Drop unused description size info from binary cache

Nothing in src:apt uses this information and that isn't all to
surprising as it is usually not that interesting to know how big
a specific stanza of a description is as the max size is available
and you are usually working with more than one description.

So this information just takes up space in our binary cache…
64 bits per structure which can quickly add up to whole MBs
depending on how many (and which) sources you have enabled.

2 files changed, 11 insertions, 5 deletions

diff --git a/apt-pkg/pkgcache.h b/apt-pkg/pkgcache.h
index f6d0ea097..d5d8fcad3 100644
--- a/apt-pkg/pkgcache.h
+++ b/apt-pkg/pkgcache.h
@@ -618,8 +618,9 @@ struct pkgCache::DescFile
    map_pointer<DescFile> NextFile;
    /** \brief position in the file */
    map_filesize_t Offset;         // File offset
-   /** @TODO document pkgCache::DescFile::Size */
-   map_filesize_t Size;
+#if APT_PKG_ABI <= 600
+   [[deprecated("No usage in src:apt, try MaxDescFileSize instead")]] map_filesize_t Size;
+#endif
 };
 									/*}}}*/
 // Version structure							/*{{{*/
diff --git a/apt-pkg/pkgcachegen.cc b/apt-pkg/pkgcachegen.cc
index aaa969a8d..76dea6266 100644
--- a/apt-pkg/pkgcachegen.cc
+++ b/apt-pkg/pkgcachegen.cc
@@ -949,9 +949,14 @@ bool pkgCacheGenerator::NewFileDesc(pkgCache::DescIterator &Desc,
    *Last = DF.MapPointer();
 
    DF->Offset = List.Offset();
-   DF->Size = List.Size();
-   if (Cache.HeaderP->MaxDescFileSize < DF->Size)
-      Cache.HeaderP->MaxDescFileSize = DF->Size;
+   auto const Size = List.Size();
+   if (Cache.HeaderP->MaxDescFileSize < Size)
+      Cache.HeaderP->MaxDescFileSize = Size;
+#if APT_PKG_ABI <= 600
+   APT_IGNORE_DEPRECATED_PUSH
+   DF->Size = Size;
+   APT_IGNORE_DEPRECATED_POP
+#endif
    Cache.HeaderP->DescFileCount++;
 
    return true;