[apt.git] / methods / rred.cc

// Copyright (c) 2014 Anthony Towns
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.

#include <config.h>

#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 <apt-pkg/configuration.h>
#include "aptmethod.h"

#include <stddef.h>
#include <iostream>
#include <string>
#include <list>
#include <vector>

#include <assert.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <apti18n.h>

#define BLOCK_SIZE (512*1024)

class MemBlock {
   char *start;
   size_t size;
   char *free;
   MemBlock *next;

   MemBlock(size_t size) : size(size), next(NULL)
   {
      free = start = new char[size];
   }

   size_t avail(void) { return size - (free - start); }

   public:

   MemBlock(void) {
      free = start = new char[BLOCK_SIZE];
      size = BLOCK_SIZE;
      next = NULL;
   }

   ~MemBlock() {
      delete [] start;
      delete next;
   }

   void clear(void) {
      free = start;
      if (next)
	 next->clear();
   }

   char *add_easy(char *src, size_t len, char *last)
   {
      if (last) {
	 for (MemBlock *k = this; k; k = k->next) {
	    if (k->free == last) {
	       if (len <= k->avail()) {
		  char *n = k->add(src, len);
		  assert(last == n);
		  if (last == n)
		     return NULL;
		  return n;
	       } else {
		  break;
	       }
	    } else if (last >= start && last < free) {
	       break;
	    }
	 }
      }
      return add(src, len);
   }

   char *add(char *src, size_t len) {
      if (len > avail()) {
	 if (!next) {
	    if (len > BLOCK_SIZE)  {
	       next = new MemBlock(len);
	    } else {
	       next = new MemBlock;
	    }
	 }
	 return next->add(src, len);
      }
      char *dst = free;
      free += len;
      memcpy(dst, src, len);
      return dst;
   }
};

struct Change {
   /* Ordering:
    *
    *   1. write out <offset> lines unchanged
    *   2. skip <del_cnt> lines from source
    *   3. write out <add_cnt> lines (<add>/<add_len>)
    */
   size_t offset;
   size_t del_cnt;
   size_t add_cnt; /* lines */
   size_t add_len; /* bytes */
   char *add;

   Change(size_t off)
   {
      offset = off;
      del_cnt = add_cnt = add_len = 0;
      add = NULL;
   }

   /* actually, don't write <lines> lines from <add> */
   void skip_lines(size_t lines)
   {
      while (lines > 0) {
	 char *s = (char*) memchr(add, '\n', add_len);
	 assert(s != NULL);
	 s++;
	 add_len -= (s - add);
	 add_cnt--;
	 lines--;
	 if (add_len == 0) {
	    add = NULL;
	    assert(add_cnt == 0);
	    assert(lines == 0);
	 } else {
	    add = s;
	    assert(add_cnt > 0);
	 }
      }
   }
};

class FileChanges {
   std::list<struct Change> changes;
   std::list<struct Change>::iterator where;
   size_t pos; // line number is as far left of iterator as possible

   bool pos_is_okay(void) const
   {
#ifdef POSDEBUG
      size_t cpos = 0;
      std::list<struct Change>::const_iterator x;
      for (x = changes.begin(); x != where; ++x) {
	 assert(x != changes.end());
	 cpos += x->offset + x->add_cnt;
      }
      return cpos == pos;
#else
      return true;
#endif
   }

   public:
   FileChanges() {
      where = changes.end();
      pos = 0;
   }

   std::list<struct Change>::iterator begin(void) { return changes.begin(); }
   std::list<struct Change>::iterator end(void) { return changes.end(); }

   std::list<struct Change>::reverse_iterator rbegin(void) { return changes.rbegin(); }
   std::list<struct Change>::reverse_iterator rend(void) { return changes.rend(); }

   void add_change(Change c) {
      assert(pos_is_okay());
      go_to_change_for(c.offset);
      assert(pos + where->offset == c.offset);
      if (c.del_cnt > 0)
	 delete_lines(c.del_cnt);
      assert(pos + where->offset == c.offset);
      if (c.add_len > 0) {
	 assert(pos_is_okay());
	 if (where->add_len > 0)
	    new_change();
	 assert(where->add_len == 0 && where->add_cnt == 0);

	 where->add_len = c.add_len;
	 where->add_cnt = c.add_cnt;
	 where->add = c.add;
      }
      assert(pos_is_okay());
      merge();
      assert(pos_is_okay());
   }

   private:
   void merge(void)
   {
      while (where->offset == 0 && where != changes.begin()) {
	 left();
      }
      std::list<struct Change>::iterator next = where;
      ++next;

      while (next != changes.end() && next->offset == 0) {
	 where->del_cnt += next->del_cnt;
	 next->del_cnt = 0;
	 if (next->add == NULL) {
	    next = changes.erase(next);
	 } else if (where->add == NULL) {
	    where->add = next->add;
	    where->add_len = next->add_len;
	    where->add_cnt = next->add_cnt;
	    next = changes.erase(next);
	 } else {
	    ++next;
	 }
      }
   }

   void go_to_change_for(size_t line)
   {
      while(where != changes.end()) {
	 if (line < pos) {
	    left();
	    continue;
	 }
	 if (pos + where->offset + where->add_cnt <= line) {
	    right();
	    continue;
	 }
	 // line is somewhere in this slot
	 if (line < pos + where->offset) {
	    break;
	 } else if (line == pos + where->offset) {
	    return;
	 } else {
	    split(line - pos);
	    right();
	    return;
	 }
      }
      /* it goes before this patch */
      insert(line-pos);
   }

   void new_change(void) { insert(where->offset); }

   void insert(size_t offset)
   {
      assert(pos_is_okay());
      assert(where == changes.end() || offset <= where->offset);
      if (where != changes.end())
	 where->offset -= offset;
      changes.insert(where, Change(offset));
      --where;
      assert(pos_is_okay());
   }

   void split(size_t offset)
   {
      assert(pos_is_okay());

      assert(where->offset < offset);
      assert(offset < where->offset + where->add_cnt);

      size_t keep_lines = offset - where->offset;

