merged sqlite and sqlite3 adapters

1 files changed, 538 insertions, 7 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
index ae5eaa5f1b..7e1041a3ab 100644
--- a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -1,4 +1,6 @@
-require 'active_record/connection_adapters/sqlite_adapter'
+require 'active_record/connection_adapters/abstract_adapter'
+require 'active_record/connection_adapters/statement_pool'
+require 'arel/visitors/bind_visitor'
 
 gem 'sqlite3', '~> 1.3.5'
 require 'sqlite3'
@@ -35,16 +37,171 @@ module ActiveRecord
   end
 
   module ConnectionAdapters #:nodoc:
-    class SQLite3Adapter < SQLiteAdapter # :nodoc:
-      def quote(value, column = nil)
-        if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary)
-          s = column.class.string_to_binary(value).unpack("H*")[0]
-          "x'#{s}'"
-        else
+    class SQLiteColumn < Column #:nodoc:
+      class <<  self
+        def binary_to_string(value)
+          if value.encoding != Encoding::ASCII_8BIT
+            value = value.force_encoding(Encoding::ASCII_8BIT)
+          end
+          value
+        end
+      end
+    end
+
+    # The SQLite adapter works with both the 2.x and 3.x series of SQLite with the sqlite-ruby
+    # drivers (available both as gems and from http://rubyforge.org/projects/sqlite-ruby/).
+    #
+    # Options:
+    #
+    # * <tt>:database</tt> - Path to the database file.
+    class SQLite3Adapter < AbstractAdapter
+      class Version
+        include Comparable
+
+        def initialize(version_string)
+          @version = version_string.split('.').map { |v| v.to_i }
+        end
+
+        def <=>(version_string)
+          @version <=> version_string.split('.').map { |v| v.to_i }
+        end
+      end
+
+      class StatementPool < ConnectionAdapters::StatementPool
+        def initialize(connection, max)
           super
+          @cache = Hash.new { |h,pid| h[pid] = {} }
+        end
+
+        def each(&block); cache.each(&block); end
+        def key?(key);    cache.key?(key); end
+        def [](key);      cache[key]; end
+        def length;       cache.length; end
+
+        def []=(sql, key)
+          while @max <= cache.size
+            dealloc(cache.shift.last[:stmt])
+          end
+          cache[sql] = key
+        end
+
+        def clear
+          cache.values.each do |hash|
+            dealloc hash[:stmt]
+          end
+          cache.clear
+        end
+
+        private
+        def cache
+          @cache[$$]
+        end
+
+        def dealloc(stmt)
+          stmt.close unless stmt.closed?
         end
       end
 
+      class BindSubstitution < Arel::Visitors::SQLite # :nodoc:
+        include Arel::Visitors::BindVisitor
+      end
+
+      def initialize(connection, logger, config)
+        super(connection, logger)
+        @statements = StatementPool.new(@connection,
+                                        config.fetch(:statement_limit) { 1000 })
+        @config = config
+
+        if config.fetch(:prepared_statements) { true }
+          @visitor = Arel::Visitors::SQLite.new self
+        else
+          @visitor = BindSubstitution.new self
+        end
+      end
+
+      def adapter_name #:nodoc:
+        'SQLite'
+      end
+
+      # Returns true if SQLite version is '2.0.0' or greater, false otherwise.
+      def supports_ddl_transactions?
+        sqlite_version >= '2.0.0'
+      end
+
+      # Returns true if SQLite version is '3.6.8' or greater, false otherwise.
+      def supports_savepoints?
+        sqlite_version >= '3.6.8'
+      end
+
+      # Returns true, since this connection adapter supports prepared statement
+      # caching.
+      def supports_statement_cache?
+        true
+      end
+
+      # Returns true, since this connection adapter supports migrations.
+      def supports_migrations? #:nodoc:
+        true
+      end
+
+      # Returns true.
+      def supports_primary_key? #:nodoc:
+        true
+      end
+
+      def requires_reloading?
+        true
+      end
+
+      # Returns true if SQLite version is '3.1.6' or greater, false otherwise.
+      def supports_add_column?
+        sqlite_version >= '3.1.6'
+      end
+
+      # Disconnects from the database if already connected. Otherwise, this
+      # method does nothing.
+      def disconnect!
+        super
+        clear_cache!
+        @connection.close rescue nil
+      end
+
+      # Clears the prepared statements cache.
+      def clear_cache!
