* merged the no-pragma branch

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

diff --git a/apt-pkg/acquire-item.h b/apt-pkg/acquire-item.h
index 34fcc2a768278f64e6e2145efc868335b0e6daf9..cc46282d66c1c05ab2d3293f0b34d25849930620 100644 (file)
--- a/apt-pkg/acquire-item.h
+++ b/apt-pkg/acquire-item.h
@@ -27,77 +27,284 @@
 #include <apt-pkg/pkgrecords.h>
 #include <apt-pkg/indexrecords.h>
 
 #include <apt-pkg/pkgrecords.h>
 #include <apt-pkg/indexrecords.h>
 

-#ifdef __GNUG__
-#pragma interface "apt-pkg/acquire-item.h"
-#endif 

 
 

-// Item to acquire
+/** \addtogroup acquire
+ *  @{
+ *
+ *  \file acquire-item.h
+ */
+
+/** \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
+ *  acquire queue when they are created by calling QueueURI(), and
+ *  remove themselves by calling Dequeue() when either Done() or
+ *  Failed() is invoked.  Item objects are also responsible for
+ *  notifying the download progress indicator (accessible via
+ *  #Owner->Log) of their status.
+ *
+ *  \see pkgAcquire
+ */

 class pkgAcquire::Item
 {  
    protected:
    
 class pkgAcquire::Item
 {  
    protected:
    

-   // Some private helper methods for registering URIs
+   /** \brief The acquire object with which this item is associated. */

    pkgAcquire *Owner;
    pkgAcquire *Owner;

+
+   /** \brief Insert this item into its owner's queue.
+    *
+    *  \param ItemDesc Metadata about this item (its URI and
+    *  description).
+    */

    inline void QueueURI(ItemDesc &Item)
                  {Owner->Enqueue(Item);};
    inline void QueueURI(ItemDesc &Item)
                  {Owner->Enqueue(Item);};

+
+   /** \brief Remove this item from its owner's queue. */

    inline void Dequeue() {Owner->Dequeue(this);};
    
    inline void Dequeue() {Owner->Dequeue(this);};
    

-   // Safe rename function with timestamp preservation
+   /** \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 #From.  If #To exists it will be
+    *  overwritten.
+    */

    void Rename(string From,string To);
    
    public:
 
    void Rename(string From,string To);
    
    public:
 

-   // State of the item
-   enum {StatIdle, StatFetching, StatDone, StatError, StatAuthError} Status;
+   /** \brief The current status of this item. */
+   enum ItemState
+     {
+       /** \brief The item is waiting to be downloaded. */
+       StatIdle,
+
+       /** \brief The item is currently being downloaded. */
+       StatFetching,
+
+       /** \brief The item has been successfully downloaded. */
+       StatDone,
+
+       /** \brief An error was encountered while downloading this
+       *  item.
+       */
+       StatError,
+
+       /** \brief The item was downloaded but its authenticity could
+       *  not be verified.
+       */
+       StatAuthError
+     } Status;
+
+   /** \brief Contains a textual description of the error encountered
+    *  if #Status is #StatError or #StatAuthError.
+    */

    string ErrorText;
    string ErrorText;

+
+   /** \brief The size of the object to fetch. */

    unsigned long FileSize;
    unsigned long FileSize;

-   unsigned long PartialSize;   
+
+   /** \brief How much of the object was already fetched. */
+   unsigned long PartialSize;
+
+   /** \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;
    const char *Mode;

+
+   /** \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.
+    *
+    *  \todo it's unused in apt itself
+    */

    unsigned long ID;
    unsigned long ID;

+
+   /** \brief If \b true, the entire object has been successfully fetched.
+    *
+    *  Subclasses should set this to \b true when appropriate.
+    */

    bool Complete;
    bool Complete;

+
+   /** \brief If \b true, the URI of this object is "local".
+    *
+    *  The only effect of this field is to exclude the object from the
+    *  download progress indicator's overall statistics.
+    */

    bool Local;
 
    bool Local;
 

-   // Number of queues we are inserted into
+   /** \brief The number of fetch queues into which this item has been
+    *  inserted.
+    *
+    *  There is one queue for each source from which an item could be
+    *  downloaded.
+    *
+    *  \sa pkgAcquire
+    */

    unsigned int QueueCounter;
    
    unsigned int QueueCounter;
    

