string_view: Drop constexpr constructor for standard compatibility

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

diff --git a/apt-pkg/acquire-item.h b/apt-pkg/acquire-item.h
index 06537bf2cad4726ac1b79cbdbdcb91b0a098c881..306b1772a77be02c52d99bb7e9c3afe7ce595267 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


@@ -43,11 +41,14 @@
  *  \file acquire-item.h
  */
 
  *  \file acquire-item.h
  */
 

-class indexRecords;

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

+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


@@ -59,35 +60,7 @@ class pkgSourceList;
  *
  *  \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. */


@@ -112,10 +85,10 @@ 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)
        */
        *  a transient network error (e.g. network down)
        */

-       StatTransientNetworkError
+       StatTransientNetworkError,

      } Status;
 
    /** \brief Contains a textual description of the error encountered
      } Status;
 
    /** \brief Contains a textual description of the error encountered


@@ -132,14 +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;
 


@@ -155,6 +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


@@ -166,7 +145,17 @@ class pkgAcquire::Item : public WeakPointable
     *  \sa pkgAcquire
     */
    unsigned int QueueCounter;
     *  \sa pkgAcquire
     */
    unsigned int QueueCounter;

-   
+
+   /** \brief The number of additional fetch items that are expected
+    *  once this item is done.
+    *
+    *  Some items like pkgAcqMeta{Index,Sig} will queue additional
+    *  items. This variable can be set by the methods if it knows
+    *  in advance how many items to expect to get a more accurate
+    *  progress.
+    */
+   unsigned int ExpectedAdditionalItems;
+

    /** \brief The name of the file into which the retrieved object
     *  will be written.
     */
    /** \brief The name of the file into which the retrieved object
     *  will be written.
     */


@@ -185,7 +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.


@@ -200,25 +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 Hash The HashSum 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 Cnf The method via which the object was fetched.
     *
     *  \sa pkgAcqMethod
     */

-   virtual void Done(std::string Message,unsigned long long Size,std::string Hash,
-                    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.
     *


@@ -228,45 +238,56 @@ 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() {return std::string();};
+   virtual std::string Custom600Headers() const;

 
    /** \brief A "descriptive" URI-like string.
     *
     *  \return a URI that should be used to describe what is being fetched.
     */
 
    /** \brief A "descriptive" URI-like string.
     *
     *  \return a URI that should be used to describe what is being fetched.
     */

-   virtual std::string DescURI() = 0;
+   virtual std::string DescURI() const = 0;

    /** \brief Short item description.
     *
     *  \return a brief description of the object being fetched.
     */
    /** \brief Short item description.
     *
     *  \return a brief description of the object being fetched.
     */

-   virtual std::string ShortDesc() {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 HashSum 
+   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 HashSum of this object, if applicable; otherwise, an
-    *  empty string.
+    * 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.

     */
     */

-   virtual std::string HashSum() {return std::string();};
+   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() {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() {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);
+   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.
     *


@@ -274,12 +295,9 @@ class pkgAcquire::Item : public WeakPointable
     *  process, but does not place it into any fetch queues (you must
     *  manually invoke QueueURI() to do so).
     *
     *  process, but does not place it into any fetch queues (you must
     *  manually invoke QueueURI() to do so).
     *

-    *  Initializes all fields of the item other than Owner to 0,
-    *  false, or the empty string.
-    *

     *  \param Owner The new owner of this item.
     */
     *  \param Owner The new owner of this item.
     */

-   Item(pkgAcquire *Owner);
+   explicit Item(pkgAcquire * const Owner);

 
    /** \brief Remove this item from its owner's queue by invoking
     *  pkgAcquire::Remove.
 
    /** \brief Remove this item from its owner's queue by invoking
     *  pkgAcquire::Remove.


