fileutl: empty file support: Avoid fstat() on -1 fd and check result

[apt.git] / apt-pkg / acquire-item.h

diff --git a/apt-pkg/acquire-item.h b/apt-pkg/acquire-item.h
index e191e255471925a874fe3cea02aa6cc4f7e726f2..e6e5ea12b2fd896368bae04379449830126d7eb2 100644 (file)
--- a/apt-pkg/acquire-item.h
+++ b/apt-pkg/acquire-item.h
@@ -1,26 +1,26 @@
 // -*- mode: cpp; mode: fold -*-
 // Description                                                         /*{{{*/
 // -*- mode: cpp; mode: fold -*-
 // Description                                                         /*{{{*/

-// $Id: acquire-item.h,v 1.26.2.3 2004/01/02 18:51:00 mdz Exp $

 /* ######################################################################
 
    Acquire Item - Item to acquire
 
    When an item is instantiated it will add it self to the local list in
 /* ######################################################################
 
    Acquire Item - Item to acquire
 
    When an item is instantiated it will add it self to the local list in

-   the Owner Acquire class. Derived classes will then call QueueURI to 
-   register all the URI's they wish to fetch at the initial moment.   
-   
+   the Owner Acquire class. Derived classes will then call QueueURI to
+   register all the URI's they wish to fetch at the initial moment.
+

    Three item classes are provided to provide functionality for
    downloading of Index, Translation and Packages files.
    Three item classes are provided to provide functionality for
    downloading of Index, Translation and Packages files.

-   
+

    A Archive class is provided for downloading .deb files. It does Hash
    checking and source location as well as a retry algorithm.
    A Archive class is provided for downloading .deb files. It does Hash
    checking and source location as well as a retry algorithm.

-   
+

    ##################################################################### */
                                                                        /*}}}*/
 #ifndef PKGLIB_ACQUIRE_ITEM_H
 #define PKGLIB_ACQUIRE_ITEM_H
 
 #include <apt-pkg/acquire.h>
    ##################################################################### */
                                                                        /*}}}*/
 #ifndef PKGLIB_ACQUIRE_ITEM_H
 #define PKGLIB_ACQUIRE_ITEM_H
 
 #include <apt-pkg/acquire.h>

+#include <apt-pkg/indexfile.h>

 #include <apt-pkg/hashes.h>
 #include <apt-pkg/weakptr.h>
 #include <apt-pkg/pkgcache.h>
 #include <apt-pkg/hashes.h>
 #include <apt-pkg/weakptr.h>
 #include <apt-pkg/pkgcache.h>


@@ -28,13 +28,11 @@
 
 #include <string>
 #include <vector>
 
 #include <string>
 #include <vector>

+#include <map>

 
 #ifndef APT_8_CLEANER_HEADERS
 
 #ifndef APT_8_CLEANER_HEADERS

-#include <apt-pkg/indexfile.h>
-#include <apt-pkg/vendor.h>

 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/pkgrecords.h>
 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/pkgrecords.h>

-#include <apt-pkg/indexrecords.h>

 #endif
 
 /** \addtogroup acquire
 #endif
 
 /** \addtogroup acquire


@@ -43,13 +41,14 @@
  *  \file acquire-item.h
  */
 
  *  \file acquire-item.h
  */
 

-class indexRecords;

 class pkgRecords;
 class pkgSourceList;
 class pkgRecords;
 class pkgSourceList;

-class IndexTarget;
-class pkgAcqMetaIndex;
+class pkgAcqMetaClearSig;
+class pkgAcqIndexMergeDiffs;
+class metaIndex;

 
 

-/** \brief Represents the process by which a pkgAcquire object should  {{{
+class pkgAcquire::Item : public WeakPointable                          /*{{{*/
+/** \brief Represents the process by which a pkgAcquire object should

  *  retrieve a file or a collection of files.
  *
  *  By convention, Item subclasses should insert themselves into the
  *  retrieve a file or a collection of files.
  *
  *  By convention, Item subclasses should insert themselves into the


@@ -61,35 +60,7 @@ class pkgAcqMetaIndex;
  *
  *  \see pkgAcquire
  */
  *
  *  \see pkgAcquire
  */

-class pkgAcquire::Item : public WeakPointable
-{  
-   protected:
-   
-   /** \brief The acquire object with which this item is associated. */
-   pkgAcquire *Owner;
-
-   /** \brief Insert this item into its owner's queue.
-    *
-    *  \param Item Metadata about this item (its URI and
-    *  description).
-    */
-   inline void QueueURI(ItemDesc &Item)
-                 {Owner->Enqueue(Item);};
-
-   /** \brief Remove this item from its owner's queue. */
-   inline void Dequeue() {Owner->Dequeue(this);};
-   
-   /** \brief Rename a file without modifying its timestamp.
-    *
-    *  Many item methods call this as their final action.
-    *
-    *  \param From The file to be renamed.
-    *
-    *  \param To The new name of \a From.  If \a To exists it will be
-    *  overwritten.
-    */
-   void Rename(std::string From,std::string To);
-
+{

    public:
 
    /** \brief The current status of this item. */
    public:
 
    /** \brief The current status of this item. */


@@ -114,7 +85,7 @@ class pkgAcquire::Item : public WeakPointable
        */
        StatAuthError,
 
        */
        StatAuthError,
 

-       /** \brief The item was could not be downloaded because of 
+       /** \brief The item was could not be downloaded because of

        *  a transient network error (e.g. network down)
        */
        StatTransientNetworkError,
        *  a transient network error (e.g. network down)
        */
        StatTransientNetworkError,


@@ -134,14 +105,19 @@ class pkgAcquire::Item : public WeakPointable
    /** \brief If not \b NULL, contains the name of a subprocess that
     *  is operating on this object (for instance, "gzip" or "gpgv").
     */
    /** \brief If not \b NULL, contains the name of a subprocess that
     *  is operating on this object (for instance, "gzip" or "gpgv").
     */

-   const char *Mode;
+   APT_DEPRECATED_MSG("Use the std::string member ActiveSubprocess instead") const char *Mode;
+
+   /** \brief contains the name of the subprocess that is operating on this object
+    * (for instance, "gzip", "rred" or "gpgv"). This is obsoleting #Mode from above
+    * as it can manage the lifetime of included string properly. */
+   std::string ActiveSubprocess;

 
    /** \brief A client-supplied unique identifier.
 
    /** \brief A client-supplied unique identifier.

-    * 
+    *

     *  This field is initalized to 0; it is meant to be filled in by
     *  clients that wish to use it to uniquely identify items.
     *
     *  This field is initalized to 0; it is meant to be filled in by
     *  clients that wish to use it to uniquely identify items.
     *

-    *  \todo it's unused in apt itself
+    *  APT progress reporting will store an ID there as shown in "Get:42 …"

     */
    unsigned long ID;
 
     */
    unsigned long ID;
 


@@ -157,6 +133,7 @@ class pkgAcquire::Item : public WeakPointable
     *  download progress indicator's overall statistics.
     */
    bool Local;
     *  download progress indicator's overall statistics.
     */
    bool Local;

+

    std::string UsedMirror;
 
    /** \brief The number of fetch queues into which this item has been
    std::string UsedMirror;
 
    /** \brief The number of fetch queues into which this item has been


@@ -169,9 +146,6 @@ class pkgAcquire::Item : public WeakPointable
     */
    unsigned int QueueCounter;
 
     */
    unsigned int QueueCounter;
 

-   /** \brief TransactionID */
-   unsigned long TransactionID;
-

    /** \brief The number of additional fetch items that are expected
     *  once this item is done.
     *
    /** \brief The number of additional fetch items that are expected
     *  once this item is done.
     *


@@ -181,15 +155,12 @@ class pkgAcquire::Item : public WeakPointable
     *  progress.
     */
    unsigned int ExpectedAdditionalItems;
     *  progress.
     */
    unsigned int ExpectedAdditionalItems;