-   // File to write the fetch into
+   /** \brief The name of the file into which the retrieved object
+    *  will be written.
+    */

    string DestFile;
 
    string DestFile;
 

-   // Action members invoked by the worker
+   /** \brief Invoked by the acquire worker when the object couldn't
+    *  be fetched.
+    *
+    *  This is a branch of the continuation of the fetch process.
+    *
+    *  \param Message An RFC822-formatted message from the acquire
+    *  method describing what went wrong.  Use LookupTag() to parse
+    *  it.
+    *
+    *  \param Cnf The method via which the worker tried to fetch this object.
+    *
+    *  \sa pkgAcqMethod
+    */

    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);

+
+   /** \brief Invoked by the acquire worker when the object was
+    *  fetched successfully.
+    *
+    *  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.
+    *
+    *  Done is often used to switch from one stage of the processing
+    *  to the next (e.g. fetching, unpacking, copying).  It is one
+    *  branch of the continuation of the fetch process.
+    *
+    *  \param Message Data from the acquire method.  Use LookupTag()
+    *  to parse it.
+    *  \param Size The size of the object that was fetched.
+    *  \param Md5Hash The MD5Sum of the object that was fetched.
+    *  \param Cnf The method via which the object was fetched.
+    *
+    *  \sa pkgAcqMethod
+    */

    virtual void Done(string Message,unsigned long Size,string Md5Hash,
                     pkgAcquire::MethodConfig *Cnf);
    virtual void Done(string Message,unsigned long Size,string Md5Hash,
                     pkgAcquire::MethodConfig *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.
+    *
+    *  \param Size The size of the object being fetched.
+    *
+    *  \sa pkgAcqMethod
+    */

    virtual void Start(string Message,unsigned long Size);
    virtual void Start(string Message,unsigned long Size);

+
+   /** \brief Custom headers to be sent to the fetch process.
+    *
+    *  \return a string containing RFC822-style headers that are to be
+    *  inserted into the 600 URI Acquire message sent to the fetch
+    *  subprocess.  The headers are inserted after a newline-less
+    *  line, so they should (if nonempty) have a leading newline and
+    *  no trailing newline.
+    */

    virtual string Custom600Headers() {return string();};
    virtual string Custom600Headers() {return string();};

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

    virtual string DescURI() = 0;
    virtual string DescURI() = 0;

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

    virtual string ShortDesc() {return DescURI();}
    virtual string ShortDesc() {return DescURI();}

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

    virtual void Finished() {};
    
    virtual void Finished() {};
    

-   // Inquire functions
+   /** \brief MD5Sum.
+    *
+    *  \return the MD5Sum of this object, if applicable; otherwise, an
+    *  empty string.
+    */

    virtual string MD5Sum() {return string();};
    virtual string MD5Sum() {return string();};

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

    pkgAcquire *GetOwner() {return Owner;};
    pkgAcquire *GetOwner() {return Owner;};

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

    virtual bool IsTrusted() {return false;};
    virtual bool IsTrusted() {return false;};

-   
+
+   /** \brief Initialize an item.
+    *
+    *  Adds the item to the list of items known to the acquire
+    *  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.
+    */

    Item(pkgAcquire *Owner);
    Item(pkgAcquire *Owner);

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

    virtual ~Item();
 };
 
    virtual ~Item();
 };
 

-// item for index diffs
-
+/** \brief Information about an index patch (aka diff). */

 struct DiffInfo {
 struct DiffInfo {

+   /** The filename of the diff. */

    string file;
    string file;

+
+   /** The sha1 hash of the diff. */

    string sha1;
    string sha1;

+
+   /** The size of the diff. */

    unsigned long size;
 };
 
    unsigned long size;
 };
 

+/** \brief An item that is responsible for fetching an index file of
+ *  package list diffs and starting the package list's download.
+ *
+ *  This item downloads the Index file and parses it, then enqueues
+ *  additional downloads of either the individual patches (using
+ *  pkgAcqIndexDiffs) or the entire Packages file (using pkgAcqIndex).
+ *
+ *  \sa pkgAcqIndexDiffs, pkgAcqIndex
+ */

 class pkgAcqDiffIndex : public pkgAcquire::Item
 {
  protected:
 class pkgAcqDiffIndex : public pkgAcquire::Item
 {
  protected:

