nucleus/library/filesystem/heavy_file_ops.cpp

   1 /*****************************************************************************\
   2 *                                                                             *
   3 *  Name   : heavy file operations                                             *
   4 *  Author : Chris Koeritz                                                     *
   5 *                                                                             *
   6 *******************************************************************************
   7 * Copyright (c) 2005-$now By Author.  This program is free software; you can  *
   8 * redistribute it and/or modify it under the terms of the GNU General Public  *
   9 * License as published by the Free Software Foundation; either version 2 of   *
  10 * the License or (at your option) any later version.  This is online at:      *
  11 *     http://www.fsf.org/copyleft/gpl.html                                    *
  12 * Please send any updates to: fred@gruntose.com                               *
  13 \*****************************************************************************/
  14
  15 #include "directory.h"
  16 #include "filename.h"
  17 #include "filename_list.h"
  18 #include "heavy_file_ops.h"
  19 #include "huge_file.h"
  20
  21 #include <basis/functions.h>
  22 #include <basis/guards.h>
  23 #include <structures/object_packers.h>
  24
  25 using namespace basis;
  26 using namespace structures;
  27
  28 namespace filesystem {
  29
  30 //#define DEBUG_HEAVY_FILE_OPS
  31   // uncomment for noisier debugging.
  32
  33 #undef LOG
  34 #include <stdio.h>
  35 #define LOG(to_print) printf("%s::%s: %s\n", static_class_name(), func, astring(to_print).s())
  36
  37 //////////////
  38
  39 // the smallest we let the packing area's available space get before we stop filling it.
  40 const int MINIMUM_ARRAY_SIZE = 1024;
  41
  42 //////////////
  43
  44 file_transfer_header::file_transfer_header(const file_time &time_stamp)
  45 : _filename(),
  46   _byte_start(0),
  47   _length(0),
  48   _time(time_stamp)
  49 {
  50 }
  51
  52 astring file_transfer_header::text_form() const
  53 {
  54   astring time_text;
  55   _time.text_form(time_text);
  56   return astring("file=") + _filename
  57       + a_sprintf(" start=%d len=%d stamp=", _byte_start, _length)
  58       + time_text;
  59 }
  60
  61 astring file_transfer_header::readable_text_form() const
  62 {
  63   astring time_text;
  64   _time.readable_text_form(time_text);
  65   return _filename
  66       + a_sprintf(" [%d bytes, mod ", _length)
  67       + time_text + "]";
  68 }
  69
  70 void file_transfer_header::pack(byte_array &packed_form) const
  71 {
  72   _filename.pack(packed_form);
  73   attach(packed_form, _byte_start);
  74   attach(packed_form, _length);
  75   _time.pack(packed_form);
  76 }
  77
  78 bool file_transfer_header::unpack(byte_array &packed_form)
  79 {
  80   if (!_filename.unpack(packed_form)) return false;
  81   if (!detach(packed_form, _byte_start)) return false;
  82   if (!detach(packed_form, _length)) return false;
  83   if (!_time.unpack(packed_form)) return false;
  84   return true;
  85 }
  86
  87 int file_transfer_header::packed_size() const
  88 {
  89 byte_array temp;
  90 attach(temp, _byte_start);
  91 //hmmm: really ugly above; we should get a more exact way to know the size of
  92 //      packed doubles.
  93   return _filename.length() + 1
  94       + temp.length()
  95       + sizeof(int)
  96       + _time.packed_size();
  97 }
  98
  99 //////////////
 100
 101 const size_t heavy_file_operations::COPY_CHUNK_FACTOR = 1 * MEGABYTE;
 102
 103 size_t heavy_file_operations::copy_chunk_factor()
 104 { return COPY_CHUNK_FACTOR; }
 105
 106 heavy_file_operations::~heavy_file_operations() {}
 107   // we only need this due to our use of the root_object class_name support.
 108
 109 const char *heavy_file_operations::outcome_name(const outcome &to_name)
 110 {
 111   switch (to_name.value()) {
 112     case SOURCE_MISSING: return "SOURCE_MISSING";
 113     case TARGET_ACCESS_ERROR: return "TARGET_ACCESS_ERROR";
 114     case TARGET_DIR_ERROR: return "TARGET_DIR_ERROR";
 115     default: return common::outcome_name(to_name);
 116   }
 117 }
 118
 119 outcome heavy_file_operations::copy_file(const astring &source,
 120     const astring &destination, int copy_chunk_factor)
 121 {
 122 #ifdef DEBUG_HEAVY_FILE_OPS
 123   FUNCDEF("copy_file");
 124 #endif
 125   // check that the source exists...