-   
+

    /** \brief The name of the file into which the retrieved object
     *  will be written.
     */
    std::string DestFile;
 
    /** \brief The name of the file into which the retrieved object
     *  will be written.
     */
    std::string DestFile;
 

-   /** \brief storge name until a transaction is finished */
-   std::string PartialFile;
-

    /** \brief Invoked by the acquire worker when the object couldn't
     *  be fetched.
     *
    /** \brief Invoked by the acquire worker when the object couldn't
     *  be fetched.
     *


@@ -203,7 +174,29 @@ class pkgAcquire::Item : public WeakPointable
     *
     *  \sa pkgAcqMethod
     */
     *
     *  \sa pkgAcqMethod
     */

-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf);
+
+   /** \brief Invoked by the acquire worker to check if the successfully
+    * fetched object is also the objected we wanted to have.
+    *
+    *  Note that the object might \e not have been written to
+    *  DestFile; check for the presence of an Alt-Filename entry in
+    *  Message to find the file to which it was really written.
+    *
+    *  This is called before Done is called and can prevent it by returning
+    *  \b false which will result in Failed being called instead.
+    *
+    *  You should prefer to use this method over calling Failed() from Done()
+    *  as this has e.g. the wrong progress reporting.
+    *
+    *  \param Message Data from the acquire method.  Use LookupTag()
+    *  to parse it.
+    *  \param Cnf The method via which the object was fetched.
+    *
+    *  \sa pkgAcqMethod
+    */
+   virtual bool VerifyDone(std::string const &Message,
+        pkgAcquire::MethodConfig const * const Cnf);

 
    /** \brief Invoked by the acquire worker when the object was
     *  fetched successfully.
 
    /** \brief Invoked by the acquire worker when the object was
     *  fetched successfully.


@@ -218,25 +211,24 @@ class pkgAcquire::Item : public WeakPointable
     *
     *  \param Message Data from the acquire method.  Use LookupTag()
     *  to parse it.
     *
     *  \param Message Data from the acquire method.  Use LookupTag()
     *  to parse it.

-    *  \param Size The size of the object that was fetched.

     *  \param Hashes The HashSums of the object that was fetched.
     *  \param Cnf The method via which the object was fetched.
     *
     *  \sa pkgAcqMethod
     */
     *  \param Hashes The HashSums of the object that was fetched.
     *  \param Cnf The method via which the object was fetched.
     *
     *  \sa pkgAcqMethod
     */

-   virtual void Done(std::string Message, unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf);

 
    /** \brief Invoked when the worker starts to fetch this object.
     *
     *  \param Message RFC822-formatted data from the worker process.
     *  Use LookupTag() to parse it.
     *
 
    /** \brief Invoked when the worker starts to fetch this object.
     *
     *  \param Message RFC822-formatted data from the worker process.
     *  Use LookupTag() to parse it.
     *

-    *  \param Size The size of the object being fetched.
+    *  \param Hashes The expected hashes of the object being fetched.

     *
     *  \sa pkgAcqMethod
     */
     *
     *  \sa pkgAcqMethod
     */

-   virtual void Start(std::string Message,unsigned long long Size);
+   virtual void Start(std::string const &Message, unsigned long long const Size);

 
    /** \brief Custom headers to be sent to the fetch process.
     *
 
    /** \brief Custom headers to be sent to the fetch process.
     *


@@ -246,7 +238,7 @@ class pkgAcquire::Item : public WeakPointable
     *  line, so they should (if nonempty) have a leading newline and
     *  no trailing newline.
     */
     *  line, so they should (if nonempty) have a leading newline and
     *  no trailing newline.
     */

-   virtual std::string Custom600Headers() const {return std::string();};
+   virtual std::string Custom600Headers() const;

 
    /** \brief A "descriptive" URI-like string.
     *
 
    /** \brief A "descriptive" URI-like string.
     *


@@ -257,35 +249,45 @@ class pkgAcquire::Item : public WeakPointable
     *
     *  \return a brief description of the object being fetched.
     */
     *
     *  \return a brief description of the object being fetched.
     */

-   virtual std::string ShortDesc() const {return DescURI();}
+   virtual std::string ShortDesc() const;

 
    /** \brief Invoked by the worker when the download is completely done. */
 
    /** \brief Invoked by the worker when the download is completely done. */

-   virtual void Finished() {};
-   
-   /** \brief HashSums
+   virtual void Finished();
+
+   /** \return HashSums the DestFile is supposed to have in this stage */
+   virtual HashStringList GetExpectedHashes() const = 0;
+   /** \return the 'best' hash for display proposes like --print-uris */
+   std::string HashSum() const;
+
+   /** \return if having no hashes is a hard failure or not

     *
     *

-    *  \return the HashSums of this object, if applicable; otherwise, an
-    *  empty list.
+    * Idealy this is always \b true for every subclass, but thanks to
+    * historical grow we don't have hashes for all files in all cases
+    * in all steps, so it is slightly more complicated than it should be.

     */
     */

-   HashStringList HashSums() const {return ExpectedHashes;};
-   std::string HashSum() const {HashStringList const hashes = HashSums(); HashString const * const hs = hashes.find(NULL); return hs != NULL ? hs->toStr() : ""; };
+   virtual bool HashesRequired() const { return true; }

 
    /** \return the acquire process with which this item is associated. */
 
    /** \return the acquire process with which this item is associated. */

-   pkgAcquire *GetOwner() const {return Owner;};
+   pkgAcquire *GetOwner() const;
+   pkgAcquire::ItemDesc &GetItemDesc();

 
    /** \return \b true if this object is being fetched from a trusted source. */
 
    /** \return \b true if this object is being fetched from a trusted source. */

-   virtual bool IsTrusted() const {return false;};
-   
-   // report mirror problems
+   virtual bool IsTrusted() const;
+

    /** \brief Report mirror problem
    /** \brief Report mirror problem

-    * 
+    *

     *  This allows reporting mirror failures back to a centralized
     *  server. The apt-report-mirror-failure script is called for this
     *  This allows reporting mirror failures back to a centralized
     *  server. The apt-report-mirror-failure script is called for this

-    * 
+    *

     *  \param FailCode A short failure string that is send
     */
     *  \param FailCode A short failure string that is send
     */

-   void ReportMirrorFailure(std::string FailCode);
+   APT_DEPRECATED_MSG("Item::Failed does this for you") void ReportMirrorFailure(std::string const &FailCode);

 
 

+   /** \brief Set the name of the current active subprocess
+    *
+    *  See also #ActiveSubprocess
+    */
+   void SetActiveSubprocess(std::string const &subprocess);

 
    /** \brief Initialize an item.
     *
 
    /** \brief Initialize an item.
     *


@@ -294,23 +296,31 @@ class pkgAcquire::Item : public WeakPointable
     *  manually invoke QueueURI() to do so).
     *
     *  \param Owner The new owner of this item.
     *  manually invoke QueueURI() to do so).
     *
     *  \param Owner The new owner of this item.