      Change before(*where);

      where->del_cnt = 0;
      where->offset = 0;
      where->skip_lines(keep_lines);

      before.add_cnt = keep_lines;
      before.add_len -= where->add_len;

      changes.insert(where, before);
      --where;
      assert(pos_is_okay());
   }

   void delete_lines(size_t cnt)
   {
      std::list<struct Change>::iterator x = where;
      assert(pos_is_okay());
      while (cnt > 0)
      {
	 size_t del;
	 del = x->add_cnt;
	 if (del > cnt)
	    del = cnt;
	 x->skip_lines(del);
	 cnt -= del;

	 ++x;
	 if (x == changes.end()) {
	    del = cnt;
	 } else {
	    del = x->offset;
	    if (del > cnt)
	       del = cnt;
	    x->offset -= del;
	 }
	 where->del_cnt += del;
	 cnt -= del;
      }
      assert(pos_is_okay());
   }

   void left(void) {
      assert(pos_is_okay());
      --where;
      pos -= where->offset + where->add_cnt;
      assert(pos_is_okay());
   }

   void right(void) {
      assert(pos_is_okay());
      pos += where->offset + where->add_cnt;
      ++where;
      assert(pos_is_okay());
   }
};

class Patch {
   FileChanges filechanges;
   MemBlock add_text;

   static bool retry_fwrite(char *b, size_t l, FileFd &f, Hashes *hash)
   {
      if (f.Write(b, l) == false)
	 return false;
      if (hash)
	 hash->Add((unsigned char*)b, l);
      return true;
   }

   static void dump_rest(FileFd &o, FileFd &i, Hashes *hash)
   {
      char buffer[BLOCK_SIZE];
      unsigned long long l = 0;
      while (i.Read(buffer, sizeof(buffer), &l)) {
	 if (l ==0  || !retry_fwrite(buffer, l, o, hash))
	    break;
      }
   }

   static void dump_lines(FileFd &o, FileFd &i, size_t n, Hashes *hash)
   {
      char buffer[BLOCK_SIZE];
      while (n > 0) {
	 if (i.ReadLine(buffer, sizeof(buffer)) == NULL)
	    buffer[0] = '\0';
	 size_t const l = strlen(buffer);
	 if (l == 0 || buffer[l-1] == '\n')
	    n--;
	 retry_fwrite(buffer, l, o, hash);
      }
   }

   static void skip_lines(FileFd &i, int n)
   {
      char buffer[BLOCK_SIZE];
      while (n > 0) {
	 if (i.ReadLine(buffer, sizeof(buffer)) == NULL)
	    buffer[0] = '\0';
	 size_t const l = strlen(buffer);
	 if (l == 0 || buffer[l-1] == '\n')
	    n--;
      }
   }

   static void dump_mem(FileFd &o, char *p, size_t s, Hashes *hash) {
      retry_fwrite(p, s, o, hash);
   }

   public:

   bool read_diff(FileFd &f, Hashes * const h)
   {
      char buffer[BLOCK_SIZE];
      bool cmdwanted = true;

      Change ch(std::numeric_limits<size_t>::max());
      if (f.ReadLine(buffer, sizeof(buffer)) == NULL)
	 return _error->Error("Reading first line of patchfile %s failed", f.Name().c_str());
      do {
	 if (h != NULL)
	    h->Add(buffer);
	 if (cmdwanted) {
	    char *m, *c;
	    size_t s, e;
	    errno = 0;
	    s = strtoul(buffer, &m, 10);
	    if (unlikely(m == buffer || s == std::numeric_limits<unsigned long>::max() || errno != 0))
	       return _error->Error("Parsing patchfile %s failed: Expected an effected line start", f.Name().c_str());
	    else if (*m == ',') {
	       ++m;
	       e = strtol(m, &c, 10);
	       if (unlikely(m == c || e == std::numeric_limits<unsigned long>::max() || errno != 0))
		  return _error->Error("Parsing patchfile %s failed: Expected an effected line end", f.Name().c_str());
	       if (unlikely(e < s))
		  return _error->Error("Parsing patchfile %s failed: Effected lines end %lu is before start %lu", f.Name().c_str(), e, s);
	    } else {
	       e = s;
	       c = m;
	    }
	    if (s > ch.offset)
	       return _error->Error("Parsing patchfile %s failed: Effected line is after previous effected line", f.Name().c_str());
	    switch(*c) {
	       case 'a':
		  cmdwanted = false;
		  ch.add = NULL;
		  ch.add_cnt = 0;
		  ch.add_len = 0;
		  ch.offset = s;
		  ch.del_cnt = 0;
		  break;
	       case 'c':
		  if (unlikely(s == 0))
		     return _error->Error("Parsing patchfile %s failed: Change command can't effect line zero", f.Name().c_str());
		  cmdwanted = false;
		  ch.add = NULL;
		  ch.add_cnt = 0;
		  ch.add_len = 0;
		  ch.offset = s - 1;
		  ch.del_cnt = e - s + 1;
		  break;
	       case 'd':
		  if (unlikely(s == 0))
		     return _error->Error("Parsing patchfile %s failed: Delete command can't effect line zero", f.Name().c_str());
		  ch.offset = s - 1;
		  ch.del_cnt = e - s + 1;
		  ch.add = NULL;
		  ch.add_cnt = 0;
		  ch.add_len = 0;
		  filechanges.add_change(ch);
		  break;
	       default:
		  return _error->Error("Parsing patchfile %s failed: Unknown command", f.Name().c_str());
	    }
	 } else { /* !cmdwanted */
	    if (strcmp(buffer, ".\n") == 0) {
	       cmdwanted = true;
	       filechanges.add_change(ch);
	    } else {
	       char *last = NULL;
	       char *add;
	       size_t l;
	       if (ch.add)
		  last = ch.add + ch.add_len;
	       l = strlen(buffer);
	       add = add_text.add_easy(buffer, l, last);
	       if (!add) {
		  ch.add_len += l;
		  ch.add_cnt++;
	       } else {
		  if (ch.add) {
		     filechanges.add_change(ch);
		     ch.del_cnt = 0;
		  }
		  ch.offset += ch.add_cnt;
		  ch.add = add;
		  ch.add_len = l;
		  ch.add_cnt = 1;
	       }
	    }
	 }
      } while(f.ReadLine(buffer, sizeof(buffer)));
      return true;
   }

   void write_diff(FileFd &f)
   {
      unsigned long long line = 0;
      std::list<struct Change>::reverse_iterator ch;
      for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) {
	 line += ch->offset + ch->del_cnt;
      }

