Class: Norikra::Query

Inherits:
Object
  • Object
show all
Defined in:
lib/norikra/query.rb,
lib/norikra/query/ast.rb

Direct Known Subclasses

SubQuery

Defined Under Namespace

Classes: ASTEventPropNode, ASTLibFunctionNode, ASTNode, ASTSelectionElementNode, ASTStreamNode, ASTSubSelectNode, ParseRuleSelectorImpl

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(param = {}) ⇒ Query

Returns a new instance of Query.



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# File 'lib/norikra/query.rb', line 15

def initialize(param={})
  @name = param[:name]
  @group = param[:group] # default nil
  @expression = param[:expression]
  @statement_name = nil
  @fieldsets = {} # { target => fieldset }
  @ast = nil
  @targets = nil
  @aliases = nil
  @subqueries = nil
  @fields = nil
end

Instance Attribute Details

#expression ⇒ Object

Returns the value of attribute expression.



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# File 'lib/norikra/query.rb', line 13

def expression
  @expression
end

#fieldsets ⇒ Object

Returns the value of attribute fieldsets.



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# File 'lib/norikra/query.rb', line 13

def fieldsets
  @fieldsets
end

#group ⇒ Object

Returns the value of attribute group.



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# File 'lib/norikra/query.rb', line 13

def group
  @group
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/norikra/query.rb', line 13

def name
  @name
end

#statement_name ⇒ Object

Returns the value of attribute statement_name.



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# File 'lib/norikra/query.rb', line 13

def statement_name
  @statement_name
end

Class Method Details

.imported_java_class?(name) ⇒ Boolean

Returns:



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# File 'lib/norikra/query/ast.rb', line 274

def self.imported_java_class?(name)
  return false unless name =~ /^[A-Z]/
  # Esper auto-imports the following Java library packages:
  # java.lang.* -> Java::JavaLang::*
  # java.math.* -> Java::JavaMath::*
  # java.text.* -> Java::JavaText::*
  # java.util.* -> Java::JavaUtil::*
  java_class('Java::JavaLang::'+name) || java_class('Java::JavaMath::'+name) ||
    java_class('Java::JavaText::'+name) || java_class('Java::JavaUtil::'+name) || false
end

.java_class(const_name) ⇒ Object 



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# File 'lib/norikra/query/ast.rb', line 285

def self.java_class(const_name)
  begin
    c = eval(const_name)
    c.class == Kernel ? nil : c
  rescue NameError
    return nil
  end
end

.rewrite_event_field_name(statement_model, mapping) ⇒ Object 



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# File 'lib/norikra/query.rb', line 157

def self.rewrite_event_field_name(statement_model, mapping)
  # mapping: {target_name => query_event_type_name}
  #  mapping is for target name rewriting of fully qualified field name access


  # model.getFromClause.getStreams[0].getViews[0].getParameters[0].getPropertyName

  # model.getSelectClause.getSelectList[0].getExpression.getPropertyName
  # model.getSelectClause.getSelectList[0].getExpression.getChildren[0].getPropertyName #=> 'field.key1.$0'

  # model.getWhereClause.getChildren[1].getChildren[0].getPropertyName #=> 'field.key1.$1'
  # model.getWhereClause.getChildren[2].getChildren[0].getChain[0].getName #=> 'opts.num.$0' from opts.num.$0.length()

  query = Norikra::Query.new(:expression => statement_model.toEPL)
  targets = query.targets
  fqfs_prefixes = targets + query.aliases

  default_target = (targets.size == 1 ? targets.first : nil)