-    *  \param ExpectedHashes of the file represented by this item

     */
     */

-   Item(pkgAcquire *Owner,
-        HashStringList const &ExpectedHashes=HashStringList(),
-        unsigned long TransactionID=0);
+   explicit Item(pkgAcquire * const Owner);

 
    /** \brief Remove this item from its owner's queue by invoking
     *  pkgAcquire::Remove.
     */
    virtual ~Item();
 
 
    /** \brief Remove this item from its owner's queue by invoking
     *  pkgAcquire::Remove.
     */
    virtual ~Item();
 

+   bool APT_HIDDEN IsRedirectionLoop(std::string const &NewURI);
+

    protected:
    protected:

+   /** \brief The acquire object with which this item is associated. */
+   pkgAcquire * const Owner;
+
+   /** \brief The item that is currently being downloaded. */
+   pkgAcquire::ItemDesc Desc;

 
    enum RenameOnErrorState {
       HashSumMismatch,
       SizeMismatch,
 
    enum RenameOnErrorState {
       HashSumMismatch,
       SizeMismatch,

-      InvalidFormat
+      InvalidFormat,
+      SignatureError,
+      NotClearsigned,
+      MaximumSizeExceeded,
+      PDiffError,

    };
 
    /** \brief Rename failed file and set error
    };
 
    /** \brief Rename failed file and set error


@@ -319,108 +329,91 @@ class pkgAcquire::Item : public WeakPointable
     */
    bool RenameOnError(RenameOnErrorState const state);
 
     */
    bool RenameOnError(RenameOnErrorState const state);
 

-   /** \brief The HashSums of the item is supposed to have than done */
-   HashStringList ExpectedHashes;
-
-   /** \brief The item that is currently being downloaded. */
-   pkgAcquire::ItemDesc Desc;
-};
-                                                                       /*}}}*/
-/** \brief Information about an index patch (aka diff). */             /*{{{*/
-struct DiffInfo {
-   /** The filename of the diff. */
-   std::string file;
-
-   /** The sha1 hash of the diff. */
-   std::string sha1;
-
-   /** The size of the diff. */
-   unsigned long size;
-};
-                                                                       /*}}}*/
-/** \brief An item that is responsible for fetching a SubIndex         {{{
- *
- *  The MetaIndex file includes only records for important indexes
- *  and records for these SubIndex files so these can carry records
- *  for addition files like PDiffs and Translations
- */
-class pkgAcqSubIndex : public pkgAcquire::Item
-{
- protected:
-   /** \brief If \b true, debugging information will be written to std::clog. */
-   bool Debug;
-
- public:
-   // Specialized action members
-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() const {return Desc.URI;};
-   virtual std::string Custom600Headers() const;
-   virtual bool ParseIndex(std::string const &IndexFile);
-
-   /** \brief Create a new pkgAcqSubIndex.
+   /** \brief Insert this item into its owner's queue.

     *
     *

-    *  \param Owner The Acquire object that owns this item.
+    *  The method is designed to check if the request would end
+    *  in an IMSHit and if it determines that it would, it isn't
+    *  queueing the Item and instead sets it to completion instantly.

     *
     *

-    *  \param URI The URI of the list file to download.
+    *  \param Item Metadata about this item (its URI and
+    *  description).
+    *  \return true if the item was inserted, false if IMSHit was detected
+    */
+   virtual bool QueueURI(ItemDesc &Item);
+
+   /** \brief Remove this item from its owner's queue. */
+   void Dequeue();
+
+   /** \brief Rename a file without modifying its timestamp.

     *
     *

-    *  \param URIDesc A long description of the list file to download.
+    *  Many item methods call this as their final action.

     *
     *

-    *  \param ShortDesc A short description of the list file to download.
+    *  \param From The file to be renamed.

     *
     *

-    *  \param ExpectedHashes The list file's hashsums which are expected.
+    *  \param To The new name of \a From.  If \a To exists it will be
+    *  overwritten. If \a From and \a To are equal nothing happens.

     */
     */

-   pkgAcqSubIndex(pkgAcquire *Owner, 
-                  unsigned long TransactionID,
-                  std::string const &URI,std::string const &URIDesc,
-                  std::string const &ShortDesc, HashStringList const &ExpectedHashes);
+   bool Rename(std::string const &From, std::string const &To);
+
+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const;
+
+   private:
+   class Private;
+   Private * const d;
+
+   friend class pkgAcqMetaBase;
+   friend class pkgAcqMetaClearSig;

 };
                                                                        /*}}}*/
 };
                                                                        /*}}}*/

-
-/** \brief An item that is responsible for downloading the meta-index  {{{
- *  file (i.e., Release) itself and verifying its signature.
- *
- *  Once the download and verification are complete, the downloads of
- *  the individual index files are queued up using pkgAcqDiffIndex.
- *  If the meta-index file had a valid signature, the expected hashsums
- *  of the index files will be the md5sums listed in the meta-index;
- *  otherwise, the expected hashsums will be "" (causing the
- *  authentication of the index files to be bypassed).
- */
-class pkgAcqMetaIndex : public pkgAcquire::Item
+class APT_HIDDEN pkgAcqTransactionItem: public pkgAcquire::Item                /*{{{*/
+/** \brief baseclass for the indexes files to manage them all together */

 {
 {

+   void * const d;

    protected:
    protected:

-   /** \brief The URI that is actually being downloaded; never
-    *  modified by pkgAcqMetaIndex.
-    */
-   std::string RealURI;
+   HashStringList GetExpectedHashesFor(std::string const &MetaKey) const;

 
 

-   /** \brief The file in which the signature for this index was stored.
-    *
-    *  If empty, the signature and the md5sums of the individual
-    *  indices will not be checked.
-    */
-   std::string SigFile;
+   bool QueueURI(pkgAcquire::ItemDesc &Item) APT_OVERRIDE;
+
+   public:
+   IndexTarget const Target;

 
 

-   /** \brief The index files to download. */
-   const std::vector<IndexTarget*>* IndexTargets;
+   /** \brief storge name until a transaction is finished */
+   std::string PartialFile;

 
 

-   /** \brief The parser for the meta-index file. */
-   indexRecords* MetaIndexParser;
+   /** \brief TransactionManager */
+   pkgAcqMetaClearSig * const TransactionManager;
+
+   enum TransactionStates {
+      TransactionStarted,
+      TransactionCommit,
+      TransactionAbort,
+   };
+   virtual bool TransactionState(TransactionStates const state);
+
+   virtual std::string DescURI() const APT_OVERRIDE { return Target.URI; }
+   virtual HashStringList GetExpectedHashes() const APT_OVERRIDE;
+   virtual std::string GetMetaKey() const;
+   virtual bool HashesRequired() const APT_OVERRIDE;
+
+
+   pkgAcqTransactionItem(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager, IndexTarget const &Target) APT_NONNULL(2, 3);
+   virtual ~pkgAcqTransactionItem();
+
+   friend class pkgAcqMetaBase;
+   friend class pkgAcqMetaClearSig;
+};
+                                                                       /*}}}*/
+class APT_HIDDEN pkgAcqMetaBase : public pkgAcqTransactionItem         /*{{{*/
+/** \brief the manager of a transaction */
+{
+   void * const d;
+ protected:
+   std::vector<pkgAcqTransactionItem*> Transaction;

 
    /** \brief If \b true, the index's signature is currently being verified.
     */
    bool AuthPass;
 
    /** \brief If \b true, the index's signature is currently being verified.
     */
    bool AuthPass;

-   // required to deal gracefully with problems caused by incorrect ims hits
-   bool IMSHit; 
-
-   /** \brief Check that the release file is a release file for the
-    *  correct distribution.
-    *
-    *  \return \b true if no fatal errors were encountered.
-    */
-   bool VerifyVendor(std::string Message);

 
    /** \brief Called when a file is finished being retrieved.
     *
 
    /** \brief Called when a file is finished being retrieved.
     *


@@ -431,7 +424,12 @@ class pkgAcqMetaIndex : public pkgAcquire::Item
     *  \param Message The message block received from the fetch
     *  subprocess.
     */
     *  \param Message The message block received from the fetch
     *  subprocess.
     */

-   void RetrievalDone(std::string Message);
+   bool CheckDownloadDone(pkgAcqTransactionItem * const I, const std::string &Message, HashStringList const &Hashes) const;
+
+   /** \brief Queue the downloaded Signature for verification */
+   void QueueForSignatureVerify(pkgAcqTransactionItem * const I, std::string const &File, std::string const &Signature);
+
+   virtual std::string Custom600Headers() const APT_OVERRIDE;

 
    /** \brief Called when authentication succeeded.
     *
 
    /** \brief Called when authentication succeeded.
     *


@@ -442,106 +440,175 @@ class pkgAcqMetaIndex : public pkgAcquire::Item
     *  \param Message The message block received from the fetch
     *  subprocess.
     */
     *  \param Message The message block received from the fetch
     *  subprocess.
     */

-   void AuthDone(std::string Message);
+   bool CheckAuthDone(std::string const &Message);

 
 

-   /** \brief Starts downloading the individual index files.
+   /** Check if the current item should fail at this point */
+   bool CheckStopAuthentication(pkgAcquire::Item * const I, const std::string &Message);
+
+   /** \brief Check that the release file is a release file for the
+    *  correct distribution.