+        @statements.clear
+      end
+
+      # Returns true if SQLite version is '3.2.6' or greater, false otherwise.
+      def supports_count_distinct? #:nodoc:
+        sqlite_version >= '3.2.6'
+      end
+
+      # Returns true if SQLite version is '3.1.0' or greater, false otherwise.
+      def supports_autoincrement? #:nodoc:
+        sqlite_version >= '3.1.0'
+      end
+
+      def supports_index_sort_order?
+        sqlite_version >= '3.3.0'
+      end
+
+      def native_database_types #:nodoc:
+        {
+          :primary_key => default_primary_key_type,
+          :string      => { :name => "varchar", :limit => 255 },
+          :text        => { :name => "text" },
+          :integer     => { :name => "integer" },
+          :float       => { :name => "float" },
+          :decimal     => { :name => "decimal" },
+          :datetime    => { :name => "datetime" },
+          :timestamp   => { :name => "datetime" },
+          :time        => { :name => "time" },
+          :date        => { :name => "date" },
+          :binary      => { :name => "blob" },
+          :boolean     => { :name => "boolean" }
+        }
+      end
+
       # Returns the current database encoding format as a string, eg: 'UTF-8'
       def encoding
         @connection.encoding.to_s
@@ -55,6 +212,50 @@ module ActiveRecord
         true
       end
 
+
+      # QUOTING ==================================================
+
+      def quote(value, column = nil)
+        if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary)
+          s = column.class.string_to_binary(value).unpack("H*")[0]
+          "x'#{s}'"
+        else
+          super
+        end
+      end
+
+
+      def quote_string(s) #:nodoc:
+        @connection.class.quote(s)
+      end
+
+      def quote_column_name(name) #:nodoc:
+        %Q("#{name.to_s.gsub('"', '""')}")
+      end
+
+      # Quote date/time values for use in SQL input. Includes microseconds
+      # if the value is a Time responding to usec.
+      def quoted_date(value) #:nodoc:
+        if value.respond_to?(:usec)
+          "#{super}.#{sprintf("%06d", value.usec)}"
+        else
+          super
+        end
+      end
+
+      def type_cast(value, column) # :nodoc:
+        return value.to_f if BigDecimal === value
+        return super unless String === value
+        return super unless column && value
+
+        value = super
+        if column.type == :string && value.encoding == Encoding::ASCII_8BIT
+          logger.error "Binary data inserted for `string` type on column `#{column.name}`" if logger
+          value.encode! 'utf-8'
+        end
+        value
+      end
+
       # DATABASE STATEMENTS ======================================
 
       def explain(arel, binds = [])
@@ -75,6 +276,336 @@ module ActiveRecord
           end.join("\n") + "\n"
         end
       end
+
+      def exec_query(sql, name = nil, binds = [])
+        log(sql, name, binds) do
+
+          # Don't cache statements without bind values
+          if binds.empty?
+            stmt    = @connection.prepare(sql)
+            cols    = stmt.columns
+            records = stmt.to_a
+            stmt.close
+            stmt = records
+          else
+            cache = @statements[sql] ||= {
+              :stmt => @connection.prepare(sql)
+            }
+            stmt = cache[:stmt]
+            cols = cache[:cols] ||= stmt.columns
+            stmt.reset!
+            stmt.bind_params binds.map { |col, val|
+              type_cast(val, col)
+            }
+          end
+
+          ActiveRecord::Result.new(cols, stmt.to_a)
+        end
+      end
+
+      def exec_delete(sql, name = 'SQL', binds = [])
+        exec_query(sql, name, binds)
+        @connection.changes
+      end
+      alias :exec_update :exec_delete
+
+      def last_inserted_id(result)
+        @connection.last_insert_row_id
+      end
+
+      def execute(sql, name = nil) #:nodoc:
+        log(sql, name) { @connection.execute(sql) }
+      end
+
+      def update_sql(sql, name = nil) #:nodoc:
+        super
+        @connection.changes
+      end
+
+      def delete_sql(sql, name = nil) #:nodoc:
+        sql += " WHERE 1=1" unless sql =~ /WHERE/i
+        super sql, name
+      end
+
+      def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil) #:nodoc:
+        super
+        id_value || @connection.last_insert_row_id
+      end
+      alias :create :insert_sql
+
+      def select_rows(sql, name = nil)
+        exec_query(sql, name).rows
+      end
+
+      def create_savepoint
+        execute("SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def rollback_to_savepoint
+        execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def release_savepoint
+        execute("RELEASE SAVEPOINT #{current_savepoint_name}")
+      end
+
+      def begin_db_transaction #:nodoc:
+        log('begin transaction',nil) { @connection.transaction }
+      end
+
+      def commit_db_transaction #:nodoc:
+        log('commit transaction',nil) { @connection.commit }
+      end
+
+      def rollback_db_transaction #:nodoc:
+        log('rollback transaction',nil) { @connection.rollback }
+      end
+
+      # SCHEMA STATEMENTS ========================================
+
+      def tables(name = 'SCHEMA', table_name = nil) #:nodoc:
+        sql = <<-SQL
+          SELECT name
+          FROM sqlite_master
+          WHERE type = 'table' AND NOT name = 'sqlite_sequence'
+        SQL
+        sql << " AND name = #{quote_table_name(table_name)}" if table_name
+
+        exec_query(sql, name).map do |row|
+          row['name']
+        end
+      end
+
+      def table_exists?(name)
+        name && tables('SCHEMA', name).any?
