+
+ /** \brief If \b true, debugging output will be written to
+ * std::clog.
+ */
+ bool Debug;
+
+ /** \brief description of the item that is currently being
+ * downloaded.
+ */
+ pkgAcquire::ItemDesc Desc;
+
+ /** \brief URI of the package index file that is being
+ * reconstructed.
+ */
+ std::string RealURI;
+
+ /** \brief HashSum of the package index file that is being
+ * reconstructed.
+ */
+ HashString ExpectedHash;
+
+ /** \brief description of the file being downloaded. */
+ std::string Description;
+
+ /** \brief information about the current patch */
+ struct DiffInfo const patch;
+
+ /** \brief list of all download items for the patches */
+ std::vector<pkgAcqIndexMergeDiffs*> const * const allPatches;
+
+ /** The current status of this patch. */
+ enum DiffState
+ {
+ /** \brief The diff is currently being fetched. */
+ StateFetchDiff,
+
+ /** \brief The diff is currently being applied. */
+ StateApplyDiff,
+
+ /** \brief the work with this diff is done */
+ StateDoneDiff,
+
+ /** \brief something bad happened and fallback was triggered */
+ StateErrorDiff
+ } 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 merge-diff item.
+ *
+ * \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 patch contains infos about the patch this item is supposed
+ * to download which were read from the index
+ *
+ * \param allPatches contains all related items so that each item can
+ * check if it was the last one to complete the download step
+ */
+ pkgAcqIndexMergeDiffs(pkgAcquire *Owner,std::string const &URI,std::string const &URIDesc,
+ std::string const &ShortDesc, HashString const &ExpectedHash,
+ DiffInfo const &patch, std::vector<pkgAcqIndexMergeDiffs*> const * const allPatches);
+};
+ /*}}}*/
+/** \brief An item that is responsible for fetching server-merge patches {{{
+ * that need to be applied to a given package index file.
+ *
+ * After downloading and applying a single patch, this item will
+ * enqueue a new pkgAcqIndexDiffs to download and apply the remaining
+ * patches. If no patch can be found that applies to an intermediate
+ * file or if one of the patches cannot be downloaded, falls back to
+ * downloading the entire package index file using pkgAcqIndex.
+ *
+ * \sa pkgAcqDiffIndex, pkgAcqIndex
+ */
+class pkgAcqIndexDiffs : public pkgAcquire::Item
+{
+ private:
+
+ /** \brief Queue up the next diff download.
+ *
+ * Search for the next available diff that applies to the file
+ * that currently exists on disk, and enqueue it by calling
+ * QueueURI().
+ *
+ * \return \b true if an applicable diff was found, \b false
+ * otherwise.
+ */
+ bool QueueNextDiff();
+
+ /** \brief Handle tasks that must be performed after the item
+ * finishes downloading.
+ *
+ * Dequeues the item and checks the resulting file's md5sum
+ * against ExpectedHash after the last patch was applied.
+ * There is no need to check the md5/sha1 after a "normal"
+ * patch because QueueNextDiff() will check the sha1 later.
+ *
+ * \param allDone If \b true, the file was entirely reconstructed,
+ * and its md5sum is verified.
+ */
+ void Finish(bool allDone=false);
+
+ protected:
+
+ /** \brief If \b true, debugging output will be written to
+ * std::clog.
+ */
+ bool Debug;
+
+ /** \brief A description of the item that is currently being
+ * downloaded.
+ */
+ pkgAcquire::ItemDesc Desc;
+
+ /** \brief The URI of the package index file that is being
+ * reconstructed.
+ */
+ std::string RealURI;
+
+ /** \brief The HashSum of the package index file that is being
+ * reconstructed.
+ */
+ HashString ExpectedHash;
+
+ /** A description of the file being downloaded. */
+ std::string Description;
+
+ /** 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: