abit v0.1.4 Abit.Counter View Source
Use atomics as an array of counters with n bits per 64 bit integer.
Possible counters:
bits | unsigned value range | signed value range
2 0..3 -2..1
4 0..15 -8..7
8 0..255 -128..127
16 0..65535 -32768..32767
32 0..4294967295 -2147483648..2147483647
If you need 64 bit counters use: Erlang counters
Link to this section Summary
Functions
Increments the value into the counter at index
.
Returns the value of counter at index
.
Returns a new %Abit.Counter{} struct.
Puts the value into the counter at index
.
Link to this section Types
Link to this type
t()
View Sourcet() :: %Abit.Counter{ atomics_ref: reference(), counters_bit_size: 2 | 4 | 8 | 16 | 32, max: non_neg_integer(), min: integer(), signed: boolean(), size: non_neg_integer() }
Link to this section Functions
Link to this function
add(counter, index, incr)
View Sourceadd(t(), non_neg_integer(), integer()) :: :ok
Increments the value into the counter at index
.
Returns :ok
.
Examples
iex> c = Abit.Counter.new(10, 8)
iex> c |> Abit.Counter.add(7, -12)
iex> c |> Abit.Counter.add(7, -12)
:ok
iex> c |> Abit.Counter.get(7)
-24
Returns the value of counter at index
.
Examples
iex> c = Abit.Counter.new(10, 8)
iex> c |> Abit.Counter.get(7)
0
Link to this function
new(size, counters_bit_size, options \\ [])
View Sourcenew(non_neg_integer(), 2 | 4 | 8 | 16 | 32, list()) :: t()
Returns a new %Abit.Counter{} struct.
size
- minimum number of counters to havecounters_bit_size
- how many bits a counter should use
Options:
signed
- whether to have signed or unsigned counters.
Examples
Abit.Counter.new(100, 8) # minimum 100 counters; 8 bits signed
Abit.Counter.new(10_000, 16, signed: false) # minimum 10_000 counters; 16 bits unsigned
Link to this function
put(counter, index, value)
View Sourceput(t(), non_neg_integer(), integer()) :: :ok
Puts the value into the counter at index
.
Returns :ok
.
Examples
iex> c = Abit.Counter.new(10, 8)
iex> c |> Abit.Counter.put(7, -12)
:ok
iex> c |> Abit.Counter.get(7)
-12