Class: RdfContext::ActiveRecordStore

Inherits:
AbstractSQLStore show all
Defined in:
lib/rdf_context/store/active_record_store.rb

Overview

ActiveRecord store context-ware and formula-aware implementation.

Uses an ActiveRecord::Base.connection to run statements

It stores it's triples in the following partitions:

  • Asserted non rdf:type statements

  • Asserted rdf:type statements (in a table which models Class membership). The motivation for this partition is primarily query speed and scalability as most graphs will always have more rdf:type statements than others

  • All Quoted statements

In addition it persists namespace mappings in a seperate table

Constant Summary

CREATE_ASSERTED_STATEMENTS_TABLE =
%(
    CREATE TABLE %s_asserted_statements (
subject       text not NULL,
predicate     text not NULL,
object        text not NULL,
context       text not NULL,
termComb      tinyint unsigned not NULL))
CREATE_ASSERTED_TYPE_STATEMENTS_TABLE =
%(
    CREATE TABLE %s_type_statements (
member        text not NULL,
klass         text not NULL,
context       text not NULL,
termComb      tinyint unsigned not NULL))
CREATE_LITERAL_STATEMENTS_TABLE =
%(
    CREATE TABLE %s_literal_statements (
subject       text not NULL,
predicate     text not NULL,
object        text,
context       text not NULL,
termComb      tinyint unsigned not NULL,
objLanguage   varchar(3),
objDatatype   text))
CREATE_QUOTED_STATEMENTS_TABLE =
%(
    CREATE TABLE %s_quoted_statements (
subject       text not NULL,
predicate     text not NULL,
object        text,
context       text not NULL,
termComb      tinyint unsigned not NULL,
objLanguage   varchar(3),
objDatatype   text))
CREATE_NS_BINDS_TABLE =
%(
    CREATE TABLE %s_namespace_binds (
prefix        varchar(20) UNIQUE not NULL,
uri           text,
PRIMARY KEY (prefix)))
DROP_ASSERTED_STATEMENTS_TABLE =
%(DROP TABLE %s_asserted_statements)
DROP_ASSERTED_TYPE_STATEMENTS_TABLE =
%(DROP TABLE %s_type_statements)
DROP_LITERAL_STATEMENTS_TABLE =
%(DROP TABLE %s_literal_statements)
DROP_QUOTED_STATEMENTS_TABLE =
%(DROP TABLE %s_quoted_statements)
DROP_NS_BINDS_TABLE =
%(DROP TABLE %s_namespace_binds)

Constants inherited from AbstractSQLStore

RdfContext::AbstractSQLStore::ASSERTED_LITERAL_PARTITION, RdfContext::AbstractSQLStore::ASSERTED_NON_TYPE_PARTITION, RdfContext::AbstractSQLStore::ASSERTED_TYPE_PARTITION, RdfContext::AbstractSQLStore::CONTEXT_SELECT, RdfContext::AbstractSQLStore::COUNT_SELECT, RdfContext::AbstractSQLStore::FULL_TRIPLE_PARTITIONS, RdfContext::AbstractSQLStore::INTERNED_PREFIX, RdfContext::AbstractSQLStore::QUOTED_PARTITION, RdfContext::AbstractSQLStore::STRONGLY_TYPED_TERMS, RdfContext::AbstractSQLStore::TRIPLE_SELECT, RdfContext::AbstractSQLStore::TRIPLE_SELECT_NO_ORDER

Constants included from TermUtils

TermUtils::CONTEXT, TermUtils::GRAPH_TERM_DICT, TermUtils::OBJECT, TermUtils::PREDICATE, TermUtils::REVERSE_TERM_COMBINATIONS, TermUtils::SUBJECT, TermUtils::TERM_COMBINATIONS, TermUtils::TERM_INSTANTIATION_DICT

Instance Attribute Summary

Attributes inherited from AbstractStore

#identifier, #nsbinding, #uri_binding

Instance Method Summary (collapse)

Methods inherited from AbstractSQLStore

#_normalizeSQLCmd, #add, #asserted_table, #asserted_type_table, #bind, #buildClause, #buildLitDTypeClause, #buildLitLanguageClause, #buildLiteralTripleSQLCommand, #buildTripleSQLCommand, #buildTypeSQLCommand, #commit, #contains?, #context_aware?, #contexts, #createTerm, #destroy, #extractTriple, #formula_aware?, #literal_table, #namespace, #namespace_binds, #normalizeTerm, #nsbinding, #prefix, #queryAnalysis, #quoted_table, #remove, #remove_context, #rollback, #size, #transaction_aware?, #triples, #unionSELECT, #uri_binding

