From 4bd16f053847f2efe347ebda9136ef2233ee0d2c Mon Sep 17 00:00:00 2001
From: hukl <contact@smyck.org>
Date: Tue, 28 Apr 2009 00:15:53 +0200
Subject: added thinking_sphinx plugin for fulltext search on nodes and heads

---
 .../lib/thinking_sphinx/attribute.rb               | 358 +++++++++++++++++++++
 1 file changed, 358 insertions(+)
 create mode 100644 vendor/plugins/thinking-sphinx/lib/thinking_sphinx/attribute.rb

(limited to 'vendor/plugins/thinking-sphinx/lib/thinking_sphinx/attribute.rb')

diff --git a/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/attribute.rb b/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/attribute.rb
new file mode 100644
index 0000000..1d45b2e
--- /dev/null
+++ b/vendor/plugins/thinking-sphinx/lib/thinking_sphinx/attribute.rb
@@ -0,0 +1,358 @@
+module ThinkingSphinx
+  # Attributes - eternally useful when it comes to filtering, sorting or
+  # grouping. This class isn't really useful to you unless you're hacking
+  # around with the internals of Thinking Sphinx - but hey, don't let that
+  # stop you.
+  #
+  # One key thing to remember - if you're using the attribute manually to
+  # generate SQL statements, you'll need to set the base model, and all the
+  # associations. Which can get messy. Use Index.link!, it really helps.
+  # 
+  class Attribute
+    attr_accessor :alias, :columns, :associations, :model, :faceted, :source
+    
+    # To create a new attribute, you'll need to pass in either a single Column
+    # or an array of them, and some (optional) options.
+    #
+    # Valid options are:
+    # - :as     => :alias_name
+    # - :type   => :attribute_type
+    # - :source => :field, :query, :ranged_query
+    #
+    # Alias is only required in three circumstances: when there's
+    # another attribute or field with the same name, when the column name is
+    # 'id', or when there's more than one column.
+    # 
+    # Type is not required, unless you want to force a column to be a certain
+    # type (but keep in mind the value will not be CASTed in the SQL
+    # statements). The only time you really need to use this is when the type
+    # can't be figured out by the column - ie: when not actually using a
+    # database column as your source.
+    # 
+    # Source is only used for multi-value attributes (MVA). By default this will
+    # use a left-join and a group_concat to obtain the values. For better performance
+    # during indexing it can be beneficial to let Sphinx use a separate query to retrieve
+    # all document,value-pairs.
+    # Either :query or :ranged_query will enable this feature, where :ranged_query will cause
+    # the query to be executed incremental.
+    #
+    # Example usage:
+    #
+    #   Attribute.new(
+    #     Column.new(:created_at)
+    #   )
+    #
+    #   Attribute.new(
+    #     Column.new(:posts, :id),
+    #     :as => :post_ids
+    #   )
+    #
+    #   Attribute.new(
+    #     Column.new(:posts, :id),
+    #     :as => :post_ids,
+    #     :source => :ranged_query
+    #   )
+    #
+    #   Attribute.new(
+    #     [Column.new(:pages, :id), Column.new(:articles, :id)],
+    #     :as => :content_ids
+    #   )
+    #
+    #   Attribute.new(
+    #     Column.new("NOW()"),
+    #     :as   => :indexed_at,
+    #     :type => :datetime
+    #   )
+    #
+    # If you're creating attributes for latitude and longitude, don't forget
+    # that Sphinx expects these values to be in radians.
+    #  
+    def initialize(columns, options = {})
+      @columns      = Array(columns)
+      @associations = {}
+      
+      raise "Cannot define a field with no columns. Maybe you are trying to index a field with a reserved name (id, name). You can fix this error by using a symbol rather than a bare name (:id instead of id)." if @columns.empty? || @columns.any? { |column| !column.respond_to?(:__stack) }
+      
+      @alias    = options[:as]
+      @type     = options[:type]
+      @faceted  = options[:facet]
+      @source   = options[:source]
+      @crc      = options[:crc]
+      
+      @type   ||= :multi    unless @source.nil?
+      @type     = :integer  if @type == :string && @crc
+    end
+    
+    # Get the part of the SELECT clause related to this attribute. Don't forget
+    # to set your model and associations first though.
