SPVM::Packer - Pack and Unpack Operations
Name Description Usage Class Methods Instance Methods pack unpack Copyright & LicenseName
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",
$objects);
my $objects_unpack =
$packer−>unpack("lqdl2a128", $binary);
}
{
my $objects = [(object)[1, 2, 3]];
my $binary = $packer−>pack("l*",
$objects);
my $objects_unpack =
$packer−>unpack("l*", $binary);
}
Class Methods
"static method new : Packer ();"
Creates a new Packer object.
Instance Methods
pack
"static method pack : string ($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