For those interested, see attached file (chooser_overview.txt).
Regards,
Henri
chooser_overview.txt:
2016-04-05 // Another attempt to create an overview ...
= precondition
- assume a "database" which reflects the info from setup.ini ...
(packagedb::packages)
- it list each package and every version of that pkg ...
- this database even tells us what version has been installed if that is the
case (reflecting installed.db)
- furthermore we (setup.exe) are able to ascertain whether the tarball,
associated with a version, is available
or not -- the source code of setup.exe uses the term "accessible" for
availability
= D w/o I (Download without Installing)
- setup.exe should show us ALL the pkgs and every version of that pkg ...
- assume all tarballs are available (stable mirror)
= I f LD (Install from Local Directory)
- setup.exe should show us the installed pkgs and the versions of that pkg
that are not installed, but are available
in the repo ...
- the tarball of an installed version may or may not be available in the
repo ...
- furthermore it should show us each non-installed pkg if at least one version
of that pkg is available in the repo
ChooserPage::OnInit has the following call flow in both cases (D w/o I and I f
LD)
ChooserPage::OnInit
packagemeta::ScanDownLoadedFiles
packagedb::setExistence
packagemeta::trustp(true, ...
= D w/o I
// (pkg.installed == version) => pkg is installed
- ScanDownloadedFiles # method name is a misnomer here
! (pkg is installed || a version is acccessible) => erase version from
packagemeta.versions
- here all versions will be kept (stable mirror) in packagemeta.versions
- setExistence
! (pkg is installed || a version is acccessible) => erase pkg from packages
- the test whether the pkg is installed or not, is useless here ...
- ... as all pkgs (i.e. all versions of each pkg) are available
(accessible): UNmodified database
End result: setup.up will show us all the pkgs and every version of each pkg
...
= I f LD
// (pkg.installed == version) => pkg is installed
- ScanDownloadedFiles
! (pkg is installed || a version is accessible) => erase version from
packagemeta.versions
- not-installed pkgs: available versions will be kept in
packagemeta.versions
- installed pkgs: the installed version will be kept
- installed pkgs: non-available versions will be removed from
packagemeta.versions
- setExistence
! (pkg is installed || a version is accessible) => erase pkg from packages
- a not-installed pkg, of which at least one version is available: this pkg
will be kept in the database
(versions will show the available versions)
- installed pkgs: these pkgs will be kept in the database
(versions will show the installed version and available versions that are
not installed)
End result: setup.exe will show us all the available versions of each pkg, if
it has not been installed yet, and all
the pkgs (both the installed version and available versions that are not
installed) which have been installed ...
----- Ignoring the issue of source tarballs ...
Each "package entry" (p, c and/or t) in setup.ini is represeneted by an object
of type packagemeta ...
- class variable packages (of type packagedb): std::map <std::string,
*packagemeta>
or: a mapping from a packagename to a pointer to an object of type
packagemeta
A simplified view of the data members of class packagemeta is as follows:
- prev of type packageversion
- curr ditto
- exp ditto
- installed ditto
- versions of type std::set <packageversion>
-
prev, curr, exp and installed reflect the "static" part of a "package entry":
these data members reflect the info from both
setup.ini and installed.db ...
"Nullifying" these data members, as currently happens in ScanDownLoadedFiles is
... stupid?
versions tells what versions of the pkg are available (accessible); versions is
managed by ScanDownLoadedFiles ...
Attempting to grasp the general flow of computation:
packagemeta::ScanDownLoadedFiles =>
for each pkg // from packagedb::packages
for each version // from metapackage::versions
[ <this>.scan() ] // packageversion::scan() -- simplified!
// (pkg.installed == version) => pkg is installed
if ! (pkg is installed || version is accessible) // packagemeta::installed,
packageversion::accessible()
erase version from versions
Note: a version is NOT erased if the version is installed OR if the version is
available
packagemeta::accessible => // called by setExistence
for each version // from metapackage::versions
if version is accessible // packageversion::accessible()
return true // pkg is available in (local) repo
return false
packageversion::accessible =>
_packageversion::accessible =>
...
packagedb::setExistence
for each pkg // from packagedb::packages
// (pkg.installed == version) => pkg is installed
if ! (pkg is installed || a version is accessible) // packagemeta::installed,
packagemeta::accessible()
erase pkg from packages
Note: a pkg is NOT erased if it is installed, OR if at least one version is
available if the pkg is not installed
packagemeta:trustp =>
... only the default trust for the moment ...
if (pkg is installed)
if (installed version > current version) // requires curr to be properly
initialized, i.e. setup.ini MUST have
// a current entry for this package
if (the experimental version is available
&& experimental version > installed version) // requires exp to be
properly initialized ...
return exp;
else
return installed;
else
if (the current version is available) // requires curr to be properly
initialized ...
return curr;
return installed;
=====
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