Deltup

From Gentoo Linux Wiki

[edit] Introduction

Deltup is a program that allows you to fetch the changes to a program, instead of the entire tarball. In other words if you already have cool-app-1.0.tar.bz and a new version is released, instead of having to download cool-app-1.1.tar.bz you would only have to download the minor differences between the two (also known as patch). This tutorial is an absolute must for dialup users.

[edit] Installation

echo "app-portage/deltup ~arch" >> /etc/portage/package.keywords
echo "dev-util/bdelta ~arch" >> /etc/portage/package.keywords
echo "app-portage/getdelta ~arch" >> /etc/portage/package.keywords

emerge --ask --verbose getdelta

Replace arch with your architecture (e.g. x86, amd64).

[edit] Configuration

To enable getdelta, you have to edit your /etc/make.conf:

FETCHCOMMAND="/usr/bin/getdelta.sh \${URI}"

Tuning of the script may be accomplished by editing /etc/deltup/getdelta.rc

[edit] What if digest verification fails?

Due to the on-the-fly-generation of the package-files the digest verification may fail. If you are sure that the package has been downloaded correctly, you can run

ebuild /path/to/ebuild digest 

to re-digest the file and try to emerge the package.