Move migrations to a separate file.

Author: rkistner

crates/core/src/lib.rs

@@ -19,6 +19,7 @@ mod error;
 mod ext;
 mod kv;
 mod macros;
+mod migrations;
 mod operations;
 mod operations_vtab;
 mod schema_management;

crates/core/src/migrations.rs

@@ -0,0 +1,288 @@
+extern crate alloc;
+
+use alloc::format;
+use alloc::string::{String, ToString};
+use alloc::vec::Vec;
+
+use sqlite::ResultCode;
+use sqlite_nostd as sqlite;
+use sqlite_nostd::{Connection, Context};
+
+use crate::error::{PSResult, SQLiteError};
+
+pub fn powersync_migrate(
+    ctx: *mut sqlite::context,
+    target_version: i32,
+) -> Result<(), SQLiteError> {
+    let local_db = ctx.db_handle();
+
+    // language=SQLite
+    local_db.exec_safe(
+        "\
+CREATE TABLE IF NOT EXISTS ps_migration(id INTEGER PRIMARY KEY, down_migrations TEXT)",
+    )?;
+
+    // language=SQLite
+    let current_version_stmt =
+        local_db.prepare_v2("SELECT ifnull(max(id), 0) as version FROM ps_migration")?;
+    let rc = current_version_stmt.step()?;
+    if rc != ResultCode::ROW {
+        return Err(SQLiteError::from(ResultCode::ABORT));
+    }
+
+    let mut current_version = current_version_stmt.column_int(0)?;
+
+    while current_version > target_version {
+        // Run down migrations.
+        // This is rare, we don't worry about optimizing this.
+
+        current_version_stmt.reset()?;
+
+        let down_migrations_stmt = local_db.prepare_v2("select e.value ->> 'sql' as sql from (select id, down_migrations from ps_migration where id > ?1 order by id desc limit 1) m, json_each(m.down_migrations) e")?;
+        down_migrations_stmt.bind_int(1, target_version)?;
+
+        let mut down_sql: Vec<String> = alloc::vec![];
+
+        while down_migrations_stmt.step()? == ResultCode::ROW {
+            let sql = down_migrations_stmt.column_text(0)?;
+            down_sql.push(sql.to_string());
+        }
+
+        for sql in down_sql {
+            let rs = local_db.exec_safe(&sql);
+            if let Err(code) = rs {
+                return Err(SQLiteError(
+                    code,
+                    Some(format!(
+                        "Down migration failed for {:} {:} {:}",
+                        current_version,
+                        sql,
+                        local_db
+                            .errmsg()
+                            .unwrap_or(String::from("Conversion error"))
+                    )),
+                ));
+            }
+        }
+
+        // Refresh the version
+        current_version_stmt.reset()?;
+        let rc = current_version_stmt.step()?;
+        if rc != ResultCode::ROW {
+            return Err(SQLiteError(
+                rc,
+                Some("Down migration failed - could not get version".to_string()),
+            ));
+        }
+        let new_version = current_version_stmt.column_int(0)?;
+        if new_version >= current_version {
+            // Database down from version $currentVersion to $version failed - version not updated after dow migration
+            return Err(SQLiteError(
+                ResultCode::ABORT,
+                Some(format!(
+                    "Down migration failed - version not updated from {:}",
+                    current_version
+                )),
+            ));
+        }
+        current_version = new_version;
+    }
+    current_version_stmt.reset()?;
+
+    if current_version < 1 {
+        // language=SQLite
+        local_db
+            .exec_safe(
+                "
+CREATE TABLE ps_oplog(
+bucket TEXT NOT NULL,
+op_id INTEGER NOT NULL,
+op INTEGER NOT NULL,
+row_type TEXT,
+row_id TEXT,
+key TEXT,
+data TEXT,
+hash INTEGER NOT NULL,
+superseded INTEGER NOT NULL);
+
+CREATE INDEX ps_oplog_by_row ON ps_oplog (row_type, row_id) WHERE superseded = 0;
+CREATE INDEX ps_oplog_by_opid ON ps_oplog (bucket, op_id);
+CREATE INDEX ps_oplog_by_key ON ps_oplog (bucket, key) WHERE superseded = 0;
+
+CREATE TABLE ps_buckets(
