Switch package file accessor classes to use BPositionIO

* PackageFileHeap{Reader,Writer} as well as Package{Reader,Writer} and
their implementation and super classes do now internally use a
BPositionIO instead of a FD to access the package file. This provides
more flexibility needed for features to come.
* BPackageReader has already grown a new Init() version with a
BPositionIO* parameter.

Repository file format: group attributes of a package

* Introduce new package attribute B_HPKG_ATTRIBUTE_ID_PACKAGE (valid
only in a repository file) to group the attributes belonging to a
package.
* BRepositoryContentHandler:
- No longer derive from BPackageContentHandler.
- Add hooks HandlePackage() and HandlePackageDone() that bracket the
attributes for a package. This is more explicit and robust than
handlers having to guess when one package ended and the next began.
* BRepositoryCache: Make use of BPackageInfoContentHandler. No need to
duplicate the code for reading a package info from package info
attributes.

hpkg format: compress the whole heap

Instead of handling compression for individual file/attribute data we
do now compress the whole heap where they are stored. This
significantly improves compression ratios. We still divide the
uncompressed data into 64 KiB chunks and use a chunk offset array for
the compressed chunks to allow for quick random access without too much
overhead. The tradeoff is a limited possible compression ratio -- i.e.
we won't be as good as tar.gz (though surprisingly with my test
archives we did better than zip).

The other package file sections (package attributes and TOC) are no
longer compressed individually. Their uncompressed data are simply
pushed onto the heap where the usual compression strategy applies. To
simplify things the repository format has been changed in the same
manner although it doesn't otherwise use the heap, since it only stores
meta data.

Due to the data compression having been exposed in public and private
API, this change touches a lot of package kit using code, including
packagefs and the boot loader packagefs support. The latter two haven't
been tested yet. Moreover packagefs needs a new kind of cache so we
avoid re-reading the same heap chunk for two different data items it
contains.

* add listing of repository attributes to 'package_repo list'


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40508 a95241bf-73f2-0310-859d-f6bbb57e9c96

* implemented repository reader and fixed some bugs in writer that
have been exposed during testing of reader

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40494 a95241bf-73f2-0310-859d-f6bbb57e9c96

Largish adjustments to PackagerReaderImpl and package attribute
handling:
* package attributes are now compatible with the low level attribute
handling of other HPKG attributes (such that 'package dump' now shows
package attributes, too)
* dropped type names from hpkg format, the attributes were identified
by IDs already and this simplifies the code considerably. Type names
are now handled in BLowLevelPackageHandler only.
* instead of rolling their own mechanism, high-level package attributes
handling is now implemented via a corresonding set of
AttributeHandler-subclasses
* adjusted package writer to only write package attributes that are
needed (empty ones are left out)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40466 a95241bf-73f2-0310-859d-f6bbb57e9c96

Switch package file accessor classes to use BPositionIO

* PackageFileHeap{Reader,Writer} as well as Package{Reader,Writer} and
their implementation and super classes do now internally use a
BPositionIO instead of a FD to access the package file. This provides
more flexibility needed for features to come.
* BPackageReader has already grown a new Init() version with a
BPositionIO* parameter.

Repository file format: group attributes of a package

* Introduce new package attribute B_HPKG_ATTRIBUTE_ID_PACKAGE (valid
only in a repository file) to group the attributes belonging to a
package.
* BRepositoryContentHandler:
- No longer derive from BPackageContentHandler.
- Add hooks HandlePackage() and HandlePackageDone() that bracket the
attributes for a package. This is more explicit and robust than
handlers having to guess when one package ended and the next began.
* BRepositoryCache: Make use of BPackageInfoContentHandler. No need to
duplicate the code for reading a package info from package info
attributes.

hpkg format: compress the whole heap

Instead of handling compression for individual file/attribute data we
do now compress the whole heap where they are stored. This
significantly improves compression ratios. We still divide the
uncompressed data into 64 KiB chunks and use a chunk offset array for
the compressed chunks to allow for quick random access without too much
overhead. The tradeoff is a limited possible compression ratio -- i.e.
we won't be as good as tar.gz (though surprisingly with my test
archives we did better than zip).

The other package file sections (package attributes and TOC) are no
longer compressed individually. Their uncompressed data are simply
pushed onto the heap where the usual compression strategy applies. To
simplify things the repository format has been changed in the same
manner although it doesn't otherwise use the heap, since it only stores
meta data.

Due to the data compression having been exposed in public and private
API, this change touches a lot of package kit using code, including
packagefs and the boot loader packagefs support. The latter two haven't
been tested yet. Moreover packagefs needs a new kind of cache so we
avoid re-reading the same heap chunk for two different data items it
contains.

* add listing of repository attributes to 'package_repo list'


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40508 a95241bf-73f2-0310-859d-f6bbb57e9c96

* implemented repository reader and fixed some bugs in writer that
have been exposed during testing of reader

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40494 a95241bf-73f2-0310-859d-f6bbb57e9c96

Largish adjustments to PackagerReaderImpl and package attribute
handling:
* package attributes are now compatible with the low level attribute
handling of other HPKG attributes (such that 'package dump' now shows
package attributes, too)
* dropped type names from hpkg format, the attributes were identified
by IDs already and this simplifies the code considerably. Type names
are now handled in BLowLevelPackageHandler only.
* instead of rolling their own mechanism, high-level package attributes
handling is now implemented via a corresonding set of
AttributeHandler-subclasses
* adjusted package writer to only write package attributes that are
needed (empty ones are left out)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40466 a95241bf-73f2-0310-859d-f6bbb57e9c96