Initial

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 371 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
new file mode 100755
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+++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb
@@ -0,0 +1,371 @@
+require 'benchmark'
+require 'date'
+
+# Method that requires a library, ensuring that rubygems is loaded
+# This is used in the database adaptors to require DB drivers. Reasons:
+# (1) database drivers are the only third-party library that Rails depend upon
+# (2) they are often installed as gems
+def require_library_or_gem(library_name)
+  begin
+    require library_name
+  rescue LoadError => cannot_require
+    # 1. Requiring the module is unsuccessful, maybe it's a gem and nobody required rubygems yet. Try.
+    begin
+      require 'rubygems'
+    rescue LoadError => rubygems_not_installed
+      raise cannot_require
+    end
+    # 2. Rubygems is installed and loaded. Try to load the library again
+    begin 
+      require library_name
+    rescue LoadError => gem_not_installed
+      raise cannot_require
+    end
+  end
+end
+
+module ActiveRecord
+  class Base
+    class ConnectionSpecification #:nodoc:
+      attr_reader :config, :adapter_method
+      def initialize (config, adapter_method)
+        @config, @adapter_method = config, adapter_method
+      end
+    end
+    
+    # The class -> [adapter_method, config] map
+    @@defined_connections = {}
+
+    # Establishes the connection to the database. Accepts a hash as input where
+    # the :adapter key must be specified with the name of a database adapter (in lower-case)
+    # example for regular databases (MySQL, Postgresql, etc):
+    #
+    #   ActiveRecord::Base.establish_connection(
+    #     :adapter  => "mysql",
+    #     :host     => "localhost",
+    #     :username => "myuser",
+    #     :password => "mypass",
+    #     :database => "somedatabase"
+    #   )
+    #
+    # Example for SQLite database:
+    #
+    #   ActiveRecord::Base.establish_connection(
+    #     :adapter => "sqlite",
+    #     :dbfile  => "path/to/dbfile"
+    #   )
+    #
+    # Also accepts keys as strings (for parsing from yaml for example):
+    #   ActiveRecord::Base.establish_connection(
+    #     "adapter" => "sqlite",
+    #     "dbfile"  => "path/to/dbfile"
+    #   )
+    #
+    # The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError
+    # may be returned on an error.
+    #
+    # == Connecting to another database for a single model
+    #
+    # To support different connections for different classes, you can
+    # simply call establish_connection with the classes you wish to have
+    # different connections for:
+    #
+    #   class Courses < ActiveRecord::Base
+    #    ...
+    #   end
+    #
+    #   Courses.establish_connection( ... )
+    def self.establish_connection(spec)
+      if spec.instance_of? ConnectionSpecification
+        @@defined_connections[self] = spec
+      elsif spec.is_a?(Symbol)
+        establish_connection(configurations[spec.to_s])
+      else
+        if spec.nil? then raise AdapterNotSpecified end
+        symbolize_strings_in_hash(spec)
+        unless spec.key?(:adapter) then raise AdapterNotSpecified end
+    
+        adapter_method = "#{spec[:adapter]}_connection"
+        unless methods.include?(adapter_method) then raise AdapterNotFound end
+        remove_connection
+        @@defined_connections[self] = ConnectionSpecification.new(spec, adapter_method)
+      end
+    end
+
+    # Locate the connection of the nearest super class. This can be an
+    # active or defined connections: if it is the latter, it will be
+    # opened and set as the active connection for the class it was defined
+    # for (not necessarily the current class).
+    def self.retrieve_connection #:nodoc:
+      klass = self
+      until klass == ActiveRecord::Base.superclass
+        Thread.current['active_connections'] ||= {}
+        if Thread.current['active_connections'][klass]
+          return Thread.current['active_connections'][klass]
+        elsif @@defined_connections[klass]
+          klass.connection = @@defined_connections[klass]
+          return self.connection
+        end
+        klass = klass.superclass
+      end
+      raise ConnectionNotEstablished
+    end
+    
+    # Returns true if a connection that's accessible to this class have already been opened.
