1 files changed, 114 insertions, 0 deletions
diff --git a/repair.cc b/repair.cc
new file mode 100644
index 0000000..8a92e59
--- /dev/null
+++ b/repair.cc
@@ -0,0 +1,114 @@
+/*  Lziprecover - Data recovery tool for lzipped files
+    Copyright (C) 2009, 2010, 2011 Antonio Diaz Diaz.
+
+    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 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#define _FILE_OFFSET_BITS 64
+
+#include <cerrno>
+#include <climits>
+#include <cstdio>
+#include <cstring>
+#include <string>
+#include <vector>
+#include <stdint.h>
+#include <sys/stat.h>
+
+#include "lzip.h"
+
+
+int repair_file( const std::string & input_filename,
+                 const std::string & output_filename, const bool force )
+  {
+  struct stat in_stats;
+  const int infd = open_instream( input_filename, &in_stats, true, true );
+  if( infd < 0 ) return 1;
+  const long long isize = lseek( infd, 0, SEEK_END );
+  if( isize < 0 )
+    { show_error( "Input file is not seekable", errno ); return 1; }
+  if( isize < 36 )
+    { show_error( "Input file is too short." ); return 2; }
+  if( !verify_single_member( infd, isize ) ) return 2;
+  if( lseek( infd, 0, SEEK_SET ) < 0 )
+    { show_error( "Seek error in input file", errno ); return 1; }
+
+  long long failure_pos = 0;
+  if( try_decompress( infd, isize, &failure_pos ) )
+    {
+    if( verbosity >= 1 )
+      std::printf( "Input file has no errors. Recovery is not needed.\n" );
+    return 0;
+    }
+  if( failure_pos >= isize - 8 ) failure_pos = isize - 8 - 1;
+  if( failure_pos < File_header::size )
+    { show_error( "Can't repair error in input file." ); return 2; }
+
+  if( lseek( infd, 0, SEEK_SET ) < 0 )
+    { show_error( "Seek error in input file", errno ); return 1; }
+
+  const int outfd = open_outstream_rw( output_filename, force );
+  if( outfd < 0 ) { close( infd ); return 1; }
+  if( !copy_file( infd, outfd ) )
+    cleanup_and_fail( output_filename, outfd, 1 );
+
+  const long long min_pos =
+    std::max( (long long)File_header::size, failure_pos - 1000 );
+  bool done = false;
+  for( long long pos = failure_pos; pos >= min_pos; --pos )
+    {
+    if( verbosity >= 1 )
+      {
+      std::printf( "Trying position %lld \r", pos );
+      std::fflush( stdout );
+      }
+    uint8_t byte;
+    if( lseek( outfd, pos, SEEK_SET ) < 0 ||
+        readblock( outfd, &byte, 1 ) != 1 )
+      { show_error( "Error reading output file", errno );
+        cleanup_and_fail( output_filename, outfd, 1 ); }
+    for( int i = 0; i < 255; ++i )
+      {
+      ++byte;
+      if( lseek( outfd, pos, SEEK_SET ) < 0 ||
+          writeblock( outfd, &byte, 1 ) != 1 ||
+          lseek( outfd, 0, SEEK_SET ) < 0 )
+        { show_error( "Error writing output file", errno );
+          cleanup_and_fail( output_filename, outfd, 1 ); }
+      if( try_decompress( outfd, isize ) )
+        { done = true; break; }
+      }
+    if( done ) break;
+    ++byte;
+    if( lseek( outfd, pos, SEEK_SET ) < 0 ||
+        writeblock( outfd, &byte, 1 ) != 1 )
+      { show_error( "Error writing output file", errno );
+        cleanup_and_fail( output_filename, outfd, 1 ); }
+    }
+  if( verbosity >= 1 ) std::printf( "\n" );
+
+  if( close( outfd ) != 0 )
+    {
+    show_error( "Error closing output file", errno );
+    cleanup_and_fail( output_filename, -1, 1 );
+    }
+  if( !done )
+    {
+    show_error( "Error is larger than 1 byte. Can't repair input file." );
+    cleanup_and_fail( output_filename, -1, 2 );
+    }
+  if( verbosity >= 1 )
+    std::printf( "Copy of input file repaired successfully.\n" );
+  return 0;
+  }