      for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) {
	 std::list<struct Change>::reverse_iterator mg_i, mg_e = ch;
	 while (ch->del_cnt == 0 && ch->offset == 0)
	    ++ch;
	 line -= ch->del_cnt;
	 std::string buf;
	 if (ch->add_cnt > 0) {
	    if (ch->del_cnt == 0) {
	       strprintf(buf, "%llua\n", line);
	    } else if (ch->del_cnt == 1) {
	       strprintf(buf, "%lluc\n", line+1);
	    } else {
	       strprintf(buf, "%llu,%lluc\n", line+1, line+ch->del_cnt);
	    }
	    f.Write(buf.c_str(), buf.length());

	    mg_i = ch;
	    do {
	       dump_mem(f, mg_i->add, mg_i->add_len, NULL);
	    } while (mg_i-- != mg_e);

	    buf = ".\n";
	    f.Write(buf.c_str(), buf.length());
	 } else if (ch->del_cnt == 1) {
	    strprintf(buf, "%llud\n", line+1);
	    f.Write(buf.c_str(), buf.length());
	 } else if (ch->del_cnt > 1) {
	    strprintf(buf, "%llu,%llud\n", line+1, line+ch->del_cnt);
	    f.Write(buf.c_str(), buf.length());
	 }
	 line -= ch->offset;
      }
   }

   void apply_against_file(FileFd &out, FileFd &in, Hashes *hash = NULL)
   {
      std::list<struct Change>::iterator ch;
      for (ch = filechanges.begin(); ch != filechanges.end(); ++ch) {
	 dump_lines(out, in, ch->offset, hash);
	 skip_lines(in, ch->del_cnt);
	 dump_mem(out, ch->add, ch->add_len, hash);
      }
      dump_rest(out, in, hash);
   }
};

class RredMethod : public aptMethod {
   private:
      bool Debug;

      struct PDiffFile {
	 std::string FileName;
	 HashStringList ExpectedHashes;
	 PDiffFile(std::string const &FileName, HashStringList const &ExpectedHashes) :
	    FileName(FileName), ExpectedHashes(ExpectedHashes) {}
      };

      HashStringList ReadExpectedHashesForPatch(unsigned int const patch, std::string const &Message)
      {
	 HashStringList ExpectedHashes;
	 for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
	 {
	    std::string tagname;
	    strprintf(tagname, "Patch-%d-%s-Hash", patch, *type);
	    std::string const hashsum = LookupTag(Message, tagname.c_str());
	    if (hashsum.empty() == false)
	       ExpectedHashes.push_back(HashString(*type, hashsum));
	 }
	 return ExpectedHashes;
      }

   protected:
      virtual bool URIAcquire(std::string const &Message, FetchItem *Itm) APT_OVERRIDE {
	 Debug = _config->FindB("Debug::pkgAcquire::RRed", false);
	 URI Get = Itm->Uri;
	 std::string Path = Get.Host + Get.Path; // rred:/path - no host

	 FetchResult Res;
	 Res.Filename = Itm->DestFile;
	 if (Itm->Uri.empty())
	 {
	    Path = Itm->DestFile;
	    Itm->DestFile.append(".result");
	 } else
	    URIStart(Res);

	 std::vector<PDiffFile> patchfiles;
	 Patch patch;

	 if (FileExists(Path + ".ed") == true)
	 {
	    HashStringList const ExpectedHashes = ReadExpectedHashesForPatch(0, Message);
	    std::string const FileName = Path + ".ed";
	    if (ExpectedHashes.usable() == false)
	       return _error->Error("No hashes found for uncompressed patch: %s", FileName.c_str());
	    patchfiles.push_back(PDiffFile(FileName, ExpectedHashes));
	 }
	 else
	 {
	    _error->PushToStack();
	    std::vector<std::string> patches = GetListOfFilesInDir(flNotFile(Path), "gz", true, false);
	    _error->RevertToStack();

	    std::string const baseName = Path + ".ed.";
	    unsigned int seen_patches = 0;
	    for (std::vector<std::string>::const_iterator p = patches.begin();
		  p != patches.end(); ++p)
	    {
	       if (p->compare(0, baseName.length(), baseName) == 0)
	       {
		  HashStringList const ExpectedHashes = ReadExpectedHashesForPatch(seen_patches, Message);
		  if (ExpectedHashes.usable() == false)
		     return _error->Error("No hashes found for uncompressed patch %d: %s", seen_patches, p->c_str());
		  patchfiles.push_back(PDiffFile(*p, ExpectedHashes));
		  ++seen_patches;
	       }
	    }
	 }

	 std::string patch_name;
	 for (std::vector<PDiffFile>::iterator I = patchfiles.begin();
	       I != patchfiles.end();
	       ++I)
	 {
	    patch_name = I->FileName;
	    if (Debug == true)
	       std::clog << "Patching " << Path << " with " << patch_name
		  << std::endl;

	    FileFd p;
	    Hashes patch_hash(I->ExpectedHashes);
	    // all patches are compressed, even if the name doesn't reflect it
	    if (p.Open(patch_name, FileFd::ReadOnly, FileFd::Gzip) == false ||
		  patch.read_diff(p, &patch_hash) == false)
	    {
	       _error->DumpErrors(std::cerr, GlobalError::DEBUG, false);
	       return false;
	    }
	    p.Close();
	    HashStringList const hsl = patch_hash.GetHashStringList();
	    if (hsl != I->ExpectedHashes)
	       return _error->Error("Hash Sum mismatch for uncompressed patch %s", patch_name.c_str());
	 }

	 if (Debug == true)
	    std::clog << "Applying patches against " << Path
	       << " and writing results to " << Itm->DestFile
	       << std::endl;

	 FileFd inp, out;
	 if (inp.Open(Path, FileFd::ReadOnly, FileFd::Extension) == false)
	 {
	    std::cerr << "FAILED to open inp " << Path << std::endl;
	    return _error->Error("Failed to open inp %s", Path.c_str());
	 }
	 if (out.Open(Itm->DestFile, FileFd::WriteOnly | FileFd::Create, FileFd::Extension) == false)
	 {
	    std::cerr << "FAILED to open out " << Itm->DestFile << std::endl;
	    return _error->Error("Failed to open out %s", Itm->DestFile.c_str());
	 }