     *
     *

-    *  \param verify If \b true, only indices whose expected hashsum
-    *  can be determined from the meta-index will be downloaded, and
-    *  the hashsums of indices will be checked (reporting
-    *  #StatAuthError if there is a mismatch).  If verify is \b false,
-    *  no hashsum checking will be performed.
+    *  \return \b true if no fatal errors were encountered.

     */
     */

-   void QueueIndexes(bool verify);
+   bool VerifyVendor(std::string const &Message);
+
+   virtual bool TransactionState(TransactionStates const state) APT_OVERRIDE;
+
+ public:
+   // This refers more to the Transaction-Manager than the actual file
+   bool IMSHit;
+   TransactionStates State;
+   std::string BaseURI;
+
+   virtual bool QueueURI(pkgAcquire::ItemDesc &Item) APT_OVERRIDE;
+   virtual HashStringList GetExpectedHashes() const APT_OVERRIDE;
+   virtual bool HashesRequired() const APT_OVERRIDE;
+
+   // transaction code
+   void Add(pkgAcqTransactionItem * const I);
+   void AbortTransaction();
+   bool TransactionHasError() const;
+   void CommitTransaction();

 
 

-   /** \brief The URI of the meta-index file for the detached signature */
-   std::string MetaIndexSigURI;
+   /** \brief Stage (queue) a copy action when the transaction is committed
+    */
+   void TransactionStageCopy(pkgAcqTransactionItem * const I,
+                             const std::string &From,
+                             const std::string &To);
+   /** \brief Stage (queue) a removal action when the transaction is committed
+    */
+   void TransactionStageRemoval(pkgAcqTransactionItem * const I, const std::string &FinalFile);

 
 

-   /** \brief A "URI-style" description of the meta-index file */
-   std::string MetaIndexSigURIDesc;
+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;

 
 

-   /** \brief A brief description of the meta-index file */
-   std::string MetaIndexSigShortDesc;
+   pkgAcqMetaBase(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                 IndexTarget const &DataTarget) APT_NONNULL(2, 3);
+   virtual ~pkgAcqMetaBase();
+};
+                                                                       /*}}}*/
+/** \brief An item that is responsible for downloading the meta-index  {{{
+ *  file (i.e., Release) itself and verifying its signature.
+ *
+ *  Once the download and verification are complete, the downloads of
+ *  the individual index files are queued up using pkgAcqDiffIndex.
+ *  If the meta-index file had a valid signature, the expected hashsums
+ *  of the index files will be the md5sums listed in the meta-index;
+ *  otherwise, the expected hashsums will be "" (causing the
+ *  authentication of the index files to be bypassed).
+ */
+class APT_HIDDEN pkgAcqMetaIndex : public pkgAcqMetaBase
+{
+   void * const d;
+   protected:
+   IndexTarget const DetachedSigTarget;

 
    /** \brief delayed constructor */
 
    /** \brief delayed constructor */

-   void Init(std::string URIDesc, std::string ShortDesc);
-   
+   void Init(std::string const &URIDesc, std::string const &ShortDesc);
+

    public:
    public:

-   
+   virtual std::string DescURI() const APT_OVERRIDE;
+

    // Specialized action members
    // Specialized action members

-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers() const;
-   virtual std::string DescURI() const {return RealURI; };
-   virtual void Finished();
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;

 
    /** \brief Create a new pkgAcqMetaIndex. */
 
    /** \brief Create a new pkgAcqMetaIndex. */

-   pkgAcqMetaIndex(pkgAcquire *Owner,
-                   unsigned long TransactionID,
-                  std::string URI,std::string URIDesc, std::string ShortDesc,
-                   std::string MetaIndexSigURI, std::string MetaIndexSigURIDesc, std::string MetaIndexSigShortDesc,
-                  const std::vector<IndexTarget*>* IndexTargets,
-                  indexRecords* MetaIndexParser);
+   pkgAcqMetaIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                  IndexTarget const &DataTarget, IndexTarget const &DetachedSigTarget) APT_NONNULL(2, 3);
+   virtual ~pkgAcqMetaIndex();
+
+   friend class pkgAcqMetaSig;

 };
                                                                        /*}}}*/
 };
                                                                        /*}}}*/

-/** \brief An item repsonsible for downloading clearsigned metaindexes {{{*/
-class pkgAcqMetaClearSig : public pkgAcqMetaIndex
+/** \brief An acquire item that downloads the detached signature       {{{
+ *  of a meta-index (Release) file, then queues up the release
+ *  file itself.
+ *
+ *  \todo Why protected members?
+ *
+ *  \sa pkgAcqMetaIndex
+ */
+class APT_HIDDEN pkgAcqMetaSig : public pkgAcqTransactionItem

 {
 {

-   /** \brief The URI of the meta-index file for the detached signature */
-   std::string MetaIndexURI;
+   void * const d;

 
 

-   /** \brief A "URI-style" description of the meta-index file */
-   std::string MetaIndexURIDesc;
+   pkgAcqMetaIndex * const MetaIndex;

 
 

-   /** \brief A brief description of the meta-index file */
-   std::string MetaIndexShortDesc;
+   /** \brief The file we use to verify the MetaIndexFile with (not always set!) */
+   std::string MetaIndexFileSignature;

 
 

-   /** \brief The URI of the detached meta-signature file if the clearsigned one failed. */
-   std::string MetaSigURI;
+   protected:

 
 

-   /** \brief A "URI-style" description of the meta-signature file */
-   std::string MetaSigURIDesc;
+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;

 
 

-   /** \brief A brief description of the meta-signature file */
-   std::string MetaSigShortDesc;
+   public:
+   virtual bool HashesRequired() const APT_OVERRIDE { return false; }

 
 

-public:
-   void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers() const;
+   // Specialized action members
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string Custom600Headers() const APT_OVERRIDE;
+
+   /** \brief Create a new pkgAcqMetaSig. */
+   pkgAcqMetaSig(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+        IndexTarget const &Target, pkgAcqMetaIndex * const MetaIndex) APT_NONNULL(2, 3, 5);
+   virtual ~pkgAcqMetaSig();
+};
+                                                                       /*}}}*/
+/** \brief An item repsonsible for downloading clearsigned metaindexes {{{*/
+class APT_HIDDEN pkgAcqMetaClearSig : public pkgAcqMetaIndex
+{
+   void * const d;
+   IndexTarget const DetachedDataTarget;
+
+ public:
+   /** \brief A package-system-specific parser for the meta-index file. */
+   metaIndex *MetaIndexParser;
+   metaIndex *LastMetaIndexParser;
+
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string Custom600Headers() const APT_OVERRIDE;
+   virtual bool VerifyDone(std::string const &Message, pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Finished() APT_OVERRIDE;
+
+   /** \brief Starts downloading the individual index files.
+    *
+    *  \param verify If \b true, only indices whose expected hashsum
+    *  can be determined from the meta-index will be downloaded, and
+    *  the hashsums of indices will be checked (reporting
+    *  #StatAuthError if there is a mismatch).  If verify is \b false,
+    *  no hashsum checking will be performed.
+    */
+   void QueueIndexes(bool const verify);

