTablesStmt) as usize - ptr as usize },
         120usize,
         concat!(
             "Offset of field: ",
@@ -452,4 +453,14 @@ fn bindgen_test_layout_crsql_ExtData() {
             stringify!(pSelectClockTablesStmt)
         )
     );
+    assert_eq!(
+        unsafe { ::std::ptr::addr_of!((*ptr).mergeEqualValues) as usize - ptr as usize },
+        128usize,
+        concat!(
+            "Offset of field: ",
+            stringify!(crsql_ExtData),
+            "::",
+            stringify!(mergeEqualValues)
+        )
+    );
 }

core/rs/core/src/changes_vtab_write.rs

@@ -19,19 +19,21 @@ use crate::util::slab_rowid;
 
 /**
  * did_cid_win does not take into account the causal length.
- * The expectation is that all cuasal length concerns have already been handle
+ * The expectation is that all causal length concerns have already been handle
  * via:
  * - early return because insert_cl < local_cl
  * - automatic win because insert_cl > local_cl
- * - come here to did_cid_win iff insert_cl = local_cl
+ * - come here to did_cid_win if insert_cl = local_cl
  */
 fn did_cid_win(
     db: *mut sqlite3,
+    ext_data: *mut crsql_ExtData,
     insert_tbl: &str,
     tbl_info: &TableInfo,
     unpacked_pks: &Vec<ColumnValue>,
     key: sqlite::int64,
     insert_val: *mut sqlite::value,
+    insert_site_id: &[u8],
     col_name: &str,
     col_version: sqlite::int64,
     errmsg: *mut *mut c_char,
@@ -89,10 +91,15 @@ fn did_cid_win(
     match step_result {
         Ok(ResultCode::ROW) => {
             let local_value = col_val_stmt.column_value(0)?;
-            let ret = crsql_compare_sqlite_values(insert_val, local_value);
+            let mut ret = crsql_compare_sqlite_values(insert_val, local_value);
             reset_cached_stmt(col_val_stmt.stmt)?;
-            // value won, take value
-            // if values are the same (ret == 0) then we return false and do not take the update
+            if ret == 0 && unsafe { (*ext_data).mergeEqualValues == 1 } {
+                // values are the same (ret == 0) and the option to tie break on site_id is true
+                ret = unsafe {
+                    let my_site_id = core::slice::from_raw_parts((*ext_data).siteId, 16);
+                    insert_site_id.cmp(my_site_id) as c_int
+                };
+            }
             return Ok(ret > 0);
         }
         _ => {
@@ -586,17 +593,19 @@ unsafe fn merge_insert(
         || !row_exists_locally
         || did_cid_win(
             db,
+            (*tab).pExtData,
             insert_tbl,
             &tbl_info,
             &unpacked_pks,
             key,
             insert_val,
+            insert_site_id,
             insert_col,
             insert_col_vrsn,
             errmsg,
         )?;
 
-    if does_cid_win == false {
+    if !does_cid_win {
         // doesCidWin == 0? compared against our clocks, nothing wins. OK and
         // Done.
         return Ok(ResultCode::OK);

core/rs/core/src/config.rs

@@ -0,0 +1,85 @@
+use alloc::format;
+
+use sqlite::{Connection, Context};
+use sqlite_nostd as sqlite;
+use sqlite_nostd::{ResultCode, Value};
+
+use crate::c::crsql_ExtData;
+
+pub const MERGE_EQUAL_VALUES: &str = "merge-equal-values";
+
+pub extern "C" fn crsql_config_set(
+    ctx: *mut sqlite::context,
+    argc: i32,
+    argv: *mut *mut sqlite::value,
+) {
+    let args = sqlite::args!(argc, argv);
+
+    let name = args[0].text();
+
+    let value = match name {
+        MERGE_EQUAL_VALUES => {
+            let value = args[1];
+            let ext_data = ctx.user_data() as *mut crsql_ExtData;
+            unsafe { (*ext_data).mergeEqualValues = value.int() };
+            value
+        }
+        _ => {
+            ctx.result_error("Unknown setting name");
+            ctx.result_error_code(ResultCode::ERROR);
+            return;
+        }
+    };
+
+    let db = ctx.db_handle();
+    match insert_config_setting(db, name, value) {
+        Ok(value) => {
+            ctx.result_value(value);
+        }
+        Err(rc) => {
+            ctx.result_error("Could not persist config in database");
+            ctx.result_error_code(rc);
+            return;
+        }
+    }
+}
+
+fn insert_config_setting(
+    db: *mut sqlite_nostd::sqlite3,
+    name: &str,
+    value: *mut sqlite::value,
+) -> Result<*mut sqlite::value, ResultCode> {
+    let stmt =
+        db.prepare_v2("INSERT OR REPLACE INTO crsql_master VALUES (?, ?) RETURNING value")?;
+
+    stmt.bind_text(1, &format!("config.{name}"), sqlite::Destructor::TRANSIENT)?;
+    stmt.bind_value(2, value)?;
+
+    if let ResultCode::ROW = stmt.step()? {
+        stmt.column_value(0)
+    } else {
+        Err(ResultCode::ERROR)
+    }
+}
+
+pub extern "C" fn crsql_config_get(
+    ctx: *mut sqlite::context,
+    argc: i32,
+    argv: *mut *mut sqlite::value,
+) {
+    let args = sqlite::args!(argc, argv);
+
+    let name = args[0].text();
+
+    match name {
+        MERGE_EQUAL_VALUES => {
+            let ext_data = ctx.user_data() as *mut crsql_ExtData;
+            ctx.result_int(unsafe { (*ext_data).mergeEqualValues });
+        }
+        _ => {
+            ctx.result_error("Unknown setting name");
+            ctx.result_error_code(ResultCode::ERROR);
+            return;
+        }
+    }
+}