+   /** \brief If \b true, debugging information will be written to std::clog. */

    bool Debug;
    bool Debug;

+
+   /** \brief The item that is currently being downloaded. */

    pkgAcquire::ItemDesc Desc;
    pkgAcquire::ItemDesc Desc;

+
+   /** \brief The URI of the index file to recreate at our end (either
+    *  by downloading it or by applying partial patches).
+    */

    string RealURI;
    string RealURI;

+
+   /** \brief The MD5Sum that the real index file should have after
+    *  all patches have been applied.
+    */

    string ExpectedMD5;
    string ExpectedMD5;

+
+   /** \brief The index file which will be patched to generate the new
+    *  file.
+    */

    string CurrentPackagesFile;
    string CurrentPackagesFile;

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

    string Description;
 
  public:
    string Description;
 
  public:


@@ -108,54 +315,199 @@ class pkgAcqDiffIndex : public pkgAcquire::Item
    virtual string DescURI() {return RealURI + "Index";};
    virtual string Custom600Headers();
 
    virtual string DescURI() {return RealURI + "Index";};
    virtual string Custom600Headers();
 

-   // helpers
+   /** \brief Parse the Index file for a set of Packages diffs.
+    *
+    *  Parses the Index file and creates additional download items as
+    *  necessary.
+    *
+    *  \param IndexDiffFile The name of the Index file.
+    *
+    *  \return \b true if the Index file was successfully parsed, \b
+    *  false otherwise.
+    */

    bool ParseDiffIndex(string IndexDiffFile);
    
    bool ParseDiffIndex(string IndexDiffFile);
    

+
+   /** \brief Create a new pkgAcqDiffIndex.
+    *
+    *  \param Owner The Acquire object that owns this item.
+    *
+    *  \param URI The URI of the list file to download.
+    *
+    *  \param URIDesc A long description of the list file to download.
+    *
+    *  \param ShortDesc A short description of the list file to download.
+    *
+    *  \param ExpectedMD5 The list file's MD5 signature.
+    */

    pkgAcqDiffIndex(pkgAcquire *Owner,string URI,string URIDesc,
    pkgAcqDiffIndex(pkgAcquire *Owner,string URI,string URIDesc,

-                  string ShortDesct, string ExpectedMD5);
+                  string ShortDesc, string ExpectedMD5);

 };
 
 };
 

+/** \brief An item that is responsible for fetching all the patches
+ *  that need to be applied to a given package index file.
+ *
+ *  After downloading and applying a single patch, this item will
+ *  enqueue a new pkgAcqIndexDiffs to download and apply the remaining
+ *  patches.  If no patch can be found that applies to an intermediate
+ *  file or if one of the patches cannot be downloaded, falls back to
+ *  downloading the entire package index file using pkgAcqIndex.
+ *
+ *  \sa pkgAcqDiffIndex, pkgAcqIndex
+ */

 class pkgAcqIndexDiffs : public pkgAcquire::Item
 {
 class pkgAcqIndexDiffs : public pkgAcquire::Item
 {

+   private:
+
+   /** \brief Queue up the next diff download.
+    *
+    *  Search for the next available diff that applies to the file
+    *  that currently exists on disk, and enqueue it by calling
+    *  QueueURI().
+    *
+    *  \return \b true if an applicable diff was found, \b false
+    *  otherwise.
+    */
+   bool QueueNextDiff();
+
+   /** \brief Handle tasks that must be performed after the item
+    *  finishes downloading.
+    *
+    *  Dequeues the item and checks the resulting file's md5sum
+    *  against ExpectedMD5 after the last patch was applied.
+    *  There is no need to check the md5/sha1 after a "normal" 
+    *  patch because QueueNextDiff() will check the sha1 later.
+    *
+    *  \param allDone If \b true, the file was entirely reconstructed,
+    *  and its md5sum is verified. 
+    */
+   void Finish(bool allDone=false);
+

    protected:
    protected:

+
+   /** \brief If \b true, debugging output will be written to
+    *  std::clog.
+    */

    bool Debug;
    bool Debug;

+
+   /** \brief A description of the item that is currently being
+    *  downloaded.
+    */

    pkgAcquire::ItemDesc Desc;
    pkgAcquire::ItemDesc Desc;

+
+   /** \brief The URI of the package index file that is being
+    *  reconstructed.
+    */

    string RealURI;
    string RealURI;