+    #
+    # This will concatenate strings and arrays of integers, and convert
+    # datetimes to timestamps, as needed.
+    # 
+    def to_select_sql
+      return nil unless include_as_association?
+      
+      clause = @columns.collect { |column|
+        column_with_prefix(column)
+      }.join(', ')
+      
+      separator = all_ints? ? ',' : ' '
+      
+      clause = adapter.concatenate(clause, separator)       if concat_ws?
+      clause = adapter.group_concatenate(clause, separator) if is_many?
+      clause = adapter.cast_to_datetime(clause)             if type == :datetime
+      clause = adapter.convert_nulls(clause)                if type == :string
+      clause = adapter.crc(clause)                          if @crc
+      
+      "#{clause} AS #{quote_column(unique_name)}"
+    end
+    
+    # Get the part of the GROUP BY clause related to this attribute - if one is
+    # needed. If not, all you'll get back is nil. The latter will happen if
+    # there isn't actually a real column to get data from, or if there's
+    # multiple data values (read: a has_many or has_and_belongs_to_many
+    # association).
+    # 
+    def to_group_sql
+      case
+      when is_many?, is_string?, ThinkingSphinx.use_group_by_shortcut?
+        nil
+      else
+        @columns.collect { |column|
+          column_with_prefix(column)
+        }
+      end
+    end
+    
+    def type_to_config
+      {
+        :multi    => :sql_attr_multi,
+        :datetime => :sql_attr_timestamp,
+        :string   => :sql_attr_str2ordinal,
+        :float    => :sql_attr_float,
+        :boolean  => :sql_attr_bool,
+        :integer  => :sql_attr_uint
+      }[type]
+    end
+    
+    def include_as_association?
+      ! (type == :multi && (source == :query || source == :ranged_query))
+    end
+    
+    # Returns the configuration value that should be used for
+    # the attribute.
+    # Special case is the multi-valued attribute that needs some
+    # extra configuration. 
+    # 
+    def config_value(offset = nil)
+      if type == :multi
+        multi_config = include_as_association? ? "field" :
+          source_value(offset).gsub(/\n\s*/, " ")
+        "uint #{unique_name} from #{multi_config}"
+      else
+        unique_name
+      end
+    end
+    
+    # Returns the unique name of the attribute - which is either the alias of
+    # the attribute, or the name of the only column - if there is only one. If
+    # there isn't, there should be an alias. Else things probably won't work.
+    # Consider yourself warned.
+    # 
+    def unique_name
+      if @columns.length == 1
+        @alias || @columns.first.__name
+      else
+        @alias
+      end
+    end
+    
+    # Returns the type of the column. If that's not already set, it returns
+    # :multi if there's the possibility of more than one value, :string if
+    # there's more than one association, otherwise it figures out what the
+    # actual column's datatype is and returns that.
+    # 
+    def type
+      @type ||= begin
+        base_type = case
+        when is_many?, is_many_ints?
+          :multi
+        when @associations.values.flatten.length > 1
+          :string
+        else
+          translated_type_from_database
+        end
+        
+        if base_type == :string && @crc
+          :integer
+        else
+          @crc = false
+          base_type
+        end
+      end
+    end
+    
+    def to_facet
+      return nil unless @faceted
+      
+      ThinkingSphinx::Facet.new(self)
+    end
+    
+    private
+    
+    def source_value(offset)
+      if is_string?
+        "#{source.to_s.dasherize}; #{columns.first.__name}"
+      elsif source == :ranged_query
+        "ranged-query; #{query offset} #{query_clause}; #{range_query}"
+      else
+        "query; #{query offset}"
+      end
+    end
+    
+    def query(offset)
+      assoc = association_for_mva
+      raise "Could not determine SQL for MVA" if assoc.nil?
