Pass max_allowed_packet through the ruby library

Co-authored-by: Kamil Gwóźdź <kamil-gwozdz@github.com>

contrib/ruby/ext/trilogy-ruby/cext.c

@@ -27,7 +27,7 @@ static ID id_socket, id_host, id_port, id_username, id_password, id_found_rows,
     id_ivar_affected_rows, id_ivar_fields, id_ivar_last_insert_id, id_ivar_rows, id_ivar_query_time, id_password,
     id_database, id_ssl_ca, id_ssl_capath, id_ssl_cert, id_ssl_cipher, id_ssl_crl, id_ssl_crlpath, id_ssl_key,
     id_ssl_mode, id_tls_ciphersuites, id_tls_min_version, id_tls_max_version, id_multi_statement, id_multi_result,
-    id_from_code, id_from_errno, id_connection_options;
+    id_from_code, id_from_errno, id_connection_options, id_max_allowed_packet;
 
 struct trilogy_ctx {
     trilogy_conn_t conn;
@@ -139,6 +139,10 @@ static void handle_trilogy_error(struct trilogy_ctx *ctx, int rc, const char *ms
         rb_raise(Trilogy_BaseConnectionError, "%" PRIsVALUE ": TRILOGY_DNS_ERROR", rbmsg);
     }
 
+    case TRILOGY_MAX_PACKET_EXCEEDED: {
+        rb_raise(Trilogy_QueryError, "%" PRIsVALUE ": TRILOGY_MAX_PACKET_EXCEEDED", rbmsg);
+    }
+
     default:
         rb_raise(Trilogy_QueryError, "%" PRIsVALUE ": %s", rbmsg, trilogy_error(rc));
     }
@@ -415,6 +419,11 @@ static VALUE rb_trilogy_initialize(VALUE self, VALUE encoding, VALUE charset, VA
         connopt.keepalive_interval = NUM2USHORT(val);
     }
 
+    if ((val = rb_hash_lookup(opts, ID2SYM(id_max_allowed_packet))) != Qnil) {
+        Check_Type(val, T_FIXNUM);
+        connopt.max_allowed_packet = NUM2SIZET(val);
+    }
+
     if ((val = rb_hash_lookup(opts, ID2SYM(id_host))) != Qnil) {
         Check_Type(val, T_STRING);
 
@@ -1114,6 +1123,7 @@ RUBY_FUNC_EXPORTED void Init_cext()
     id_connect_timeout = rb_intern("connect_timeout");
     id_read_timeout = rb_intern("read_timeout");
     id_write_timeout = rb_intern("write_timeout");
+    id_max_allowed_packet = rb_intern("max_allowed_packet");
     id_keepalive_enabled = rb_intern("keepalive_enabled");
     id_keepalive_idle = rb_intern("keepalive_idle");
     id_keepalive_count = rb_intern("keepalive_count");

contrib/ruby/test/client_test.rb

@@ -745,28 +745,116 @@ def test_connect_by_multiple_names
     Trilogy.new(host: "localhost")
   end
 
+  PADDED_QUERY_TEMPLATE = "SELECT LENGTH('%s')"
+  PROTOCOL_OVERHEAD = 2 # One byte for the 0x03 (COM_QUERY); one because the packet is actually required to be shorter than the "max"
+  PADDED_QUERY_OVERHEAD =
+    PADDED_QUERY_TEMPLATE.size - "%s".size + PROTOCOL_OVERHEAD
+
+  def query_for_target_packet_size(size)
+    PADDED_QUERY_TEMPLATE % ("x" * (size - PADDED_QUERY_OVERHEAD))
+  end
+
   def set_max_allowed_packet(size)
     client = new_tcp_client
     client.query "SET GLOBAL max_allowed_packet = #{size}"
   ensure
     ensure_closed client
   end
 
