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);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] [Meanings]
a string A input/output binary is a string. It will be null padded in pack method.
c Byte or byte[] A input/output binary is a 8-bit integer(both singed and unsinged).
s Short or short[] A input/output binary is a 16-bit integer(both singed and unsinged).
l Int or int[] A input/output binary is a 32-bit integer(both singed and unsinged).
q Long or long[] A input/output binary is a 64-bit integer(both singed and unsinged).
f Float or float[] A input/output binary is a 32-bit floating point number.
d Double or double[] A input/output binary is a 64-bit floating point number.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. If a length 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