	 Hashes hash(Itm->ExpectedHashes);
	 patch.apply_against_file(out, inp, &hash);

	 out.Close();
	 inp.Close();

	 if (Debug == true) {
	    std::clog << "rred: finished file patching of " << Path  << "." << std::endl;
	 }

	 struct stat bufbase, bufpatch;
	 if (stat(Path.c_str(), &bufbase) != 0 ||
	       stat(patch_name.c_str(), &bufpatch) != 0)
	    return _error->Errno("stat", _("Failed to stat"));

	 struct timeval times[2];
	 times[0].tv_sec = bufbase.st_atime;
	 times[1].tv_sec = bufpatch.st_mtime;
	 times[0].tv_usec = times[1].tv_usec = 0;
	 if (utimes(Itm->DestFile.c_str(), times) != 0)
	    return _error->Errno("utimes",_("Failed to set modification time"));

	 if (stat(Itm->DestFile.c_str(), &bufbase) != 0)
	    return _error->Errno("stat", _("Failed to stat"));

	 Res.LastModified = bufbase.st_mtime;
	 Res.Size = bufbase.st_size;
	 Res.TakeHashes(hash);
	 URIDone(Res);

	 return true;
      }

   public:
      RredMethod() : aptMethod("rred", "2.0",SingleInstance | SendConfig), Debug(false) {}
};

int main(int argc, char **argv)
{
   int i;
   bool just_diff = true;
   Patch patch;

   if (argc <= 1) {
      RredMethod Mth;
      return Mth.Run();
   }

   if (argc > 1 && strcmp(argv[1], "-f") == 0) {
      just_diff = false;
      i = 2;
   } else {
      i = 1;
   }

   for (; i < argc; i++) {
      FileFd p;
      if (p.Open(argv[i], FileFd::ReadOnly) == false) {
	 _error->DumpErrors(std::cerr);
	 exit(1);
      }
      if (patch.read_diff(p, NULL) == false)
      {
	 _error->DumpErrors(std::cerr);
	 exit(2);
      }
   }