+
+   /** \brief The MD5Sum of the package index file that is being
+    *  reconstructed.
+    */

    string ExpectedMD5;
 
    string ExpectedMD5;
 

-   // this is the SHA-1 sum we expect after the patching
+   /** A description of the file being downloaded. */

    string Description;
    string Description;

+
+   /** The patches that remain to be downloaded, including the patch
+    *  being downloaded right now.  This list should be ordered so
+    *  that each diff appears before any diff that depends on it.
+    *
+    *  \todo These are indexed by sha1sum; why not use some sort of
+    *  dictionary instead of relying on ordering and stripping them
+    *  off the front?
+    */

    vector<DiffInfo> available_patches;
    vector<DiffInfo> available_patches;

-   enum {StateFetchIndex,StateFetchDiff,StateUnzipDiff,StateApplyDiff} State;
+   /** The current status of this patch. */
+   enum DiffState
+     {
+       /** \brief The diff is in an unknown state. */
+        StateFetchUnkown,
+
+        /** \brief The diff is currently being fetched. */
+        StateFetchDiff,
+        
+        /** \brief The diff is currently being uncompressed. */
+        StateUnzipDiff,
+
+        /** \brief The diff is currently being applied. */
+        StateApplyDiff
+   } State;

 
    public:
    
 
    public:
    

-   // Specialized action members
+   /** \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(string Message,pkgAcquire::MethodConfig *Cnf);
    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);

+

    virtual void Done(string Message,unsigned long Size,string Md5Hash,
                     pkgAcquire::MethodConfig *Cnf);
    virtual string DescURI() {return RealURI + "Index";};
 
    virtual void Done(string Message,unsigned long Size,string Md5Hash,
                     pkgAcquire::MethodConfig *Cnf);
    virtual string DescURI() {return RealURI + "Index";};
 

-   // various helpers
-   bool QueueNextDiff();
-   bool ApplyDiff(string PatchFile);
-   void Finish(bool allDone=false);
-
+   /** \brief Create an index diff item.
+    *
+    *  After filling in its basic fields, this invokes Finish(true) if
+    *  #diffs is empty, or QueueNextDiff() otherwise.
+    *
+    *  \param Owner The pkgAcquire object that owns this item.
+    *
+    *  \param URI The URI of the package index file being
+    *  reconstructed.
+    *
+    *  \param URIDesc A long description of this item.
+    *
+    *  \param ShortDesc A brief description of this item.
+    *
+    *  \param ExpectedMD5 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 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,string URI,string URIDesc,
    pkgAcqIndexDiffs(pkgAcquire *Owner,string URI,string URIDesc,

-                   string ShortDesct, string ExpectedMD5,
+                   string ShortDesc, string ExpectedMD5,

                    vector<DiffInfo> diffs=vector<DiffInfo>());
 };
 
                    vector<DiffInfo> diffs=vector<DiffInfo>());
 };
 

-// Item class for index files
+/** \brief An acquire item that is responsible for fetching an index
+ *  file (e.g., Packages or Sources).
+ *
+ *  \sa pkgAcqDiffIndex, pkgAcqIndexDiffs, pkgAcqIndexTrans
+ *
+ *  \todo Why does pkgAcqIndex have protected members?
+ */

 class pkgAcqIndex : public pkgAcquire::Item
 {
    protected:
 class pkgAcqIndex : public pkgAcquire::Item
 {
    protected:

-   
+
+   /** \brief If \b true, the index file has been decompressed. */

    bool Decompression;
    bool Decompression;

+
+   /** \brief If \b true, the partially downloaded file will be
+    *  removed when the download completes.
+    */

    bool Erase;
    bool Erase;

+
+   /** \brief The download request that is currently being
+    *   processed.
+    */

    pkgAcquire::ItemDesc Desc;
    pkgAcquire::ItemDesc Desc;

+
+   /** \brief The object that is actually being fetched (minus any
+    *  compression-related extensions).
+    */

    string RealURI;
    string RealURI;

+
+   /** \brief The expected md5sum of the decompressed index file. */

    string ExpectedMD5;
    string ExpectedMD5;

+
+   /** \brief The compression-related file extension that is being
+    *  added to the downloaded file (e.g., ".gz" or ".bz2").
+    */

    string CompressionExtension;
 
    public:
    string CompressionExtension;
 
    public:


