Class: Tapsoob::DataStream

Inherits:
Object
  • Object
show all
Defined in:
lib/tapsoob/data_stream.rb

Direct Known Subclasses

DataStreamKeyed

Constant Summary collapse

DEFAULT_CHUNKSIZE = 
1000

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db, state, opts = {}) ⇒ DataStream

Returns a new instance of DataStream.



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# File 'lib/tapsoob/data_stream.rb', line 11

def initialize(db, state, opts = {})
  @db = db
  @state = {
    :offset          => 0,
    :avg_chunksize   => 0,
    :num_chunksize   => 0,
    :total_chunksize => 0
  }.merge(state)
  @state[:chunksize] ||= DEFAULT_CHUNKSIZE
  @options = opts
  @complete = false
end

Instance Attribute Details

#db ⇒ Object (readonly)

Returns the value of attribute db.



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# File 'lib/tapsoob/data_stream.rb', line 9

def db
  @db
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/tapsoob/data_stream.rb', line 9

def options
  @options
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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# File 'lib/tapsoob/data_stream.rb', line 9

def state
  @state
end

Class Method Details

.factory(db, state, opts) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 250

def self.factory(db, state, opts)
  if defined?(Sequel::MySQL) && Sequel::MySQL.respond_to?(:convert_invalid_date_time=)
    Sequel::MySQL.convert_invalid_date_time = :nil
  end

  if state.has_key?(:klass)
    return eval(state[:klass]).new(db, state, opts)
  end

  if Tapsoob::Utils.single_integer_primary_key(db, state[:table_name].to_sym)
    DataStreamKeyed.new(db, state, opts)
  else
    DataStream.new(db, state, opts)
  end
end

.parse_json(json) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 167

def self.parse_json(json)
  hash = JSON.parse(json).symbolize_keys
  hash[:state].symbolize_keys! if hash.has_key?(:state)
  hash
end

Instance Method Details

#complete? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/tapsoob/data_stream.rb', line 142

def complete?
  state[:offset] >= state[:size]
end

#encode_rows(rows) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 122

def encode_rows(rows)
  Tapsoob::Utils.base64encode(Marshal.dump(rows))
end

#error ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 33

def error
  state[:error] || false
end

#error=(val) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 29

def error=(val)
  state[:error] = val
end

#fetch(opts = {}) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 126

def fetch(opts = {})
  opts = (opts.empty? ? { :type => "database", :source => db.uri } : opts)

  log.debug "DataStream#fetch state -> #{state.inspect}"

  t1 = Time.now
  rows = (opts[:type] == "file" ? fetch_file(opts[:source]) : fetch_rows)
  encoded_data = encode_rows(rows)
  t2 = Time.now
  elapsed_time = t2 - t1

  state[:offset] += (rows == {} ? 0 : rows[:data].size)

  [encoded_data, (rows == {} ? 0 : rows[:data].size), elapsed_time]
end

#fetch_data_from_database(params) {|rows| ... } ⇒ Object

Yields:

  • (rows) 


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# File 'lib/tapsoob/data_stream.rb', line 146

def fetch_data_from_database(params)
  encoded_data = params[:encoded_data]

  rows = parse_encoded_data(encoded_data, params[:checksum])

  # update local state
  state.merge!(params[:state].merge(:chunksize => state[:chunksize]))

  yield rows if block_given?
  (rows == {} ? 0 : rows[:data].size)
end

#fetch_data_to_database(params) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 158

def fetch_data_to_database(params)
  encoded_data = params[:encoded_data]

  rows = parse_encoded_data(encoded_data, params[:checksum])
  
  import_rows(rows)
  (rows == {} ? 0 : rows[:data].size)
end

#fetch_file(dump_path) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 88

def fetch_file(dump_path)
  #state[:chunksize] = fetch_chunksize
  ds = JSON.parse(File.read(File.join(dump_path, "data", "#{table_name}.json")))
  state[:size] = ds["data"].size
  log.debug "DataStream#fetch_file"
  rows = {
    :table_name => ds["table_name"],
    :header     => ds["header"],
    :data       => ((@options[:"skip-duplicates"] ? ds["data"].uniq : ds["data"])[state[:offset], (state[:offset] + state[:chunksize])] || [ ]),
    :types      => ds["types"]
  }
  update_chunksize_stats
  rows
end

#fetch_rows ⇒ Object

keep a record of the average chunksize within the first few hundred thousand records, after chunksize goes below 100 or maybe if offset is > 1000



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# File 'lib/tapsoob/data_stream.rb', line 74

def fetch_rows
  #state[:chunksize] = fetch_chunksize
  ds = table.order(*order_by).limit(state[:chunksize], state[:offset])
  state[:size] = table.count
  log.debug "DataStream#fetch_rows SQL -> #{ds.sql}"
  rows = Tapsoob::Utils.format_data(db, ds.all,
    :string_columns => string_columns,
    :schema => db.schema(table_name),
    :table => table_name
  )
  update_chunksize_stats
  rows
end