 
    /** \brief Create a new pkgAcqMetaClearSig. */
 
    /** \brief Create a new pkgAcqMetaClearSig. */

-   pkgAcqMetaClearSig(pkgAcquire *Owner,
-               std::string const &URI, std::string const &URIDesc, std::string const &ShortDesc,
-               std::string const &MetaIndexURI, std::string const &MetaIndexURIDesc, std::string const &MetaIndexShortDesc,
-               std::string const &MetaSigURI, std::string const &MetaSigURIDesc, std::string const &MetaSigShortDesc,
-               const std::vector<IndexTarget*>* IndexTargets,
-               indexRecords* MetaIndexParser);
+   pkgAcqMetaClearSig(pkgAcquire * const Owner,
+               IndexTarget const &ClearsignedTarget,
+               IndexTarget const &DetachedDataTarget,
+               IndexTarget const &DetachedSigTarget,
+               metaIndex * const MetaIndexParser);

    virtual ~pkgAcqMetaClearSig();
 };
                                                                        /*}}}*/
    virtual ~pkgAcqMetaClearSig();
 };
                                                                        /*}}}*/

+/** \brief Common base class for all classes that deal with fetching indexes   {{{*/
+class APT_HIDDEN pkgAcqBaseIndex : public pkgAcqTransactionItem
+{
+   void * const d;

 
 

+ public:
+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;

 
 

-/** \brief Common base class for all classes that deal with fetching   {{{
-           indexes
- */
-class pkgAcqBaseIndex : public pkgAcquire::Item
-{
- protected:
-   /** \brief Pointer to the IndexTarget data
-    */
-   const struct IndexTarget * Target;
-   indexRecords *MetaIndexParser;
-   /** \brief The MetaIndex Key */
-   std::string MetaKey;
-
-   pkgAcqBaseIndex(pkgAcquire *Owner,
-                   unsigned long TransactionID,
-                   struct IndexTarget const * const Target,
-                   HashStringList const &ExpectedHashes,
-                   indexRecords *MetaIndexParser)
-      : Item(Owner, ExpectedHashes, TransactionID), Target(Target), 
-        MetaIndexParser(MetaIndexParser) {};
+   pkgAcqBaseIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                   IndexTarget const &Target) APT_NONNULL(2, 3);
+   virtual ~pkgAcqBaseIndex();

 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching an index file of   {{{
 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching an index file of   {{{


@@ -553,34 +620,34 @@ class pkgAcqBaseIndex : public pkgAcquire::Item
  *
  *  \sa pkgAcqIndexDiffs, pkgAcqIndex
  */
  *
  *  \sa pkgAcqIndexDiffs, pkgAcqIndex
  */

-class pkgAcqDiffIndex : public pkgAcqBaseIndex
+class APT_HIDDEN pkgAcqDiffIndex : public pkgAcqBaseIndex

 {
 {

+   void * const d;
+   std::vector<pkgAcqIndexMergeDiffs*> * diffs;
+

  protected:
    /** \brief If \b true, debugging information will be written to std::clog. */
    bool Debug;
 
  protected:
    /** \brief If \b true, debugging information will be written to std::clog. */
    bool Debug;
 

-   /** \brief The URI of the index file to recreate at our end (either
-    *  by downloading it or by applying partial patches).
-    */
-   std::string RealURI;
-
-   /** \brief The index file which will be patched to generate the new
-    *  file.
-    */
-   std::string CurrentPackagesFile;
-

    /** \brief A description of the Packages file (stored in
     *  pkgAcquire::ItemDesc::Description).
     */
    std::string Description;
 
    /** \brief A description of the Packages file (stored in
     *  pkgAcquire::ItemDesc::Description).
     */
    std::string Description;
 

+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;
+
+   virtual bool QueueURI(pkgAcquire::ItemDesc &Item) APT_OVERRIDE;
+
+   virtual bool TransactionState(TransactionStates const state) APT_OVERRIDE;

  public:
    // Specialized action members
  public:
    // Specialized action members

-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() const {return RealURI + "Index";};
-   virtual std::string Custom600Headers() const;
+   virtual void Failed(std::string const &Message, pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string DescURI() const APT_OVERRIDE {return Target.URI + "Index";};
+   virtual std::string Custom600Headers() const APT_OVERRIDE;
+   virtual std::string GetMetaKey() const APT_OVERRIDE;

 
    /** \brief Parse the Index file for a set of Packages diffs.
     *
 
    /** \brief Parse the Index file for a set of Packages diffs.
     *


@@ -592,8 +659,7 @@ class pkgAcqDiffIndex : public pkgAcqBaseIndex
     *  \return \b true if the Index file was successfully parsed, \b
     *  false otherwise.
     */
     *  \return \b true if the Index file was successfully parsed, \b
     *  false otherwise.
     */

-   bool ParseDiffIndex(std::string IndexDiffFile);
-   
+   bool ParseDiffIndex(std::string const &IndexDiffFile);

 
    /** \brief Create a new pkgAcqDiffIndex.
     *
 
    /** \brief Create a new pkgAcqDiffIndex.
     *


@@ -604,14 +670,26 @@ class pkgAcqDiffIndex : public pkgAcqBaseIndex
     *  \param URIDesc A long description of the list file to download.
     *
     *  \param ShortDesc A short description 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 ExpectedHashes The list file's hashsums which are expected.

     */
     */

-   pkgAcqDiffIndex(pkgAcquire *Owner,
-                   unsigned long TransactionID,
-                   struct IndexTarget const * const Target,
-                   HashStringList const &ExpectedHashes,
-                   indexRecords *MetaIndexParser);
+   pkgAcqDiffIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                   IndexTarget const &Target) APT_NONNULL(2, 3);
+   virtual ~pkgAcqDiffIndex();
+ private:
+   APT_HIDDEN void QueueOnIMSHit() const;
+};
+                                                                       /*}}}*/
+struct APT_HIDDEN DiffInfo {                                           /*{{{*/
+   /** The filename of the diff. */
+   std::string file;
+
+   /** The hashes of the file after the diff is applied */
+   HashStringList result_hashes;
+
+   /** The hashes of the diff */
+   HashStringList patch_hashes;
+
+   /** The hashes of the compressed diff */
+   HashStringList download_hashes;

 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching client-merge patches {{{
 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching client-merge patches {{{


@@ -625,8 +703,10 @@ class pkgAcqDiffIndex : public pkgAcqBaseIndex
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */

-class pkgAcqIndexMergeDiffs : public pkgAcqBaseIndex
+class APT_HIDDEN pkgAcqIndexMergeDiffs : public pkgAcqBaseIndex

 {
 {

+   void * const d;
+

    protected:
 
    /** \brief If \b true, debugging output will be written to
    protected:
 
    /** \brief If \b true, debugging output will be written to


@@ -634,11 +714,6 @@ class pkgAcqIndexMergeDiffs : public pkgAcqBaseIndex
     */
    bool Debug;
 
     */
    bool Debug;
 

-   /** \brief URI of the package index file that is being
-    *  reconstructed.
-    */
-   std::string RealURI;
-

    /** \brief description of the file being downloaded. */
    std::string Description;
 
    /** \brief description of the file being downloaded. */
    std::string Description;
 


@@ -670,10 +745,13 @@ class pkgAcqIndexMergeDiffs : public pkgAcqBaseIndex
     *  This method will fall back to downloading the whole index file
     *  outright; its arguments are ignored.
     */
     *  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, HashStringList const &Hashes,
-        pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() const {return RealURI + "Index";};
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+        pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string Custom600Headers() const APT_OVERRIDE;
+   virtual std::string DescURI() const APT_OVERRIDE {return Target.URI + "Index";};
+   virtual HashStringList GetExpectedHashes() const APT_OVERRIDE;
+   virtual bool HashesRequired() const APT_OVERRIDE;

 
    /** \brief Create an index merge-diff item.
     *
 
    /** \brief Create an index merge-diff item.
     *


@@ -686,23 +764,16 @@ class pkgAcqIndexMergeDiffs : public pkgAcqBaseIndex
     *
     *  \param ShortDesc A brief description of this item.
     *
     *
     *  \param ShortDesc A brief description of this item.
     *