@@ -167,36 +519,120 @@ class pkgAcqIndex : public pkgAcquire::Item
    virtual string Custom600Headers();
    virtual string DescURI() {return RealURI + CompressionExtension;};
 
    virtual string Custom600Headers();
    virtual string DescURI() {return RealURI + CompressionExtension;};
 

+   /** \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 ExpectedMD5 The expected md5sum of this index file.
+    *
+    *  \param compressExt The compression-related extension with which
+    *  this index file should be downloaded, or "" to autodetect
+    *  (".bz2" is used if bzip2 is installed, ".gz" otherwise).
+    */

    pkgAcqIndex(pkgAcquire *Owner,string URI,string URIDesc,
    pkgAcqIndex(pkgAcquire *Owner,string URI,string URIDesc,

-              string ShortDesct, string ExpectedMD5, string compressExt="");
+              string ShortDesc, string ExpectedMD5, string compressExt="");

 };
 
 };
 

-// Item class for translated package index files
+/** \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(string Message,pkgAcquire::MethodConfig *Cnf);
 class pkgAcqIndexTrans : public pkgAcqIndex
 {
    public:
   
    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);

+
+   /** \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.
+    *
+    *  \param ExpectedMD5 The expected md5sum of this index file.
+    *
+    *  \param compressExt The compression-related extension with which
+    *  this index file should be downloaded, or "" to autodetect
+    *  (".bz2" is used if bzip2 is installed, ".gz" otherwise).
+    */

    pkgAcqIndexTrans(pkgAcquire *Owner,string URI,string URIDesc,
    pkgAcqIndexTrans(pkgAcquire *Owner,string URI,string URIDesc,

-                   string ShortDesct);
+                   string ShortDesc);

 };
 
 };
 

+/** \brief Information about an index file. */

 struct IndexTarget
 {
 struct IndexTarget
 {

+   /** \brief A URI from which the index file can be downloaded. */

    string URI;
    string URI;

+
+   /** \brief A description of the index file. */

    string Description;
    string Description;

+
+   /** \brief A shorter description of the index file. */

    string ShortDesc;
    string ShortDesc;

+
+   /** \brief The key by which this index file should be
+    *  looked up within the meta signature file.
+    */

    string MetaKey;
 };
 
    string MetaKey;
 };
 

-// Item class for index signatures
+/** \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:
 class pkgAcqMetaSig : public pkgAcquire::Item
 {
    protected:

-   
+   /** \brief The fetch request that is currently being processed. */

    pkgAcquire::ItemDesc Desc;
    pkgAcquire::ItemDesc Desc;

-   string RealURI,MetaIndexURI,MetaIndexURIDesc,MetaIndexShortDesc;
+
+   /** \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.
+    */
+   string RealURI;
+
+   /** \brief The URI of the meta-index file to be fetched after the signature. */
+   string MetaIndexURI;
+
+   /** \brief A "URI-style" description of the meta-index file to be
+    *  fetched after the signature.
+    */
+   string MetaIndexURIDesc;
+
+   /** \brief A brief description of the meta-index file to be fetched
+    *  after the signature.
+    */
+   string MetaIndexShortDesc;
+
+   /** \brief A package-system-specific parser for the meta-index file. */

    indexRecords* MetaIndexParser;
    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 vector<struct IndexTarget*>* IndexTargets;
 
    public:
    const vector<struct IndexTarget*>* IndexTargets;
 
    public:


@@ -208,27 +644,90 @@ class pkgAcqMetaSig : public pkgAcquire::Item
    virtual string Custom600Headers();
    virtual string DescURI() {return RealURI; };
 
    virtual string Custom600Headers();
    virtual string DescURI() {return RealURI; };
 

+   /** \brief Create a new pkgAcqMetaSig. */

    pkgAcqMetaSig(pkgAcquire *Owner,string URI,string URIDesc, string ShortDesc,
                 string MetaIndexURI, string MetaIndexURIDesc, string MetaIndexShortDesc,
                 const vector<struct IndexTarget*>* IndexTargets,
                 indexRecords* MetaIndexParser);
 };
 
    pkgAcqMetaSig(pkgAcquire *Owner,string URI,string URIDesc, string ShortDesc,
                 string MetaIndexURI, string MetaIndexURIDesc, string MetaIndexShortDesc,
                 const vector<struct IndexTarget*>* IndexTargets,
                 indexRecords* MetaIndexParser);
 };
 

