+ protected:
+ /** \brief If \b true, debugging information will be written to std::clog. */
+ bool Debug;
+
+ /** \brief The item that is currently being downloaded. */
+ pkgAcquire::ItemDesc Desc;
+
+ /** \brief The URI of the index file to recreate at our end (either
+ * by downloading it or by applying partial patches).
+ */
+ string RealURI;
+
+ /** \brief The Hash that the real index file should have after
+ * all patches have been applied.
+ */
+ HashString ExpectedHash;
+
+ /** \brief The index file which will be patched to generate the new
+ * file.
+ */
+ string CurrentPackagesFile;
+
+ /** \brief A description of the Packages file (stored in
+ * pkgAcquire::ItemDesc::Description).
+ */
+ string Description;
+
+ public:
+ // Specialized action members
+ virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
+ virtual void Done(string Message,unsigned long Size,string Md5Hash,
+ pkgAcquire::MethodConfig *Cnf);
+ virtual string DescURI() {return RealURI + "Index";};
+ virtual string Custom600Headers();
+
+ /** \brief Parse the Index file for a set of Packages diffs.
+ *
+ * Parses the Index file and creates additional download items as
+ * necessary.
+ *
+ * \param IndexDiffFile The name of the Index file.
+ *
+ * \return \b true if the Index file was successfully parsed, \b
+ * false otherwise.
+ */
+ bool ParseDiffIndex(string IndexDiffFile);
+
+
+ /** \brief Create a new pkgAcqDiffIndex.
+ *
+ * \param Owner The Acquire object that owns this item.
+ *
+ * \param URI The URI of the list file to download.
+ *
+ * \param URIDesc A long description of the list file to download.
+ *
+ * \param ShortDesc A short description of the list file to download.
+ *
+ * \param ExpectedHash The list file's MD5 signature.
+ */
+ pkgAcqDiffIndex(pkgAcquire *Owner,string URI,string URIDesc,
+ string ShortDesc, HashString ExpectedHash);
+};
+ /*}}}*/
+/** \brief An item that is responsible for fetching all the 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);
+