More specific exception classes

ext/mysql2/client.c

@@ -15,7 +15,7 @@
 #include "mysql_enc_name_to_ruby.h"
 
 VALUE cMysql2Client;
-extern VALUE mMysql2, cMysql2Error;
+extern VALUE mMysql2, cMysql2Error, cMysql2TimeoutError;
 static VALUE sym_id, sym_version, sym_header_version, sym_async, sym_symbolize_keys, sym_as, sym_array, sym_stream;
 static ID intern_brackets, intern_merge, intern_merge_bang, intern_new_with_args;
 
@@ -650,7 +650,7 @@ static VALUE do_query(void *args) {
     retval = rb_wait_for_single_fd(async_args->fd, RB_WAITFD_IN, tvp);
 
     if (retval == 0) {
-      rb_raise(cMysql2Error, "Timeout waiting for a response from the last query. (waited %d seconds)", FIX2INT(read_timeout));
+      rb_raise(cMysql2TimeoutError, "Timeout waiting for a response from the last query. (waited %d seconds)", FIX2INT(read_timeout));
     }
 
     if (retval < 0) {

ext/mysql2/mysql2_ext.c

@@ -1,11 +1,12 @@
 #include <mysql2_ext.h>
 
-VALUE mMysql2, cMysql2Error;
+VALUE mMysql2, cMysql2Error, cMysql2TimeoutError;
 
 /* Ruby Extension initializer */
 void Init_mysql2() {
   mMysql2      = rb_define_module("Mysql2");
   cMysql2Error = rb_const_get(mMysql2, rb_intern("Error"));
+  cMysql2TimeoutError = rb_const_get(cMysql2Error, rb_intern("TimeoutError"));
 
   init_mysql2_client();
   init_mysql2_result();

ext/mysql2/statement.c

@@ -1,7 +1,7 @@
 #include <mysql2_ext.h>
 
 VALUE cMysql2Statement;
-extern VALUE mMysql2, cMysql2Error, cBigDecimal, cDateTime, cDate;
+extern VALUE mMysql2, cMysql2Error, cMysql2TimeoutError, cBigDecimal, cDateTime, cDate;
 static VALUE sym_stream, intern_new_with_args, intern_each, intern_to_s;
 static VALUE intern_sec_fraction, intern_usec, intern_sec, intern_min, intern_hour, intern_day, intern_month, intern_year;
 #ifndef HAVE_RB_BIG_CMP

lib/mysql2/error.rb

@@ -8,25 +8,64 @@ class Error < StandardError
       :replace => '?'.freeze,
     }.freeze
 
+    ConnectionError = Class.new(Error)
+    TimeoutError = Class.new(Error)
+
+    CODES = {
+      1205 => TimeoutError, # ER_LOCK_WAIT_TIMEOUT
+    }
+
+    [
+      1044, # ER_DBACCESS_DENIED_ERROR
+      1045, # ER_ACCESS_DENIED_ERROR
+      1152, # ER_ABORTING_CONNECTION
+      1153, # ER_NET_PACKET_TOO_LARGE
+      1154, # ER_NET_READ_ERROR_FROM_PIPE
+      1155, # ER_NET_FCNTL_ERROR
+      1156, # ER_NET_PACKETS_OUT_OF_ORDER
+      1157, # ER_NET_UNCOMPRESS_ERROR
+      1158, # ER_NET_READ_ERROR
+      1159, # ER_NET_READ_INTERRUPTED
+      1160, # ER_NET_ERROR_ON_WRITE
+      1161, # ER_NET_WRITE_INTERRUPTED
+
+      2001, # CR_SOCKET_CREATE_ERROR
+      2002, # CR_CONNECTION_ERROR
+      2003, # CR_CONN_HOST_ERROR
+      2004, # CR_IPSOCK_ERROR
+      2005, # CR_UNKNOWN_HOST
+      2006, # CR_SERVER_GONE_ERROR
+      2007, # CR_VERSION_ERROR
+      2009, # CR_WRONG_HOST_INFO
+      2012, # CR_SERVER_HANDSHAKE_ERR
+      2013, # CR_SERVER_LOST
+      2020, # CR_NET_PACKET_TOO_LARGE
+      2026, # CR_SSL_CONNECTION_ERROR
+      2027, # CR_MALFORMED_PACKET
+      2047, # CR_CONN_UNKNOW_PROTOCOL
+      2048, # CR_INVALID_CONN_HANDLE
+      2049, # CR_UNUSED_1
+    ].each { |c| CODES[c] = ConnectionError }
+
+    CODES.freeze
+
     attr_reader :error_number, :sql_state
 
     # Mysql gem compatibility
     alias_method :errno, :error_number
     alias_method :error, :message
 
-    def initialize(msg)
-      @server_version ||= nil
+    def initialize(msg, server_version = nil, error_number = nil, sql_state = nil)
+      @server_version = server_version
+      @error_number = error_number
+      @sql_state = sql_state.respond_to?(:encode) ? sql_state.encode(ENCODE_OPTS) : sql_state
 
       super(clean_message(msg))
     end
 
     def self.new_with_args(msg, server_version, error_number, sql_state)
-      err = allocate
-      err.instance_variable_set('@server_version', server_version)
-      err.instance_variable_set('@error_number', error_number)
-      err.instance_variable_set('@sql_state', sql_state.respond_to?(:encode) ? sql_state.encode(ENCODE_OPTS) : sql_state)
-      err.send(:initialize, msg)
-      err
+      error_class = CODES.fetch(error_number, self)
+      error_class.new(msg, server_version, error_number, sql_state)
     end
 
     private

spec/mysql2/client_spec.rb

@@ -18,12 +18,12 @@
     end
   end
 
-  it "should raise an exception upon connection failure" do
+  it "should raise a Mysql::Error::ConnectionError upon connection failure" do
     expect {
       # The odd local host IP address forces the mysql client library to
       # use a TCP socket rather than a domain socket.
       new_client('host' => '127.0.0.2', 'port' => 999999)
-    }.to raise_error(Mysql2::Error)
+    }.to raise_error(Mysql2::Error::ConnectionError)
   end
 
   it "should raise an exception on create for invalid encodings" do
@@ -538,7 +538,7 @@ def run_gc
         client = new_client(:read_timeout => 0)
         expect {
           client.query('SELECT SLEEP(0.1)')
-        }.to raise_error(Mysql2::Error)
+        }.to raise_error(Mysql2::Error::TimeoutError)
       end
 
       # XXX this test is not deterministic (because Unix signal handling is not)
@@ -918,10 +918,10 @@ def run_gc
     end
   end
 
-  it "should raise a Mysql2::Error exception upon connection failure" do
+  it "should raise a Mysql2::Error::ConnectionError exception upon connection failure due to invalid credentials" do
     expect {
       new_client(:host => "localhost", :username => 'asdfasdf8d2h', :password => 'asdfasdfw42')
-    }.to raise_error(Mysql2::Error)
+    }.to raise_error(Mysql2::Error::ConnectionError)
 
     expect {
       new_client(DatabaseCredentials['root'])