@@ -287,11 +305,20 @@ class pkgAcquire::Item : public WeakPointable
    virtual ~Item();
 
    protected:
    virtual ~Item();
 
    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


@@ -299,62 +326,291 @@ class pkgAcquire::Item : public WeakPointable
     * \param state respresenting the error we encountered
     */
    bool RenameOnError(RenameOnErrorState const state);
     * \param state respresenting the error we encountered
     */
    bool RenameOnError(RenameOnErrorState const state);

+
+   /** \brief Insert this item into its owner's queue.
+    *
+    *  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 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.
+    *
+    *  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. If \a From and \a To are equal nothing happens.
+    */
+   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:
+   void * const d;
+
+   friend class pkgAcqMetaBase;
+   friend class pkgAcqMetaClearSig;

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

-/** \brief Information about an index patch (aka diff). */             /*{{{*/
-struct DiffInfo {
-   /** The filename of the diff. */
-   std::string file;
+class APT_HIDDEN pkgAcqTransactionItem: public pkgAcquire::Item                /*{{{*/
+/** \brief baseclass for the indexes files to manage them all together */
+{
+   void * const d;
+   protected:
+   IndexTarget const Target;
+   HashStringList GetExpectedHashesFor(std::string const &MetaKey) const;
+
+   bool QueueURI(pkgAcquire::ItemDesc &Item) APT_OVERRIDE;
+
+   public:
+   /** \brief storge name until a transaction is finished */
+   std::string PartialFile;
+
+   /** \brief TransactionManager */
+   pkgAcqMetaClearSig * const TransactionManager;
+
+   enum TransactionStates {
+      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;

 
 

-   /** The sha1 hash of the diff. */
-   std::string sha1;

 
 

-   /** The size of the diff. */
-   unsigned long size;
+   pkgAcqTransactionItem(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager, IndexTarget const &Target);
+   virtual ~pkgAcqTransactionItem();
+
+   friend class pkgAcqMetaBase;
+   friend class pkgAcqMetaClearSig;

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

-/** \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
+class APT_HIDDEN pkgAcqMetaBase : public pkgAcqTransactionItem         /*{{{*/
+/** \brief the manager of a transaction */

 {
 {

+   void * const d;

  protected:
  protected:

-   /** \brief If \b true, debugging information will be written to std::clog. */
-   bool Debug;
+   std::vector<pkgAcqTransactionItem*> Transaction;

 
 

-   /** \brief The item that is currently being downloaded. */
-   pkgAcquire::ItemDesc Desc;
+   /** \brief The index files which should be looked up in the meta-index
+    *  and then downloaded.
+    */
+   std::vector<IndexTarget> IndexTargets;

 
 

-   /** \brief The Hash that this file should have after download
+   /** \brief If \b true, the index's signature is currently being verified.

     */
     */

-   HashString ExpectedHash;
+   bool AuthPass;

 
 

- public:
-   // Specialized action members
-   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 Desc.URI;};
-   virtual std::string Custom600Headers();
-   virtual bool ParseIndex(std::string const &IndexFile);
+   /** \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 pkgAcqSubIndex.
+   /** \brief Called when a file is finished being retrieved.

     *
     *

-    *  \param Owner The Acquire object that owns this item.
+    *  If the file was not downloaded to DestFile, a copy process is
+    *  set up to copy it to DestFile; otherwise, Complete is set to \b
+    *  true and the file is moved to its final location.

     *
     *

-    *  \param URI The URI of the list file to download.
+    *  \param Message The message block received from the fetch
+    *  subprocess.
+    */
+   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.

     *
     *

-    *  \param URIDesc A long description of the list file to download.
+    *  Sanity-checks the authenticated file, queues up the individual
+    *  index files for download, and saves the signature in the lists
+    *  directory next to the authenticated list file.

     *
     *

-    *  \param ShortDesc A short description of the list file to download.
+    *  \param Message The message block received from the fetch
+    *  subprocess.
+    */
+   bool CheckAuthDone(std::string const &Message);
+
+   /** 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 ExpectedHash The list file's MD5 signature.
+    *  \return \b true if no fatal errors were encountered.