+name TEXT PRIMARY KEY,
+last_applied_op INTEGER NOT NULL DEFAULT 0,
+last_op INTEGER NOT NULL DEFAULT 0,
+target_op INTEGER NOT NULL DEFAULT 0,
+add_checksum INTEGER NOT NULL DEFAULT 0,
+pending_delete INTEGER NOT NULL DEFAULT 0
+);
+
+CREATE TABLE ps_untyped(type TEXT NOT NULL, id TEXT NOT NULL, data TEXT, PRIMARY KEY (type, id));
+
+CREATE TABLE ps_crud (id INTEGER PRIMARY KEY AUTOINCREMENT, data TEXT);
+
+INSERT INTO ps_migration(id, down_migrations) VALUES(1, NULL);
+",
+            )
+            .into_db_result(local_db)?;
+    }
+
+    if current_version < 2 && target_version >= 2 {
+        // language=SQLite
+        local_db.exec_safe("\
+CREATE TABLE ps_tx(id INTEGER PRIMARY KEY NOT NULL, current_tx INTEGER, next_tx INTEGER);
+INSERT INTO ps_tx(id, current_tx, next_tx) VALUES(1, NULL, 1);
+
+ALTER TABLE ps_crud ADD COLUMN tx_id INTEGER;
+
+INSERT INTO ps_migration(id, down_migrations) VALUES(2, json_array(json_object('sql', 'DELETE FROM ps_migration WHERE id >= 2', 'params', json_array()), json_object('sql', 'DROP TABLE ps_tx', 'params', json_array()), json_object('sql', 'ALTER TABLE ps_crud DROP COLUMN tx_id', 'params', json_array())));
+").into_db_result(local_db)?;
+    }
+
+    if current_version < 3 && target_version >= 3 {
+        // language=SQLite
+        local_db.exec_safe("\
+CREATE TABLE ps_kv(key TEXT PRIMARY KEY NOT NULL, value BLOB);
+INSERT INTO ps_kv(key, value) values('client_id', uuid());
+
+INSERT INTO ps_migration(id, down_migrations) VALUES(3, json_array(json_object('sql', 'DELETE FROM ps_migration WHERE id >= 3'), json_object('sql', 'DROP TABLE ps_kv')));
+  ").into_db_result(local_db)?;
+    }
+
+    if current_version < 4 && target_version >= 4 {
+        // language=SQLite
+        local_db.exec_safe("\
+ALTER TABLE ps_buckets ADD COLUMN op_checksum INTEGER NOT NULL DEFAULT 0;
+ALTER TABLE ps_buckets ADD COLUMN remove_operations INTEGER NOT NULL DEFAULT 0;
+
+UPDATE ps_buckets SET op_checksum = (
+SELECT IFNULL(SUM(ps_oplog.hash), 0) & 0xffffffff FROM ps_oplog WHERE ps_oplog.bucket = ps_buckets.name
+);
+
+INSERT INTO ps_migration(id, down_migrations)
+VALUES(4,
+  json_array(
+    json_object('sql', 'DELETE FROM ps_migration WHERE id >= 4'),
+    json_object('sql', 'ALTER TABLE ps_buckets DROP COLUMN op_checksum'),
+    json_object('sql', 'ALTER TABLE ps_buckets DROP COLUMN remove_operations')
+  ));
+  ").into_db_result(local_db)?;
+    }
+
+    if current_version < 5 && target_version >= 5 {
+        // Start by dropping all existing views and triggers (but not tables).
+        // This is because the triggers are restructured in this version, and
+        // need to be re-created from scratch. Not dropping them can make it
+        // refer to tables or columns not existing anymore, which can case
+        // issues later on.
+        // The same applies for the down migration.
+
+        // language=SQLite
+        local_db
+          .exec_safe(
+              "\
+SELECT powersync_drop_view(view.name)
+FROM sqlite_master view
+WHERE view.type = 'view'
+  AND view.sql GLOB  '*-- powersync-auto-generated';
+
+ALTER TABLE ps_buckets RENAME TO ps_buckets_old;
+ALTER TABLE ps_oplog RENAME TO ps_oplog_old;
+
+CREATE TABLE ps_buckets(
+  id INTEGER PRIMARY KEY,
+  name TEXT NOT NULL,
+  last_applied_op INTEGER NOT NULL DEFAULT 0,
+  last_op INTEGER NOT NULL DEFAULT 0,
+  target_op INTEGER NOT NULL DEFAULT 0,
+  add_checksum INTEGER NOT NULL DEFAULT 0,
+  op_checksum INTEGER NOT NULL DEFAULT 0,
+  pending_delete INTEGER NOT NULL DEFAULT 0
+) STRICT;
+
+CREATE UNIQUE INDEX ps_buckets_name ON ps_buckets (name);
+
+CREATE TABLE ps_oplog(
+  bucket INTEGER NOT NULL,
+  op_id INTEGER NOT NULL,
+  row_type TEXT,
+  row_id TEXT,
+  key TEXT,
+  data TEXT,
+  hash INTEGER NOT NULL) STRICT;
+
+CREATE INDEX ps_oplog_row ON ps_oplog (row_type, row_id);
+CREATE INDEX ps_oplog_opid ON ps_oplog (bucket, op_id);
+CREATE INDEX ps_oplog_key ON ps_oplog (bucket, key);
+