+    def self.connected?
+      klass = self
+      until klass == ActiveRecord::Base.superclass
+        if Thread.current['active_connections'].is_a?(Hash) && Thread.current['active_connections'][klass]
+          return true 
+        else
+          klass = klass.superclass
+        end
+      end
+      return false
+    end
+    
+    # Remove the connection for this class. This will close the active
+    # connection and the defined connection (if they exist). The result
+    # can be used as argument for establish_connection, for easy
+    # re-establishing of the connection.
+    def self.remove_connection(klass=self)
+      conn = @@defined_connections[klass]
+      @@defined_connections.delete(klass)
+      Thread.current['active_connections'] ||= {}
+      Thread.current['active_connections'][klass] = nil
+      conn.config if conn
+    end
+    
+    # Set the connection for the class.
+    def self.connection=(spec)
+      raise ConnectionNotEstablished unless spec
+      conn = self.send(spec.adapter_method, spec.config)
+      Thread.current['active_connections'] ||= {}
+      Thread.current['active_connections'][self] = conn
+    end
+
+    # Converts all strings in a hash to symbols.
+    def self.symbolize_strings_in_hash(hash)
+      hash.each do |key, value|
+        if key.class == String
+          hash.delete key
+          hash[key.intern] = value
+        end
+      end
+    end
+  end
+
+  module ConnectionAdapters # :nodoc:
+    class Column # :nodoc:
+      attr_reader :name, :default, :type, :limit
+      # The name should contain the name of the column, such as "name" in "name varchar(250)"
+      # The default should contain the type-casted default of the column, such as 1 in "count int(11) DEFAULT 1"
+      # The type parameter should either contain :integer, :float, :datetime, :date, :text, or :string
+      # The sql_type is just used for extracting the limit, such as 10 in "varchar(10)"
+      def initialize(name, default, sql_type = nil)
+        @name, @default, @type = name, default, simplified_type(sql_type)
+        @limit = extract_limit(sql_type) unless sql_type.nil?
+      end
+
+      def default
+        type_cast(@default)
+      end
+
+      def klass
+        case type
+          when :integer       then Fixnum
+          when :float         then Float
+          when :datetime      then Time
+          when :date          then Date
+          when :text, :string then String
+          when :boolean       then Object
+        end
+      end
+      
+      def type_cast(value)
+        if value.nil? then return nil end
+        case type
+          when :string   then value
+          when :text     then value
+          when :integer  then value.to_i
+          when :float    then value.to_f
+          when :datetime then string_to_time(value)
+          when :date     then string_to_date(value)
+          when :boolean  then (value == "t" or value == true ? true : false)
+          else value
+        end
+      end
+      
+      def human_name
+        Base.human_attribute_name(@name)
+      end
+
+      private
+        def string_to_date(string)
+          return string if Date === string
+          date_array = ParseDate.parsedate(string)
+          # treat 0000-00-00 as nil
+          Date.new(date_array[0], date_array[1], date_array[2]) rescue nil
+        end
+        
+        def string_to_time(string)
+          return string if Time === string
+          time_array = ParseDate.parsedate(string).compact
+          # treat 0000-00-00 00:00:00 as nil
+          Time.local(*time_array) rescue nil
+        end
+
+        def extract_limit(sql_type)
+          $1.to_i if sql_type =~ /\((.*)\)/
+        end
+
+        def simplified_type(field_type)
+          case field_type
+            when /int/i
+              :integer
+            when /float|double|decimal|numeric/i
+              :float
+            when /time/i
+              :datetime
+            when /date/i
+              :date
+            when /(c|b)lob/i, /text/i
+              :text
+            when /char/i, /string/i
+              :string
+            when /boolean/i
+              :boolean
+          end
+        end
+    end
+
+    # All the concrete database adapters follow the interface laid down in this class.
+    # You can use this interface directly by borrowing the database connection from the Base with
+    # Base.connection.