#import_rows(rows) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 187

def import_rows(rows)
  columns = rows[:header]
  data    = rows[:data]

  # Only import existing columns
  if table.columns.size != columns.size
    existing_columns        = table.columns.map(&:to_s)
    additional_columns      = columns - existing_columns
    additional_columns_idxs = additional_columns.map { |c| columns.index(c) }
    additional_columns_idxs.reverse.each do |idx|
      columns.delete_at(idx)
      rows[:types].delete_at(idx)
    end
    data.each_index { |didx| additional_columns_idxs.reverse.each { |idx| data[didx].delete_at(idx) } }
  end

  # Decode blobs
  if rows.has_key?(:types) && rows[:types].include?("blob")
    blob_indices = rows[:types].each_index.select { |idx| rows[:types][idx] == "blob" }
    data.each_index do |idx|
      blob_indices.each do |bi|
        data[idx][bi] = Sequel::SQL::Blob.new(Tapsoob::Utils.base64decode(data[idx][bi])) unless data[idx][bi].nil?
      end
    end
  end

  # Parse date/datetime/time columns
  if rows.has_key?(:types)
    %w(date datetime time).each do |type|
      if rows[:types].include?(type)
        type_indices = rows[:types].each_index.select { |idx| rows[:types][idx] == type }
        data.each_index do |idx|
          type_indices.each do |ti|
            data[idx][ti] = Sequel.send("string_to_#{type}".to_sym, data[idx][ti]) unless data[idx][ti].nil?
          end
        end
      end
    end
  end

  # Remove id column
  if @options[:"discard-identity"] && rows[:header].include?("id")
    columns = rows[:header] - ["id"]
    data    = data.map { |d| d[1..-1] }
  end

  table.import(columns, data, :commit_every => 100)
rescue Exception => ex
  case ex.message
  when /integer out of range/ then
    raise Tapsoob::InvalidData, <<-ERROR, []
  \nDetected integer data that exceeds the maximum allowable size for an integer type.
  This generally occurs when importing from SQLite due to the fact that SQLite does
  not enforce maximum values on integer types.
    ERROR
  else raise ex
  end
end

#increment(row_count) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 68

def increment(row_count)
  state[:offset] += row_count
end

#log ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 24

def log
  Tapsoob.log.level = Logger::DEBUG if state[:debug]
  Tapsoob.log
end

#max_chunksize_training ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 103

def max_chunksize_training
  20
end

#order_by(name = nil) ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 61

def order_by(name=nil)
  @order_by ||= begin
    name ||= table_name
    Tapsoob::Utils.order_by(db, name)
  end
end

#parse_encoded_data(encoded_data, checksum) ⇒ Object

Raises:



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# File 'lib/tapsoob/data_stream.rb', line 173

def parse_encoded_data(encoded_data, checksum)
  raise Tapsoob::CorruptedData.new("Checksum Failed") unless Tapsoob::Utils.valid_data?(encoded_data, checksum)

  begin
    return Marshal.load(Tapsoob::Utils.base64decode(encoded_data))
  rescue Object => e
    unless ENV['NO_DUMP_MARSHAL_ERRORS']
      puts "Error encountered loading data, wrote the data chunk to dump.#{Process.pid}.dat"
      File.open("dump.#{Process.pid}.dat", "w") { |f| f.write(encoded_data) }
    end
    raise e
  end
end

#string_columns ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 53

def string_columns
  @string_columns ||= Tapsoob::Utils.incorrect_blobs(db, table_name)
end

#table ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 57

def table
  @table ||= db[table_name_sql]
end

#table_name ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 37

def table_name
  state[:table_name].to_sym
end

#table_name_sql ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 41

def table_name_sql
  table_name
end

#to_hash ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 45

def to_hash
  state.merge(:klass => self.class.to_s)
end

#to_json ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 49

def to_json
  JSON.generate(to_hash)
end

#update_chunksize_stats ⇒ Object

def fetch_chunksize

chunksize = state[:chunksize]
return chunksize if state[:num_chunksize] < max_chunksize_training
return chunksize if state[:avg_chunksize] == 0
return chunksize if state[:error]
state[:avg_chunksize] > chunksize ? state[:avg_chunksize] : chunksize

end



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# File 'lib/tapsoob/data_stream.rb', line 115

def update_chunksize_stats
  return if state[:num_chunksize] >= max_chunksize_training
  state[:total_chunksize] += state[:chunksize]
  state[:num_chunksize] += 1
  state[:avg_chunksize] = state[:total_chunksize] / state[:num_chunksize] rescue state[:chunksize]
end

#verify_stream ⇒ Object 



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# File 'lib/tapsoob/data_stream.rb', line 246

def verify_stream
  state[:offset] = table.count
end