Class: Calvin::Readcaster

Inherits:
Object
  • Object
show all
Defined in:
lib/spinoza/calvin/readcaster.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(node: nil) ⇒ Readcaster

Returns a new instance of Readcaster.



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# File 'lib/spinoza/calvin/readcaster.rb', line 7

def initialize node: nil
  @node = node
  @links = nil
  @tables = node.tables
end

Instance Attribute Details

#node ⇒ Object (readonly)

Returns the value of attribute node.



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# File 'lib/spinoza/calvin/readcaster.rb', line 5

def node
  @node
end

Instance Method Details

#execute_local_reads(txn) ⇒ Object 



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# File 'lib/spinoza/calvin/readcaster.rb', line 32

def execute_local_reads txn
  local_reads = txn.all_read_ops.select {|r| @tables.include? r.table}
  node.store.execute *local_reads
end

#inspect ⇒ Object 



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# File 'lib/spinoza/calvin/readcaster.rb', line 13

def inspect
  "<#{self.class} on #{node.inspect}>"
end

#links ⇒ Object

Pre-computed map, by table, of which nodes might need data from this node: => Set[link, …] In other, words, excludes ‘table,link` pairs for which link.dst already has `table`.



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# File 'lib/spinoza/calvin/readcaster.rb', line 20

def links
  unless @links
    @links = Hash.new {|h,k| h[k] = Set[]}
    node.links.each do |there, link|
      (@tables - there.tables).each do |table|
        @links[table] << link
      end
    end
  end
  @links
end

#send_read(link, **opts) ⇒ Object 



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# File 'lib/spinoza/calvin/readcaster.rb', line 47

def send_read link, **opts
  link.send_message **opts
end

#serve_reads(txn, local_read_results) ⇒ Object 



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# File 'lib/spinoza/calvin/readcaster.rb', line 37

def serve_reads txn, local_read_results
  local_read_results.group_by {|r| r.op.table}.each do |table, results|
    links[table].each do |link|
      if txn.active?(link.dst)
        send_read link, transaction: txn, table: table, read_results: results
      end
    end
  end
end