-// Item class for index signatures
+/** \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 md5sums
+ *  of the index files will be the md5sums listed in the meta-index;
+ *  otherwise, the expected md5sums will be "" (causing the
+ *  authentication of the index files to be bypassed).
+ */

 class pkgAcqMetaIndex : public pkgAcquire::Item
 {
    protected:
 class pkgAcqMetaIndex : public pkgAcquire::Item
 {
    protected:

-   
+   /** \brief The fetch command that is currently being processed. */

    pkgAcquire::ItemDesc Desc;
    pkgAcquire::ItemDesc Desc;

-   string RealURI; // FIXME: is this redundant w/ Desc.URI?
+
+   /** \brief The URI that is actually being downloaded; never
+    *  modified by pkgAcqMetaIndex.
+    */
+   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.
+    */

    string SigFile;
    string SigFile;

+
+   /** \brief The index files to download. */

    const vector<struct IndexTarget*>* IndexTargets;
    const vector<struct IndexTarget*>* IndexTargets;

+
+   /** \brief The parser for the meta-index file. */

    indexRecords* MetaIndexParser;
    indexRecords* MetaIndexParser;

-   bool AuthPass;

 
 

-   bool VerifyVendor();
+   /** \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(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(string Message);
    void RetrievalDone(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(string Message);
    void AuthDone(string Message);

+
+   /** \brief Starts downloading the individual index files.
+    *
+    *  \param verify If \b true, only indices whose expected md5sum
+    *  can be determined from the meta-index will be downloaded, and
+    *  the md5sums of indices will be checked (reporting
+    *  #StatAuthError if there is a mismatch).  If verify is \b false,
+    *  no md5sum checking will be performed.
+    */

    void QueueIndexes(bool verify);
    
    public:
    void QueueIndexes(bool verify);
    
    public:


@@ -240,6 +739,7 @@ class pkgAcqMetaIndex : public pkgAcquire::Item
    virtual string Custom600Headers();
    virtual string DescURI() {return RealURI; };
 
    virtual string Custom600Headers();
    virtual string DescURI() {return RealURI; };
 

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

    pkgAcqMetaIndex(pkgAcquire *Owner,
                   string URI,string URIDesc, string ShortDesc,
                   string SigFile,
    pkgAcqMetaIndex(pkgAcquire *Owner,
                   string URI,string URIDesc, string ShortDesc,
                   string SigFile,


@@ -247,28 +747,58 @@ class pkgAcqMetaIndex : public pkgAcquire::Item
                   indexRecords* MetaIndexParser);
 };
 
                   indexRecords* MetaIndexParser);
 };
 

-// Item class for archive files
+/** \brief An item that is responsible for fetching a package file.
+ *
+ *  If the package file already exists in the cache, nothing will be
+ *  done.
+ */

 class pkgAcqArchive : public pkgAcquire::Item
 {
    protected:
 class pkgAcqArchive : public pkgAcquire::Item
 {
    protected:

-   
-   // State information for the retry mechanism
+   /** \brief The package version being fetched. */

    pkgCache::VerIterator Version;
    pkgCache::VerIterator Version;

+
+   /** \brief The fetch command that is currently being processed. */

    pkgAcquire::ItemDesc Desc;
    pkgAcquire::ItemDesc Desc;

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

    pkgSourceList *Sources;
    pkgSourceList *Sources;

+
+   /** \brief A package records object, used to look up the file
+    *  corresponding to each version of the package.
+    */

    pkgRecords *Recs;
    pkgRecords *Recs;

+
+   /** \brief The md5sum of this package. */

    string MD5;
    string MD5;

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

    string &StoreFilename;
    string &StoreFilename;

+
+   /** \brief The next file for this version to try to download. */

    pkgCache::VerFileIterator Vf;
    pkgCache::VerFileIterator Vf;

+
+   /** \brief How many (more) times to try to find a new source from
+    *  which to download this package version if it fails.
+    *
+    *  Set from Acquire::Retries.
+    */

    unsigned int Retries;
    unsigned int Retries;

+
+   /** \brief \b true if this version file is being downloaded from a
+    *  trusted source.
+    */

    bool Trusted; 
 
    bool Trusted; 
 