-    *  \param ExpectedHashes 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
     */
     *  \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,
-                         unsigned long TransactionID,
-                         struct IndexTarget const * const Target,
-                         HashStringList const &ExpectedHash,
-                         indexRecords *MetaIndexParser,
-                         DiffInfo const &patch, 
-                         std::vector<pkgAcqIndexMergeDiffs*> const * const allPatches);
+   pkgAcqIndexMergeDiffs(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                         IndexTarget const &Target, DiffInfo const &patch,
+                         std::vector<pkgAcqIndexMergeDiffs*> const * const allPatches) APT_NONNULL(2, 3, 6);
+   virtual ~pkgAcqIndexMergeDiffs();

 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching server-merge patches {{{
 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching server-merge patches {{{


@@ -716,8 +787,10 @@ class pkgAcqIndexMergeDiffs : public pkgAcqBaseIndex
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */

-class pkgAcqIndexDiffs : public pkgAcqBaseIndex
+class APT_HIDDEN pkgAcqIndexDiffs : public pkgAcqBaseIndex

 {
 {

+   void * const d;
+

    private:
 
    /** \brief Queue up the next diff download.
    private:
 
    /** \brief Queue up the next diff download.


@@ -729,7 +802,7 @@ class pkgAcqIndexDiffs : public pkgAcqBaseIndex
     *  \return \b true if an applicable diff was found, \b false
     *  otherwise.
     */
     *  \return \b true if an applicable diff was found, \b false
     *  otherwise.
     */

-   bool QueueNextDiff();
+   APT_HIDDEN bool QueueNextDiff();

 
    /** \brief Handle tasks that must be performed after the item
     *  finishes downloading.
 
    /** \brief Handle tasks that must be performed after the item
     *  finishes downloading.


@@ -742,7 +815,7 @@ class pkgAcqIndexDiffs : public pkgAcqBaseIndex
     *  \param allDone If \b true, the file was entirely reconstructed,
     *  and its md5sum is verified. 
     */
     *  \param allDone If \b true, the file was entirely reconstructed,
     *  and its md5sum is verified. 
     */

-   void Finish(bool allDone=false);
+   APT_HIDDEN void Finish(bool const allDone=false);

 
    protected:
 
 
    protected:
 


@@ -751,11 +824,6 @@ class pkgAcqIndexDiffs : public pkgAcqBaseIndex
     */
    bool Debug;
 
     */
    bool Debug;
 

-   /** \brief The URI of the package index file that is being
-    *  reconstructed.
-    */
-   std::string RealURI;
-

    /** A description of the file being downloaded. */
    std::string Description;
 
    /** A description of the file being downloaded. */
    std::string Description;
 


@@ -769,37 +837,31 @@ class pkgAcqIndexDiffs : public pkgAcqBaseIndex
     */
    std::vector<DiffInfo> available_patches;
 
     */
    std::vector<DiffInfo> available_patches;
 

-   /** Stop applying patches when reaching that sha1 */
-   std::string ServerSha1;
-

    /** The current status of this patch. */
    enum DiffState
    /** 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 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 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.
     */
    /** \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 Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;

 
 

-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() const {return RealURI + "Index";};
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string Custom600Headers() const APT_OVERRIDE;
+   virtual std::string DescURI() const APT_OVERRIDE {return Target.URI + "IndexDiffs";};
+   virtual HashStringList GetExpectedHashes() const APT_OVERRIDE;
+   virtual bool HashesRequired() const APT_OVERRIDE;

 
    /** \brief Create an index diff item.
     *
 
    /** \brief Create an index diff item.
     *


@@ -815,23 +877,14 @@ class pkgAcqIndexDiffs : public pkgAcqBaseIndex
     *
     *  \param ShortDesc A brief description of this item.
     *
     *
     *  \param ShortDesc A brief description of this item.
     *

-    *  \param ExpectedHashes 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.
     */
     *  \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,
-                    unsigned long TransactionID,
-                    struct IndexTarget const * const Target,
-                    HashStringList const &ExpectedHash,
-                    indexRecords *MetaIndexParser,
-                   std::string ServerSha1,
-                   std::vector<DiffInfo> diffs=std::vector<DiffInfo>());
+   pkgAcqIndexDiffs(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                    IndexTarget const &Target,
+                   std::vector<DiffInfo> const &diffs=std::vector<DiffInfo>()) APT_NONNULL(2, 3);
+   virtual ~pkgAcqIndexDiffs();

 };
                                                                        /*}}}*/
 /** \brief An acquire item that is responsible for fetching an index   {{{
 };
                                                                        /*}}}*/
 /** \brief An acquire item that is responsible for fetching an index   {{{


@@ -841,220 +894,68 @@ class pkgAcqIndexDiffs : public pkgAcqBaseIndex
  *
  *  \todo Why does pkgAcqIndex have protected members?
  */
  *
  *  \todo Why does pkgAcqIndex have protected members?
  */

-class pkgAcqIndex : public pkgAcqBaseIndex
+class APT_HIDDEN pkgAcqIndex : public pkgAcqBaseIndex

 {
 {

-   protected:
-
-   /** \brief If \b true, the index file has been decompressed. */
-   bool Decompression;
+   void * const d;

 
 

-   /** \brief If \b true, the partially downloaded file will be
-    *  removed when the download completes.
-    */
-   bool Erase;
-
-   // FIXME:
-   // Unused, used to be used to verify that "Packages: " header was there
-   bool __DELME_ON_NEXT_ABI_BREAK_Verify;
-
-   /** \brief The object that is actually being fetched (minus any
-    *  compression-related extensions).
-    */
-   std::string RealURI;
-
-   /** \brief The compression-related file extensions that are being
-    *  added to the downloaded file one by one if first fails (e.g., "gz bz2").
-    */
-   std::string CompressionExtension;
-
-   /** \brief Do the changes needed to fetch via AptByHash (if needed) */
-   void InitByHashIfNeeded(const std::string MetaKey);
-
-   /** \brief Auto select the right compression to use */
-   void AutoSelectCompression();
-
-   public:
-   
-   // Specialized action members
-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers() const;
-   virtual std::string DescURI() const {return Desc.URI;};
-
-   /** \brief Create a pkgAcqIndex.
-    *
-    *  \param Owner The pkgAcquire object with which this item is
-    *  associated.
-    *
-    *  \param URI The URI of the index file that is to be downloaded.
-    *
-    *  \param URIDesc A "URI-style" description of this index file.
-    *
-    *  \param ShortDesc A brief description of this index file.
-    *
-    *  \param ExpectedHashes The expected hashsum of this index file.
-    *
-    *  \param compressExt The compression-related extension with which
-    *  this index file should be downloaded, or "" to autodetect
-    *  Compression types can be set with config Acquire::CompressionTypes,
-    *  default is ".lzma" or ".bz2" (if the needed binaries are present)
-    *  fallback is ".gz" or none.
-    */
-   pkgAcqIndex(pkgAcquire *Owner,std::string URI,std::string URIDesc,
-              std::string ShortDesc, HashStringList const &ExpectedHashes,
-              std::string compressExt="");
-   pkgAcqIndex(pkgAcquire *Owner, unsigned long TransactionID,
-               IndexTarget const * const Target,
-               HashStringList const &ExpectedHash,
-               indexRecords *MetaIndexParser);
-               
-   void Init(std::string const &URI, std::string const &URIDesc,
-             std::string const &ShortDesc);
-};
-                                                                       /*}}}*/
-/** \brief An acquire item that is responsible for fetching a          {{{
- *  translated index file.
- *
- *  The only difference from pkgAcqIndex is that transient failures
- *  are suppressed: no error occurs if the translated index file is
- *  missing.
- */
-class pkgAcqIndexTrans : public pkgAcqIndex
-{
-   public:
-  
-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers() const;
+   protected:

 
 

