Class: ActiveRecord::Materialized::SummaryDelta Private

Inherits:
Object
  • Object
show all
Defined in:
lib/activerecord/materialized/summary_delta.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

Accumulates signed per-partition, per-column numeric changes for a delta-maintainable view (partition key tuple => mv column => amount).

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(buckets = {}) ⇒ SummaryDelta

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of SummaryDelta.



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# File 'lib/activerecord/materialized/summary_delta.rb', line 12

def initialize(buckets = {})
  @buckets = buckets
end

Instance Attribute Details

#buckets ⇒ Object (readonly)

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/activerecord/materialized/summary_delta.rb', line 10

def buckets
  @buckets
end

Class Method Details

.deserialize(payload) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/activerecord/materialized/summary_delta.rb', line 50

def self.deserialize(payload)
  rows = payload && payload["summary"]
  return nil if rows.nil?

  buckets = {}
  rows.each { |row| buckets[row.fetch("key")] = row.fetch("columns") }
  new(buckets)
end

Instance Method Details

#add(key_tuple, column, amount) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/activerecord/materialized/summary_delta.rb', line 16

def add(key_tuple, column, amount)
  bucket = (@buckets[key_tuple] ||= {})
  bucket[column] = (bucket[column] || 0) + amount
end

#empty? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns:

  • (Boolean) 


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# File 'lib/activerecord/materialized/summary_delta.rb', line 21

def empty?
  @buckets.empty?
end

#merge(other) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/activerecord/materialized/summary_delta.rb', line 37

def merge(other)
  merged = SummaryDelta.new(@buckets.transform_values(&:dup))
  other.buckets.each do |key_tuple, columns|
    columns.each { |column, amount| merged.add(key_tuple, column, amount) }
  end
  merged
end

#prune! ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Drops net-zero columns (no-op changes) and the partitions left empty.



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# File 'lib/activerecord/materialized/summary_delta.rb', line 31

def prune!
  @buckets.each_value { |columns| columns.reject! { |_column, amount| amount.zero? } }
  @buckets.reject! { |_key_tuple, columns| columns.empty? }
  self
end

#serialize ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

A list of "key" => tuple, "columns" => … entries so array keys survive JSON.



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# File 'lib/activerecord/materialized/summary_delta.rb', line 46

def serialize
  { "summary" => @buckets.map { |key_tuple, columns| { "key" => key_tuple, "columns" => columns } } }
end

#tracked_partition_count ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Number of distinct partitions (buckets) accumulated so far.



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# File 'lib/activerecord/materialized/summary_delta.rb', line 26

def tracked_partition_count
  @buckets.size
end