+    class AbstractAdapter
+      @@row_even = true
+
+      include Benchmark
+
+      def initialize(connection, logger = nil) # :nodoc:
+        @connection, @logger = connection, logger
+        @runtime = 0
+      end
+
+      # Returns an array of record hashes with the column names as a keys and fields as values.
+      def select_all(sql, name = nil) end
+      
+      # Returns a record hash with the column names as a keys and fields as values.
+      def select_one(sql, name = nil) end
+
+      # Returns an array of column objects for the table specified by +table_name+.
+      def columns(table_name, name = nil) end
+
+      # Returns the last auto-generated ID from the affected table.
+      def insert(sql, name = nil, pk = nil, id_value = nil) end
+
+      # Executes the update statement.
+      def update(sql, name = nil) end
+
+      # Executes the delete statement.
+      def delete(sql, name = nil) end
+
+      def reset_runtime # :nodoc:
+        rt = @runtime
+        @runtime = 0
+        return rt
+      end
+
+      # Wrap a block in a transaction.  Returns result of block.
+      def transaction
+        begin
+          if block_given?
+            begin_db_transaction
+            result = yield
+            commit_db_transaction
+            result
+          end
+        rescue Exception => database_transaction_rollback
+          rollback_db_transaction
+          raise
+        end
+      end
+
+      # Begins the transaction (and turns off auto-committing).
+      def begin_db_transaction()    end
+      
+      # Commits the transaction (and turns on auto-committing). 
+      def commit_db_transaction()   end
+
+      # Rollsback the transaction (and turns on auto-committing). Must be done if the transaction block
+      # raises an exception or returns false.
+      def rollback_db_transaction() end
+
+      def quote(value, column = nil)
+        case value
+          when String                      then "'#{quote_string(value)}'" # ' (for ruby-mode)
+          when NilClass                    then "NULL"
+          when TrueClass                   then (column && column.type == :boolean ? "'t'" : "1")
+          when FalseClass                  then (column && column.type == :boolean ? "'f'" : "0")
+          when Float, Fixnum, Bignum, Date then "'#{value.to_s}'" 
+          when Time, DateTime              then "'#{value.strftime("%Y-%m-%d %H:%M:%S")}'"
+          else                                  "'#{quote_string(value.to_yaml)}'"
+        end
+      end
+
+      def quote_string(s)
+        s.gsub(/\\/, '\&\&').gsub(/'/, "''") # ' (for ruby-mode)
+      end
+
+      def quote_column_name(name)
+        return name
+      end
+
+      # Returns a string of the CREATE TABLE SQL statements for recreating the entire structure of the database.
+      def structure_dump() end
+
+      protected
+        def log(sql, name, connection, &action)
+          begin
+            if @logger.nil?
+              action.call(connection)
+            else
+              result = nil
+              bm = measure { result = action.call(connection) }
+              @runtime += bm.real
+              log_info(sql, name, bm.real)
+              result
+            end
+          rescue => e
+            log_info("#{e.message}: #{sql}", name, 0)
+            raise ActiveRecord::StatementInvalid, "#{e.message}: #{sql}"
+          end
+        end
+
+        def log_info(sql, name, runtime)
+          if @logger.nil? then return end
+
+          @logger.info(
+            format_log_entry(
+              "#{name.nil? ? "SQL" : name} (#{sprintf("%f", runtime)})", 
+              sql.gsub(/ +/, " ")
+            )
+          )
+        end
+
+        def format_log_entry(message, dump = nil)
+          if @@row_even then
+            @@row_even = false; caller_color = "1;32"; message_color = "4;33"; dump_color = "1;37"
+          else
+            @@row_even = true; caller_color = "1;36"; message_color = "4;35"; dump_color = "0;37"
+          end
+          
+          log_entry = "  \e[#{message_color}m#{message}\e[m"
+          log_entry << "   \e[#{dump_color}m%s\e[m" % dump if dump.kind_of?(String) && !dump.nil?
+          log_entry << "   \e[#{dump_color}m%p\e[m" % dump if !dump.kind_of?(String) && !dump.nil?
+          log_entry
+        end
+    end
+    
+  end
+end