   if (just_diff) {
      FileFd out;
      out.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly | FileFd::Create);
      patch.write_diff(out);
   } else {
      FileFd out, inp;
      out.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly | FileFd::Create);
      inp.OpenDescriptor(STDIN_FILENO, FileFd::ReadOnly);
      patch.apply_against_file(out, inp);
   }
   return 0;
}
Commit	Line	Data
dbd5418b AT	1	// Copyright (c) 2014 Anthony Towns
	2	//
	3	// This program is free software; you can redistribute it and/or modify
	4	// it under the terms of the GNU General Public License as published by
	5	// the Free Software Foundation; either version 2 of the License, or
	6	// (at your option) any later version.
	7
ea542140 DK	8	#include <config.h>
ea542140 DK	9
2e178d1c MV	10	#include <apt-pkg/fileutl.h>
	11	#include <apt-pkg/error.h>
	12	#include <apt-pkg/acquire-method.h>
	13	#include <apt-pkg/strutl.h>
	14	#include <apt-pkg/hashes.h>
472ff00e	15	#include <apt-pkg/configuration.h>
23e64f6d	16	#include "aptmethod.h"
2e178d1c	17
453b82a3 DK	18	#include <stddef.h>
453b82a3 DK	19	#include <iostream>
dbd5418b AT	20	#include <string>
	21	#include <list>
	22	#include <vector>
dbd5418b AT	23
dbd5418b AT	24	#include <assert.h>
6d3e5bd8	25	#include <errno.h>
dbd5418b AT	26	#include <stdio.h>
	27	#include <stdlib.h>
	28	#include <string.h>
2e178d1c	29	#include <sys/stat.h>
246bbb61	30	#include <sys/time.h>
dbd5418b	31
2e178d1c	32	#include <apti18n.h>
dbd5418b AT	33
	34	#define BLOCK_SIZE (512*1024)
	35
	36	class MemBlock {
	37	char *start;
	38	size_t size;
	39	char *free;
6d3e5bd8	40	MemBlock *next;
dbd5418b	41
25d99f3b	42	MemBlock(size_t size) : size(size), next(NULL)
dbd5418b AT	43	{
dbd5418b AT	44	free = start = new char[size];
dbd5418b AT	45	}
	46
	47	size_t avail(void) { return size - (free - start); }
	48
	49	public:
	50
	51	MemBlock(void) {
	52	free = start = new char[BLOCK_SIZE];
	53	size = BLOCK_SIZE;
	54	next = NULL;
	55	}
	56
	57	~MemBlock() {
	58	delete [] start;
	59	delete next;
	60	}
	61
	62	void clear(void) {
	63	free = start;
	64	if (next)
	65	next->clear();
	66	}
	67
	68	char add_easy(char src, size_t len, char *last)
	69	{
	70	if (last) {
	71	for (MemBlock *k = this; k; k = k->next) {
	72	if (k->free == last) {
	73	if (len <= k->avail()) {
	74	char *n = k->add(src, len);
	75	assert(last == n);
	76	if (last == n)
	77	return NULL;
	78	return n;
	79	} else {
	80	break;
	81	}
	82	} else if (last >= start && last < free) {
	83	break;
	84	}
	85	}
	86	}
	87	return add(src, len);
	88	}
	89
	90	char add(char src, size_t len) {
	91	if (len > avail()) {
	92	if (!next) {
	93	if (len > BLOCK_SIZE) {
	94	next = new MemBlock(len);
	95	} else {
	96	next = new MemBlock;
	97	}
	98	}
	99	return next->add(src, len);
	100	}
	101	char *dst = free;
	102	free += len;
	103	memcpy(dst, src, len);
	104	return dst;
	105	}
2e178d1c	106	};
dbd5418b AT	107
	108	struct Change {
	109	/* Ordering:
	110	*
	111	* 1. write out <offset> lines unchanged
	112	* 2. skip <del_cnt> lines from source
	113	* 3. write out <add_cnt> lines (<add>/<add_len>)
	114	*/
	115	size_t offset;
	116	size_t del_cnt;
	117	size_t add_cnt; /* lines */
	118	size_t add_len; /* bytes */
	119	char *add;
	120
6d3e5bd8	121	Change(size_t off)
dbd5418b AT	122	{
	123	offset = off;
	124	del_cnt = add_cnt = add_len = 0;
	125	add = NULL;
	126	}
	127
	128	/* actually, don't write <lines> lines from <add> */
	129	void skip_lines(size_t lines)
	130	{
	131	while (lines > 0) {
	132	char s = (char) memchr(add, '\n', add_len);
	133	assert(s != NULL);
	134	s++;
	135	add_len -= (s - add);
	136	add_cnt--;
	137	lines--;
	138	if (add_len == 0) {
	139	add = NULL;
	140	assert(add_cnt == 0);
	141	assert(lines == 0);
	142	} else {
	143	add = s;
	144	assert(add_cnt > 0);
	145	}
d84cd865 MV	146	}
d84cd865 MV	147	}
bb1293d9	148	};
dbd5418b AT	149
	150	class FileChanges {
	151	std::list<struct Change> changes;
	152	std::list<struct Change>::iterator where;
	153	size_t pos; // line number is as far left of iterator as possible
	154
9dd940ed	155	bool pos_is_okay(void) const
dbd5418b AT	156	{
	157	#ifdef POSDEBUG
	158	size_t cpos = 0;
9dd940ed	159	std::list<struct Change>::const_iterator x;
25d99f3b	160	for (x = changes.begin(); x != where; ++x) {
dbd5418b AT	161	assert(x != changes.end());
	162	cpos += x->offset + x->add_cnt;
	163	}
	164	return cpos == pos;
bb1293d9	165	#else
dbd5418b	166	return true;
bb1293d9	167	#endif
dbd5418b AT	168	}
	169
	170	public:
	171	FileChanges() {
	172	where = changes.end();
	173	pos = 0;
	174	}
	175
	176	std::list<struct Change>::iterator begin(void) { return changes.begin(); }
	177	std::list<struct Change>::iterator end(void) { return changes.end(); }
	178
	179	std::list<struct Change>::reverse_iterator rbegin(void) { return changes.rbegin(); }
	180	std::list<struct Change>::reverse_iterator rend(void) { return changes.rend(); }
	181
	182	void add_change(Change c) {
	183	assert(pos_is_okay());
	184	go_to_change_for(c.offset);
	185	assert(pos + where->offset == c.offset);
	186	if (c.del_cnt > 0)
	187	delete_lines(c.del_cnt);
	188	assert(pos + where->offset == c.offset);
	189	if (c.add_len > 0) {
	190	assert(pos_is_okay());
	191	if (where->add_len > 0)
	192	new_change();
	193	assert(where->add_len == 0 && where->add_cnt == 0);
	194
	195	where->add_len = c.add_len;
	196	where->add_cnt = c.add_cnt;
	197	where->add = c.add;
	198	}
	199	assert(pos_is_okay());
	200	merge();
	201	assert(pos_is_okay());
	202	}
	203
	204	private:
	205	void merge(void)
	206	{
	207	while (where->offset == 0 && where != changes.begin()) {