  rewrite_name = lambda {|node,getter,setter|
    name = node.send(getter)
    if name && name.index('.')
      prefix = nil
      body = nil
      first_part = name.split('.').first
      if fqfs_prefixes.include?(first_part) or mapping.has_key?(first_part) # fully qualified field specification
        prefix = first_part
        if mapping[prefix]
          prefix = mapping[prefix]
        end
        body = name.split('.')[1..-1].join('.')
      elsif default_target # default target field (outside of join context)
        body = name
      else
        raise Norikra::QueryError, "target cannot be determined for field '#{name}'"
      end
      encoded = (prefix ? "#{prefix}." : "") + Norikra::Field.escape_name(body)
      node.send(setter, encoded)
    end
  }

  rewriter = lambda {|node|
    if node.respond_to?(:getPropertyName)
      rewrite_name.call(node, :getPropertyName, :setPropertyName)
    elsif node.respond_to?(:getChain)
      node.getChain.each do |chain|
        rewrite_name.call(chain, :getName, :setName)
      end
    end
  }
  recaller = lambda {|node|
    Norikra::Query.rewrite_event_field_name(node.getModel, mapping)
  }

  traverse_fields(rewriter, recaller, statement_model)
end

.rewrite_event_type_name(statement_model, mapping) ⇒ Object 



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# File 'lib/norikra/query.rb', line 214

def self.rewrite_event_type_name(statement_model, mapping)
  # mapping: {target_name => query_event_type_name}

  ### esper-4.9.0/esper/doc/reference/html/epl_clauses.html#epl-subqueries
  # Subqueries can only consist of a select clause, a from clause and a where clause.
  # The group by and having clauses, as well as joins, outer-joins and output rate limiting are not permitted within subqueries.

  # model.getFromClause.getStreams[0].getFilter.setEventTypeName("hoge")

  # model.getSelectClause.getSelectList[1].getExpression => #<Java::ComEspertechEsperClientSoda::SubqueryExpression:0x3344c133>
  # model.getSelectClause.getSelectList[1].getExpression.getModel.getFromClause.getStreams[0].getFilter.getEventTypeName
  # model.getWhereClause.getChildren[1]                 .getModel.getFromClause.getStreams[0].getFilter.getEventTypeName

  statement_model.getFromClause.getStreams.each do |stream|
    target_name = stream.getFilter.getEventTypeName
    unless mapping[target_name]
      raise RuntimeError, "target missing in mapping, maybe BUG"
    end
    stream.getFilter.setEventTypeName(mapping[target_name])
  end

  rewriter = lambda {|node|
    # nothing for query expression clauses
  }
  recaller = lambda {|node|
    Norikra::Query.rewrite_event_type_name(node.getModel, mapping)
  }
  traverse_fields(rewriter, recaller, statement_model)
end

.rewrite_query(statement_model, mapping) ⇒ Object 



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# File 'lib/norikra/query.rb', line 152

def self.rewrite_query(statement_model, mapping)
  rewrite_event_type_name(statement_model, mapping)
  rewrite_event_field_name(statement_model, mapping)
end

.traverse_fields(rewriter, recaller, statement_model) ⇒ Object

model.methods.select{|m| m.to_s.start_with?(‘get’)} :getContextName, :getCreateContext, :getCreateDataFlow, :getCreateExpression, :getCreateIndex, :getCreateSchema, :getCreateVariable, :getCreateWindow, :getExpressionDeclarations, :getFireAndForgetClause, :getForClause, (*) :getFromClause, (*) :getGroupByClause, :getHavingClause, :getInsertInto, :getMatchRecognizeClause, :getOnExpr, (*) :getOrderByClause, :getOutputLimitClause, :getRowLimitClause, :getScriptExpressions, (*) :getSelectClause, :getTreeObjectName, :getUpdateClause, (*) :getWhereClause,



