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{{Warning|This page has not been revisited since 2014.  Please refer to the GNU Octave manual for information about {{manual|pkg}}.}}
    
== Abstract ==
 
== Abstract ==
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This document attempts to design a solution for this.
 
This document attempts to design a solution for this.
   −
The main idea of the solution is to keep database files with each package location
+
The main idea is to have multiple databases with information from installed packages
and dependencies, and allow for the merge of such files.
+
in different locations in the filesystem. While this is similar to the current implementation,
 +
we plan to design solutions for when package installations clash.
   −
To allow reinstallation of the packages, we propose to keep the source of the package.
+
This proposal also suggests to keep the source of the packages. This will allow for
This would also make it easier to run the tests of packages.
+
easy reinstall of packages (after an Octave upgrade) and test of .oct files from
 +
packages (since their tests are in the .cc sources).
   −
== Rationale and examples ==
+
== Rationale ==
This design is meant to allow the following:
+
This design is meant to make allow the following:
  * keeping multiple versions of the same package installed and load a specific one
+
* keep multiple versions of the same package installed side-by-side
  * keep packages installed for multiple versions of Octave, specially in the case of
+
* keep multiple versions of Octave in a system using the same installed packages
    .oct files which need to be rebuilt for each octave function
+
* deal with dependencies correctly when multiple Octave and packages co-exist
  * reinstall a package from its cache after installing new octave version
+
* allow use of packages that may have been installed anywhere
  * run the tests from packages (find tests in .cc sources)
+
* reinstall a package
  * clean the package cache
+
* test installed packages
  * usage of alternate database files
  −
  * usage of packages in remote directories which may not be available at all
  −
    times
     −
=== Case 1 ===
+
See the user cases section below for several examples.
 +
 
 +
The definition of a package manager according to wikipedia:
 +
 
 +
* Verifying file checksums to ensure correct and complete packages;
 +
* Verifying digital signatures to authenticate the origin of packages;
 +
* Applying file archivers to manage encapsulated files;
 +
* Upgrading software with latest versions, typically from a software repository;
 +
* Grouping of packages by function to reduce user confusion;
 +
* Managing dependencies to ensure a package is installed with all packages it requires. This resolved the problem known as Dependency Hell.
 +
 
 +
== Available vs Loaded ==
 +
To avoid problems reading this document, the distinction between available and loaded
 +
package should be done early.
 +
 
 +
An available package is a package that is currently available to pkg for loading,
 +
unloading or reinstall. It is already installed but not necessarily loaded.
 +
 
 +
A loaded package is an installed package whose functions have been added to Octave's
 +
function search path.
 +
 
 +
== Types of package installs ==
 +
This design supports 3 types of package installations: global (relative to the
 +
Octave installation), local (user specific) and external (in any other place).
 +
 
 +
;global install
 +
: available from startup to everyone.
 +
;local install
 +
: available from startup only for the user that installed it.
 +
;external install
 +
: needs to be made available first. Octave install has no information about it.
 +
 
 +
Note that Octave itself can be installed in some different ways. It might be a system-wide
 +
installation (located somewhere in {{Path|/usr/local/}} for example), a local installation
 +
of a normal user ({{Path|/home/user/anywhere}}), or installed in the home
 +
directory of a system user (anywhere really).
 +
 
 +
=== Global installs ===
 +
Packages installed globally will be available to everyone from startup. This is the
 +
type of package installation that a system administrator would most likely do. The
 +
meaning of global here is relative to the Octave installation though. If an Octave
 +
installation is local (installed by a user in {{Path|~/my-builds}}), a global installation
 +
of a package will still place its files in the home directory of the user (in
 +
{{Path|~/my-builds}}).
 +
 
 +
A global installation is performed automatically if the user installing the package
 +
has write permissions to those directories (''localfcnfiledir'' and ''localapioctfiledir'').
 +
In case it has no permissions, a local package installation is performed instead.
 +
 
 +
=== Local installs ===
 +
Local packages are specific to a user. They are located in that user home directory
 +
into an {{Path|.octave}} directory. As with global package installations, they are available
 +
from startup. Unlike global, they are user specific, only available to the user that
 +
installed it. A local install for a user can be an external install for some other
 +
user.
 +
 
 +
This are the type of package installation done by users that want to have the latest
 +
package version before is available in their system repository, but are not going to
 +
build Octave themselves. Also to be used by those who run Octave in a system that they
 +
do not maintain where Octave is installed but not packages.
 +
 