     */
     */

-   pkgAcqSubIndex(pkgAcquire *Owner, std::string const &URI,std::string const &URIDesc,
-                  std::string const &ShortDesc, HashString const &ExpectedHash);
+   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;
+
+   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 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 Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;
+
+   pkgAcqMetaBase(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                 std::vector<IndexTarget> const &IndexTargets,
+                 IndexTarget const &DataTarget);
+   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 */
+   void Init(std::string const &URIDesc, std::string const &ShortDesc);
+
+   public:
+   virtual std::string DescURI() const APT_OVERRIDE;
+
+   // 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 void Finished() APT_OVERRIDE;
+
+   /** \brief Create a new pkgAcqMetaIndex. */
+   pkgAcqMetaIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                  IndexTarget const &DataTarget, IndexTarget const &DetachedSigTarget,
+                  std::vector<IndexTarget> const &IndexTargets);
+   virtual ~pkgAcqMetaIndex();
+
+   friend class pkgAcqMetaSig;
+};
+                                                                       /*}}}*/
+/** \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
+{
+   void * const d;
+
+   pkgAcqMetaIndex * const MetaIndex;
+
+   /** \brief The file we use to verify the MetaIndexFile with (not always set!) */
+   std::string MetaIndexFileSignature;
+
+   protected:
+
+   /** \brief Get the full pathname of the final file for the current URI */
+   virtual std::string GetFinalFilename() const APT_OVERRIDE;
+
+   public:
+   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 &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);
+   virtual ~pkgAcqMetaSig();
+};
+                                                                       /*}}}*/
+/** \brief An item repsonsible for downloading clearsigned metaindexes {{{*/
+class APT_HIDDEN pkgAcqMetaClearSig : public pkgAcqMetaIndex
+{
+   void * const d;
+
+   IndexTarget const ClearsignedTarget;
+   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;
+
+   /** \brief Create a new pkgAcqMetaClearSig. */
+   pkgAcqMetaClearSig(pkgAcquire * const Owner,
+               IndexTarget const &ClearsignedTarget,
+               IndexTarget const &DetachedDataTarget,
+               IndexTarget const &DetachedSigTarget,
+               std::vector<IndexTarget> const &IndexTargets,
+               metaIndex * const MetaIndexParser);
+   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;
+
+   pkgAcqBaseIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                   IndexTarget const &Target);
+   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   {{{


@@ -366,42 +622,34 @@ class pkgAcqSubIndex : public pkgAcquire::Item
  *
  *  \sa pkgAcqIndexDiffs, pkgAcqIndex
  */
  *
  *  \sa pkgAcqIndexDiffs, pkgAcqIndex
  */

-class pkgAcqDiffIndex : public pkgAcquire::Item
+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 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).
-    */
-   std::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.
-    */
-   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,std::string Md5Hash,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() {return RealURI + "Index";};
-   virtual std::string Custom600Headers();
+   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.
     *


@@ -413,8 +661,7 @@ class pkgAcqDiffIndex : public pkgAcquire::Item
     *  \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.
     *


@@ -425,11 +672,26 @@ class pkgAcqDiffIndex : public pkgAcquire::Item
     *  \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 ExpectedHash The list file's MD5 signature.

     */
     */

-   pkgAcqDiffIndex(pkgAcquire *Owner,std::string URI,std::string URIDesc,
-                  std::string ShortDesc, HashString ExpectedHash);
+   pkgAcqDiffIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                   IndexTarget const &Target);
+   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 {{{


@@ -443,8 +705,10 @@ class pkgAcqDiffIndex : public pkgAcquire::Item
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */

-class pkgAcqIndexMergeDiffs : public pkgAcquire::Item
+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


@@ -452,21 +716,6 @@ class pkgAcqIndexMergeDiffs : public pkgAcquire::Item
     */
    bool Debug;
 
     */
    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 description of the file being downloaded. */
    std::string Description;
 


@@ -498,11 +747,13 @@ class pkgAcqIndexMergeDiffs : public pkgAcquire::Item
     *  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,std::string Md5Hash,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() {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.
     *


@@ -515,19 +766,16 @@ class pkgAcqIndexMergeDiffs : public pkgAcquire::Item
     *
     *  \param ShortDesc A brief 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
     */
     *  \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);
+   pkgAcqIndexMergeDiffs(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                         IndexTarget const &Target, DiffInfo const &patch,
+                         std::vector<pkgAcqIndexMergeDiffs*> const * const allPatches);
+   virtual ~pkgAcqIndexMergeDiffs();

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


@@ -541,8 +789,10 @@ class pkgAcqIndexMergeDiffs : public pkgAcquire::Item
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */
  *
  *  \sa pkgAcqDiffIndex, pkgAcqIndex
  */

-class pkgAcqIndexDiffs : public pkgAcquire::Item
+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.


