deal better with acquiring the same URI multiple times

[apt.git] / methods / file.cc

// -*- mode: cpp; mode: fold -*-
// Description								/*{{{*/
// $Id: file.cc,v 1.9.2.1 2004/01/16 18:58:50 mdz Exp $
/* ######################################################################

   File URI method for APT
   
   This simply checks that the file specified exists, if so the relevant
   information is returned. If a .gz filename is specified then the file
   name with .gz removed will also be checked and information about it
   will be returned in Alt-*
   
   ##################################################################### */
									/*}}}*/
// Include Files							/*{{{*/
#include <config.h>

#include <apt-pkg/acquire-method.h>
#include <apt-pkg/aptconfiguration.h>
#include <apt-pkg/error.h>
#include <apt-pkg/hashes.h>
#include <apt-pkg/fileutl.h>
#include <apt-pkg/strutl.h>

#include <string>
#include <sys/stat.h>

#include <apti18n.h>
									/*}}}*/

class FileMethod : public pkgAcqMethod
{
   virtual bool Fetch(FetchItem *Itm);
   
   public:
   
   FileMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig | LocalOnly) {};
};

// FileMethod::Fetch - Fetch a file					/*{{{*/
// ---------------------------------------------------------------------
/* */
bool FileMethod::Fetch(FetchItem *Itm)
{
   URI Get = Itm->Uri;
   std::string File = Get.Path;
   FetchResult Res;
   if (Get.Host.empty() == false)
      return _error->Error(_("Invalid URI, local URIS must not start with //"));

   struct stat Buf;
   // deal with destination files which might linger around
   if (lstat(Itm->DestFile.c_str(), &Buf) == 0)
   {
      if ((Buf.st_mode & S_IFREG) != 0)
      {
	 if (Itm->LastModified == Buf.st_mtime && Itm->LastModified != 0)
	 {
	    HashStringList const hsl = Itm->ExpectedHashes;
	    if (Itm->ExpectedHashes.VerifyFile(File))
	       Res.IMSHit = true;
	 }
      }
   }
   if (Res.IMSHit != true)
      unlink(Itm->DestFile.c_str());

   // See if the file exists
   if (stat(File.c_str(),&Buf) == 0)
   {
      Res.Size = Buf.st_size;
      Res.Filename = File;
      Res.LastModified = Buf.st_mtime;
      Res.IMSHit = false;
      if (Itm->LastModified == Buf.st_mtime && Itm->LastModified != 0)
      {
	 unsigned long long const filesize = Itm->ExpectedHashes.FileSize();
	 if (filesize != 0 && filesize == Res.Size)
	    Res.IMSHit = true;
      }
   }

   // See if the uncompressed file exists and reuse it
   FetchResult AltRes;
   AltRes.Filename.clear();
   std::vector<std::string> extensions = APT::Configuration::getCompressorExtensions();
   for (std::vector<std::string>::const_iterator ext = extensions.begin(); ext != extensions.end(); ++ext)
   {
      if (APT::String::Endswith(File, *ext) == true)
      {
	 std::string const unfile = File.substr(0, File.length() - ext->length() - 1);
	 if (stat(unfile.c_str(),&Buf) == 0)
	 {
	    AltRes.Size = Buf.st_size;
	    AltRes.Filename = unfile;
	    AltRes.LastModified = Buf.st_mtime;
	    AltRes.IMSHit = false;
	    if (Itm->LastModified == Buf.st_mtime && Itm->LastModified != 0)
	       AltRes.IMSHit = true;
	    break;
	 }
	 // no break here as we could have situations similar to '.gz' vs '.tar.gz' here
      }
   }

   if (Res.Filename.empty() == false)
   {
      Hashes Hash(Itm->ExpectedHashes);
      FileFd Fd(Res.Filename, FileFd::ReadOnly);
      Hash.AddFD(Fd);
      Res.TakeHashes(Hash);
   }

   if (AltRes.Filename.empty() == false)
      URIDone(Res,&AltRes);
   else if (Res.Filename.empty() == false)
      URIDone(Res);
   else
      return _error->Error(_("File not found"));

   return true;
}
									/*}}}*/

int main()
{
   setlocale(LC_ALL, "");

   FileMethod Mth;
   return Mth.Run();
}