Class: Litesearch::Schema

Inherits:
Object
  • Object
show all
Defined in:
lib/litestack/litesearch.rb,
lib/litestack/litesearch/schema.rb

Defined Under Namespace

Classes: BackedAdapter, BasicAdapter, ContentlessAdapter, StandaloneAdapter

Constant Summary collapse

TOKENIZERS = 
{
  porter: "porter unicode61 remove_diacritics 2",
  unicode: "unicode61 remove_diacritics 2",
  ascii: "ascii",
  trigram: "trigram"
}
INDEX_TYPES = 
{
  standalone: Litesearch::Schema::StandaloneAdapter,
  contentless: Litesearch::Schema::ContentlessAdapter,
  backed: Litesearch::Schema::BackedAdapter
}
DEFAULT_SCHEMA = 
{
  name: nil,
  type: :standalone,
  fields: nil,
  table: nil,
  filter_column: nil,
  tokenizer: :porter,
  auto_create: true,
  auto_modify: true,
  rebuild_on_create: false,
  rebuild_on_modify: false
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(schema = {}) ⇒ Schema

Returns a new instance of Schema.



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# File 'lib/litestack/litesearch/schema.rb', line 33

def initialize(schema = {})
  @schema = schema # DEFAULT_SCHEMA.merge(schema)
  @schema[:fields] = {} unless @schema[:fields]
end

Instance Attribute Details

#schema ⇒ Object

Returns the value of attribute schema.



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# File 'lib/litestack/litesearch/schema.rb', line 31

def schema
  @schema
end

Instance Method Details

#adapter ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 110

def adapter
  @adapter ||= INDEX_TYPES[@schema[:type]].new(@schema)
end

#allowed_attributes ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 188

def allowed_attributes
  [:weight, :col, :target, :source, :conditions, :reference]
end

#auto_create(boolean) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 75

def auto_create(boolean)
  @schema[:auto_create] = boolean
end

#auto_modify(boolean) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 79

def auto_modify(boolean)
  @schema[:auto_modify] = boolean
end

#clean ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 183

def clean
  removable = @schema[:fields].select { |name, f| f[:weight] == 0 }.collect { |name, f| name }
  removable.each { |name| @schema[:fields].delete(name) }
end

#compare(other_schema) ⇒ Object

should we do this at the schema objects level?



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# File 'lib/litestack/litesearch/schema.rb', line 123

def compare(other_schema)
  other_schema = other_schema.schema
  # are the schemas identical?
  # 1 - same fields?
  [:type, :tokenizer, :name, :table].each do |key|
    other_schema[key] = @schema[key] if other_schema[key].nil?
  end
  if @schema[:type] != other_schema[:type]
    raise Litesearch::SchemaChangeException.new "Cannot change the index type, please drop the index before creating it again with the new type"
  end
  changes = {tokenizer: @schema[:tokenizer] != other_schema[:tokenizer], table: @schema[:table] != other_schema[:table], removed_fields_count: 0, filter_column: @schema[:filter_column] != other_schema[:filter_column]}
  # check tokenizer changes
  if changes[:tokenizer] && !other_schema[:rebuild_on_modify]
    raise Litesearch::SchemaChangeException.new "Cannot change the tokenizer without an index rebuild!"
  end

  # check field changes
  keys = @schema[:fields].keys.sort
  other_keys = other_schema[:fields].keys.sort

  extra_keys = other_keys - keys
  extra_keys.each do |key|
    if other_schema[:fields][key][:weight] == 0
      other_schema[:fields].delete(key)
    end
  end

  other_keys = other_schema[:fields].keys.sort

  changes[:fields] = keys != other_keys # only acceptable change is adding extra fields
  changes[:extra_fields_count] = other_keys.count - keys.count
  # check for missing fields (please note that adding fields can work without a rebuild)
  if keys - other_keys != []
    raise Litesearch::SchemaChangeException.new "Missing fields from existing schema, they have to exist with weight zero until the next rebuild!"
  end

  # check field weights
  weights = keys.collect { |key| @schema[:fields][key][:weight] }
  other_weights = other_keys.collect { |key| other_schema[:fields][key][:weight] }
  changes[:weights] = weights != other_weights # will always be true if fields are added
  if (removed_count = other_weights.count { |w| w == 0 }) > 0
    changes[:removed_fields_count] = removed_count
  end
  # check field attributes, only backed tables have attributes
  attrs = keys.collect do |key|
    f = @schema[:fields][key].dup
    f.delete(:weight)
    f.select { |k, v| allowed_attributes.include? k }
  end
  other_attrs = other_keys.collect do |key|
    f = other_schema[:fields][key].dup
    f.delete(:weight)
    f.select { |k, v| allowed_attributes.include? k }
  end
  changes[:attributes] if other_attrs != attrs # this means that we will need to redefine the triggers if any are there and also the table definition if needed

  # return the changes
  changes
end

#field(name, attributes = {}) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 60

def field(name, attributes = {})
  name = name.to_s.downcase.to_sym
  attributes = {weight: 1}.merge(attributes).select { |k, v| allowed_attributes.include?(k) } # only allow attributes we know, to ease schema comparison later
  @schema[:fields][name] = attributes
end

#fields(field_names) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 56

def fields(field_names)
  field_names.each { |f| field f }
end

#filter_column(filter_column) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 71

def filter_column(filter_column)
  @schema[:filter_column] = filter_column
end

#get(key) ⇒ Object

schema data structure API



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# File 'lib/litestack/litesearch/schema.rb', line 102

def get(key)
  @schema[key]
end

#get_field(name) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 106

def get_field(name)
  @schema[:fields][name]
end

#merge(other_schema) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 38

def merge(other_schema)
  @schema.merge!(other_schema.schema)
end

#name(new_name) ⇒ Object

schema definition API



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# File 'lib/litestack/litesearch/schema.rb', line 43

def name(new_name)
  @schema[:name] = new_name
end

#order_fields(old_schema) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 118

def order_fields(old_schema)
  adapter.order_fields(old_schema)
end

#post_init ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 91

def post_init
  @schema = DEFAULT_SCHEMA.merge(@schema)
end

#rebuild_on_create(boolean) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 83

def rebuild_on_create(boolean)
  @schema[:rebuild_on_create] = boolean
end

#rebuild_on_modify(boolean) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 87

def rebuild_on_modify(boolean)
  @schema[:rebuild_on_modify] = boolean
end

#reset_sql ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 114

def reset_sql
  adapter.generate_sql
end

#sql_for(method, *args) ⇒ Object

schema sql generation API



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# File 'lib/litestack/litesearch/schema.rb', line 97

def sql_for(method, *args)
  adapter.sql_for(method, *args)
end

#table(table_name) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 52

def table(table_name)
  @schema[:table] = table_name
end

#tokenizer(new_tokenizer) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 66

def tokenizer(new_tokenizer)
  raise "Unknown tokenizer" if TOKENIZERS[new_tokenizer].nil?
  @schema[:tokenizer] = new_tokenizer
end

#type(new_type) ⇒ Object 



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# File 'lib/litestack/litesearch/schema.rb', line 47

def type(new_type)
  raise "Unknown index type" if INDEX_TYPES[new_type].nil?
  @schema[:type] = new_type
end