+ /** The patches that remain to be downloaded, including the patch
+ * being downloaded right now. This list should be ordered so
+ * that each diff appears before any diff that depends on it.
+ *
+ * \todo These are indexed by sha1sum; why not use some sort of
+ * dictionary instead of relying on ordering and stripping them
+ * off the front?
+ */
+ std::vector<DiffInfo> available_patches;
+
+ /** Stop applying patches when reaching that sha1 */
+ std::string ServerSha1;
+
+ /** The current status of this patch. */
+ enum DiffState
+ {
+ /** \brief The diff is in an unknown state. */
+ StateFetchUnkown,
+
+ /** \brief The diff is currently being fetched. */
+ StateFetchDiff,
+
+ /** \brief The diff is currently being uncompressed. */
+ StateUnzipDiff, // FIXME: No longer used
+
+ /** \brief The diff is currently being applied. */
+ StateApplyDiff
+ } State;
+
+ public:
+
+ /** \brief Called when the patch file failed to be downloaded.
+ *
+ * This method will fall back to downloading the whole index file
+ * outright; its arguments are ignored.
+ */
+ virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
+
+ virtual void Done(std::string Message,unsigned long long Size,std::string Md5Hash,
+ pkgAcquire::MethodConfig *Cnf);
+ virtual std::string DescURI() {return RealURI + "Index";};
+
+ /** \brief Create an index diff item.
+ *
+ * After filling in its basic fields, this invokes Finish(true) if
+ * \a diffs is empty, or QueueNextDiff() otherwise.
+ *
+ * \param Owner The pkgAcquire object that owns this item.
+ *
+ * \param URI The URI of the package index file being
+ * reconstructed.
+ *
+ * \param URIDesc A long description of this item.
+ *
+ * \param ShortDesc A brief description of this item.
+ *
+ * \param ExpectedHash The expected md5sum of the completely
+ * reconstructed package index file; the index file will be tested
+ * against this value when it is entirely reconstructed.
+ *
+ * \param ServerSha1 is the sha1sum of the current file on the server
+ *
+ * \param diffs The remaining diffs from the index of diffs. They
+ * should be ordered so that each diff appears before any diff
+ * that depends on it.
+ */
+ pkgAcqIndexDiffs(pkgAcquire *Owner,std::string URI,std::string URIDesc,
+ std::string ShortDesc, HashString ExpectedHash,
+ std::string ServerSha1,
+ std::vector<DiffInfo> diffs=std::vector<DiffInfo>());
+};
+ /*}}}*/
+/** \brief An acquire item that is responsible for fetching an index {{{
+ * file (e.g., Packages or Sources).
+ *
+ * \sa pkgAcqDiffIndex, pkgAcqIndexDiffs, pkgAcqIndexTrans
+ *
+ * \todo Why does pkgAcqIndex have protected members?
+ */