Class: Redstruct::Hash

Inherits:
Struct
  • Object
show all
Includes:
Utils::Iterable
Defined in:
lib/redstruct/hash.rb

Overview

Class to manipulate redis hashes, modeled after Ruby's Hash class.

Instance Attribute Summary

Attributes inherited from Struct

#key

Instance Method Summary collapse

Methods inherited from Struct

#delete, #dump, #exists?, #expire, #expire_at, #initialize, #inspectable_attributes, #persist, #restore, #ttl, #type

Constructor Details

This class inherits a constructor from Redstruct::Struct

Instance Method Details

#[](key) ⇒ nil, String

Returns the value at key

Parameters:

  • key (#to_s) —

    the hash key

Returns:

  • (nil, String) —

    the value at key, or nil if nothing



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# File 'lib/redstruct/hash.rb', line 14

def [](key)
  return self.connection.hget(@key, key)
end

#[]=(key, value) ⇒ Boolean

Sets or updates the value at key

Parameters:

  • key (#to_s) —

    the hash key

  • value (#to_s) —

    the new value to set

Returns:

  • (Boolean) —

    true if the field was set (not updated!), false otherwise



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# File 'lib/redstruct/hash.rb', line 31

def []=(key, value)
  set(key, value, overwrite: true)
end

#decrement(key, by: 1) ⇒ Integer, Float

Decrements the value at the given key

Parameters:

  • key (#to_s) —

    the hash key

  • by (Integer, Float) —

    defaults to 1

Returns:

  • (Integer, Float) —

    returns the decremented value



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# File 'lib/redstruct/hash.rb', line 86

def decrement(key, by: 1)
  return increment(key, by: -by)
end

#empty? ⇒ Boolean

Returns true if the hash contains no elements

Returns:

  • (Boolean) —

    true if the hash contains no elements



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# File 'lib/redstruct/hash.rb', line 91

def empty?
  return !exists?
end

#get(*keys) ⇒ Hash<String, String>

Returns the value at key

Parameters:

  • keys (Array<#to_s>) —

    a list of keys to fetch; can be only one

Returns:

  • (Hash<String, String>) —

    if only one key was passed, then return the value for it; otherwise returns a Ruby hash where each key in the `keys` is mapped to the value returned by redis



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# File 'lib/redstruct/hash.rb', line 22

def get(*keys)
  return self.connection.hget(@key, keys.first) if keys.size == 1
  return self.connection.mapped_hmget(@key, *keys).reject { |_, v| v.nil? }
end

#increment(key, by: 1) ⇒ Integer, Float

Increments the value at the given key

Parameters:

  • key (#to_s) —

    the hash key

  • by (Integer, Float) —

    defaults to 1

Returns:

  • (Integer, Float) —

    returns the incremented value



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# File 'lib/redstruct/hash.rb', line 74

def increment(key, by: 1)
  if by.is_a?(Float)
    self.connection.hincrbyfloat(@key, key, by.to_f).to_f
  else
    self.connection.hincrby(@key, key, by.to_i).to_i
  end
end

#key?(key) ⇒ Boolean

Checks if a key has a value

Parameters:

  • key (#to_s) —

    the key to check for

Returns:

  • (Boolean) —

    true if the key has a value associated, false otherwise



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# File 'lib/redstruct/hash.rb', line 66

def key?(key)
  return coerce_bool(self.connection.hexists(@key, key))
end

#keys ⇒ Array<String>

Returns a list of all hash keys with values associated

Returns:

  • (Array<String>) —

    a list of all hash keys with values associated



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# File 'lib/redstruct/hash.rb', line 103

def keys
  return self.connection.hkeys(@key)
end

#remove(*keys) ⇒ Integer

Removes all items for the given keys

Parameters:

  • keys (Array<#to_s>) —

    the list of keys to remove

Returns:

  • (Integer) —

    the number of keys removed



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# File 'lib/redstruct/hash.rb', line 59

def remove(*keys)
  return self.connection.hdel(@key, keys)
end

#set(key, value, overwrite: true) ⇒ Boolean

Sets or updates the value at key

Parameters:

  • key (#to_s) —

    the hash key

  • value (#to_s) —

    the new value to set

Returns:

  • (Boolean) —

    true if the field was set (not updated!), false otherwise



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# File 'lib/redstruct/hash.rb', line 39

def set(key, value, overwrite: true)
  result = if overwrite
    self.connection.hset(@key, key, value)
  else
    self.connection.hsetnx(@key, key, value)
  end

  return coerce_bool(result)
end

#size ⇒ Integer

Returns the number of key value pairs stored for this hash

Returns:

  • (Integer) —

    the number of key value pairs stored for this hash



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# File 'lib/redstruct/hash.rb', line 113

def size
  return self.connection.hlen(@key)
end

#to_enum(match: '*', count: 10) ⇒ Enumerator

Use redis-rb hscan_each method to iterate over particular keys

Returns:

  • (Enumerator) —

    base enumerator to iterate of the namespaced keys



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# File 'lib/redstruct/hash.rb', line 119

def to_enum(match: '*', count: 10)
  return self.connection.hscan_each(@key, match: match, count: count)
end

#to_h ⇒ Hash<String, String>

Loads all the hash members in memory NOTE: if the hash is expected to be large, use to_enum

Returns:



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# File 'lib/redstruct/hash.rb', line 98

def to_h
  return self.connection.hgetall(@key)
end

#update(hash) ⇒ Boolean

Updates the underlying redis hash using the given Ruby hash's key/value mapping

Parameters:

  • hash (Hash) —

    the key/value mapping to use

Returns:

  • (Boolean) —

    true if updated, false otherwise



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# File 'lib/redstruct/hash.rb', line 52

def update(hash)
  coerce_bool(self.connection.mapped_hmset(@key, hash))
end

#values ⇒ Array<Strign>

Returns a list of all hash values

Returns:

  • (Array<Strign>) —

    a list of all hash values



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# File 'lib/redstruct/hash.rb', line 108

def values
  return self.connection.hvals(@key)
end