-   // Queue the next available file for download.
+   /** \brief Queue up the next available file for this version. */

    bool QueueNext();
    
    public:
    
    bool QueueNext();
    
    public:
    

-   // Specialized action members

    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
    virtual void Done(string Message,unsigned long Size,string Md5Hash,
                     pkgAcquire::MethodConfig *Cnf);
    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
    virtual void Done(string Message,unsigned long Size,string Md5Hash,
                     pkgAcquire::MethodConfig *Cnf);


@@ -276,18 +806,49 @@ class pkgAcqArchive : public pkgAcquire::Item
    virtual string DescURI() {return Desc.URI;};
    virtual string ShortDesc() {return Desc.ShortDesc;};
    virtual void Finished();
    virtual string DescURI() {return Desc.URI;};
    virtual string ShortDesc() {return Desc.ShortDesc;};
    virtual void Finished();

+

    virtual bool IsTrusted();
    
    virtual bool IsTrusted();
    

+   /** \brief Create a new pkgAcqArchive.
+    *
+    *  \param Owner The pkgAcquire object with which this item is
+    *  associated.
+    *
+    *  \param Sources The sources from which to download version
+    *  files.
+    *
+    *  \param Recs A package records object, used to look up the file
+    *  corresponding to each version of the package.
+    *
+    *  \param Version The package version to download.
+    *
+    *  \param StoreFilename A location in which the actual filename of
+    *  the package should be stored.  It will be set to a guessed
+    *  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,
                 string &StoreFilename);
 };
 
    pkgAcqArchive(pkgAcquire *Owner,pkgSourceList *Sources,
                 pkgRecords *Recs,pkgCache::VerIterator const &Version,
                 string &StoreFilename);
 };
 

-// Fetch a generic file to the current directory
+/** \brief Retrieve an arbitrary file to the current directory.
+ *
+ *  The file is retrieved even if it is accessed via a URL type that
+ *  normally is a NOP, such as "file".  If the download fails, the
+ *  partial file is renamed to get a ".FAILED" extension.
+ */

 class pkgAcqFile : public pkgAcquire::Item
 {
 class pkgAcqFile : public pkgAcquire::Item
 {

+   /** \brief The currently active download process. */

    pkgAcquire::ItemDesc Desc;
    pkgAcquire::ItemDesc Desc;

+
+   /** \brief The md5sum of the file to download, if it is known. */

    string Md5Hash;
    string Md5Hash;

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

    unsigned int Retries;
    
    public:
    unsigned int Retries;
    
    public:


@@ -298,9 +859,41 @@ class pkgAcqFile : public pkgAcquire::Item
                     pkgAcquire::MethodConfig *Cnf);
    virtual string MD5Sum() {return Md5Hash;};
    virtual string DescURI() {return Desc.URI;};
                     pkgAcquire::MethodConfig *Cnf);
    virtual string MD5Sum() {return Md5Hash;};
    virtual string DescURI() {return Desc.URI;};

-   
-   pkgAcqFile(pkgAcquire *Owner,string URI,string MD5,unsigned long Size,
-                 string Desc,string ShortDesc);
+
+   /** \brief Create a new pkgAcqFile object.
+    *
+    *  \param Owner The pkgAcquire object with which this object is
+    *  associated.
+    *
+    *  \param URI The URI to download.
+    *
+    *  \param MD5 The md5sum of the file to download, if it is known;
+    *  otherwise "".
+    *
+    *  \param Size The size of the file to download, if it is known;
+    *  otherwise 0.
+    *
+    *  \param Desc A description of the file being downloaded.
+    *
+    *  \param ShortDesc A brief description of the file being
+    *  downloaded.
+    *
+    *  \param DestDir The directory the file should be downloaded into.
+    *
+    *  \param DestFilename The filename+path the file is downloaded to.
+    *
+    *
+    * If DestFilename is empty, download to DestDir/<basename> if
+    * DestDir is non-empty, $CWD/<basename> otherwise.  If
+    * DestFilename is NOT empty, DestDir is ignored and DestFilename
+    * is the absolute name to which the file should be downloaded.
+    */
+
+   pkgAcqFile(pkgAcquire *Owner, string URI, string MD5, unsigned long Size,
+             string Desc, string ShortDesc,
+             const string &DestDir="", const string &DestFilename="");

 };
 
 };
 

+/** @} */
+

 #endif
 #endif