 +
=== External installs ===
 +
These are like local packages but in a non-standard location. Octave does not know
 +
about this installations at startup even though they might have been installing the
 +
same Octave that is running at the moment. These can be packages installed in a
 +
filesystem that is not always mounted, local packages installs from another user
 +
in the same system, or anything else really.
 +
 
 +
An external package was still installed with pkg, the difference being that the
 +
record is not kept by Octave after it. An external package install will have a db
 +
associated file just like the db files for the local installs. To load an external
 +
package, the path for the db file needs to be passed to pkg and the db named (because
 +
there may be more than one db.
 +
 
 +
These are most like the less used type of packages and will require a bit more
 +
knowledge (they will need to point pkg to a .db file, that is all). They will be
 +
mostly used for places that develop their own packages and people who don't want to
 +
install the package themselves, instead simply using a local install of others as
 +
an external package.
 +
 
 +
=== Playing nice with downstream packagers ===
 +
The recommended method for installing Octave and its packages is to use their OS packaging
 +
system. Downstream packagers should have the packaging systems make global installs of the
 +
packages. If a user wants to install a new version of a package that is not yet available
 +
on its system repository, it should make a local package install (default since has a normal
 +
user he won't have write permissions to the Octave directory).
 +
 
 +
If the user decides to make a global package install (install the package using pkg while
 +
running Octave with sudo), then he's trying to act as system administrator and should know
 +
what he's doing. If he breaks it, its his own fault. Installation of system-wide software
 +
is meant to be handled by the system packaging tool. It is just not possible to make pkg
 +
cover all of them.
 +
 
 +
== Package names ==
 +
For the parsing of the commands and files, some limitations on package names are required. This will
 +
limit what pkg commands can do. For example, if a package name is allowed to use a hyphen, then
 +
commands such as "pkg load image-2.0.0" can no longer be used to load a specific package version.
 +
Something such as "pkg load image::2.0.0" would have to be used. Using this alternative syntax
 +
means that package names cannot have colons.
 +
 
 +
This is not only limited to package versions. As pkg is to be expanded to load pkg databases from
 +
other files (packages in a not always mounted directory for example), it becomes a possibility to
 +
have more than one package with the same version available to "pkg load". This means that it
 +
becomes necessary to specify which package to load. Something like "pkg load image-lab-2.0.0" can
 +
be used. A nice thing would also be "pkg load image-2.0.0 from lab" but that would add one of following
 +
2 limitations: either no package can be named from; or pkg load becomes limited to load only
 +
one package.
 +
 
 +
Also, supporting multiple packages versions means that the word "all" to refer to all
 +
packages has new limitations. Should we load only the latest version of each package?
 +
And if there's multiple packages with the same version on various db, which one should
 +
be loaded? I'd propose the default to be:
 +
 
 +
- load the latest version available
 +
- load the local install of the package
 +
- load the global install of the package
 +
- load the package from the external .db, starting from the latest added in case there's more than one.
 +
 
 +
For package names, the proposal is to limit package names to the same as variable
 +
names (makes it even easier to check validity with isvarname). So package name
 +
must start with a letter, and otherwise be comprised of alphanumeric and underscores
 +
characters. Unlike variable names, package names will not be case sensitive since
 +
it would create problems when installing packages in filesystems that are not case
 +
sensitive (creating directories named Image and image would not be possible in FAT
 +
systems).
 +
 
 +
== Version numbers ==
 +
 
 +
=== specifying version ===
 +
Actions dependent on a package version can be specified with a -version modifier for that
 +
action. It is however necessary to define the default order. Comparison operators
 +
should be used to specify versions. If no comparison is use then greater than or
 +
equal is assumed. So that the following:
 +
 
 +
;pkg load image
 +
: loads latest version of the image package. If package is not installed, give error
 +
;pkg load -version 1.0.5 image
 +
: load the latest version greater than or equal to 1.0.5. If no such version found, give error
 +
;pkg load -version >=1.0.5 image
 +
: same as not specifying comparison
 +
;pkg load -version >1.0.5 image
 +
: load anything above that version (does it make sense supporting this? It's not a lot of trouble...)
 +
;pkg load -version =1.0.5 image
 +
: load image package only if the same version (should we use == instead? Why not only =? Should not support both syntax)
 +
;pkg load -version !1.0.5 image
 +
: load any image package available except 1.0.5 (because regressions do exist)
 +
 
