Adapter#reset!

README.md

@@ -34,6 +34,7 @@ job.save  # => true
   def exec(sql) : Nil
   def lastval : Int64
   def scalar(*args)
+  def reset! : Nil
 
   # CRUD
   def insert(fields, params)
@@ -103,6 +104,7 @@ Pon.query_logging=(v : Bool) # writes queries into the logger or not
   - [ ] escape
   - [x] migrator
 - Adapter Drivers
+  - [x] reset connections
   - RDB
     - [x] mysql
     - [x] pg

spec/adapter_spec.cr

@@ -42,7 +42,6 @@ end
 {% for adapter in ADAPTERS %}
 module {{adapter.upcase.id}}
   describe "[{{adapter.upcase.id}}](ODBC)" do
-
     describe "#databases" do
       it "returns database names as Array(String)" do
         Job.adapter.databases.should be_a(Array(String))
@@ -54,11 +53,9 @@ module {{adapter.upcase.id}}
         Job.adapter.tables.should contain("jobs")
       end
     end
-
   end
 
   describe "[{{adapter.upcase.id}}](Trasaction)" do
-
     describe "#transaction" do
       {% if adapter == "mysql" %}
       pending "ensures transaction" do
@@ -71,7 +68,17 @@ module {{adapter.upcase.id}}
         end
       end
     end
+  end
 
+  describe "[{{adapter.upcase.id}}](Reset)" do
+    describe "#reset!" do
+      it "closes and re-builds connection" do
+        id1 = Job.adapter.database.object_id
+        Job.adapter.reset!
+        id2 = Job.adapter.database.object_id
+        id1.should_not eq(id2)
+      end
+    end
   end
 end
 {% end %}

src/pon/adapter.cr

@@ -15,7 +15,8 @@ abstract class Pon::Adapter
     databases[setting.url] ||= build_database(setting)
   end
 
-  private def self.build_database(setting) : DB::Database
+  # used from instances
+  def self.build_database(setting) : DB::Database
     db = ::DB.open(setting.url)
     db.setup_connection do |con|
       if sql = setting.init_connect?
@@ -25,6 +26,13 @@ abstract class Pon::Adapter
     end
     return db
   end
+
+  def self.reset!(setting : Setting) : Nil
+    if db = databases[setting.url]?
+      db.close
+      databases.delete(setting.url)
+    end
+  end
 end
 
 require "./adapter/rdb"

src/pon/adapter/rdb.cr

@@ -1,12 +1,12 @@
 # base class for crystal-db
 abstract class Pon::Adapter::RDB < Pon::Adapter
-  abstract def db : ::DB::Database
   abstract def table_name : String
   abstract def logger : Logger
   abstract def exec(query : String, params = [] of String)
   abstract def lastval : Int64
   abstract def scalar(*args)
   abstract def transaction(&block) : Nil
+  abstract def reset! : Nil
 
   abstract def insert(fields, params)
   abstract def all(fields : Array(String), as types : Tuple, limit = nil)
@@ -21,7 +21,7 @@ abstract class Pon::Adapter::RDB < Pon::Adapter
   abstract def tables : Array(String)
 
   delegate quote, to: self.class
-  delegate query_one?, query_all, scalar, to: db
+  delegate query_one?, query_all, scalar, to: database
 
   enum BindType
     Question = 1                # "?"
@@ -48,22 +48,36 @@ abstract class Pon::Adapter::RDB < Pon::Adapter
     @qt : String                # quoted table name
     @qp : String                # quoted primary name
 
-    getter db : ::DB::Database
     getter table_name
 
-    def initialize(klass, @table_name : String, @primary_name : String, @setting : ::Pon::Setting = ::Pon::Setting.new, db : ::DB::Database? = nil)
+    def initialize(klass, @table_name : String, @primary_name : String, @setting : ::Pon::Setting = ::Pon::Setting.new, @db : ::DB::Database? = nil)
       # bind class setting to default only if default is not set
       if @setting.default? == nil
         @setting.default = self.class.setting
       end
 
       @qt = quote(@table_name)
       @qp = quote(@primary_name)
-      @db = db || Pon::Adapter.database(@setting)
     end
 
-    ### ODBC
+    # `database` abstracts unique connections and access to shared connections.
+    # Querying each time accessing without caching slightly degrades performance,
+    # but this mechanism is required when resetting shared connections.
+    def database : ::DB::Database
+      @db || Pon::Adapter.database(@setting)
+    end
 
+    def reset! : Nil
+      if db = @db
+        db.close
+        @db = Pon::Adapter.build_database(@setting)
+      else
+        Pon::Adapter.reset!(@setting)
+      end
+    end
+
+    ### ODBC
+
     def databases : Array(String)
       query = @setting.query_show_databases
       query_all query, as: String
@@ -78,7 +92,7 @@ abstract class Pon::Adapter::RDB < Pon::Adapter
     def exec(query : String, params = [] of String)
       query = underlying_prepared(query) if params.any?
       query_log "#{query}: #{params}", "exec"
-      db.exec query, params
+      database.exec query, params
     end
 
     def transaction(&block) : Nil