Make ActiveRecord structure load/dump configurable

Without this patch it's impossible to pass extra flags to
mysqldump/pg_dump when running `rake db:structure:dump` or `load`

The following config variables (`structure_load_flags` and `structure_dump_flags`)
make it better configurable.

4 files changed, 28 insertions, 11 deletions

diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index c6204ac36f..fd215eeb86 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -35,6 +35,16 @@ module ActiveRecord
     #
     #   DatabaseTasks.create_current('production')
     module DatabaseTasks
+      ##
+      # :singleton-method:
+      # Extra flags passed to database CLI tool (mysqldump/pg_dump) when calling db:structure:dump
+      mattr_accessor :structure_dump_flags, instance_accessor: false
+
+      ##
+      # :singleton-method:
+      # Extra flags passed to database CLI tool when calling db:structure:load
+      mattr_accessor :structure_load_flags, instance_accessor: false
+
       extend self
 
       attr_writer :current_config, :db_dir, :migrations_paths, :fixtures_path, :root, :env, :seed_loader
@@ -204,13 +214,13 @@ module ActiveRecord
       def structure_dump(*arguments)
         configuration = arguments.first
         filename = arguments.delete_at 1
-        class_for_adapter(configuration["adapter"]).new(*arguments).structure_dump(filename)
+        class_for_adapter(configuration["adapter"]).new(*arguments).structure_dump(filename, structure_dump_flags)
       end
 
       def structure_load(*arguments)
         configuration = arguments.first
         filename = arguments.delete_at 1
-        class_for_adapter(configuration["adapter"]).new(*arguments).structure_load(filename)
+        class_for_adapter(configuration["adapter"]).new(*arguments).structure_load(filename, structure_load_flags)
       end
 
       def load_schema(configuration, format = ActiveRecord::Base.schema_format, file = nil) # :nodoc:
diff --git a/activerecord/lib/active_record/tasks/mysql_database_tasks.rb b/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
index 5cdb3d53f6..920830b9cf 100644
--- a/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/mysql_database_tasks.rb
@@ -53,21 +53,23 @@ module ActiveRecord
         connection.collation
       end
 
-      def structure_dump(filename)
+      def structure_dump(filename, extra_flags)
         args = prepare_command_options
         args.concat(["--result-file", "#{filename}"])
         args.concat(["--no-data"])
         args.concat(["--routines"])
         args.concat(["--skip-comments"])
+        args.concat(Array(extra_flags)) if extra_flags
         args.concat(["#{configuration['database']}"])
 
         run_cmd("mysqldump", args, "dumping")
       end
 
-      def structure_load(filename)
+      def structure_load(filename, extra_flags)
         args = prepare_command_options
         args.concat(["--execute", %{SET FOREIGN_KEY_CHECKS = 0; SOURCE #{filename}; SET FOREIGN_KEY_CHECKS = 1}])
         args.concat(["--database", "#{configuration['database']}"])
+        args.concat(Array(extra_flags)) if extra_flags
 
         run_cmd("mysql", args, "loading")
       end
diff --git a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
index 4e9897f7b0..5155ced0e2 100644
--- a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
@@ -43,7 +43,7 @@ module ActiveRecord
         create true
       end
 
-      def structure_dump(filename)
+      def structure_dump(filename, extra_flags)
         set_psql_env
 
         search_path = \
@@ -57,6 +57,7 @@ module ActiveRecord
           end
 
         args = ["-s", "-x", "-O", "-f", filename]
+        args.concat(Array(extra_flags)) if extra_flags
         unless search_path.blank?
           args += search_path.split(",").map do |part|
             "--schema=#{part.strip}"
@@ -67,9 +68,11 @@ module ActiveRecord
         File.open(filename, "a") { |f| f << "SET search_path TO #{connection.schema_search_path};\n\n" }
       end
 
-      def structure_load(filename)
+      def structure_load(filename, extra_flags)
         set_psql_env
-        args = [ "-v", ON_ERROR_STOP_1, "-q", "-f", filename, configuration["database"] ]
+        args = ["-v", ON_ERROR_STOP_1, "-q", "-f", filename]
+        args.concat(Array(extra_flags)) if extra_flags
+        args << configuration["database"]
         run_cmd("psql", args, "loading")
       end
 
diff --git a/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb b/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
index 31f1b7efd4..0419b67081 100644
--- a/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/sqlite_database_tasks.rb
@@ -35,14 +35,16 @@ module ActiveRecord
         connection.encoding
       end
 
-      def structure_dump(filename)
+      def structure_dump(filename, extra_flags)
         dbfile = configuration["database"]
-        `sqlite3 #{dbfile} .schema > #{filename}`
+        flags = extra_flags.try!(:join, " ")
+        `sqlite3 #{flags} #{dbfile} .schema > #{filename}`
       end
 
-      def structure_load(filename)
+      def structure_load(filename, extra_flags)
         dbfile = configuration["database"]
-        `sqlite3 #{dbfile} < "#{filename}"`
+        flags = extra_flags.try!(:join, " ")
+        `sqlite3 #{flags} #{dbfile} < "#{filename}"`
       end
 
       private