Ssandler upstream changes (#88)

* perf optimization in ColumnExpression, avoid expensive Str\split call

* perf optimization in FromClause to avoid nested loops when strictSchemaMode is enabled

src/Expressions/ColumnExpression.php

@@ -56,19 +56,9 @@ public function evaluateImpl(row $row, AsyncMysqlConnection $_conn): mixed {
       // didn't find row by alias, so search without alias instead
       // but only if the column expression didn't have an explicit table name on it
       // OR if we are explicitly allowing fallthrough to the full row, which we do in the ORDER BY clause
+      $dot_column_name = '.'.$this->columnName;
       foreach ($row as $key => $col) {
-        $parts = Str\split($key, '.');
-
-        // find the last part of the string - as an optimization, we deliberately don't call C\lastx
-        $did_iterate = false;
-        $last_part = null;
-        foreach ($parts as $part) {
-          $did_iterate = true;
-          $last_part = $part;
-        }
-        invariant($did_iterate, 'Column name was empty');
-
-        if ($last_part === $this->columnName) {
+        if (Str\ends_with($key, $dot_column_name)) {
           return $col;
         }
       }

src/Query/FromClause.php

@@ -66,7 +66,16 @@ public function process(AsyncMysqlConnection $conn, string $sql): dataset {
       invariant($res is KeyedContainer<_, _>, 'evaluated result of SubqueryExpression must be dataset');
 
       $new_dataset = vec[];
-      if ($schema !== null) {
+      if ($schema is nonnull && QueryContext::$strictSchemaMode) {
+         foreach ($res as $row) {
+          $row as dict<_, _>;
+          $m = dict[];
+          foreach ($row as $field => $val) {
+            $m["{$name}.{$field}"] = $val;
+          }
+          $new_dataset[] = $m;
+        }
+      } else if ($schema is nonnull) {
         // if schema is set, order the fields in the right order on each row
         $ordered_fields = keyset[];
         foreach ($schema['fields'] as $field) {