+      
+      <<-SQL
+SELECT #{foreign_key_for_mva assoc}
+  #{ThinkingSphinx.unique_id_expression(offset)} AS #{quote_column('id')},
+  #{primary_key_for_mva(assoc)} AS #{quote_column(unique_name)}
+FROM #{quote_table_name assoc.table}
+      SQL
+    end
+    
+    def query_clause
+      foreign_key = foreign_key_for_mva association_for_mva
+      "WHERE #{foreign_key} >= $start AND #{foreign_key} <= $end"
+    end
+    
+    def range_query
+      assoc       = association_for_mva
+      foreign_key = foreign_key_for_mva assoc
+      "SELECT MIN(#{foreign_key}), MAX(#{foreign_key}) FROM #{quote_table_name assoc.table}"
+    end
+    
+    def primary_key_for_mva(assoc)
+      quote_with_table(
+        assoc.table, assoc.primary_key_from_reflection || columns.first.__name
+      )
+    end
+    
+    def foreign_key_for_mva(assoc)
+      quote_with_table assoc.table, assoc.reflection.primary_key_name
+    end
+    
+    def association_for_mva
+      @association_for_mva ||= associations[columns.first].detect { |assoc|
+        assoc.has_column?(columns.first.__name)
+      }
+    end
+    
+    def adapter
+      @adapter ||= @model.sphinx_database_adapter
+    end
+    
+    def quote_with_table(table, column)
+      "#{quote_table_name(table)}.#{quote_column(column)}"
+    end
+    
+    def quote_column(column)
+      @model.connection.quote_column_name(column)
+    end
+    
+    def quote_table_name(table_name)
+      @model.connection.quote_table_name(table_name)
+    end
+    
+    # Indication of whether the columns should be concatenated with a space
+    # between each value. True if there's either multiple sources or multiple
+    # associations.
+    # 
+    def concat_ws?
+      multiple_associations? || @columns.length > 1
+    end
+        
+    # Checks whether any column requires multiple associations (which only
+    # happens for polymorphic situations).
+    # 
+    def multiple_associations?
+      associations.any? { |col,assocs| assocs.length > 1 }
+    end
+    
+    # Builds a column reference tied to the appropriate associations. This
+    # dives into the associations hash and their corresponding joins to
+    # figure out how to correctly reference a column in SQL.
+    # 
+    def column_with_prefix(column)
+      if column.is_string?
+        column.__name
+      elsif associations[column].empty?
+        "#{@model.quoted_table_name}.#{quote_column(column.__name)}"
+      else
+        associations[column].collect { |assoc|
+          assoc.has_column?(column.__name) ?
+          "#{quote_table_name(assoc.join.aliased_table_name)}" + 
+          ".#{quote_column(column.__name)}" :
+          nil
+        }.compact.join(', ')
+      end
+    end
+    
+    # Could there be more than one value related to the parent record? If so,
+    # then this will return true. If not, false. It's that simple.
+    # 
+    def is_many?
+      associations.values.flatten.any? { |assoc| assoc.is_many? }
+    end
+    
+    def is_many_ints?
+      concat_ws? && all_ints?
+    end
+    
+    # Returns true if any of the columns are string values, instead of database
+    # column references.
+    def is_string?
+      columns.all? { |col| col.is_string? }
+    end
+    
+    def all_ints?
+      @columns.all? { |col|
+        klasses = @associations[col].empty? ? [@model] :
+          @associations[col].collect { |assoc| assoc.reflection.klass }
+        klasses.all? { |klass|
+          column = klass.columns.detect { |column| column.name == col.__name.to_s }
+          !column.nil? && column.type == :integer
+        }
+      }
+    end
+    
+    def type_from_database
+      klass = @associations.values.flatten.first ? 
+        @associations.values.flatten.first.reflection.klass : @model
+      
+      klass.columns.detect { |col|
+        @columns.collect { |c| c.__name.to_s }.include? col.name
+      }.type
+    end
+    
+    def translated_type_from_database
+      case type_from_db = type_from_database
+      when :datetime, :string, :float, :boolean, :integer
+        type_from_db
+      when :decimal
+        :float
+      when :timestamp, :date
+        :datetime
+      else
+        raise <<-MESSAGE
+
+Cannot automatically map column type #{type_from_db} to an equivalent Sphinx
+type (integer, float, boolean, datetime, string as ordinal). You could try to
+explicitly convert the column's value in your define_index block:
+  has "CAST(column AS INT)", :type => :integer, :as => :column
+        MESSAGE
+      end
+    end
+  end
+end
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