+      end
+
+      # Returns an array of +SQLiteColumn+ objects for the table specified by +table_name+.
+      def columns(table_name) #:nodoc:
+        table_structure(table_name).map do |field|
+          case field["dflt_value"]
+          when /^null$/i
+            field["dflt_value"] = nil
+          when /^'(.*)'$/
+            field["dflt_value"] = $1.gsub("''", "'")
+          when /^"(.*)"$/
+            field["dflt_value"] = $1.gsub('""', '"')
+          end
+
+          SQLiteColumn.new(field['name'], field['dflt_value'], field['type'], field['notnull'].to_i == 0)
+        end
+      end
+
+      # Returns an array of indexes for the given table.
+      def indexes(table_name, name = nil) #:nodoc:
+        exec_query("PRAGMA index_list(#{quote_table_name(table_name)})", name).map do |row|
+          IndexDefinition.new(
+            table_name,
+            row['name'],
+            row['unique'] != 0,
+            exec_query("PRAGMA index_info('#{row['name']}')").map { |col|
+              col['name']
+            })
+        end
+      end
+
+      def primary_key(table_name) #:nodoc:
+        column = table_structure(table_name).find { |field|
+          field['pk'] == 1
+        }
+        column && column['name']
+      end
+
+      def remove_index!(table_name, index_name) #:nodoc:
+        exec_query "DROP INDEX #{quote_column_name(index_name)}"
+      end
+
+      # Renames a table.
+      #
+      # Example:
+      #   rename_table('octopuses', 'octopi')
+      def rename_table(name, new_name)
+        exec_query "ALTER TABLE #{quote_table_name(name)} RENAME TO #{quote_table_name(new_name)}"
+      end
+
+      # See: http://www.sqlite.org/lang_altertable.html
+      # SQLite has an additional restriction on the ALTER TABLE statement
+      def valid_alter_table_options( type, options)
+        type.to_sym != :primary_key
+      end
+
+      def add_column(table_name, column_name, type, options = {}) #:nodoc:
+        if supports_add_column? && valid_alter_table_options( type, options )
+          super(table_name, column_name, type, options)
+        else
+          alter_table(table_name) do |definition|
+            definition.column(column_name, type, options)
+          end
+        end
+      end
+
+      def remove_column(table_name, *column_names) #:nodoc:
+        raise ArgumentError.new("You must specify at least one column name. Example: remove_column(:people, :first_name)") if column_names.empty?
+        column_names.flatten.each do |column_name|
+          alter_table(table_name) do |definition|
+            definition.columns.delete(definition[column_name])
+          end
+        end
+      end
+      alias :remove_columns :remove_column
+
+      def change_column_default(table_name, column_name, default) #:nodoc:
+        alter_table(table_name) do |definition|
+          definition[column_name].default = default
+        end
+      end
+
+      def change_column_null(table_name, column_name, null, default = nil)
+        unless null || default.nil?