@@ -554,20 +804,20 @@ class pkgAcqIndexDiffs : public pkgAcquire::Item
     *  \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.
     *

-    *  Dequeues the item and checks the resulting file's md5sum
-    *  against ExpectedHash after the last patch was applied.
+    *  Dequeues the item and checks the resulting file's hashsums
+    *  against ExpectedHashes 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. 
     */
     *  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);
+   APT_HIDDEN void Finish(bool const allDone=false);

 
    protected:
 
 
    protected:
 


@@ -576,21 +826,6 @@ class pkgAcqIndexDiffs : public pkgAcquire::Item
     */
    bool Debug;
 
     */
    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;
 
    /** A description of the file being downloaded. */
    std::string Description;
 


@@ -604,37 +839,31 @@ class pkgAcqIndexDiffs : public pkgAcquire::Item
     */
    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,std::string Md5Hash,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() {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.
     *


@@ -650,20 +879,14 @@ class pkgAcqIndexDiffs : public pkgAcquire::Item
     *
     *  \param ShortDesc A brief 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.
     */
     *  \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>());
+   pkgAcqIndexDiffs(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+                    IndexTarget const &Target,
+                   std::vector<DiffInfo> const &diffs=std::vector<DiffInfo>());
+   virtual ~pkgAcqIndexDiffs();

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


@@ -673,350 +896,68 @@ class pkgAcqIndexDiffs : public pkgAcquire::Item
  *
  *  \todo Why does pkgAcqIndex have protected members?
  */
  *
  *  \todo Why does pkgAcqIndex have protected members?
  */

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

 {
 {

-   protected:
+   void * const d;

 
 

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

 
 

-   /** \brief If \b true, the partially downloaded file will be
-    *  removed when the download completes.
+   /** \brief The stages the method goes through
+    *
+    *  The method first downloads the indexfile, then its decompressed (or
+    *  copied) and verified

     */
     */

-   bool Erase;
+   enum AllStages {
+      STAGE_DOWNLOAD,
+      STAGE_DECOMPRESS_AND_VERIFY,
+   };
+   AllStages Stage;

 
 

-   // Unused, used to be used to verify that "Packages: " header was there
-   bool __DELME_ON_NEXT_ABI_BREAK_Verify;
+   /** \brief Handle what needs to be done when the download is done */
+   void StageDownloadDone(std::string const &Message);

 
 

-   /** \brief The download request that is currently being
-    *   processed.
+   /** \brief Handle what needs to be done when the decompression/copy is
+    *         done 

     */
     */

-   pkgAcquire::ItemDesc Desc;
+   void StageDecompressDone();

 
 

-   /** \brief The object that is actually being fetched (minus any
-    *  compression-related extensions).
+   /** \brief If \b set, this partially downloaded file will be
+    *  removed when the download completes.

     */
     */

-   std::string RealURI;
-
-   /** \brief The expected hashsum of the decompressed index file. */
-   HashString ExpectedHash;
+   std::string EraseFileName;

 
    /** \brief The compression-related file extensions that are being
     *  added to the downloaded file one by one if first fails (e.g., "gz bz2").
     */
 
