SipHash v2.1.0 SipHash.Util
Utility module for minor masking and binary conversions.
Summary
Functions
Applies a 64 bit mask to the passed in number to force it to use only 64 bits. Any bits extending further than the 64th bit are zeroed and dropped
Converts a binary input to an unsigned number using little endian
Chunks a binary input into groups of N, where N is passed in. If a group does not have enough chars to be chunked again, it will be added to the list as is
Formats a resulting hash into a chosen format. Arguments are provided by the
options passed in by the user when SipHash.hash/3
is called. The /2
version
of this function is overridden by a NIF which uses sprintf
to do the any
formatting. The Elixir implementation just pattern matches on the format chars
and provides an backup. The NIF implementation is roughly 1 microsecond quicker,
so it’s worth the override
Loads any NIFs needed for this module, logging out a message depending on whether the load was successful or not. Because we have a valid fallback implementation, we don’t have to exit on failure
Pads a binary input with zeroes. If the provided input is not a binary, simply return the value passed in
Converts a binary input to the provided case. If the provided input is not a binary, simply return the value passed in
Converts a number input to a base-16 output (as a string). If the first arg is not a number, simple return the first argument as is
Functions
Specs
apply_mask64(number) :: number
Applies a 64 bit mask to the passed in number to force it to use only 64 bits. Any bits extending further than the 64th bit are zeroed and dropped.
Examples
iex> SipHash.Util.apply_mask64(9223372036854775808)
9223372036854775808
iex> SipHash.Util.apply_mask64(92233720368547758077)
18446744073709551613
iex> SipHash.Util.apply_mask64("test_string")
** (FunctionClauseError) no function clause matching in SipHash.Util.apply_mask64/1
Specs
bytes_to_long(binary) :: number
Converts a binary input to an unsigned number using little endian.
Examples
iex> SipHash.Util.bytes_to_long(<<169,138,199>>)
13077161
iex> SipHash.Util.bytes_to_long("test_string")
125040764888893876906190196
iex> SipHash.Util.bytes_to_long(5)
** (FunctionClauseError) no function clause matching in SipHash.Util.bytes_to_long/1
Specs
chunk_string(binary, number) :: list
Chunks a binary input into groups of N, where N is passed in. If a group does not have enough chars to be chunked again, it will be added to the list as is.
Examples
iex> SipHash.Util.chunk_string("12345678", 4)
["1234","5678"]
Formats a resulting hash into a chosen format. Arguments are provided by the
options passed in by the user when SipHash.hash/3
is called. The /2
version
of this function is overridden by a NIF which uses sprintf
to do the any
formatting. The Elixir implementation just pattern matches on the format chars
and provides an backup. The NIF implementation is roughly 1 microsecond quicker,
so it’s worth the override.
Examples
iex> SipHash.Util.format(699588702094987020, false, :upper)
699588702094987020
iex> SipHash.Util.format(699588702094987020, true, :upper)
"09B57037CD3F8F0C"
iex> SipHash.Util.format(699588702094987020, true, :lower)
"09b57037cd3f8f0c"
Loads any NIFs needed for this module, logging out a message depending on whether the load was successful or not. Because we have a valid fallback implementation, we don’t have to exit on failure.
Specs
pad_left(binary) :: binary
Pads a binary input with zeroes. If the provided input is not a binary, simply return the value passed in.
Examples
iex> SipHash.Util.pad_left("12345678")
"0000000012345678"
iex> SipHash.Util.pad_left(12345678)
12345678
Specs
to_case(binary, atom) :: binary
Converts a binary input to the provided case. If the provided input is not a binary, simply return the value passed in.
Examples
iex> SipHash.Util.to_case("TEST", :lower)
"test"
iex> SipHash.Util.to_case("test", :upper)
"TEST"
iex> SipHash.Util.to_case(5, :upper)
5