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# File 'lib/norikra/query.rb', line 271

def self.traverse_fields(rewriter, recaller, statement_model)
  #NOTICE: SQLStream is not supported yet.
  #TODO: other clauses with fields, especially: Having, For

  dig = lambda {|node|
    rewriter.call(node)

    if node.is_a?(Java::ComEspertechEsperClientSoda::SubqueryExpression)
      recaller.call(node)
    end
    if node.respond_to?(:getFilter)
      dig.call(node.getFilter)
    end
    if node.respond_to?(:getChildren)
      node.getChildren.each do |c|
        dig.call(c)
      end
    end
    if node.respond_to?(:getParameters)
      node.getParameters.each do |p|
        dig.call(p)
      end
    end
    if node.respond_to?(:getChain)
      node.getChain.each do |c|
        dig.call(c)
      end
    end
  }

  statement_model.getFromClause.getStreams.each do |stream|
    if stream.respond_to?(:getExpression) # PatternStream < ProjectedStream
      dig.call(stream.getExpression)
    end
    if stream.respond_to?(:getFilter) # Filter < ProjectedStream
      dig.call(stream.getFilter.getFilter) #=> Expression
    end
    if stream.respond_to?(:getParameterExpressions) # MethodInvocationStream
      dig.call(stream.getParameterExpressions)
    end
    if stream.respond_to?(:getViews) # ProjectedStream
      stream.getViews.each do |view|
        view.getParameters.each do |parameter|
          dig.call(parameter)
        end
      end
    end
  end

  if statement_model.getSelectClause
    statement_model.getSelectClause.getSelectList.each do |item|
      if item.respond_to?(:getExpression)
        dig.call(item.getExpression)
      end
    end
  end

  if statement_model.getWhereClause
    statement_model.getWhereClause.getChildren.each do |child|
      dig.call(child)
    end
  end

  if statement_model.getGroupByClause
    statement_model.getGroupByClause.getGroupByExpressions.each do |child|
      dig.call(child)
    end
  end

  if statement_model.getOrderByClause
    statement_model.getOrderByClause.getOrderByExpressions.each do |item|
      if item.respond_to?(:getExpression)
        dig.call(item.getExpression)
      end
    end
  end

  statement_model
end

Instance Method Details

#aliases ⇒ Object 



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# File 'lib/norikra/query.rb', line 42

def aliases
  return @aliases if @aliases
  @aliases = (self.ast.listup(:stream).map(&:alias) + self.subqueries.map(&:aliases).flatten).sort.uniq
  @aliases
end

#ast ⇒ Object 



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# File 'lib/norikra/query.rb', line 139

def ast
  return @ast if @ast
  rule = ParseRuleSelectorImpl.new
  target = @expression.dup
  forerrmsg = @expression.dup
  result = com.espertech.esper.epl.parse.ParseHelper.parse(target, forerrmsg, true, rule, false)

  @ast = astnode(result.getTree)
  @ast
rescue Java::ComEspertechEsperClient::EPStatementSyntaxException => e
  raise Norikra::QueryError, e.message
end

#astnode(tree) ⇒ Object

[“EPL_EXPR”,

["SELECTION_EXPR", ["SELECTION_ELEMENT_EXPR", "count", "cnt"]],
["STREAM_EXPR",
 ["EVENT_FILTER_EXPR", "TestTable"],
 ["VIEW_EXPR", "win", "time_batch", ["TIME_PERIOD", ["SECOND_PART", "10"]]]],
["WHERE_EXPR",
 ["EVAL_AND_EXPR",
  ["EVAL_EQUALS_EXPR",
   ["EVENT_PROP_EXPR",
    ["EVENT_PROP_SIMPLE", "params"],
    ["EVENT_PROP_SIMPLE", "$$path"],
    ["EVENT_PROP_SIMPLE", "$1"]],
   "\"/\""],
  [">",
   ["EVENT_PROP_EXPR",
    ["EVENT_PROP_SIMPLE", "size"],
    ["EVENT_PROP_SIMPLE", "$0"],
    ["EVENT_PROP_SIMPLE", "bytes"]],
   "100"],
  [">",
   ["LIB_FUNC_CHAIN", ["LIB_FUNCTION", "opts.num.seq", "length", "("]],
   "0"]]]]