-   /** \brief Create a pkgAcqIndexTrans.
-    *
-    *  \param Owner The pkgAcquire object with which this item is
-    *  associated.
-    *
-    *  \param URI The URI of the index file that is to be downloaded.
-    *
-    *  \param URIDesc A "URI-style" description of this index file.
+   /** \brief The stages the method goes through

     *
     *

-    *  \param ShortDesc A brief description of this index file.
+    *  The method first downloads the indexfile, then its decompressed (or
+    *  copied) and verified

     */
     */

-   pkgAcqIndexTrans(pkgAcquire *Owner,
-                    std::string URI,std::string URIDesc,
-                   std::string ShortDesc);
-   pkgAcqIndexTrans(pkgAcquire *Owner,
-                    unsigned long TransactionID,
-                    IndexTarget const * const Target,
-                    HashStringList const &ExpectedHashes,
-                    indexRecords *MetaIndexParser);
-};
-                                                                       /*}}}*/
-/** \brief Information about an index file. */                         /*{{{*/
-class IndexTarget
-{
- public:
-   /** \brief A URI from which the index file can be downloaded. */
-   std::string URI;
-
-   /** \brief A description of the index file. */
-   std::string Description;
+   enum AllStages {
+      STAGE_DOWNLOAD,
+      STAGE_DECOMPRESS_AND_VERIFY,
+   };
+   AllStages Stage;

 
 

-   /** \brief A shorter description of the index file. */
-   std::string ShortDesc;
+   /** \brief Handle what needs to be done when the download is done */
+   void StageDownloadDone(std::string const &Message);

 
 

-   /** \brief The key by which this index file should be
-    *  looked up within the meta signature file.
+   /** \brief Handle what needs to be done when the decompression/copy is
+    *         done 

     */
     */

-   std::string MetaKey;
-
-   virtual bool IsOptional() const {
-      return false;
-   }
-   virtual bool IsSubIndex() const {
-      return false;
-   }
-};
-                                                                       /*}}}*/
-/** \brief Information about an optional index file. */                        /*{{{*/
-class OptionalIndexTarget : public IndexTarget
-{
-   virtual bool IsOptional() const {
-      return true;
-   }
-};
-                                                                       /*}}}*/
-/** \brief Information about an subindex index file. */                        /*{{{*/
-class SubIndexTarget : public IndexTarget
-{
-   virtual bool IsSubIndex() const {
-      return true;
-   }
-};
-                                                                       /*}}}*/
-/** \brief Information about an subindex index file. */                        /*{{{*/
-class OptionalSubIndexTarget : public OptionalIndexTarget
-{
-   virtual bool IsSubIndex() const {
-      return true;
-   }
-};
-                                                                       /*}}}*/
+   void StageDecompressDone();

 
 

-/** \brief An acquire item that downloads the detached signature       {{{
- *  of a meta-index (Release) file, then queues up the release
- *  file itself.
- *
- *  \todo Why protected members?
- *
- *  \sa pkgAcqMetaIndex
- */
-class pkgAcqMetaSig : public pkgAcquire::Item
-{
-   protected:
-   /** \brief The last good signature file */
-   std::string LastGoodSig;
-
-   /** \brief The URI of the signature file.  Unlike Desc.URI, this is
-    *  never modified; it is used to determine the file that is being
-    *  downloaded.
+   /** \brief If \b set, this partially downloaded file will be
+    *  removed when the download completes.

     */
     */

-   std::string RealURI;
+   std::string EraseFileName;

 
 

-   /** \brief A package-system-specific parser for the meta-index file. */
-   indexRecords* MetaIndexParser;
+   /** \brief The compression-related file extensions that are being
+    *  added to the downloaded file one by one if first fails (e.g., "gz bz2").
+    */
+   std::string CompressionExtensions;

 
 

-   /** \brief The file we need to verify */
-   std::string MetaIndexFile;
+   /** \brief The actual compression extension currently used */
+   std::string CurrentCompressionExtension;

 
 

-   /** \brief The index files which should be looked up in the meta-index
-    *  and then downloaded.
-    *
-    *  \todo Why a list of pointers instead of a list of structs?
-    */
-   const std::vector<IndexTarget*>* IndexTargets;
+   /** \brief Do the changes needed to fetch via AptByHash (if needed) */
+   void InitByHashIfNeeded();

 
 

-   /** \brief If we are in fetching or download state */
-   bool AuthPass;
+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;

 
 

-   /** \brief Was this file already on disk */
-   bool IMSHit;
+   virtual bool TransactionState(TransactionStates const state) APT_OVERRIDE;

 
    public:
 
    public:

-   

    // Specialized action members
    // Specialized action members

-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers() const;
-   virtual std::string DescURI() const {return RealURI; };
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string Custom600Headers() const APT_OVERRIDE;
+   virtual std::string DescURI() const APT_OVERRIDE {return Desc.URI;};
+   virtual std::string GetMetaKey() const APT_OVERRIDE;

 
 

-   /** \brief Create a new pkgAcqMetaSig. */
-   pkgAcqMetaSig(pkgAcquire *Owner,
-                 unsigned long TransactionID,
-                 std::string URI,std::string URIDesc, std::string ShortDesc,
-                 std::string MetaIndexFile,
-                const std::vector<IndexTarget*>* IndexTargets,
-                indexRecords* MetaIndexParser);
-   virtual ~pkgAcqMetaSig();
+   pkgAcqIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+               IndexTarget const &Target) APT_NONNULL(2, 3);
+   virtual ~pkgAcqIndex();
+
+   private:
+   APT_HIDDEN void Init(std::string const &URI, std::string const &URIDesc,
+             std::string const &ShortDesc);

 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching a package file.    {{{
 };
                                                                        /*}}}*/
 /** \brief An item that is responsible for fetching a package file.    {{{


@@ -1064,6 +965,11 @@ class pkgAcqMetaSig : public pkgAcquire::Item
  */
 class pkgAcqArchive : public pkgAcquire::Item
 {
  */
 class pkgAcqArchive : public pkgAcquire::Item
 {

+   void * const d;
+
+   bool LocalSource;
+   HashStringList ExpectedHashes;
+

    protected:
    /** \brief The package version being fetched. */
    pkgCache::VerIterator Version;
    protected:
    /** \brief The package version being fetched. */
    pkgCache::VerIterator Version;


@@ -1096,21 +1002,26 @@ class pkgAcqArchive : public pkgAcquire::Item
    /** \brief \b true if this version file is being downloaded from a
     *  trusted source.
     */
    /** \brief \b true if this version file is being downloaded from a
     *  trusted source.
     */

-   bool Trusted; 
+   bool Trusted;

 
    /** \brief Queue up the next available file for this version. */
    bool QueueNext();
 
    /** \brief Queue up the next available file for this version. */
    bool QueueNext();

-   
+
+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;
+

    public:
    public:

-   
-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &Hashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() const {return Desc.URI;};
-   virtual std::string ShortDesc() const {return Desc.ShortDesc;};
-   virtual void Finished();
-   virtual bool IsTrusted() const;
-   
+
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &Hashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string DescURI() const APT_OVERRIDE;
+   virtual std::string ShortDesc() const APT_OVERRIDE;
+   virtual void Finished() APT_OVERRIDE;
+   virtual bool IsTrusted() const APT_OVERRIDE;
+   virtual HashStringList GetExpectedHashes() const APT_OVERRIDE;
+   virtual bool HashesRequired() const APT_OVERRIDE;
+

    /** \brief Create a new pkgAcqArchive.
     *
     *  \param Owner The pkgAcquire object with which this item is
    /** \brief Create a new pkgAcqArchive.
     *
     *  \param Owner The pkgAcquire object with which this item is


@@ -1129,9 +1040,125 @@ class pkgAcqArchive : public pkgAcquire::Item
     *  basename in the constructor, and filled in with a fully
     *  qualified filename once the download finishes.
     */
     *  basename in the constructor, and filled in with a fully
     *  qualified filename once the download finishes.
     */