Methods included from TermUtils

#constructGraph, #normalizeGraph, #statement2TermCombination, #term2Letter, #type2TermCombination

Methods inherited from AbstractStore

#add, #bind, #bnodes, #commit, #contains?, #context_aware?, #contexts, #destroy, #formula_aware?, #inspect, #item, #namespace, #objects, #predicates, #prefix, #remove, #rollback, #size, #subjects, #transaction_aware?, #triples

Constructor Details

- (ActiveRecordStore) initialize(identifier = nil, configuration = {})

Create a new ActiveRecordStore Store @param configuration Specific to type of storage

Parameters:

  • identifier (URIRef) (defaults to: nil)


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# File 'lib/rdf_context/store/active_record_store.rb', line 22

def initialize(identifier = nil, configuration = {})
  super(identifier, configuration)
  @autocommit_default = false
end

Instance Method Details

- (Object) buildContextClause(context, tableName) (protected)

Where clase utility functions



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# File 'lib/rdf_context/store/active_record_store.rb', line 164

def buildContextClause(context, tableName)
  context = normalizeTerm(context) if context

  #    case context
  #    when REGEXTerm
  #    when Array
  #    else
    ["#{tableName}.context=?", context] if context
  #    end
end

- (Object) buildObjClause(object, tableName) (protected)

Where clase utility functions



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# File 'lib/rdf_context/store/active_record_store.rb', line 152

def buildObjClause(object, tableName)
  case object
  #    when REGEXTerm
  #    when Array
when Graph
  ["#{tableName}.object=?", self.normalizeTerm(object.identifier)]
  else
    ["#{tableName}.object=?", object] if object
  end
end

- (Object) buildPredClause(predicate, tableName) (protected)



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# File 'lib/rdf_context/store/active_record_store.rb', line 142

def buildPredClause(predicate, tableName)
  #    case predicate
  #    when REGEXTerm
  #    when Array
  #    else
    ["#{tableName}.predicate=?", predicate] if predicate
  #    end
end

- (Object) buildSubjClause(subject, tableName) (protected)

Where clase utility functions



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# File 'lib/rdf_context/store/active_record_store.rb', line 131

def buildSubjClause(subject, tableName)
  case subject
  #    when REGEXTerm
  #    when Array
  when Graph
     ["#{tableName}.subject=?", self.normalizeTerm(subject.identifier)]
  else
    ["#{tableName}.subject=?", subject] if subject
  end
end

- (Object) buildTypeClassClause(object, tableName) (protected)

Where clase utility functions



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# File 'lib/rdf_context/store/active_record_store.rb', line 186

def buildTypeClassClause(object, tableName)
  #    case context
  #    when REGEXTerm
  #    else
    ["#{tableName}.klass=?", object] if object
  #    end
end

- (Object) buildTypeMemberClause(subject, tableName) (protected)

Where clase utility functions



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# File 'lib/rdf_context/store/active_record_store.rb', line 176

def buildTypeMemberClause(subject, tableName)
  #    case context
  #    when REGEXTerm
  #    when Array
  #    else
    ["#{tableName}.member=?", subject] if subject
  #    end
end

- (Object) close(commit_pending_transactions = false)



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# File 'lib/rdf_context/store/active_record_store.rb', line 30

def close(commit_pending_transactions = false)
  ActiveRecord::Base.connection.commit_db_transaction if commit_pending_transactions
end

- (Object) executeSQL(qStr, *params, &block) (protected)

This takes the query string and parameters and (depending on the SQL implementation) either fill in the parameter in-place or pass it on to the DB impl (if it supports this). The default (here) is to fill the parameters in-place surrounding each param with quote characters

Yields each row



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# File 'lib/rdf_context/store/active_record_store.rb', line 199

def executeSQL(qStr, *params, &block)
  conn = ActiveRecord::Base.connection

  puts "executeSQL: params=#{params.flatten.inspect}" if ::RdfContext::debug?
  puts "executeSQL: '#{params.dup.unshift(qStr).join("', '")}'" if ::RdfContext::debug?
  qStr = ActiveRecord::Base.send(:replace_bind_variables, qStr, params.flatten)
  puts "  => '#{qStr}'" if ::RdfContext::debug?

  if block_given?
    conn.select_rows(qStr).each do |row|
      yield(row)
    end
  else
    puts "executeSQL no block given" if ::RdfContext::debug?
    conn.select_rows(qStr)
  end
rescue StandardError => e
  puts "SQL Exception (ignored): #{e.message}" if ::RdfContext::debug?
end