	208	left();
	209	}
	210	std::list<struct Change>::iterator next = where;
25d99f3b	211	++next;
dbd5418b AT	212
	213	while (next != changes.end() && next->offset == 0) {
	214	where->del_cnt += next->del_cnt;
	215	next->del_cnt = 0;
	216	if (next->add == NULL) {
	217	next = changes.erase(next);
	218	} else if (where->add == NULL) {
	219	where->add = next->add;
	220	where->add_len = next->add_len;
	221	where->add_cnt = next->add_cnt;
	222	next = changes.erase(next);
	223	} else {
25d99f3b	224	++next;
dbd5418b AT	225	}
	226	}
	227	}
	228
	229	void go_to_change_for(size_t line)
47d2bc78	230	{
dbd5418b AT	231	while(where != changes.end()) {
	232	if (line < pos) {
	233	left();
	234	continue;
	235	}
	236	if (pos + where->offset + where->add_cnt <= line) {
	237	right();
	238	continue;
	239	}
	240	// line is somewhere in this slot
	241	if (line < pos + where->offset) {
	242	break;
	243	} else if (line == pos + where->offset) {
	244	return;
	245	} else {
	246	split(line - pos);
	247	right();
	248	return;
47d2bc78	249	}
bb1293d9	250	}
dbd5418b AT	251	/* it goes before this patch */
	252	insert(line-pos);
	253	}
	254
	255	void new_change(void) { insert(where->offset); }
	256
	257	void insert(size_t offset)
	258	{
	259	assert(pos_is_okay());
	260	assert(where == changes.end() \|\| offset <= where->offset);
	261	if (where != changes.end())
	262	where->offset -= offset;
	263	changes.insert(where, Change(offset));
25d99f3b	264	--where;
dbd5418b AT	265	assert(pos_is_okay());
	266	}
	267
	268	void split(size_t offset)
	269	{
	270	assert(pos_is_okay());
	271
	272	assert(where->offset < offset);
	273	assert(offset < where->offset + where->add_cnt);
	274
	275	size_t keep_lines = offset - where->offset;
	276
	277	Change before(*where);
47d2bc78	278
dbd5418b AT	279	where->del_cnt = 0;
	280	where->offset = 0;
	281	where->skip_lines(keep_lines);
	282
	283	before.add_cnt = keep_lines;
	284	before.add_len -= where->add_len;
	285
	286	changes.insert(where, before);
25d99f3b	287	--where;
dbd5418b	288	assert(pos_is_okay());
3de9ff77	289	}
dbd5418b	290
dbd5418b AT	291	void delete_lines(size_t cnt)
	292	{
	293	std::list<struct Change>::iterator x = where;
	294	assert(pos_is_okay());
	295	while (cnt > 0)
	296	{
	297	size_t del;
	298	del = x->add_cnt;
	299	if (del > cnt)
	300	del = cnt;
	301	x->skip_lines(del);
	302	cnt -= del;
	303
25d99f3b	304	++x;
dbd5418b AT	305	if (x == changes.end()) {
	306	del = cnt;
	307	} else {
	308	del = x->offset;
	309	if (del > cnt)
	310	del = cnt;
	311	x->offset -= del;
	312	}
	313	where->del_cnt += del;
	314	cnt -= del;
	315	}
	316	assert(pos_is_okay());
	317	}
47d2bc78	318
dbd5418b AT	319	void left(void) {
dbd5418b AT	320	assert(pos_is_okay());
25d99f3b	321	--where;
dbd5418b AT	322	pos -= where->offset + where->add_cnt;
	323	assert(pos_is_okay());
	324	}
47d2bc78	325
dbd5418b AT	326	void right(void) {
	327	assert(pos_is_okay());
	328	pos += where->offset + where->add_cnt;
25d99f3b	329	++where;
dbd5418b AT	330	assert(pos_is_okay());
	331	}
	332	};
	333
	334	class Patch {
	335	FileChanges filechanges;
	336	MemBlock add_text;
	337
d7a51997	338	static bool retry_fwrite(char b, size_t l, FileFd &f, Hashes hash)
2fd754cf	339	{
d7a51997 DK	340	if (f.Write(b, l) == false)
	341	return false;
	342	if (hash)
	343	hash->Add((unsigned char*)b, l);
	344	return true;
2fd754cf AT	345	}
2fd754cf AT	346
d7a51997	347	static void dump_rest(FileFd &o, FileFd &i, Hashes *hash)
dbd5418b AT	348	{
dbd5418b AT	349	char buffer[BLOCK_SIZE];
d7a51997 DK	350	unsigned long long l = 0;
	351	while (i.Read(buffer, sizeof(buffer), &l)) {
	352	if (l ==0 \|\| !retry_fwrite(buffer, l, o, hash))
2fd754cf	353	break;
dbd5418b AT	354	}
	355	}
	356
d7a51997	357	static void dump_lines(FileFd &o, FileFd &i, size_t n, Hashes *hash)
dbd5418b AT	358	{
dbd5418b AT	359	char buffer[BLOCK_SIZE];
dbd5418b	360	while (n > 0) {
d7a51997	361	if (i.ReadLine(buffer, sizeof(buffer)) == NULL)
dbd5418b	362	buffer[0] = '\0';
25d99f3b	363	size_t const l = strlen(buffer);
dbd5418b AT	364	if (l == 0 \|\| buffer[l-1] == '\n')
dbd5418b AT	365	n--;
2fd754cf	366	retry_fwrite(buffer, l, o, hash);
dbd5418b AT	367	}
	368	}
	369
d7a51997	370	static void skip_lines(FileFd &i, int n)
dbd5418b AT	371	{
dbd5418b AT	372	char buffer[BLOCK_SIZE];
dbd5418b	373	while (n > 0) {
d7a51997	374	if (i.ReadLine(buffer, sizeof(buffer)) == NULL)
dbd5418b	375	buffer[0] = '\0';
25d99f3b	376	size_t const l = strlen(buffer);
dbd5418b AT	377	if (l == 0 \|\| buffer[l-1] == '\n')
	378	n--;
	379	}
	380	}
	381
d7a51997	382	static void dump_mem(FileFd &o, char p, size_t s, Hashes hash) {
2fd754cf	383	retry_fwrite(p, s, o, hash);
dbd5418b AT	384	}
	385
	386	public:
	387
6d3e5bd8	388	bool read_diff(FileFd &f, Hashes * const h)
dbd5418b AT	389	{
	390	char buffer[BLOCK_SIZE];
	391	bool cmdwanted = true;
	392
6d3e5bd8 DK	393	Change ch(std::numeric_limits<size_t>::max());
	394	if (f.ReadLine(buffer, sizeof(buffer)) == NULL)
	395	return _error->Error("Reading first line of patchfile %s failed", f.Name().c_str());
	396	do {
36795154 DK	397	if (h != NULL)
36795154 DK	398	h->Add(buffer);
dbd5418b AT	399	if (cmdwanted) {
	400	char m, c;
	401	size_t s, e;
6d3e5bd8 DK	402	errno = 0;
6d3e5bd8 DK	403	s = strtoul(buffer, &m, 10);
c69e8370	404	if (unlikely(m == buffer \|\| s == std::numeric_limits<unsigned long>::max() \|\| errno != 0))
6d3e5bd8 DK	405	return _error->Error("Parsing patchfile %s failed: Expected an effected line start", f.Name().c_str());
	406	else if (*m == ',') {
	407	++m;
dbd5418b	408	e = strtol(m, &c, 10);
c69e8370	409	if (unlikely(m == c \|\| e == std::numeric_limits<unsigned long>::max() \|\| errno != 0))