-   pkgAcqArchive(pkgAcquire *Owner,pkgSourceList *Sources,
-                pkgRecords *Recs,pkgCache::VerIterator const &Version,
+   pkgAcqArchive(pkgAcquire * const Owner,pkgSourceList * const Sources,
+                pkgRecords * const Recs,pkgCache::VerIterator const &Version,

                 std::string &StoreFilename);
                 std::string &StoreFilename);

+   virtual ~pkgAcqArchive();
+};
+                                                                       /*}}}*/
+/** \brief Retrieve the changelog for the given version                        {{{
+ *
+ *  Downloads the changelog to a temporary file it will also remove again
+ *  while it is deconstructed or downloads it to a named location.
+ */
+class pkgAcqChangelog : public pkgAcquire::Item
+{
+   class Private;
+   Private * const d;
+   std::string TemporaryDirectory;
+   std::string const SrcName;
+   std::string const SrcVersion;
+
+   public:
+   // we will never have hashes for changelogs.
+   // If you need verified ones, download the deb and extract the changelog.
+   virtual HashStringList GetExpectedHashes() const APT_OVERRIDE { return HashStringList(); }
+   virtual bool HashesRequired() const APT_OVERRIDE { return false; }
+
+   // Specialized action members
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &CalcHashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string DescURI() const APT_OVERRIDE {return Desc.URI;};
+
+   /** returns the URI to the changelog of this version
+    *
+    * @param Ver is the version to get the changelog for
+    * @return the URI which will be used to acquire the changelog
+    */
+   static std::string URI(pkgCache::VerIterator const &Ver);
+
+   /** returns the URI to the changelog of this version
+    *
+    *  \param Rls is the Release file the package comes from
+    *  \param Component in which the package resides, can be empty
+    *  \param SrcName is the source package name
+    *  \param SrcVersion is the source package version
+    * @return the URI which will be used to acquire the changelog
+    */
+   static std::string URI(pkgCache::RlsFileIterator const &Rls,
+        char const * const Component, char const * const SrcName,
+        char const * const SrcVersion);
+
+   /** returns the URI to the changelog of this version
+    *
+    *  \param Template URI where @CHANGEPATH@ has to be filled in
+    *  \param Component in which the package resides, can be empty
+    *  \param SrcName is the source package name
+    *  \param SrcVersion is the source package version
+    * @return the URI which will be used to acquire the changelog
+    */
+   static std::string URI(std::string const &Template,
+        char const * const Component, char const * const SrcName,
+        char const * const SrcVersion);
+
+   /** returns the URI template for this release file
+    *
+    *  \param Rls is a Release file
+    * @return the URI template to use for this release file
+    */
+   static std::string URITemplate(pkgCache::RlsFileIterator const &Rls);
+
+   /** \brief Create a new pkgAcqChangelog object.
+    *
+    *  \param Owner The pkgAcquire object with which this object is
+    *  associated.
+    *  \param Ver is the version to get the changelog for
+    *  \param DestDir The directory the file should be downloaded into.
+    *  Will be an autocreated (and cleaned up) temporary directory if not set.
+    *  \param DestFilename The filename the file should have in #DestDir
+    *  Defaults to sourcepackagename.changelog if not set.
+    */
+   pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::VerIterator const &Ver,
+        std::string const &DestDir="", std::string const &DestFilename="");
+
+   /** \brief Create a new pkgAcqChangelog object.
+    *
+    *  \param Owner The pkgAcquire object with which this object is
+    *  associated.
+    *  \param Rls is the Release file the package comes from
+    *  \param Component in which the package resides, can be empty
+    *  \param SrcName is the source package name
+    *  \param SrcVersion is the source package version
+    *  \param DestDir The directory the file should be downloaded into.
+    *  Will be an autocreated (and cleaned up) temporary directory if not set.
+    *  \param DestFilename The filename the file should have in #DestDir
+    *  Defaults to sourcepackagename.changelog if not set.
+    */
+   pkgAcqChangelog(pkgAcquire * const Owner, pkgCache::RlsFileIterator const &Rls,
+        char const * const Component, char const * const SrcName, char const * const SrcVersion,
+        std::string const &DestDir="", std::string const &DestFilename="");
+
+   /** \brief Create a new pkgAcqChangelog object.
+    *
+    *  \param Owner The pkgAcquire object with which this object is
+    *  associated.
+    *  \param URI is to be used to get the changelog
+    *  \param SrcName is the source package name
+    *  \param SrcVersion is the source package version
+    *  \param DestDir The directory the file should be downloaded into.
+    *  Will be an autocreated (and cleaned up) temporary directory if not set.
+    *  \param DestFilename The filename the file should have in #DestDir
+    *  Defaults to sourcepackagename.changelog if not set.
+    */
+   pkgAcqChangelog(pkgAcquire * const Owner, std::string const &URI,
+        char const * const SrcName, char const * const SrcVersion,
+        std::string const &DestDir="", std::string const &DestFilename="");
+
+   virtual ~pkgAcqChangelog();
+
+private:
+   APT_HIDDEN void Init(std::string const &DestDir, std::string const &DestFilename);

 };
                                                                        /*}}}*/
 /** \brief Retrieve an arbitrary file to the current directory.                {{{
 };
                                                                        /*}}}*/
 /** \brief Retrieve an arbitrary file to the current directory.                {{{


@@ -1142,22 +1169,27 @@ class pkgAcqArchive : public pkgAcquire::Item
  */
 class pkgAcqFile : public pkgAcquire::Item
 {
  */
 class pkgAcqFile : public pkgAcquire::Item
 {

+   void * const d;
+

    /** \brief How many times to retry the download, set from
     *  Acquire::Retries.
     */
    unsigned int Retries;
    /** \brief How many times to retry the download, set from
     *  Acquire::Retries.
     */
    unsigned int Retries;

-   
+

    /** \brief Should this file be considered a index file */
    bool IsIndexFile;
 
    /** \brief Should this file be considered a index file */
    bool IsIndexFile;
 

+   HashStringList const ExpectedHashes;

    public:
    public:

-   
+   virtual HashStringList GetExpectedHashes() const APT_OVERRIDE;
+   virtual bool HashesRequired() const APT_OVERRIDE;
+

    // Specialized action members
    // Specialized action members

-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, HashStringList const &CalcHashes,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() const {return Desc.URI;};
-   virtual std::string Custom600Headers() const;
+   virtual void Failed(std::string const &Message,pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual void Done(std::string const &Message, HashStringList const &CalcHashes,
+                    pkgAcquire::MethodConfig const * const Cnf) APT_OVERRIDE;
+   virtual std::string DescURI() const APT_OVERRIDE {return Desc.URI;};
+   virtual std::string Custom600Headers() const APT_OVERRIDE;

 
    /** \brief Create a new pkgAcqFile object.
     *
 
    /** \brief Create a new pkgAcqFile object.
     *


@@ -1190,10 +1222,11 @@ class pkgAcqFile : public pkgAcquire::Item
     * is the absolute name to which the file should be downloaded.
     */
 
     * is the absolute name to which the file should be downloaded.
     */
 

-   pkgAcqFile(pkgAcquire *Owner, std::string URI, HashStringList const &Hashes, unsigned long long Size,
-             std::string Desc, std::string ShortDesc,
-             const std::string &DestDir="", const std::string &DestFilename="",
-             bool IsIndexFile=false);
+   pkgAcqFile(pkgAcquire * const Owner, std::string const &URI, HashStringList const &Hashes, unsigned long long const Size,
+             std::string const &Desc, std::string const &ShortDesc,
+             std::string const &DestDir="", std::string const &DestFilename="",
+             bool const IsIndexFile=false);
+   virtual ~pkgAcqFile();

 };
                                                                        /*}}}*/
 /** @} */
 };
                                                                        /*}}}*/
 /** @} */