ensure valid or remove destination file in file method

[apt.git] / methods / file.cc

diff --git a/methods/file.cc b/methods/file.cc
index 9fc4cd76c32b18f9adfb98318413eafde94354c1..5d5fffa67b289399165b53207a2575b98e263a37 100644 (file)
--- a/methods/file.cc
+++ b/methods/file.cc
@@ -5,7 +5,7 @@
 
    File URI method for APT
    
-   This simply checks that the file specified exists, if so the relevent
+   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-*
@@ -16,12 +16,15 @@
 #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 <unistd.h>
+
 #include <apti18n.h>
                                                                        /*}}}*/
 
@@ -31,7 +34,7 @@ class FileMethod : public pkgAcqMethod
    
    public:
    
-   FileMethod() : pkgAcqMethod("1.0",SingleInstance | LocalOnly) {};
+   FileMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig | LocalOnly) {};
 };
 
 // FileMethod::Fetch - Fetch a file                                    /*{{{*/
@@ -40,13 +43,29 @@ class FileMethod : public pkgAcqMethod
 bool FileMethod::Fetch(FetchItem *Itm)
 {
    URI Get = Itm->Uri;
-   string File = Get.Path;
+   std::string File = Get.Path;
    FetchResult Res;
    if (Get.Host.empty() == false)
       return _error->Error(_("Invalid URI, local URIS must not start with //"));
 
-   // See if the file exists
    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;
@@ -54,37 +73,51 @@ bool FileMethod::Fetch(FetchItem *Itm)
       Res.LastModified = Buf.st_mtime;
       Res.IMSHit = false;
       if (Itm->LastModified == Buf.st_mtime && Itm->LastModified != 0)
-        Res.IMSHit = true;
+      {
+        unsigned long long const filesize = Itm->ExpectedHashes.FileSize();
+        if (filesize != 0 && filesize == Res.Size)
+           Res.IMSHit = true;
+      }
    }
-   
-   // See if we can compute a file without a .gz exentsion
-   string::size_type Pos = File.rfind(".gz");
-   if (Pos + 3 == File.length())
+
+   // 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)
    {
-      File = string(File,0,Pos);
-      if (stat(File.c_str(),&Buf) == 0)
+      if (APT::String::Endswith(File, *ext) == true)
       {
-        FetchResult AltRes;
-        AltRes.Size = Buf.st_size;
-        AltRes.Filename = File;
-        AltRes.LastModified = Buf.st_mtime;
-        AltRes.IMSHit = false;
-        if (Itm->LastModified == Buf.st_mtime && Itm->LastModified != 0)
-           AltRes.IMSHit = true;
-        
-        URIDone(Res,&AltRes);
-        return 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() == true)
+
+   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"));
 
-   Hashes Hash;
-   FileFd Fd(Res.Filename, FileFd::ReadOnly);
-   Hash.AddFD(Fd.Fd(), Fd.Size());
-   Res.TakeHashes(Hash);
-   URIDone(Res);
    return true;
 }
                                                                        /*}}}*/