1 files changed, 262 insertions, 0 deletions
diff --git a/methods/rred.cc b/methods/rred.cc
new file mode 100644
index 00000000..6fa57f3a
--- /dev/null
+++ b/methods/rred.cc
@@ -0,0 +1,262 @@
+#include <apt-pkg/fileutl.h>
+#include <apt-pkg/error.h>
+#include <apt-pkg/acquire-method.h>
+#include <apt-pkg/strutl.h>
+#include <apt-pkg/hashes.h>
+
+#include <sys/stat.h>
+#include <unistd.h>
+#include <utime.h>
+#include <stdio.h>
+#include <errno.h>
+#include <apti18n.h>
+
+/* this method implements a patch functionality similar to "patch --ed" that is
+ * used by the "tiffany" incremental packages download stuff. it differs from 
+ * "ed" insofar that it is way more restricted (and therefore secure). in the
+ * moment only the "c", "a" and "d" commands of ed are implemented (diff 
+ * doesn't output any other). additionally the records must be reverse sorted 
+ * by line number and may not overlap (diff *seems* to produce this kind of 
+ * output). 
+ * */
+
+const char *Prog;
+
+class RredMethod : public pkgAcqMethod
+{
+   bool Debug;
+   // the size of this doesn't really matter (except for performance)    
+   const static int BUF_SIZE = 1024;
+   // the ed commands
+   enum Mode {MODE_CHANGED, MODE_DELETED, MODE_ADDED};
+   // return values
+   enum State {ED_OK, ED_ORDERING, ED_PARSER, ED_FAILURE};
+   // this applies a single hunk, it uses a tail recursion to 
+   // reverse the hunks in the file
+   int ed_rec(FILE *ed_cmds, FILE *in_file, FILE *out_file, int line, 
+      char *buffer, unsigned int bufsize, Hashes *hash);
+   // apply a patch file
+   int ed_file(FILE *ed_cmds, FILE *in_file, FILE *out_file, Hashes *hash);
+   // the methods main method
+   virtual bool Fetch(FetchItem *Itm);
+   
+   public:
+   
+   RredMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
+};
+
+int RredMethod::ed_rec(FILE *ed_cmds, FILE *in_file, FILE *out_file, int line, 
+      char *buffer, unsigned int bufsize, Hashes *hash) {
+   int pos;
+   int startline;
+   int stopline;
+   int mode;
+   int written;
+   char *idx;
+
+   /* get the current command and parse it*/
+   if (fgets(buffer, bufsize, ed_cmds) == NULL) {
+      return line;
+   }
+   startline = strtol(buffer, &idx, 10);
+   if (startline < line) {
+      return ED_ORDERING;
+   }
+   if (*idx == ',') {
+      idx++;
+      stopline = strtol(idx, &idx, 10);
+   }
+   else {
+      stopline = startline;
+   }
+   if (*idx == 'c') {
+      mode = MODE_CHANGED;
+	   if (Debug == true) {
+		   std::clog << "changing from line " << startline 
+			     << " to " << stopline << std::endl;
+	   }
+   }
+   else if (*idx == 'a') {
+      mode = MODE_ADDED;
+	   if (Debug == true) {
+		   std::clog << "adding after line " << startline << std::endl;
+	   }
+   }
+   else if (*idx == 'd') {
+      mode = MODE_DELETED;
+	   if (Debug == true) {
+		   std::clog << "deleting from line " << startline 
+			     <<  " to " << stopline << std::endl;
+	   }
+   }
+   else {
+      return ED_PARSER;
+   }
+   /* get the current position */
+   pos = ftell(ed_cmds);
+   /* if this is add or change then go to the next full stop */
+   if ((mode == MODE_CHANGED) || (mode == MODE_ADDED)) {
+      do {
+         fgets(buffer, bufsize, ed_cmds);
+         while ((strlen(buffer) == (bufsize - 1)) 
+               && (buffer[bufsize - 2] != '\n')) {
+            fgets(buffer, bufsize, ed_cmds);
+            buffer[0] = ' ';
+         }
+      } while (strncmp(buffer, ".", 1) != 0);
+   }
+   /* do the recursive call */
+   line = ed_rec(ed_cmds, in_file, out_file, line, buffer, bufsize, 
+         hash);
+   /* pass on errors */
+   if (line < 0) {
+      return line;
+   }
+   /* apply our hunk */
+   fseek(ed_cmds, pos, SEEK_SET); 
+   /* first wind to the current position */
+   if (mode != MODE_ADDED) {
+      startline -= 1;
+   }
+   while (line < startline) {
+      fgets(buffer, bufsize, in_file);
+      written = fwrite(buffer, 1, strlen(buffer), out_file);
+      hash->Add((unsigned char*)buffer, written);
+      while ((strlen(buffer) == (bufsize - 1)) 