+CREATE TABLE ps_updated_rows(
+  row_type TEXT,
+  row_id TEXT) STRICT;
+
+CREATE UNIQUE INDEX ps_updated_rows_row ON ps_updated_rows (row_type, row_id);
+
+INSERT INTO ps_buckets(name, last_applied_op, last_op, target_op, add_checksum, op_checksum, pending_delete)
+SELECT name, last_applied_op, last_op, target_op, add_checksum, op_checksum, pending_delete FROM ps_buckets_old;
+
+DROP TABLE ps_buckets_old;
+
+INSERT INTO ps_oplog(bucket, op_id, row_type, row_id, key, data, hash)
+SELECT ps_buckets.id, oplog.op_id, oplog.row_type, oplog.row_id, oplog.key, oplog.data, oplog.hash
+  FROM ps_oplog_old oplog
+  JOIN ps_buckets
+    ON ps_buckets.name = oplog.bucket
+    WHERE oplog.superseded = 0 AND oplog.op = 3
+    ORDER BY oplog.bucket, oplog.op_id;
+
+INSERT OR IGNORE INTO ps_updated_rows(row_type, row_id)
+SELECT row_type, row_id
+ FROM ps_oplog_old oplog
+ WHERE oplog.op != 3;
+
+UPDATE ps_buckets SET add_checksum = 0xffffffff & (add_checksum + (
+SELECT IFNULL(SUM(oplog.hash), 0)
+  FROM ps_oplog_old oplog
+  WHERE oplog.bucket = ps_buckets.name
+    AND (oplog.superseded = 1 OR oplog.op != 3)
+));
+
+UPDATE ps_buckets SET op_checksum = 0xffffffff & (op_checksum - (
+  SELECT IFNULL(SUM(oplog.hash), 0)
+    FROM ps_oplog_old oplog
+    WHERE oplog.bucket = ps_buckets.name
+      AND (oplog.superseded = 1 OR oplog.op != 3)
+));
+
+DROP TABLE ps_oplog_old;
+
+INSERT INTO ps_migration(id, down_migrations)
+VALUES(5,
+  json_array(
+    -- Drop existing views and triggers if any
+    json_object('sql', 'SELECT powersync_drop_view(view.name)\n  FROM sqlite_master view\n  WHERE view.type = ''view''\n    AND view.sql GLOB  ''*-- powersync-auto-generated'''),
+
+    json_object('sql', 'ALTER TABLE ps_buckets RENAME TO ps_buckets_5'),
+    json_object('sql', 'ALTER TABLE ps_oplog RENAME TO ps_oplog_5'),
+    json_object('sql', 'CREATE TABLE ps_buckets(\n  name TEXT PRIMARY KEY,\n  last_applied_op INTEGER NOT NULL DEFAULT 0,\n  last_op INTEGER NOT NULL DEFAULT 0,\n  target_op INTEGER NOT NULL DEFAULT 0,\n  add_checksum INTEGER NOT NULL DEFAULT 0,\n  pending_delete INTEGER NOT NULL DEFAULT 0\n, op_checksum INTEGER NOT NULL DEFAULT 0, remove_operations INTEGER NOT NULL DEFAULT 0)'),
+    json_object('sql', 'INSERT INTO ps_buckets(name, last_applied_op, last_op, target_op, add_checksum, op_checksum, pending_delete)\n    SELECT name, last_applied_op, last_op, target_op, add_checksum, op_checksum, pending_delete FROM ps_buckets_5'),
+    json_object('sql', 'CREATE TABLE ps_oplog(\n  bucket TEXT NOT NULL,\n  op_id INTEGER NOT NULL,\n  op INTEGER NOT NULL,\n  row_type TEXT,\n  row_id TEXT,\n  key TEXT,\n  data TEXT,\n  hash INTEGER NOT NULL,\n  superseded INTEGER NOT NULL)'),
+    json_object('sql', 'CREATE INDEX ps_oplog_by_row ON ps_oplog (row_type, row_id) WHERE superseded = 0'),
+    json_object('sql', 'CREATE INDEX ps_oplog_by_opid ON ps_oplog (bucket, op_id)'),
+    json_object('sql', 'CREATE INDEX ps_oplog_by_key ON ps_oplog (bucket, key) WHERE superseded = 0'),
+    json_object('sql', 'INSERT INTO ps_oplog(bucket, op_id, op, row_type, row_id, key, data, hash, superseded)\n    SELECT ps_buckets_5.name, oplog.op_id, 3, oplog.row_type, oplog.row_id, oplog.key, oplog.data, oplog.hash, 0\n    FROM ps_oplog_5 oplog\n    JOIN ps_buckets_5\n        ON ps_buckets_5.id = oplog.bucket'),
+    json_object('sql', 'DROP TABLE ps_oplog_5'),
+    json_object('sql', 'DROP TABLE ps_buckets_5'),
+    json_object('sql', 'INSERT INTO ps_oplog(bucket, op_id, op, row_type, row_id, hash, superseded)\n    SELECT ''$local'', 1, 4, r.row_type, r.row_id, 0, 0\n    FROM ps_updated_rows r'),
+    json_object('sql', 'INSERT OR REPLACE INTO ps_buckets(name, pending_delete, last_op, target_op) VALUES(''$local'', 1, 0, 9223372036854775807)'),
+    json_object('sql', 'DROP TABLE ps_updated_rows'),
+
+    json_object('sql', 'DELETE FROM ps_migration WHERE id >= 5')
+  ));
+  ",
+          )
+          .into_db_result(local_db)?;
+    }
+
+    Ok(())
+}