Name
SPVM::Packer - Pack and Unpack Operations
Description
Packer class in SPVM has methods for pack and unpack operations
Usage
use Packer;
my $packer = Packer->new;
{
my $objects = [(object)1, 2L, 0.5, [1, 2], "abc"];
my $binary = $packer->pack("lqdl2a128");
my $objects_unpack = $packer->unpack($binary);
}
{
my $objects = [(object)[1, 2, 3]];
my $binary = $packer->pack("l*");
my $objects_unpack = $packer->unpack($binary);
}Class Methods
static method new : Packer ();
Creates a new Packer object.
Instance Methods
pack
static method pack : string ($template : string, $objects : object[]);
Converts the objects $objects to a binary data according to the template $template, and returns it.
Template Syntax:
A template is a string. It consist of specifier parts.
TEMPLATE := "SpecifierPart1SpecifierPart2SpecifierPartN"A specifier part is consist of a speficier, an endian, and a length. An endian and a length are optional.
SpecifierPart := Specifier[Endian][Length]Here is the list of specifiers.
[Specifiers] [Types] [An output binary in pack or an input binary in unpack]
a string string. It is null padded in pack method.
h string A hex string (low nybble first)
H string A hex string (high nybble first)
c Byte or byte[] Singed 8-bit integers
C Byte or byte[] Unsinged 8-bit integers
s Short or short[] Singed 16-bit integers
S Short or short[] Unsinged 16-bit integers
l Int or int[] Singed 32-bit integers
L Int or int[] Unsinged 32-bit integers
q Long or long[] Singed 64-bit integers
Q Long or long[] Unsinged 64-bit integers
f Float or float[] 32-bit floating point numbers.
d Double or double[] 64-bit floating point numbers.An endian is big-endian > or little-endian >.
If big-endian is specified, the binary data is converted from big-endian to system-endian in "pack" method, or from system-endian to big-endian in "unpack" method.
If little-endian is specified, the binary data is converted from little-endian to system-endian in "pack" method, or from system-endian to little-endian in "unpack" method.
A length must be a positive integer or a wildcard *. If a length or a wildcard is specified, the type(such as Int) becomes a corresponding array type(such as int[]).
Exceptions:
If template syntax is invalid, an exception is thrown.
The template $template must be defined. Otherwise an exception is thrown.
The objects $objects must be defined. Otherwise an exception is thrown.
The length of the specifiers in the template $template must be less than or equal to the lenght of the objects $objects. Otherwise an exception is thrown.
The type of the element in the objects $objects is invalid, an exception is thrown.
unpack
static method unpack : object[] ($template : string, $binary : string);
Converts the binary data $binary to the objects $objects according to the template $template, and returns it.
See "pack" method about templates.
Exceptions:
If template syntax is invalid, an exception is thrown.
The template $template must be defined. Otherwise an exception is thrown.
The binary data $binary must be defined. Otherwise an exception is thrown.
The current offset $binary_offset plus (the size $size * the length $length of the specifier) must be less than the length($binary_length) of the binary data $binary. Otherwise an exception is thrown.
Copyright & License
Copyright (c) 2024 Yuki Kimoto
MIT License