    /** \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;
-
-   public:
-   
-   // Specialized action members
-   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 Custom600Headers();
-   virtual std::string DescURI() {return Desc.URI;};
-   virtual std::string HashSum() {return ExpectedHash.toStr(); };
-
-   /** \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 ExpectedHash 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, HashString ExpectedHash, 
-              std::string compressExt="");
-   pkgAcqIndex(pkgAcquire *Owner, struct IndexTarget const * const Target,
-                        HashString const &ExpectedHash, indexRecords const *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();
-
-   /** \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.
-    *
-    *  \param ShortDesc A brief description of this index file.
-    */
-   pkgAcqIndexTrans(pkgAcquire *Owner,std::string URI,std::string URIDesc,
-                   std::string ShortDesc);
-   pkgAcqIndexTrans(pkgAcquire *Owner, struct IndexTarget const * const Target,
-                   HashString const &ExpectedHash, indexRecords const *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;
-
-   /** \brief A shorter description of the index file. */
-   std::string ShortDesc;
-
-   /** \brief The key by which this index file should be
-    *  looked up within the meta signature file.
-    */
-   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;
-   }
-};
-                                                                       /*}}}*/
-
-/** \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 fetch request that is currently being processed. */
-   pkgAcquire::ItemDesc Desc;
+   std::string CompressionExtensions;

 
 

-   /** \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.
-    */
-   std::string RealURI;
+   /** \brief The actual compression extension currently used */
+   std::string CurrentCompressionExtension;

 
 

-   /** \brief The URI of the meta-index file to be fetched after the signature. */
-   std::string MetaIndexURI;
+   /** \brief Do the changes needed to fetch via AptByHash (if needed) */
+   void InitByHashIfNeeded();

 
 

-   /** \brief A "URI-style" description of the meta-index file to be
-    *  fetched after the signature.
-    */
-   std::string MetaIndexURIDesc;
+   /** \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 to be fetched
-    *  after the signature.
-    */
-   std::string MetaIndexShortDesc;
-
-   /** \brief A package-system-specific parser for the meta-index file. */
-   indexRecords* MetaIndexParser;
-
-   /** \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<struct IndexTarget*>* IndexTargets;
+   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,std::string Md5Hash,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers();
-   virtual std::string DescURI() {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,std::string URI,std::string URIDesc, std::string ShortDesc,
-                std::string MetaIndexURI, std::string MetaIndexURIDesc, std::string MetaIndexShortDesc,
-                const std::vector<struct IndexTarget*>* IndexTargets,
-                indexRecords* MetaIndexParser);
-   virtual ~pkgAcqMetaSig();
-};
-                                                                       /*}}}*/
-/** \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
-{
-   protected:
-   /** \brief The fetch command that is currently being processed. */
-   pkgAcquire::ItemDesc Desc;
-
-   /** \brief The URI that is actually being downloaded; never
-    *  modified by pkgAcqMetaIndex.
-    */
-   std::string RealURI;
-
-   /** \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;
-
-   /** \brief The index files to download. */
-   const std::vector<struct IndexTarget*>* IndexTargets;
-
-   /** \brief The parser for the meta-index file. */
-   indexRecords* MetaIndexParser;
-
-   /** \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.
-    *
-    *  If the file was not downloaded to DestFile, a copy process is
-    *  set up to copy it to DestFile; otherwise, Complete is set to \b
-    *  true and the file is moved to its final location.
-    *
-    *  \param Message The message block received from the fetch
-    *  subprocess.
-    */
-   void RetrievalDone(std::string Message);
-
-   /** \brief Called when authentication succeeded.
-    *
-    *  Sanity-checks the authenticated file, queues up the individual
-    *  index files for download, and saves the signature in the lists
-    *  directory next to the authenticated list file.
-    *
-    *  \param Message The message block received from the fetch
-    *  subprocess.
-    */
-   void AuthDone(std::string Message);
-
-   /** \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 verify);
-   
-   public:
-   
-   // Specialized action members
-   virtual void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual void Done(std::string Message,unsigned long long Size, std::string Hash,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers();
-   virtual std::string DescURI() {return RealURI; };
-
-   /** \brief Create a new pkgAcqMetaIndex. */
-   pkgAcqMetaIndex(pkgAcquire *Owner,
-                  std::string URI,std::string URIDesc, std::string ShortDesc,
-                  std::string SigFile,
-                  const std::vector<struct IndexTarget*>* IndexTargets,
-                  indexRecords* MetaIndexParser);
-};
-                                                                       /*}}}*/
-/** \brief An item repsonsible for downloading clearsigned metaindexes {{{*/
-class pkgAcqMetaClearSig : public pkgAcqMetaIndex
-{
-   /** \brief The URI of the meta-index file for the detached signature */
-   std::string MetaIndexURI;
-
-   /** \brief A "URI-style" description of the meta-index file */
-   std::string MetaIndexURIDesc;
-
-   /** \brief A brief description of the meta-index file */
-   std::string MetaIndexShortDesc;
-
-   /** \brief The URI of the detached meta-signature file if the clearsigned one failed. */
-   std::string MetaSigURI;
-
-   /** \brief A "URI-style" description of the meta-signature file */
-   std::string MetaSigURIDesc;
-
-   /** \brief A brief description of the meta-signature file */
-   std::string MetaSigShortDesc;
+   pkgAcqIndex(pkgAcquire * const Owner, pkgAcqMetaClearSig * const TransactionManager,
+               IndexTarget const &Target);
+   virtual ~pkgAcqIndex();

