[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 <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, FILE *f, Hashes *hash)
   {
      size_t r = 1;
      while (r > 0 && l > 0)
      {
         r = fwrite(b, 1, l, f);
	 if (hash)
	    hash->Add((unsigned char*)b, r);
	 l -= r;
	 b += r;
      }
      return l == 0;
   }

   static void dump_rest(FILE *o, FILE *i, Hashes *hash)
   {
      char buffer[BLOCK_SIZE];
      size_t l;
      while (0 < (l = fread(buffer, 1, sizeof(buffer), i))) {
	 if (!retry_fwrite(buffer, l, o, hash))
	    break;
      }
   }

   static void dump_lines(FILE *o, FILE *i, size_t n, Hashes *hash)
   {
      char buffer[BLOCK_SIZE];
      while (n > 0) {
	 if (fgets(buffer, sizeof(buffer), i) == 0)
	    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(FILE *i, int n)
   {
      char buffer[BLOCK_SIZE];
      while (n > 0) {
	 if (fgets(buffer, sizeof(buffer), i) == 0)
	    buffer[0] = '\0';
	 size_t const l = strlen(buffer);
	 if (l == 0 || buffer[l-1] == '\n')
	    n--;
      }
   }

   static void dump_mem(FILE *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(FILE *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;
	 if (ch->add_cnt > 0) {
	    if (ch->del_cnt == 0) {
	       fprintf(f, "%llua\n", line);
	    } else if (ch->del_cnt == 1) {
	       fprintf(f, "%lluc\n", line+1);
	    } else {
	       fprintf(f, "%llu,%lluc\n", line+1, line+ch->del_cnt);
	    }

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

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

   void apply_against_file(FILE *out, FILE *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 pkgAcqMethod {
   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);
	       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;

	 FILE *inp = fopen(Path.c_str(), "r");
	 FILE *out = fopen(Itm->DestFile.c_str(), "w");

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

	 fclose(out);
	 fclose(inp);

	 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;
      }

      bool Configuration(std::string Message) APT_OVERRIDE
      {
	 if (pkgAcqMethod::Configuration(Message) == false)
	    return false;

	 DropPrivsOrDie();

	 return true;
      }

   public:
      RredMethod() : pkgAcqMethod("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) {
      patch.write_diff(stdout);
   } else {
      FILE *out, *inp;
      out = stdout;
      inp = stdin;

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