Allow the FileFd to use an external Compressor to uncompress a given file

internally so that it is exported and can be used like a "normal"
uncompressed file with FileFd

This allows us to hide th zlib usage in the implementation and use gzip
instead if we don't have zlib builtin (the same for other compressors).

The code includes quiet a few FIXME's so while all tests are working
it shouldn't be used just yet outside of libapt as it might break.

1 files changed, 8 insertions, 1 deletions

diff --git a/apt-pkg/contrib/mmap.cc b/apt-pkg/contrib/mmap.cc
index 1fb84b0af..a67ab3698 100644
--- a/apt-pkg/contrib/mmap.cc
+++ b/apt-pkg/contrib/mmap.cc
@@ -66,7 +66,7 @@ MMap::~MMap()
 bool MMap::Map(FileFd &Fd)
 {
    iSize = Fd.Size();
-   
+
    // Set the permissions.
    int Prot = PROT_READ;
    int Map = MAP_SHARED;
@@ -97,6 +97,13 @@ bool MMap::Map(FileFd &Fd)
       {
 	 // The filesystem doesn't support this particular kind of mmap.
 	 // So we allocate a buffer and read the whole file into it.
+	 if ((Flags & ReadOnly) == ReadOnly)
+	 {
+	    // for readonly, we don't need sync, so make it simple
+	    Base = new unsigned char[iSize];
+	    return Fd.Read(Base, iSize);
+	 }
+	 // FIXME: Writing to compressed fd's ?
 	 int const dupped_fd = dup(Fd.Fd());
 	 if (dupped_fd == -1)
 	    return _error->Errno("mmap", _("Couldn't duplicate file descriptor %i"), Fd.Fd());