 +
For the other 2 remaining comparisons (< and <=), the question used for > and >=
 +
is the same. Does it make sense to support both? For ''greater than'', the only
 +
thing that makes sense is ''greater than or equal'' and for ''lesser than'', the
 +
only think that makes sense is ''only lesser than'' since people will mark them
 +
as the first release that implemented, or the first release that no longer had,
 +
a specific feature.
 +
 
 +
Whatever code is used on this section should also be used for solving package
 +
dependencies.
 +
 
 +
Should versions take precedence over the database for loading order? For example,
 +
if there is a global installation of image 1.0.5 and a 2.0.0 version on an external
 +
database named labdev, what version should be loaded?
 +
 
 +
;pkg load image
 +
: load version 1.0.5 from global (database takes precedence over version)
 +
;pkg load -version >1.0.0 image
 +
: load version 1.0.5 from global (database takes precedence over version)
 +
;pkg load -version >2.0.0 image
 +
: load version 2.0.0 from labdev (only version that meets the requirements)
 +
;pkg load -version >1.0.0 -db labdev image
 +
: load version 2.0.0 from labdev (while database takes precedence, labdev was specified so we load the latest)
 +
 
 +
Should the -db modifier make pkg ignore completely version? If a system has signal
 +
version 1.0.0 on an external named labdev, and 1.2.0 on a global, what should be loaded?
 +
 
 +
;pkg load signal
 +
: load version 1.2.0 from global
 +
;pkg load -db labdev image
 +
: load latest version from global or from labdev?
 +
 
 +
=== version definition ===
 +
The current implementation only accepts versions on the format x.y.z. This does
 +
not allow for dev versions, beta or release candidates releases such x.y.z-rc0, x.y.z+, etc
 +
 
 +
We have compare_versions in core to check for version numbers, whatever is decided
 +
should be used with compare_version (or compare_version should be made to support it).
 +
 
 +
== User cases ==
 +
=== User case #1: global, local and external ===
 +
Jenny is using Octave on the department cluster. She is not the administrator but
 +
there's already a system-wide installation of Octave with the general and
 +
signal image installed. She starts Octave and has these 2 packages available to
 +
her. These are globally installed packages, available to everyone that starts
 +
Octave.
 +
 
 +
But Jenny also requires the image package and she installs it with "pkg install -forge image". She
 +
does not have permissions to administer the system so the image package is installed
 +
locally in her home directory. When she starts Octave, she now has 3 packages available,
 +
general and signal package which are global (available to everyone that starts Octave), and
 +
the image package which is local (available only to her).
 +
 
 +
Jenny's supervisor is working on a new package (img_analysis) that he makes available
 +
for all his students and wants Jenny to use it. Rather than sending them the packages,
 +
he wants them to use the package he has installed on his own home directory and tells
 +
them to load it as an external package. Jenny uses
 +
"pkg load-db boss /home/supervisor/.octave/octave_packages.db" to make his supervisor
 +
packages available to her. She now has 4 available packages, the new one (img_analysis)
 +
being an external package. However, relative to her supervisor, the same package is a
 +
local installation.
 +
 
 +
The next time she starts Octave, there is no trace of the external packages, pkg still
 +
only have 3 available packages so she adds the "pkg load-db" command to her {{Path|.octaverc}}
 +
file.
 +
 
 +
In this case however, her supervisor would do better in installing his img_analysis package
 +
in some other place to avoid clash with his own local packages. For example, he could
 +
have installed it at {{Path|/home/supervisor/group/octave}}. Or he could have a filesystem
 +
on the network that his students could mount whenever they needed it.
 +
 
 +
=== User case #2: keeping tarball ===
 
Denise installs Octave 3.4.3 and installs the latest version of the financial (1.0.4) and
 
Denise installs Octave 3.4.3 and installs the latest version of the financial (1.0.4) and
 
image (2.0.0) package with "pkg install -forge financial image". After installing the packages,
 
image (2.0.0) package with "pkg install -forge financial image". After installing the packages,
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tests in the package (using the cached package to run the tests in the .cc files).
 
tests in the package (using the cached package to run the tests in the .cc files).
   −
 
+
==== different package versions ====
 
Later, Denise installs Octave 3.6.2 but keeps the previous version of Octave on the
 
Later, Denise installs Octave 3.6.2 but keeps the previous version of Octave on the
 
system since some of her old code no longer runs correctly. Loading the financial
 
system since some of her old code no longer runs correctly. Loading the financial
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While using Octave 3.6.2, Denise installs the new version of the package
 
While using Octave 3.6.2, Denise installs the new version of the package
 
"pkg install -forge financial".  The files for the previous version of the package
 
