calculate only expected hashes in methods

Methods get told which hashes are expected by the acquire system, which
means we can use this list to restrict what we calculate in the methods
as any extra we are calculating is wasted effort as we can't compare it
with anything anyway.

Adding support for a new hash algorithm is therefore 'free' now and if a
algorithm is no longer provided in a repository for a file, we
automatically stop calculating it.

In practice this results in a speed-up in Debian as we don't have SHA512
here (so far), so we practically stop calculating it.

13 files changed, 23 insertions, 23 deletions

diff --git a/methods/cdrom.cc b/methods/cdrom.cc
index 74e2ecc6b..10cb29f66 100644
--- a/methods/cdrom.cc
+++ b/methods/cdrom.cc
@@ -266,7 +266,7 @@ bool CDROMMethod::Fetch(FetchItem *Itm)
    Res.LastModified = Buf.st_mtime;
    Res.Size = Buf.st_size;
 
-   Hashes Hash;
+   Hashes Hash(Itm->ExpectedHashes);
    FileFd Fd(Res.Filename, FileFd::ReadOnly);
    Hash.AddFD(Fd);
    Res.TakeHashes(Hash);
diff --git a/methods/copy.cc b/methods/copy.cc
index f3cd84215..a8e289df5 100644
--- a/methods/copy.cc
+++ b/methods/copy.cc
@@ -28,16 +28,16 @@
 class CopyMethod : public pkgAcqMethod
 {
    virtual bool Fetch(FetchItem *Itm);
-   void CalculateHashes(FetchResult &Res);
+   void CalculateHashes(FetchItem const * const Itm, FetchResult &Res);
    
    public:
    
    CopyMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
 };
 
-void CopyMethod::CalculateHashes(FetchResult &Res)
+void CopyMethod::CalculateHashes(FetchItem const * const Itm, FetchResult &Res)
 {
-   Hashes Hash;
+   Hashes Hash(Itm->ExpectedHashes);
    FileFd::CompressMode CompressMode = FileFd::None;
    if (_config->FindB("Acquire::GzipIndexes", false) == true)
       CompressMode = FileFd::Extension;
@@ -71,7 +71,7 @@ bool CopyMethod::Fetch(FetchItem *Itm)
    // just calc the hashes if the source and destination are identical
    if (File == Itm->DestFile)
    {
-      CalculateHashes(Res);
+      CalculateHashes(Itm, Res);
       URIDone(Res);
       return true;
    }
@@ -104,7 +104,7 @@ bool CopyMethod::Fetch(FetchItem *Itm)
    if (utimes(Res.Filename.c_str(), times) != 0)
       return _error->Errno("utimes",_("Failed to set modification time"));
 
-   CalculateHashes(Res);
+   CalculateHashes(Itm, Res);
 
    URIDone(Res);
    return true;
diff --git a/methods/file.cc b/methods/file.cc
index 5d9d7b951..043ab04b8 100644
--- a/methods/file.cc
+++ b/methods/file.cc
@@ -87,7 +87,7 @@ bool FileMethod::Fetch(FetchItem *Itm)
    if (Res.Filename.empty() == true)
       return _error->Error(_("File not found"));
 
-   Hashes Hash;
+   Hashes Hash(Itm->ExpectedHashes);
    FileFd Fd(Res.Filename, FileFd::ReadOnly);
    Hash.AddFD(Fd);
    Res.TakeHashes(Hash);
diff --git a/methods/ftp.cc b/methods/ftp.cc
index 7764acf6a..92d8573f1 100644
--- a/methods/ftp.cc
+++ b/methods/ftp.cc
@@ -1064,7 +1064,7 @@ bool FtpMethod::Fetch(FetchItem *Itm)
    }
    
    // Open the file
-   Hashes Hash;
+   Hashes Hash(Itm->ExpectedHashes);
    {
       FileFd Fd(Itm->DestFile,FileFd::WriteAny);
       if (_error->PendingError() == true)
diff --git a/methods/gzip.cc b/methods/gzip.cc
index 387c05f2e..65519633c 100644
--- a/methods/gzip.cc
+++ b/methods/gzip.cc
@@ -91,7 +91,7 @@ bool GzipMethod::Fetch(FetchItem *Itm)
       return false;
 
    // Read data from source, generate checksums and write
-   Hashes Hash;
+   Hashes Hash(Itm->ExpectedHashes);
    bool Failed = false;
    while (1) 
    {
diff --git a/methods/http.cc b/methods/http.cc
index 947002cc6..e4773b0e2 100644
--- a/methods/http.cc
+++ b/methods/http.cc
@@ -64,8 +64,8 @@ const unsigned int CircleBuf::BW_HZ=10;
 // CircleBuf::CircleBuf - Circular input buffer				/*{{{*/
 // ---------------------------------------------------------------------
 /* */
-CircleBuf::CircleBuf(unsigned long long Size) 
-   : Size(Size), Hash(0), TotalWriten(0)
+CircleBuf::CircleBuf(unsigned long long Size)
+   : Size(Size), Hash(NULL), TotalWriten(0)
 {
    Buf = new unsigned char[Size];
    Reset();
@@ -84,10 +84,10 @@ void CircleBuf::Reset()
    TotalWriten = 0;
    MaxGet = (unsigned long long)-1;
    OutQueue = string();
-   if (Hash != 0)
+   if (Hash != NULL)
    {
       delete Hash;
-      Hash = new Hashes;
+      Hash = NULL;
    }
 }
 									/*}}}*/
@@ -222,7 +222,7 @@ bool CircleBuf::Write(int Fd)
 