+          exec_query("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL")
+        end
+        alter_table(table_name) do |definition|
+          definition[column_name].null = null
+        end
+      end
+
+      def change_column(table_name, column_name, type, options = {}) #:nodoc:
+        alter_table(table_name) do |definition|
+          include_default = options_include_default?(options)
+          definition[column_name].instance_eval do
+            self.type    = type
+            self.limit   = options[:limit] if options.include?(:limit)
+            self.default = options[:default] if include_default
+            self.null    = options[:null] if options.include?(:null)
+            self.precision = options[:precision] if options.include?(:precision)
+            self.scale   = options[:scale] if options.include?(:scale)
+          end
+        end
+      end
+
+      def rename_column(table_name, column_name, new_column_name) #:nodoc:
+        unless columns(table_name).detect{|c| c.name == column_name.to_s }
+          raise ActiveRecord::ActiveRecordError, "Missing column #{table_name}.#{column_name}"
+        end
+        alter_table(table_name, :rename => {column_name.to_s => new_column_name.to_s})
+      end
+
+      def empty_insert_statement_value
+        "VALUES(NULL)"
+      end
+
+      protected
+        def select(sql, name = nil, binds = []) #:nodoc:
+          exec_query(sql, name, binds)
+        end
+
+        def table_structure(table_name)
+          structure = exec_query("PRAGMA table_info(#{quote_table_name(table_name)})", 'SCHEMA').to_hash
+          raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
+          structure
+        end
+
+        def alter_table(table_name, options = {}) #:nodoc:
+          altered_table_name = "altered_#{table_name}"
+          caller = lambda {|definition| yield definition if block_given?}
+
+          transaction do
+            move_table(table_name, altered_table_name,
+              options.merge(:temporary => true))
+            move_table(altered_table_name, table_name, &caller)
+          end
+        end
+
+        def move_table(from, to, options = {}, &block) #:nodoc:
+          copy_table(from, to, options, &block)
+          drop_table(from)
+        end
+
+        def copy_table(from, to, options = {}) #:nodoc:
+          options = options.merge(:id => (!columns(from).detect{|c| c.name == 'id'}.nil? && 'id' == primary_key(from).to_s))
+          create_table(to, options) do |definition|
+            @definition = definition
+            columns(from).each do |column|
+              column_name = options[:rename] ?
+                (options[:rename][column.name] ||
+                 options[:rename][column.name.to_sym] ||
+                 column.name) : column.name
+
+              @definition.column(column_name, column.type,
+                :limit => column.limit, :default => column.default,
+                :precision => column.precision, :scale => column.scale,
+                :null => column.null)
+            end
+            @definition.primary_key(primary_key(from)) if primary_key(from)
+            yield @definition if block_given?
+          end
+
+          copy_table_indexes(from, to, options[:rename] || {})
+          copy_table_contents(from, to,
+            @definition.columns.map {|column| column.name},
+            options[:rename] || {})
+        end
+
+        def copy_table_indexes(from, to, rename = {}) #:nodoc:
+          indexes(from).each do |index|
+            name = index.name
+            if to == "altered_#{from}"
+              name = "temp_#{name}"
+            elsif from == "altered_#{to}"
+              name = name[5..-1]
+            end
+
+            to_column_names = columns(to).map { |c| c.name }
+            columns = index.columns.map {|c| rename[c] || c }.select do |column|
+              to_column_names.include?(column)
+            end
+
+            unless columns.empty?
+              # index name can't be the same
+              opts = { :name => name.gsub(/_(#{from})_/, "_#{to}_") }
+              opts[:unique] = true if index.unique
+              add_index(to, columns, opts)
+            end
+          end
+        end
+
+        def copy_table_contents(from, to, columns, rename = {}) #:nodoc:
+          column_mappings = Hash[columns.map {|name| [name, name]}]
+          rename.each { |a| column_mappings[a.last] = a.first }
+          from_columns = columns(from).collect {|col| col.name}
+          columns = columns.find_all{|col| from_columns.include?(column_mappings[col])}
+          quoted_columns = columns.map { |col| quote_column_name(col) } * ','
+
+          quoted_to = quote_table_name(to)
+          exec_query("SELECT * FROM #{quote_table_name(from)}").each do |row|
+            sql = "INSERT INTO #{quoted_to} (#{quoted_columns}) VALUES ("
+            sql << columns.map {|col| quote row[column_mappings[col]]} * ', '
+            sql << ')'
+            exec_query sql
+          end
+        end
+
+        def sqlite_version
+          @sqlite_version ||= SQLite3Adapter::Version.new(select_value('select sqlite_version(*)'))
+        end
+
+        def default_primary_key_type
+          if supports_autoincrement?
+            'INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL'
+          else
+            'INTEGER PRIMARY KEY NOT NULL'
+          end
+        end
+
+        def translate_exception(exception, message)
+          case exception.message
+          when /column(s)? .* (is|are) not unique/
+            RecordNotUnique.new(message, exception)
+          else
+            super
+          end
+        end
+
     end
   end
 end