 
 

-public:
-   void Failed(std::string Message,pkgAcquire::MethodConfig *Cnf);
-   virtual std::string Custom600Headers();
-
-   /** \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<struct IndexTarget*>* IndexTargets,
-               indexRecords* MetaIndexParser);
-   virtual ~pkgAcqMetaClearSig();
+   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.    {{{


@@ -1026,13 +967,15 @@ public:
  */
 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;
 

-   /** \brief The fetch command that is currently being processed. */
-   pkgAcquire::ItemDesc Desc;
-

    /** \brief The list of sources from which to pick archives to
     *  download this package from.
     */
    /** \brief The list of sources from which to pick archives to
     *  download this package from.
     */


@@ -1043,9 +986,6 @@ class pkgAcqArchive : public pkgAcquire::Item
     */
    pkgRecords *Recs;
 
     */
    pkgRecords *Recs;
 

-   /** \brief The hashsum of this package. */
-   HashString ExpectedHash;
-

    /** \brief A location in which the actual filename of the package
     *  should be stored.
     */
    /** \brief A location in which the actual filename of the package
     *  should be stored.
     */


@@ -1064,22 +1004,26 @@ 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,std::string Hash,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() {return Desc.URI;};
-   virtual std::string ShortDesc() {return Desc.ShortDesc;};
-   virtual void Finished();
-   virtual std::string HashSum() {return ExpectedHash.toStr(); };
-   virtual bool IsTrusted();
-   
+
+   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


@@ -1098,9 +1042,124 @@ 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
+{
+   void * 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.                {{{


@@ -1111,29 +1170,27 @@ class pkgAcqArchive : public pkgAcquire::Item
  */
 class pkgAcqFile : public pkgAcquire::Item
 {
  */
 class pkgAcqFile : public pkgAcquire::Item
 {

-   /** \brief The currently active download process. */
-   pkgAcquire::ItemDesc Desc;
-
-   /** \brief The hashsum of the file to download, if it is known. */
-   HashString ExpectedHash;
+   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,std::string CalcHash,
-                    pkgAcquire::MethodConfig *Cnf);
-   virtual std::string DescURI() {return Desc.URI;};
-   virtual std::string HashSum() {return ExpectedHash.toStr(); };
-   virtual std::string Custom600Headers();
+   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.
     *


@@ -1142,8 +1199,8 @@ class pkgAcqFile : public pkgAcquire::Item
     *
     *  \param URI The URI to download.
     *
     *
     *  \param URI The URI to download.
     *

-    *  \param Hash The hashsum of the file to download, if it is known;
-    *  otherwise "".
+    *  \param Hashes The hashsums of the file to download, if they are known;
+    *  otherwise empty list.

     *
     *  \param Size The size of the file to download, if it is known;
     *  otherwise 0.
     *
     *  \param Size The size of the file to download, if it is known;
     *  otherwise 0.


@@ -1166,10 +1223,11 @@ 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, std::string Hash, 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();

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