"pkg install -forge financial".  The files for the previous version of the package
are kept altough "pkg load financial" will only load the latest version. However, when
+
are kept although "pkg load financial" will only load the latest version. However, when
 
Denise is using Octave 3.4.3, as financial 1.2.0 requires Octave 3.6.0, pkg load
 
Denise is using Octave 3.4.3, as financial 1.2.0 requires Octave 3.6.0, pkg load
 
will only load financial 1.0.4.
 
will only load financial 1.0.4.
   −
==== comments ====
+
=== User case #3: installing and loading different package versions ===
 
  −
shouldn't `rebuild` be used instead of `reinstall` ?
  −
 
  −
=== Case 2 ===
   
Owen is stuck using the financial package 1.0.4 because some of his code no
 
Owen is stuck using the financial package 1.0.4 because some of his code no
 
longer works in the latest versions. However the latest version of financial
 
longer works in the latest versions. However the latest version of financial
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while "pkg load financial" always loads the latest version of the package.
 
while "pkg load financial" always loads the latest version of the package.
   −
=== Case 3 ===
+
=== User case #4: Local installation of packages and Octave ===
 
Lisa is using Octave in a remote machine on the biochemistry department.  The
 
Lisa is using Octave in a remote machine on the biochemistry department.  The
 
system administrator installed Octave 3.6.2, signal package 1.2.0, and
 
system administrator installed Octave 3.6.2, signal package 1.2.0, and
general 1.0.0. Lisas uses all of them but she also requires the image package.
+
general 1.0.0. Lisa uses all of them but she also requires the image package.
 
However, the system administrator does not have time to access security issues
 
However, the system administrator does not have time to access security issues
 
with the package and tells her to install that package locally. She runs "pkg
 
with the package and tells her to install that package locally. She runs "pkg
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When Octave 3.6.3 is released, Lisa wants to use the new version since it fixes
 
When Octave 3.6.3 is released, Lisa wants to use the new version since it fixes
one bug that has been aanoying her for a long time but the system administrator
+
one bug that has been annoying her for a long time but the system administrator
 
does not want to make the update and tells her to build it herself locally
 
does not want to make the update and tells her to build it herself locally
   −
=== Case 4 ===
+
=== User case #5: users (no sudo) sharing Octave installation with local & global packages ===
 
Diana is a student that wants to run her code in the departmental cluster. However,
 
Diana is a student that wants to run her code in the departmental cluster. However,
 
the system does not have an installation of Octave and she needs to install it on
 
the system does not have an installation of Octave and she needs to install it on
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to her own list of available packages. which she can load.
 
to her own list of available packages. which she can load.
   −
==== comments ====
+
=== User case #6: Automatic dependency tracking ===
 
  −
why not store the "packages.db" together with the packages? instead of loading the a packages database file,
  −
then, Diana could just say
  −
 
  −
pkg addpath ~Ligia/octave
  −
 
  −
=== Case 5 ===
   
John is a professor of biomechanics and uses Octave on his classes. Most of the
 
John is a professor of biomechanics and uses Octave on his classes. Most of the
 
exercises he gives to the class require the use of multiple packages in Octave
 
exercises he gives to the class require the use of multiple packages in Octave
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metapackage for his student listing all required packages. The students install
 
metapackage for his student listing all required packages. The students install
 
it with "pkg install -url path-to-his-metapackage". The metapackage has no file
 
it with "pkg install -url path-to-his-metapackage". The metapackage has no file
it simply lists a bunch of package has dependencies. Since pkg solves this
+
it simply lists a bunch of package as dependencies. Since pkg solves this
 
dependencies automatically, a message showing which packages will be installed
 
dependencies automatically, a message showing which packages will be installed
 
is displayed before doing it.
 
is displayed before doing it.
   −
=== Where to install things ===
+
=== User case #7: Package testing ===
 +
"pkg test" command that would run all tests for a given package.
 +
 
 +
== Where to install things ==
 
These should not be hardcoded and taken from octave_config_info. There's many paths there whose purpose is explained on octave sources [http://hg.savannah.gnu.org/hgweb/octave/file/default/build-aux/common.mk buil-aux/common.mk] (see the ''Where To Install Things'' and ''Octave-specific directories'' sections on that file.)
 
These should not be hardcoded and taken from octave_config_info. There's many paths there whose purpose is explained on octave sources [http://hg.savannah.gnu.org/hgweb/octave/file/default/build-aux/common.mk buil-aux/common.mk] (see the ''Where To Install Things'' and ''Octave-specific directories'' sections on that file.)
 +
 +
[[Category:Packages]]

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