From 00084e4e97d94cdab04ca1eb16275e0ed88c9490 Mon Sep 17 00:00:00 2001
From: Alex Rothenberg <alex@alexrothenberg.com>
Date: Wed, 19 Aug 2009 14:42:02 -0400
Subject: [PATCH] added optional dbms_output logging on each call

---
 .../oracle_enhanced_adapter.rb                | 44 ++++++++++++-
 .../oracle_enhanced_adapter_spec.rb           | 62 +++++++++++++++++++
 2 files changed, 105 insertions(+), 1 deletion(-)

diff --git a/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb b/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb
index 789da3729..19145b1b2 100644
--- a/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb
+++ b/lib/active_record/connection_adapters/oracle_enhanced_adapter.rb
@@ -524,7 +524,6 @@ def disconnect! #:nodoc:
         @connection.logoff rescue nil
       end
 
-
       # DATABASE STATEMENTS ======================================
       #
       # see: abstract/database_statements.rb
@@ -1152,6 +1151,49 @@ def column_for(table_name, column_name)
         column
       end
 
+      public
+      # DBMS_OUTPUT =============================================
+      #
+      # PL/SQL in Oracle uses dbms_output for logging print statements
+      # These methods stick that output into the Rails log so Ruby and PL/SQL
+      # code can can be debugged together in a single application 
+      DBMS_OUTPUT_BUFFER_SIZE = 10000  #can be 1-1000000
+      DBMS_LINE_MAX_SIZE      = 1000  
+      # Turn DBMS_Output logging on
+      def enable_dbms_output
+        @enable_dbms_output = true
+        execute "BEGIN dbms_output.enable(#{DBMS_OUTPUT_BUFFER_SIZE}); END;"
+      end
+      # Turn DBMS_Output logging off
+      def disable_dbms_output
+        @enable_dbms_output = false
+        execute "BEGIN dbms_output.disable(); END;"
+      end
+      # Is DBMD_Output logging enabled?
+      def dbms_output_enabled?
+        @enable_dbms_output
+      end
+
+      protected
+      def log(sql, name)
+        super sql, name
+      ensure
+        log_dbms_output if dbms_output_enabled?
+      end
+      
+      private  
+      def log_next_line_of_dbms_output
+        dbms_output_text, status = @connection.exec "BEGIN dbms_output.get_line(:return, :status); END;", ' '*DBMS_LINE_MAX_SIZE, 1
+        got_text = (status == 0)
+        @logger.debug "DBMS_OUTPUT: #{dbms_output_text}" if got_text
+        got_text
+      end
+      
+      def log_dbms_output
+        while log_next_line_of_dbms_output do
+        end
+      end
+
     end
   end
 end
diff --git a/spec/active_record/connection_adapters/oracle_enhanced_adapter_spec.rb b/spec/active_record/connection_adapters/oracle_enhanced_adapter_spec.rb
index d217c3586..dead9b993 100644
--- a/spec/active_record/connection_adapters/oracle_enhanced_adapter_spec.rb
+++ b/spec/active_record/connection_adapters/oracle_enhanced_adapter_spec.rb
@@ -657,3 +657,65 @@ class ::TestEmployee < ActiveRecord::Base; end
   end
 
 end
+
+describe "logging dbms_output from plsql" do
+  include LoggerSpecHelper
+
+  before(:all) do
+    @buffer = StringIO.new
+    ActiveRecord::Base.establish_connection(CONNECTION_PARAMS)
+    ActiveRecord::Base.connection.execute <<-SQL
+    create or replace
+    FUNCTION MORE_THAN_FIVE_CHARACTERS_LONG (some_text VARCHAR2) RETURN INTEGER
+    AS
+      longer_than_five INTEGER;
+    BEGIN
+      dbms_output.put_line('before the if -' || some_text || '-');
+      IF length(some_text) > 5 THEN
+        dbms_output.put_line('it is longer than 5');
+        longer_than_five := 1;
+      ELSE
+        dbms_output.put_line('it is 5 or shorter');
+        longer_than_five := 0;
+      END IF;
+      dbms_output.put_line('about to return: ' || longer_than_five);
+      RETURN longer_than_five;
+    END;
+    SQL
+  end
+
+  before(:each) do
+    @buffer = StringIO.new
+    log_to @buffer
+    ActiveRecord::Base.establish_connection(CONNECTION_PARAMS)
+    @conn = ActiveRecord::Base.connection
+  end
+
+  it "should NOT log dbms output when dbms output is disabled" do
+    @conn.disable_dbms_output
+
+    @conn.select_all("select more_than_five_characters_long('hi there') is_it_long from dual").should == [{'is_it_long'=>1}]
+    
+    @buffer.string.should_not match(/^DBMS_OUTPUT/)
+  end
+
+  it "should log dbms output lines to the rails log" do
+    @conn.enable_dbms_output
+
+    @conn.select_all("select more_than_five_characters_long('hi there') is_it_long from dual").should == [{'is_it_long'=>1}]
+    
+    @buffer.string.should match(/^DBMS_OUTPUT: before the if -hi there-$/)
+    @buffer.string.should match(/^DBMS_OUTPUT: it is longer than 5$/)
+    @buffer.string.should match(/^DBMS_OUTPUT: about to return: 1$/)
+  end
+
+  it "should log dbms output lines to the rails log" do
+    @conn.enable_dbms_output
+
+    @conn.select_all("select more_than_five_characters_long('short') is_it_long from dual").should == [{'is_it_long'=>0}]
+    
+    @buffer.string.should match(/^DBMS_OUTPUT: before the if -short-$/)
+    @buffer.string.should match(/^DBMS_OUTPUT: it is 5 or shorter$/)
+    @buffer.string.should match(/^DBMS_OUTPUT: about to return: 0$/)
+  end
+end
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