Class: Nodepile::CrudeCalculationCache

Inherits:
Object
  • Object
show all
Defined in:
lib/nodepile/base_structs.rb

Overview

Caches the result of named calculations and their parameters and provides a crude flushing

Constant Summary collapse

@@global_disable_cache =
false

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(disable_cache: false) ⇒ CrudeCalculationCache

Returns a new instance of CrudeCalculationCache.

Parameters:

  • disable_cache (Boolean) (defaults to: false)

    if truthy, then caching is never triggered for this object



16
17
18
19
# File 'lib/nodepile/base_structs.rb', line 16

def initialize(disable_cache: false)
   @h = Hash.new
   @disable_cache = disable_cache
end

Class Method Details

.global_disable_cache(flag) ⇒ Object

Used to disable use of cache by all instances of this class. Note that this is extremely useful during testing.



12
# File 'lib/nodepile/base_structs.rb', line 12

def self.global_disable_cache(flag) = @@universally_disable_cache = flag

Instance Method Details

#cache(sym, *parms) ⇒ Object

Will either retrieve the value matching these parameters from the cache or will do the calculation, cache the value, and return the result



49
50
51
52
53
54
55
56
57
# File 'lib/nodepile/base_structs.rb', line 49

def cache(sym,*parms)
    raise "Calculation block expected" unless block_given?
    key = form_cache_key(sym,*parms)
    if @h.include?(key) && !@disable_cache && !@@global_disable_cache
        return @h[key]
    else
        return @h[sym] = yield(*parms)
    end
end

#fetch_cache(sym, *parms) ⇒ Object



41
42
43
44
45
# File 'lib/nodepile/base_structs.rb', line 41

def fetch_cache(sym,*parms)
    key = form_cache_key(sym,*parms)
    raise "This item is not in the cache #{key.inspect}" unless @h.include?(key)
    return @h[key]
end

#flush_cache(name = nil, *params) ⇒ Object

Empties the entire cache forcing recalculation of some or all entries

Parameters:

  • name (String, Symbol, nil) (defaults to: nil)

    Name of the calculation or nil if all calculations are to be flushed

  • params

    If empty, all cached values for the given name will be flushed



25
26
27
28
29
30
31
32
33
34
35
# File 'lib/nodepile/base_structs.rb', line 25

def flush_cache(name = nil, *params) 
    if key.nil?
        @h.clear
    elsif params.empty?
        @h.delete(name) # delete simple keys
        @h.delete{|(cname,*cparams)| cname == name }
    else
        @h.delete([key,*params])
    end
    return nil
end

#form_cache_key(sym, *parms) ⇒ Object



37
# File 'lib/nodepile/base_structs.rb', line 37

def form_cache_key(sym,*parms) = parms.empty? ? sym : [sym,*parms]

#has_cache?(sym, *parms) ⇒ Boolean

Returns:

  • (Boolean)


39
# File 'lib/nodepile/base_structs.rb', line 39

def has_cache?(sym,*parms) = @h.include?(form_cache_key(sym,*parms))

#stuff_cache(val, sym, *parms) ⇒ Object



38
# File 'lib/nodepile/base_structs.rb', line 38

def stuff_cache(val,sym,*parms) = @h[form_cache_key(sym,*parms)] = val