add volatile sources support in libapt-pkg

Sources are usually defined in sources.list (and co) and are pretty
stable, but once in a while a frontend might want to add an additional
"source" like a local .deb file to install this package (No support for
'real' sources being added this way as this is a multistep process).

We had a hack in place to allow apt-get and apt to pull this of for a
short while now, but other frontends are either left in the cold by this
and/or the code for it looks dirty with FIXMEs plastering it and has on
top of this also some problems (like including these 'volatile' sources
in the srcpkgcache.bin file).

So the biggest part in this commit is actually the rewrite of the cache
generation as it is now potentially a three step process. The biggest
problem with adding support now through is that this makes a bunch of
previously mostly unusable by externs and therefore hidden classes
public, so a bit of further tuneing on this now public API is in order…

1 files changed, 19 insertions, 0 deletions

diff --git a/apt-pkg/sourcelist.h b/apt-pkg/sourcelist.h
index d80131438..47a562d18 100644
--- a/apt-pkg/sourcelist.h
+++ b/apt-pkg/sourcelist.h
@@ -50,6 +50,7 @@ class metaIndex;
 class pkgSourceList
 {
    void * const d;
+   std::vector<pkgIndexFile*> VolatileFiles;
    public:
 
    // List of supported source list types
@@ -113,6 +114,24 @@ class pkgSourceList
    // query last-modified time
    time_t GetLastModifiedTime();
 
+   /** \brief add file for parsing, but not to the cache
+    *
+    *  pkgIndexFiles origining from pkgSourcesList are included in
+    *  srcpkgcache, the status files added via #AddStatusFiles are
+    *  included in pkgcache, but these files here are not included in
+    *  any cache to have the possibility of having a file included just
+    *  for a single run like a local .deb/.dsc file.
+    *
+    *  The volatile files do not count as "normal" sourceslist entries,
+    *  can't be iterated over with #begin and #end and can't be
+    *  downloaded, but they can be found via #FindIndex.
+    *
+    *  @param File is an index file; pointer-ownership is transferred
+    */
+   void AddVolatileFile(pkgIndexFile * const File);
+   /** @return list of files registered with #AddVolatileFile */
+   std::vector<pkgIndexFile*> GetVolatileFiles() const;
+
    pkgSourceList();
    virtual ~pkgSourceList();
 };