-  def test_packet_size
+  def test_packet_size_lower_than_trilogy_max_packet_len
+    set_max_allowed_packet(4 * 1024 * 1024) # TRILOGY_MAX_PACKET_LEN is 16MB
+
+    client = new_tcp_client(max_allowed_packet: 4 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(1 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(2 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(4 * 1024 * 1024)
+
+    exception = assert_raises Trilogy::QueryError do
+      client.query query_for_target_packet_size(4 * 1024 * 1024 + 1)
+    end
+
+    assert_equal exception.message, "trilogy_query_send: TRILOGY_MAX_PACKET_EXCEEDED"
+  ensure
+    ensure_closed client
+  end
+
+  def test_packet_size_greater_than_trilogy_max_packet_len
+    set_max_allowed_packet(32 * 1024 * 1024) # TRILOGY_MAX_PACKET_LEN is 16MB
+
+    client = new_tcp_client(max_allowed_packet: 32 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(16 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(32 * 1024 * 1024)
+
+    exception = assert_raises Trilogy::QueryError do
+      client.query query_for_target_packet_size(32 * 1024 * 1024 + 1)
+    end
+
+    assert_equal exception.message, "trilogy_query_send: TRILOGY_MAX_PACKET_EXCEEDED"
+  ensure
+    ensure_closed client
+  end
+
+  def test_configured_max_packet_below_server
     set_max_allowed_packet(32 * 1024 * 1024)
 
-    client = new_tcp_client
+    client = new_tcp_client(max_allowed_packet: 24 * 1024 * 1024)
 
-    create_test_table(client)
-    client.query "TRUNCATE trilogy_test"
+    assert client.query query_for_target_packet_size(16 * 1024 * 1024)
 
-    result = client.query "INSERT INTO trilogy_test (blob_test) VALUES ('#{"x" * (15 * 1024 * 1024)}')"
-    assert result
-    assert_equal 1, client.last_insert_id
+    assert client.query query_for_target_packet_size(24 * 1024 * 1024)
 
-    result = client.query "INSERT INTO trilogy_test (blob_test) VALUES ('#{"x" * (31 * 1024 * 1024)}')"
-    assert result
-    assert_equal 2, client.last_insert_id
+    exception = assert_raises Trilogy::QueryError do
+      client.query query_for_target_packet_size(24 * 1024 * 1024 + 1)
+    end
+
+    assert_equal exception.message, "trilogy_query_send: TRILOGY_MAX_PACKET_EXCEEDED"
+  ensure
+    ensure_closed client
+  end
+
+  def test_configured_max_packet_above_server
+    set_max_allowed_packet(24 * 1024 * 1024)
+
+    client = new_tcp_client(max_allowed_packet: 32 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(16 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(24 * 1024 * 1024)
+
+    exception = assert_raises Trilogy::QueryError do
+      client.query query_for_target_packet_size(32 * 1024 * 1024 + 1)
+    end
+
+    assert_equal exception.message, "trilogy_query_send: TRILOGY_MAX_PACKET_EXCEEDED"
+
+    exception = assert_raises Trilogy::QueryError do
+      client.query query_for_target_packet_size(24 * 1024 * 1024 + 1)
+    end
+
+    refute_match exception.message, /TRILOGY_MAX_PACKET_EXCEEDED/
+  ensure
+    ensure_closed client
+  end
+
+  def test_absolute_maximum_packet_size
+    skip unless ENV["CI"]
+
+    set_max_allowed_packet(1024 * 1024 * 1024) # 1GB is the highest maximum allowed
+
+    client = new_tcp_client(max_allowed_packet: 1024 * 1024 * 1024)
+
+    assert client.query query_for_target_packet_size(1024 * 1024 * 1024)
+
+    exception = assert_raises Trilogy::QueryError do
+      client.query query_for_target_packet_size(1024 * 1024 * 1024 + 1)
+    end
+
+    assert_equal exception.message, "trilogy_query_send: TRILOGY_MAX_PACKET_EXCEEDED"
   ensure
     ensure_closed client
   end