Trilogy::ProtocolError should use SQL codes to determine error class

Instead of raising all ProtocolErrors as connection errors,
we use the SQL error code to determine the type of error to raise
when handling the Trilogy error in the Ruby bindings.

The mapping of error codes to error classes was taken from the mysql2
implementation: https://github.com/brianmario/mysql2/blob/master/lib/mysql2/error.rb#L13-L27

Note that we don't need to care about the 2xxx errors because those
are raised by the libmysql client, which Trilogy doesn't deal with.

Co-authored-by: Jean Boussier <jean.boussier@shopify.com>

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

@@ -21,7 +21,7 @@ static ID id_socket, id_host, id_port, id_username, id_password, id_found_rows,
     id_write_timeout, id_keepalive_enabled, id_keepalive_idle, id_keepalive_interval, id_keepalive_count,
     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_ssl_mode, id_tls_ciphersuites, id_tls_min_version, id_tls_max_version, id_multi_statement, id_from_code;
 
 struct trilogy_ctx {
     trilogy_conn_t conn;
@@ -91,12 +91,7 @@ static void handle_trilogy_error(struct trilogy_ctx *ctx, int rc, const char *ms
 
     case TRILOGY_ERR: {
         VALUE message = rb_str_new(ctx->conn.error_message, ctx->conn.error_message_len);
-        VALUE exc = rb_exc_new3(Trilogy_ProtocolError,
-                                rb_sprintf("%" PRIsVALUE ": %d %" PRIsVALUE, rbmsg, ctx->conn.error_code, message));
-
-        rb_ivar_set(exc, rb_intern("@error_code"), INT2FIX(ctx->conn.error_code));
-        rb_ivar_set(exc, rb_intern("@error_message"), message);
-
+        VALUE exc = rb_funcall(Trilogy_ProtocolError, id_from_code, 2, message, INT2NUM(ctx->conn.error_code));
         rb_exc_raise(exc);
     }
 
@@ -1038,7 +1033,7 @@ void Init_cext()
     id_tls_min_version = rb_intern("tls_min_version");
     id_tls_max_version = rb_intern("tls_max_version");
     id_multi_statement = rb_intern("multi_statement");
-
+    id_from_code = rb_intern("from_code");
     id_ivar_affected_rows = rb_intern("@affected_rows");
     id_ivar_fields = rb_intern("@fields");
     id_ivar_last_insert_id = rb_intern("@last_insert_id");

contrib/ruby/lib/trilogy.rb

@@ -28,10 +28,42 @@ class QueryError < ClientError
   class CastError < ClientError
   end
 
-  class ProtocolError < BaseError
+
+  class TimeoutError < Errno::ETIMEDOUT
     include ConnectionError
+  end
+
+  class ProtocolError < BaseError
+    ERROR_CODES = {
+      1205 => TimeoutError, # ER_LOCK_WAIT_TIMEOUT
+      1044 => ConnectionError, # ER_DBACCESS_DENIED_ERROR
+      1045 => ConnectionError, # ER_ACCESS_DENIED_ERROR
+      1152 => ConnectionError, # ER_ABORTING_CONNECTION
+      1153 => ConnectionError, # ER_NET_PACKET_TOO_LARGE
+      1154 => ConnectionError, # ER_NET_READ_ERROR_FROM_PIPE
+      1155 => ConnectionError, # ER_NET_FCNTL_ERROR
+      1156 => ConnectionError, # ER_NET_PACKETS_OUT_OF_ORDER
+      1157 => ConnectionError, # ER_NET_UNCOMPRESS_ERROR
+      1158 => ConnectionError, # ER_NET_READ_ERROR
+      1159 => ConnectionError, # ER_NET_READ_INTERRUPTED
+      1160 => ConnectionError, # ER_NET_ERROR_ON_WRITE
+      1161 => ConnectionError, # ER_NET_WRITE_INTERRUPTED
+      1927 => ConnectionError, # ER_CONNECTION_KILLED
+    }
 
     attr_reader :error_code, :error_message
+
+    class << self
+      def from_code(message, code)
+        ERROR_CODES.fetch(code, self).new(message, code)
+      end
+    end
+
+    def initialize(error_message, error_code)
+      super("#{error_code}: #{error_message}")
+      @error_code = error_code
+      @error_message = error_message
+    end
   end
 
   class SSLError < BaseError
@@ -42,10 +74,6 @@ class ConnectionClosed < IOError
     include ConnectionError
   end
 
-  class TimeoutError < Errno::ETIMEDOUT
-    include ConnectionError
-  end
-
   def in_transaction?
     (server_status & SERVER_STATUS_IN_TRANS) != 0
   end

contrib/ruby/test/client_test.rb

@@ -511,6 +511,23 @@ def test_timeout_deadlines
     end
   end
 
+  def test_timeout_error
+    client_1 = new_tcp_client
+    client_2 = new_tcp_client
+
+    create_test_table(client_1)
+    client_2.change_db("test")
+
+    client_1.query("SET GLOBAL innodb_lock_wait_timeout = 2;")
+    client_1.query("INSERT INTO trilogy_test (varchar_test) VALUES ('a')")
+    client_1.query("BEGIN")
+    client_1.query("SELECT * FROM trilogy_test FOR UPDATE")
+
+    assert_raises Trilogy::TimeoutError do
+      client_2.query("SELECT * FROM trilogy_test FOR UPDATE")
+    end
+  end
+
   def test_database_error
     client = new_tcp_client