6d3e5bd8 DK	410	return _error->Error("Parsing patchfile %s failed: Expected an effected line end", f.Name().c_str());
	411	if (unlikely(e < s))
	412	return _error->Error("Parsing patchfile %s failed: Effected lines end %lu is before start %lu", f.Name().c_str(), e, s);
dbd5418b AT	413	} else {
	414	e = s;
	415	c = m;
	416	}
6d3e5bd8 DK	417	if (s > ch.offset)
6d3e5bd8 DK	418	return _error->Error("Parsing patchfile %s failed: Effected line is after previous effected line", f.Name().c_str());
dbd5418b AT	419	switch(*c) {
	420	case 'a':
	421	cmdwanted = false;
	422	ch.add = NULL;
	423	ch.add_cnt = 0;
	424	ch.add_len = 0;
	425	ch.offset = s;
	426	ch.del_cnt = 0;
	427	break;
	428	case 'c':
6d3e5bd8 DK	429	if (unlikely(s == 0))
6d3e5bd8 DK	430	return _error->Error("Parsing patchfile %s failed: Change command can't effect line zero", f.Name().c_str());
dbd5418b AT	431	cmdwanted = false;
	432	ch.add = NULL;
	433	ch.add_cnt = 0;
	434	ch.add_len = 0;
	435	ch.offset = s - 1;
	436	ch.del_cnt = e - s + 1;
	437	break;
	438	case 'd':
6d3e5bd8 DK	439	if (unlikely(s == 0))
6d3e5bd8 DK	440	return _error->Error("Parsing patchfile %s failed: Delete command can't effect line zero", f.Name().c_str());
dbd5418b AT	441	ch.offset = s - 1;
	442	ch.del_cnt = e - s + 1;
	443	ch.add = NULL;
	444	ch.add_cnt = 0;
	445	ch.add_len = 0;
	446	filechanges.add_change(ch);
	447	break;
6d3e5bd8 DK	448	default:
6d3e5bd8 DK	449	return _error->Error("Parsing patchfile %s failed: Unknown command", f.Name().c_str());
dbd5418b	450	}
2fd754cf	451	} else { /* !cmdwanted */
6d3e5bd8	452	if (strcmp(buffer, ".\n") == 0) {
dbd5418b AT	453	cmdwanted = true;
	454	filechanges.add_change(ch);
	455	} else {
	456	char *last = NULL;
	457	char *add;
	458	size_t l;
	459	if (ch.add)
	460	last = ch.add + ch.add_len;
	461	l = strlen(buffer);
	462	add = add_text.add_easy(buffer, l, last);
	463	if (!add) {
	464	ch.add_len += l;
	465	ch.add_cnt++;
	466	} else {
	467	if (ch.add) {
	468	filechanges.add_change(ch);
	469	ch.del_cnt = 0;
	470	}
	471	ch.offset += ch.add_cnt;
	472	ch.add = add;
	473	ch.add_len = l;
	474	ch.add_cnt = 1;
	475	}
	476	}
	477	}
6d3e5bd8 DK	478	} while(f.ReadLine(buffer, sizeof(buffer)));
6d3e5bd8 DK	479	return true;
dbd5418b AT	480	}
dbd5418b AT	481
d7a51997	482	void write_diff(FileFd &f)
dbd5418b	483	{
6298ff8b	484	unsigned long long line = 0;
dbd5418b	485	std::list<struct Change>::reverse_iterator ch;
25d99f3b	486	for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) {
dbd5418b AT	487	line += ch->offset + ch->del_cnt;
	488	}
	489
25d99f3b	490	for (ch = filechanges.rbegin(); ch != filechanges.rend(); ++ch) {
dbd5418b AT	491	std::list<struct Change>::reverse_iterator mg_i, mg_e = ch;
dbd5418b AT	492	while (ch->del_cnt == 0 && ch->offset == 0)
25d99f3b	493	++ch;
dbd5418b	494	line -= ch->del_cnt;
d7a51997	495	std::string buf;
dbd5418b AT	496	if (ch->add_cnt > 0) {
dbd5418b AT	497	if (ch->del_cnt == 0) {
d7a51997	498	strprintf(buf, "%llua\n", line);
dbd5418b	499	} else if (ch->del_cnt == 1) {
d7a51997	500	strprintf(buf, "%lluc\n", line+1);
dbd5418b	501	} else {
d7a51997	502	strprintf(buf, "%llu,%lluc\n", line+1, line+ch->del_cnt);
dbd5418b	503	}
d7a51997	504	f.Write(buf.c_str(), buf.length());
dbd5418b AT	505
	506	mg_i = ch;
	507	do {
	508	dump_mem(f, mg_i->add, mg_i->add_len, NULL);
	509	} while (mg_i-- != mg_e);
	510
d7a51997 DK	511	buf = ".\n";
d7a51997 DK	512	f.Write(buf.c_str(), buf.length());
dbd5418b	513	} else if (ch->del_cnt == 1) {
d7a51997 DK	514	strprintf(buf, "%llud\n", line+1);
d7a51997 DK	515	f.Write(buf.c_str(), buf.length());
dbd5418b	516	} else if (ch->del_cnt > 1) {
d7a51997 DK	517	strprintf(buf, "%llu,%llud\n", line+1, line+ch->del_cnt);
d7a51997 DK	518	f.Write(buf.c_str(), buf.length());
dbd5418b AT	519	}
	520	line -= ch->offset;
	521	}
	522	}
47d2bc78	523
d7a51997	524	void apply_against_file(FileFd &out, FileFd &in, Hashes *hash = NULL)
dbd5418b AT	525	{
dbd5418b AT	526	std::list<struct Change>::iterator ch;
25d99f3b	527	for (ch = filechanges.begin(); ch != filechanges.end(); ++ch) {
dbd5418b AT	528	dump_lines(out, in, ch->offset, hash);
	529	skip_lines(in, ch->del_cnt);
	530	dump_mem(out, ch->add, ch->add_len, hash);
	531	}
	532	dump_rest(out, in, hash);
47d2bc78	533	}
dbd5418b AT	534	};
dbd5418b AT	535
23e64f6d	536	class RredMethod : public aptMethod {
dbd5418b AT	537	private:
dbd5418b AT	538	bool Debug;
dbd5418b	539
36795154 DK	540	struct PDiffFile {
	541	std::string FileName;
	542	HashStringList ExpectedHashes;
	543	PDiffFile(std::string const &FileName, HashStringList const &ExpectedHashes) :
	544	FileName(FileName), ExpectedHashes(ExpectedHashes) {}
	545	};
	546
	547	HashStringList ReadExpectedHashesForPatch(unsigned int const patch, std::string const &Message)
	548	{
	549	HashStringList ExpectedHashes;
	550	for (char const * const * type = HashString::SupportedHashes(); *type != NULL; ++type)
	551	{
	552	std::string tagname;
	553	strprintf(tagname, "Patch-%d-%s-Hash", patch, *type);
	554	std::string const hashsum = LookupTag(Message, tagname.c_str());
	555	if (hashsum.empty() == false)
	556	ExpectedHashes.push_back(HashString(*type, hashsum));
	557	}
	558	return ExpectedHashes;
	559	}
	560
dbd5418b	561	protected:
3b302846	562	virtual bool URIAcquire(std::string const &Message, FetchItem *Itm) APT_OVERRIDE {
dbd5418b AT	563	Debug = _config->FindB("Debug::pkgAcquire::RRed", false);
	564	URI Get = Itm->Uri;
	565	std::string Path = Get.Host + Get.Path; // rred:/path - no host
	566
	567	FetchResult Res;
	568	Res.Filename = Itm->DestFile;