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# File 'lib/norikra/query/ast.rb', line 82

def astnode(tree)
  children = if tree.children
               tree.children.map{|c| astnode(c)}
             else
               []
             end
  case tree.text
  when 'EVENT_PROP_EXPR'
    ASTEventPropNode.new(tree.text, children)
  when 'SELECTION_ELEMENT_EXPR'
    ASTSelectionElementNode.new(tree.text, children)
  when 'LIB_FUNCTION'
    ASTLibFunctionNode.new(tree.text, children)
  when 'STREAM_EXPR'
    ASTStreamNode.new(tree.text, children)
  when 'SUBSELECT_EXPR'
    ASTSubSelectNode.new(tree.text, children)
  else
    ASTNode.new(tree.text, children)
  end
end

#dup ⇒ Object 



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# File 'lib/norikra/query.rb', line 28

def dup
  self.class.new(:name => @name, :group => @group, :expression => @expression.dup)
end

#explore(outer_targets = [], alias_overridden = {}) ⇒ Object 



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# File 'lib/norikra/query.rb', line 54

def explore(outer_targets=[], alias_overridden={})
  fields = {}
  alias_map = {}.merge(alias_overridden)

  all = []
  unknowns = []
  self.ast.listup(:stream).each do |node|
    if node.alias
      alias_map[node.alias] = node.target
    end
    fields[node.target] = []
  end

  dup_aliases = (alias_map.keys & fields.keys)
  unless dup_aliases.empty?
    raise Norikra::ClientError, "Invalid alias '#{dup_aliases.join(',')}', same with target name"
  end

  default_target = fields.keys.size == 1 ? fields.keys.first : nil

  outer_targets.each do |t|
    fields[t] ||= []
  end

  field_bag = []
  self.subqueries.each do |subquery|
    field_bag.push(subquery.explore(fields.keys, alias_map))
  end

  # names of 'AS'
  field_aliases = self.ast.listup(:selection).map(&:alias).compact

  known_targets_aliases = fields.keys + alias_map.keys
  self.ast.fields(default_target, known_targets_aliases).each do |field_def|
    f = field_def[:f]
    next if field_aliases.include?(f)

    all.push(f)

    if field_def[:t]
      t = alias_map[field_def[:t]] || field_def[:t]
      unless fields[t]
        raise Norikra::ClientError, "unknown target alias name for: #{field_def[:t]}.#{field_def[:f]}"
      end
      fields[t].push(f)

    else
      unknowns.push(f)
    end
  end

  field_bag.each do |bag|
    all += bag['']
    unknowns += bag[nil]
    bag.keys.each do |t|
      fields[t] ||= []
      fields[t] += bag[t]
    end
  end

  fields.keys.each do |target|
    fields[target] = fields[target].sort.uniq
  end
  fields[''] = all.sort.uniq
  fields[nil] = unknowns.sort.uniq

  fields
end

#fields(target = '') ⇒ Object 



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# File 'lib/norikra/query.rb', line 123

def fields(target='')
  # target '': fields for all targets (without target name)
  # target nil: fields for unknown targets
  return @fields[target] if @fields

  @fields = explore()
  @fields[target]
end

#subqueries ⇒ Object 



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# File 'lib/norikra/query.rb', line 48

def subqueries
  return @subqueries if @subqueries
  @subqueries = self.ast.listup(:subquery).map{|n| Norikra::SubQuery.new(n)}
  @subqueries
end

#targets ⇒ Object 



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# File 'lib/norikra/query.rb', line 36

def targets
  return @targets if @targets
  @targets = (self.ast.listup(:stream).map(&:target) + self.subqueries.map(&:targets).flatten).sort.uniq
  @targets
end

#to_hash ⇒ Object 



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# File 'lib/norikra/query.rb', line 32

def to_hash
  {'name' => @name, 'group' => @group, 'expression' => @expression, 'targets' => self.targets}
end