+            && (buffer[bufsize - 2] != '\n')) {
+         fgets(buffer, bufsize, in_file);
+         written = fwrite(buffer, 1, strlen(buffer), out_file);
+         hash->Add((unsigned char*)buffer, written);
+      }
+      line++;
+   }
+   /* include from ed script */
+   if ((mode == MODE_ADDED) || (mode == MODE_CHANGED)) {
+      do {
+         fgets(buffer, bufsize, ed_cmds);
+         if (strncmp(buffer, ".", 1) != 0) {
+            written = fwrite(buffer, 1, strlen(buffer), out_file);
+            hash->Add((unsigned char*)buffer, written);
+            while ((strlen(buffer) == (bufsize - 1)) 
+                  && (buffer[bufsize - 2] != '\n')) {
+               fgets(buffer, bufsize, ed_cmds);
+               written = fwrite(buffer, 1, strlen(buffer), out_file);
+               hash->Add((unsigned char*)buffer, written);
+            }
+         }
+         else {
+            break;
+         }
+      } while (1);
+   }
+   /* ignore the corresponding number of lines from input */
+   if ((mode == MODE_DELETED) || (mode == MODE_CHANGED)) {
+      while (line < stopline) {
+         fgets(buffer, bufsize, in_file);
+         while ((strlen(buffer) == (bufsize - 1)) 
+               && (buffer[bufsize - 2] != '\n')) {
+            fgets(buffer, bufsize, in_file);
+         }
+         line++;
+      }
+   }
+   return line;
+}
+
+int RredMethod::ed_file(FILE *ed_cmds, FILE *in_file, FILE *out_file, 
+      Hashes *hash) {
+   char buffer[BUF_SIZE];
+   int result;
+   int written;
+   
+   /* we do a tail recursion to read the commands in the right order */
+   result = ed_rec(ed_cmds, in_file, out_file, 0, buffer, BUF_SIZE, 
+         hash);
+   
+   /* read the rest from infile */
+   if (result > 0) {
+      while (fgets(buffer, BUF_SIZE, in_file) != NULL) {
+         written = fwrite(buffer, 1, strlen(buffer), out_file);
+         hash->Add((unsigned char*)buffer, written);
+      }
+   }
+   else {
+      return ED_FAILURE;
+   }
+   return ED_OK;
+}
+
+
+bool RredMethod::Fetch(FetchItem *Itm)
+{
+   Debug = _config->FindB("Debug::pkgAcquire::RRed",false);
+   URI Get = Itm->Uri;
+   string Path = Get.Host + Get.Path; // To account for relative paths
+   // Path contains the filename to patch
+   FetchResult Res;
+   Res.Filename = Itm->DestFile;
+   URIStart(Res);
+   // Res.Filename the destination filename
+
+   if (Debug == true) 
+      std::clog << "Patching " << Path << " with " << Path 
+         << ".ed and putting result into " << Itm->DestFile << std::endl;
+   // Open the source and destination files (the d'tor of FileFd will do 
+   // the cleanup/closing of the fds)
+   FileFd From(Path,FileFd::ReadOnly);
+   FileFd Patch(Path+".ed",FileFd::ReadOnly);
+   FileFd To(Itm->DestFile,FileFd::WriteEmpty);   
+   To.EraseOnFailure();
+   if (_error->PendingError() == true)
+      return false;
+   
+   Hashes Hash;
+   FILE* fFrom = fdopen(From.Fd(), "r");
+   FILE* fPatch = fdopen(Patch.Fd(), "r");
+   FILE* fTo = fdopen(To.Fd(), "w");
+   // now do the actual patching
+   if (ed_file(fPatch, fFrom, fTo, &Hash) != ED_OK) {
+     _error->Errno("rred", _("Could not patch file"));  
+      return false;
+   }
+
+   // write out the result
+   fflush(fFrom);
+   fflush(fPatch);
+   fflush(fTo);
+   From.Close();
+   Patch.Close();
+   To.Close();
+
+   // Transfer the modification times
+   struct stat Buf;
+   if (stat(Path.c_str(),&Buf) != 0)
+      return _error->Errno("stat",_("Failed to stat"));
+
+   struct utimbuf TimeBuf;
+   TimeBuf.actime = Buf.st_atime;
+   TimeBuf.modtime = Buf.st_mtime;
+   if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
+      return _error->Errno("utime",_("Failed to set modification time"));
+
+   if (stat(Itm->DestFile.c_str(),&Buf) != 0)
+      return _error->Errno("stat",_("Failed to stat"));
+
+   // return done
+   Res.LastModified = Buf.st_mtime;
+   Res.Size = Buf.st_size;
+   Res.TakeHashes(Hash);
+   URIDone(Res);
+
+   return true;
+}
+
+int main(int argc, char *argv[])
+{
+   RredMethod Mth;
+
+   Prog = strrchr(argv[0],'/');
+   Prog++;
+   
+   return Mth.Run();
+}