50bd6fd3 DK	569	if (Itm->Uri.empty())
50bd6fd3 DK	570	{
dbd5418b AT	571	Path = Itm->DestFile;
	572	Itm->DestFile.append(".result");
	573	} else
	574	URIStart(Res);
	575
36795154	576	std::vector<PDiffFile> patchfiles;
dbd5418b AT	577	Patch patch;
dbd5418b AT	578
50bd6fd3	579	if (FileExists(Path + ".ed") == true)
36795154 DK	580	{
	581	HashStringList const ExpectedHashes = ReadExpectedHashesForPatch(0, Message);
	582	std::string const FileName = Path + ".ed";
	583	if (ExpectedHashes.usable() == false)
	584	return _error->Error("No hashes found for uncompressed patch: %s", FileName.c_str());
	585	patchfiles.push_back(PDiffFile(FileName, ExpectedHashes));
	586	}
50bd6fd3 DK	587	else
	588	{
	589	_error->PushToStack();
	590	std::vector<std::string> patches = GetListOfFilesInDir(flNotFile(Path), "gz", true, false);
	591	_error->RevertToStack();
	592
	593	std::string const baseName = Path + ".ed.";
36795154	594	unsigned int seen_patches = 0;
50bd6fd3 DK	595	for (std::vector<std::string>::const_iterator p = patches.begin();
50bd6fd3 DK	596	p != patches.end(); ++p)
36795154	597	{
50bd6fd3	598	if (p->compare(0, baseName.length(), baseName) == 0)
36795154 DK	599	{
	600	HashStringList const ExpectedHashes = ReadExpectedHashesForPatch(seen_patches, Message);
	601	if (ExpectedHashes.usable() == false)
	602	return _error->Error("No hashes found for uncompressed patch %d: %s", seen_patches, p->c_str());
	603	patchfiles.push_back(PDiffFile(*p, ExpectedHashes));
	604	++seen_patches;
	605	}
	606	}
dbd5418b AT	607	}
	608
	609	std::string patch_name;
36795154 DK	610	for (std::vector<PDiffFile>::iterator I = patchfiles.begin();
36795154 DK	611	I != patchfiles.end();
25d99f3b	612	++I)
dbd5418b	613	{
36795154	614	patch_name = I->FileName;
dbd5418b AT	615	if (Debug == true)
	616	std::clog << "Patching " << Path << " with " << patch_name
	617	<< std::endl;
	618
50bd6fd3	619	FileFd p;
6d3e5bd8	620	Hashes patch_hash(I->ExpectedHashes);
50bd6fd3	621	// all patches are compressed, even if the name doesn't reflect it
6d3e5bd8 DK	622	if (p.Open(patch_name, FileFd::ReadOnly, FileFd::Gzip) == false \|\|
	623	patch.read_diff(p, &patch_hash) == false)
	624	{
95278287	625	_error->DumpErrors(std::cerr, GlobalError::DEBUG, false);
6d3e5bd8	626	return false;
dbd5418b	627	}
50bd6fd3	628	p.Close();
36795154 DK	629	HashStringList const hsl = patch_hash.GetHashStringList();
36795154 DK	630	if (hsl != I->ExpectedHashes)
4f51fd86	631	return _error->Error("Hash Sum mismatch for uncompressed patch %s", patch_name.c_str());
dbd5418b AT	632	}
	633
	634	if (Debug == true)
	635	std::clog << "Applying patches against " << Path
	636	<< " and writing results to " << Itm->DestFile
	637	<< std::endl;
	638
d7a51997 DK	639	FileFd inp, out;
	640	if (inp.Open(Path, FileFd::ReadOnly, FileFd::Extension) == false)
	641	{
	642	std::cerr << "FAILED to open inp " << Path << std::endl;
	643	return _error->Error("Failed to open inp %s", Path.c_str());
	644	}
	645	if (out.Open(Itm->DestFile, FileFd::WriteOnly \| FileFd::Create, FileFd::Extension) == false)
	646	{
	647	std::cerr << "FAILED to open out " << Itm->DestFile << std::endl;
	648	return _error->Error("Failed to open out %s", Itm->DestFile.c_str());
	649	}
dbd5418b	650
9224ce3d	651	Hashes hash(Itm->ExpectedHashes);
dbd5418b AT	652	patch.apply_against_file(out, inp, &hash);
dbd5418b AT	653
d7a51997 DK	654	out.Close();
d7a51997 DK	655	inp.Close();
dbd5418b AT	656
	657	if (Debug == true) {
	658	std::clog << "rred: finished file patching of " << Path << "." << std::endl;
	659	}
	660
	661	struct stat bufbase, bufpatch;
	662	if (stat(Path.c_str(), &bufbase) != 0 \|\|
	663	stat(patch_name.c_str(), &bufpatch) != 0)
	664	return _error->Errno("stat", _("Failed to stat"));
	665
246bbb61	666	struct timeval times[2];
25d99f3b DK	667	times[0].tv_sec = bufbase.st_atime;
25d99f3b DK	668	times[1].tv_sec = bufpatch.st_mtime;
246bbb61 DK	669	times[0].tv_usec = times[1].tv_usec = 0;
	670	if (utimes(Itm->DestFile.c_str(), times) != 0)
	671	return _error->Errno("utimes",_("Failed to set modification time"));
dbd5418b AT	672
	673	if (stat(Itm->DestFile.c_str(), &bufbase) != 0)
	674	return _error->Errno("stat", _("Failed to stat"));
	675
	676	Res.LastModified = bufbase.st_mtime;
	677	Res.Size = bufbase.st_size;
	678	Res.TakeHashes(hash);
	679	URIDone(Res);
	680
	681	return true;
	682	}
	683
	684	public:
23e64f6d	685	RredMethod() : aptMethod("rred", "2.0",SingleInstance \| SendConfig), Debug(false) {}
bb1293d9	686	};
dbd5418b AT	687
	688	int main(int argc, char **argv)
	689	{
	690	int i;
	691	bool just_diff = true;
	692	Patch patch;
	693
	694	if (argc <= 1) {
	695	RredMethod Mth;
	696	return Mth.Run();
	697	}
	698
	699	if (argc > 1 && strcmp(argv[1], "-f") == 0) {
	700	just_diff = false;
	701	i = 2;
	702	} else {
	703	i = 1;
	704	}
	705
	706	for (; i < argc; i++) {
50bd6fd3 DK	707	FileFd p;
	708	if (p.Open(argv[i], FileFd::ReadOnly) == false) {
	709	_error->DumpErrors(std::cerr);
dbd5418b AT	710	exit(1);
dbd5418b AT	711	}
6d3e5bd8 DK	712	if (patch.read_diff(p, NULL) == false)
	713	{
	714	_error->DumpErrors(std::cerr);
	715	exit(2);
	716	}
dbd5418b AT	717	}
	718
	719	if (just_diff) {
d7a51997 DK	720	FileFd out;
	721	out.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly \| FileFd::Create);
	722	patch.write_diff(out);
dbd5418b	723	} else {
d7a51997 DK	724	FileFd out, inp;
	725	out.OpenDescriptor(STDOUT_FILENO, FileFd::WriteOnly \| FileFd::Create);
	726	inp.OpenDescriptor(STDIN_FILENO, FileFd::ReadOnly);
dbd5418b AT	727	patch.apply_against_file(out, inp);
	728	}
	729	return 0;
2e178d1c	730	}