Merge 'core/pragma: Add support for update user_version' from Diego Reis

It also changes the type from u32 to i32 since
sqlite supports negative values

Closes #1559

COMPAT.md

@@ -170,7 +170,7 @@ Limbo aims to be fully compatible with SQLite, with opt-in features not supporte
 | PRAGMA temp_store_directory      | Not Needed | deprecated in SQLite                         |
 | PRAGMA threads                   | No         |                                              |
 | PRAGMA trusted_schema            | No         |                                              |
-| PRAGMA user_version              | Partial    | Only read implemented                        |
+| PRAGMA user_version              | Yes        |                                              |
 | PRAGMA vdbe_addoptrace           | No         |                                              |
 | PRAGMA vdbe_debug                | No         |                                              |
 | PRAGMA vdbe_listing              | No         |                                              |

core/storage/sqlite3_ondisk.rs

@@ -141,7 +141,7 @@ pub struct DatabaseHeader {
     text_encoding: u32,
 
     /// The "user version" as read and set by the user_version pragma.
-    pub user_version: u32,
+    pub user_version: i32,
 
     /// True (non-zero) for incremental-vacuum mode. False (zero) otherwise.
     incremental_vacuum_enabled: u32,
@@ -321,7 +321,7 @@ fn finish_read_database_header(
     }
     header.vacuum_mode_largest_root_page = u32::from_be_bytes([buf[52], buf[53], buf[54], buf[55]]);
     header.text_encoding = u32::from_be_bytes([buf[56], buf[57], buf[58], buf[59]]);
-    header.user_version = u32::from_be_bytes([buf[60], buf[61], buf[62], buf[63]]);
+    header.user_version = i32::from_be_bytes([buf[60], buf[61], buf[62], buf[63]]);
     header.incremental_vacuum_enabled = u32::from_be_bytes([buf[64], buf[65], buf[66], buf[67]]);
     header.application_id = u32::from_be_bytes([buf[68], buf[69], buf[70], buf[71]]);
     header.reserved_for_expansion.copy_from_slice(&buf[72..92]);

core/translate/pragma.rs

@@ -142,8 +142,28 @@ fn update_pragma(
             Ok(())
         }
         PragmaName::UserVersion => {
-            // TODO: Implement updating user_version
-            todo!("updating user_version not yet implemented")
+            let version_value = match value {
+                ast::Expr::Literal(ast::Literal::Numeric(numeric_value)) => {
+                    numeric_value.parse::<i32>()?
+                }
+                ast::Expr::Unary(ast::UnaryOperator::Negative, expr) => match *expr {
+                    ast::Expr::Literal(ast::Literal::Numeric(numeric_value)) => {
+                        -numeric_value.parse::<i32>()?
+                    }
+                    _ => bail_parse_error!("Not a valid value"),
+                },
+                _ => bail_parse_error!("Not a valid value"),
+            };
+
+            let mut header_guard = header.lock();
+
+            // update in-memory
+            header_guard.user_version = version_value;
+
+            // update in disk
+            pager.write_database_header(&header_guard);
+
+            Ok(())
         }
         PragmaName::SchemaVersion => {
             // TODO: Implement updating schema_version
@@ -286,14 +306,15 @@ fn update_cache_size(value: i64, header: Arc<SpinLock<DatabaseHeader>>, pager: R
         cache_size_unformatted = MIN_PAGE_CACHE_SIZE as i64;
     }
 
+    let mut header_guard = header.lock();
+
     // update in-memory header
-    header.lock().default_page_cache_size = cache_size_unformatted
+    header_guard.default_page_cache_size = cache_size_unformatted
         .try_into()
         .unwrap_or_else(|_| panic!("invalid value, too big for a i32 {}", value));
 
     // update in disk
-    let header_copy = header.lock().clone();
-    pager.write_database_header(&header_copy);
+    pager.write_database_header(&header_guard);
 
     // update cache size
     pager

testing/pragma.test

@@ -49,4 +49,9 @@ do_execsql_test_on_specific_db "testing/testing_user_version_10.db" pragma-user-
 
 do_execsql_test_on_specific_db ":memory:" pragma-user-version-default {
   PRAGMA user_version
-} {0}
+} {0}
+
+do_execsql_test_on_specific_db ":memory:" pragma-user-version-update {
+  PRAGMA user_version = 42;
+  PRAGMA user_version;
+} {42}