       TotalWriten += Res;
       
-      if (Hash != 0)
+      if (Hash != NULL)
 	 Hash->Add(Buf + (OutP%Size),Res);
       
       OutP += Res;
@@ -484,10 +484,10 @@ APT_PURE bool HttpServerState::IsOpen()					/*{{{*/
    return (ServerFd != -1);
 }
 									/*}}}*/
-bool HttpServerState::InitHashes(FileFd &File)				/*{{{*/
+bool HttpServerState::InitHashes(FileFd &File, HashStringList const &ExpectedHashes)/*{{{*/
 {
    delete In.Hash;
-   In.Hash = new Hashes;
+   In.Hash = new Hashes(ExpectedHashes);
 
    // Set the expected size and read file for the hashes
    File.Truncate(StartPos);
diff --git a/methods/http.h b/methods/http.h
index 40a88a7be..6dc872659 100644
--- a/methods/http.h
+++ b/methods/http.h
@@ -111,7 +111,7 @@ struct HttpServerState: public ServerState
    virtual bool Open();
    virtual bool IsOpen();
    virtual bool Close();
-   virtual bool InitHashes(FileFd &File);
+   virtual bool InitHashes(FileFd &File, HashStringList const &ExpectedHashes);
    virtual Hashes * GetHashes();
    virtual bool Die(FileFd &File);
    virtual bool Flush(FileFd * const File);
diff --git a/methods/https.cc b/methods/https.cc
index 70f6a1046..81903b239 100644
--- a/methods/https.cc
+++ b/methods/https.cc
@@ -443,7 +443,7 @@ bool HttpsMethod::Fetch(FetchItem *Itm)
       Res.LastModified = resultStat.st_mtime;
 
    // take hashes
-   Hashes Hash;
+   Hashes Hash(Itm->ExpectedHashes);
    FileFd Fd(Res.Filename, FileFd::ReadOnly);
    Hash.AddFD(Fd);
    Res.TakeHashes(Hash);
diff --git a/methods/https.h b/methods/https.h
index 4cc48fc34..dc0ff3322 100644
--- a/methods/https.h
+++ b/methods/https.h
@@ -42,7 +42,7 @@ class HttpsServerState : public ServerState
    virtual bool Open() { return false; }
    virtual bool IsOpen() { return false; }
    virtual bool Close() { return false; }
-   virtual bool InitHashes(FileFd &/*File*/) { return false; }
+   virtual bool InitHashes(FileFd &/*File*/, HashStringList const &/*ExpectedHashes*/) { return false; }
    virtual Hashes * GetHashes() { return NULL; }
    virtual bool Die(FileFd &/*File*/) { return false; }
    virtual bool Flush(FileFd * const /*File*/) { return false; }
diff --git a/methods/rred.cc b/methods/rred.cc
index 774b58a40..554ac99b4 100644
--- a/methods/rred.cc
+++ b/methods/rred.cc
@@ -581,7 +581,7 @@ class RredMethod : public pkgAcqMethod {
 	 FILE *inp = fopen(Path.c_str(), "r");
 	 FILE *out = fopen(Itm->DestFile.c_str(), "w");
 
-	 Hashes hash;
+	 Hashes hash(Itm->ExpectedHashes);
 
 	 patch.apply_against_file(out, inp, &hash);
 
diff --git a/methods/rsh.cc b/methods/rsh.cc
index 0e949160b..52349c61c 100644
--- a/methods/rsh.cc
+++ b/methods/rsh.cc
@@ -477,7 +477,7 @@ bool RSHMethod::Fetch(FetchItem *Itm)
    }
 
    // Open the file
-   Hashes Hash;
+   Hashes Hash(Itm->ExpectedHashes);
    {
       FileFd Fd(Itm->DestFile,FileFd::WriteAny);
       if (_error->PendingError() == true)
diff --git a/methods/server.cc b/methods/server.cc
index 91ec824d1..e403f1071 100644
--- a/methods/server.cc
+++ b/methods/server.cc
@@ -357,7 +357,7 @@ ServerMethod::DealWithHeaders(FetchResult &Res)
    FailFd = File->Fd();
    FailTime = Server->Date;
 
-   if (Server->InitHashes(*File) == false)
+   if (Server->InitHashes(*File, Queue->ExpectedHashes) == false)
    {
       _error->Errno("read",_("Problem hashing file"));
       return ERROR_NOT_FROM_SERVER;
diff --git a/methods/server.h b/methods/server.h
index b974ec89a..45622dd34 100644
--- a/methods/server.h
+++ b/methods/server.h
@@ -85,7 +85,7 @@ struct ServerState
    virtual bool Open() = 0;
    virtual bool IsOpen() = 0;
    virtual bool Close() = 0;
-   virtual bool InitHashes(FileFd &File) = 0;
+   virtual bool InitHashes(FileFd &File, HashStringList const &ExpectedHashes) = 0;
    virtual Hashes * GetHashes() = 0;
    virtual bool Die(FileFd &File) = 0;
    virtual bool Flush(FileFd * const File) = 0;