- (Object) open(options)



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# File 'lib/rdf_context/store/active_record_store.rb', line 27

def open(options)
end

- (Object) setup

Create necessary tables and indecies for this database



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# File 'lib/rdf_context/store/active_record_store.rb', line 35

def setup
  executeSQL(CREATE_ASSERTED_STATEMENTS_TABLE % @internedId)
  executeSQL(CREATE_ASSERTED_TYPE_STATEMENTS_TABLE % @internedId)
  executeSQL(CREATE_QUOTED_STATEMENTS_TABLE % @internedId)
  executeSQL(CREATE_NS_BINDS_TABLE % @internedId)
  executeSQL(CREATE_LITERAL_STATEMENTS_TABLE % @internedId)

  # Create indicies
  {
    asserted_table => {
      "#{@internedId}_A_termComb_index" => %w(termComb),
      "#{@internedId}_A_s_index" => %w(subject),
      "#{@internedId}_A_p_index" => %w(predicate),
      "#{@internedId}_A_o_index" => %w(object),
      "#{@internedId}_A_c_index" => %w(context),
    },
    asserted_type_table => {
      "#{@internedId}_T_termComb_index" => %w(termComb),
      "#{@internedId}_T_member_index" => %w(member),
      "#{@internedId}_T_klass_index" => %w(klass),
      "#{@internedId}_T_c_index" => %w(context),
    },
    literal_table => {
      "#{@internedId}_L_termComb_index" => %w(termComb),
      "#{@internedId}_L_s_index" => %w(subject),
      "#{@internedId}_L_p_index" => %w(predicate),
      "#{@internedId}_L_c_index" => %w(context),
    },
    quoted_table => {
      "#{@internedId}_Q_termComb_index" => %w(termComb),
      "#{@internedId}_Q_s_index" => %w(subject),
      "#{@internedId}_Q_p_index" => %w(predicate),
      "#{@internedId}_Q_o_index" => %w(object),
      "#{@internedId}_Q_c_index" => %w(context),
    },
    namespace_binds => {
      "#{@internedId}_uri_index" => %w(uri),
    }
  }.each_pair do |tablename, indicies|
    indicies.each_pair do |index, columns|
      executeSQL("CREATE INDEX #{index} on #{tablename} ('#{columns.join(', ')}')")
    end
  end
end

- (Object) teardown

Teardown DB files



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# File 'lib/rdf_context/store/active_record_store.rb', line 81

def teardown
  # Drop indicies
  {
    asserted_table => {
      "#{@internedId}_A_termComb_index" => %w(termComb),
      "#{@internedId}_A_s_index" => %w(subject),
      "#{@internedId}_A_p_index" => %w(predicate),
      "#{@internedId}_A_o_index" => %w(object),
      "#{@internedId}_A_c_index" => %w(context),
    },
    asserted_type_table => {
      "#{@internedId}_T_termComb_index" => %w(termComb),
      "#{@internedId}_T_member_index" => %w(member),
      "#{@internedId}_T_klass_index" => %w(klass),
      "#{@internedId}_T_c_index" => %w(context),
    },
    literal_table => {
      "#{@internedId}_L_termComb_index" => %w(termComb),
      "#{@internedId}_L_s_index" => %w(subject),
      "#{@internedId}_L_p_index" => %w(predicate),
      "#{@internedId}_L_c_index" => %w(context),
    },
    quoted_table => {
      "#{@internedId}_Q_termComb_index" => %w(termComb),
      "#{@internedId}_Q_s_index" => %w(subject),
      "#{@internedId}_Q_p_index" => %w(predicate),
      "#{@internedId}_Q_o_index" => %w(object),
      "#{@internedId}_Q_c_index" => %w(context),
    },
    namespace_binds => {
      "#{@internedId}_uri_index" => %w(uri),
    }
  }.each_pair do |tablename, indicies|
    tn = "#{@internedId}_#{tablename}"
    indicies.each_pair do |index, columns|
      executeSQL("DROP INDEX #{index} ON #{tn}")
    end
  end

  # Drop tables
  executeSQL("DROP TABLE #{namespace_binds}")
  executeSQL("DROP TABLE #{quoted_table}")
  executeSQL("DROP TABLE #{literal_table}")
  executeSQL("DROP TABLE #{asserted_type_table}")
  executeSQL("DROP TABLE #{asserted_table}")
end