 126   filename source_path(source);
 127   if (!source_path.exists()) return SOURCE_MISSING;
 128   file_time source_time(source_path);  // get the time on the source.
 129
 130   // make sure the target directory exists...
 131   filename target_path(destination);
 132   filename targ_dir = target_path.dirname();
 133   if (!directory::recursive_create(targ_dir.raw())) return TARGET_DIR_ERROR;
 134
 135   // open the source for reading.
 136   huge_file source_file(source, "rb");
 137   if (!source_file.good()) return SOURCE_MISSING;
 138 //hmmm: could be source is not accessible instead.
 139
 140   // open target file for writing.
 141   huge_file target_file(destination, "wb");
 142   if (!target_file.good()) return TARGET_ACCESS_ERROR;
 143
 144   byte_array chunk;
 145   int bytes_read = 0;
 146   outcome ret;
 147   while ( (ret = source_file.read(chunk, copy_chunk_factor, bytes_read))
 148       == huge_file::OKAY) {
 149     int bytes_stored;
 150     ret = target_file.write(chunk, bytes_stored);
 151     if (bytes_stored != bytes_read) return TARGET_ACCESS_ERROR;
 152     if (source_file.eof()) break;  // time to escape.
 153   }
 154
 155   // set the time on the target file from the source's time.
 156   source_time.set_time(target_path);
 157
 158 #ifdef DEBUG_HEAVY_FILE_OPS
 159   astring time;
 160   source_time.text_form(time);
 161   LOG(astring("setting file time for ") + source + " to " + time);
 162 #endif
 163
 164   return OKAY;
 165 }
 166
 167 outcome heavy_file_operations::write_file_chunk(const astring &target,
 168     double byte_start, const byte_array &chunk, bool truncate,
 169     int copy_chunk_factor)
 170 {
 171   FUNCDEF("write_file_chunk");
 172   if (byte_start < 0) return BAD_INPUT;
 173
 174   filename targ_name(target);
 175   astring targ_dir = targ_name.dirname().raw();
 176 #ifdef DEBUG_HEAVY_FILE_OPS
 177   LOG(astring("creating target's directory: ") + targ_name.dirname().raw());
 178 #endif
 179   if (!directory::recursive_create(targ_dir)) {
 180     LOG(astring("failed to create directory: ") + targ_name.dirname().raw());
 181     return TARGET_DIR_ERROR;
 182   }
 183
 184   if (!targ_name.exists()) {
 185     huge_file target_file(target, "w");
 186   }
 187
 188   huge_file target_file(target, "r+b");
 189     // open the file for updating (either read or write).
 190   if (!target_file.good()) return TARGET_ACCESS_ERROR;
 191   double curr_len = target_file.length();
 192   target_file.touch();
 193
 194   if (curr_len < byte_start) {
 195     byte_array new_chunk;
 196     while (curr_len < byte_start) {
 197       target_file.seek(0, byte_filer::FROM_END);  // go to the end of the file.
 198       new_chunk.reset(minimum(copy_chunk_factor,
 199           int(curr_len - byte_start + 1)));
 200       int written;
 201       outcome ret = target_file.write(new_chunk, written);
 202       if (written < new_chunk.length()) return TARGET_ACCESS_ERROR;
 203       curr_len = target_file.length();
 204     }
 205   }
 206   target_file.seek(byte_start, byte_filer::FROM_START);
 207     // jump to the proper location in the file.
 208   int wrote;
 209   outcome ret = target_file.write(chunk, wrote);
 210   if (wrote != chunk.length()) return TARGET_ACCESS_ERROR;
 211   if (truncate) {
 212     target_file.truncate();
 213   }
 214   return OKAY;
 215 }
 216
 217 basis::outcome heavy_file_operations::advance(const filename_list &to_transfer,
 218     file_transfer_header &last_action)
 219 {
 220   FUNCDEF("advance");
 221   int indy = to_transfer.locate(last_action._filename);
 222   if (negative(indy)) return BAD_INPUT;  // error, file not found in list.
 223   if (indy >= to_transfer.elements() - 1) return FINISHED;  // done.
 224   const file_info *currfile = to_transfer.get(indy + 1);
 225   last_action._filename = currfile->raw();
 226   last_action._time = currfile->_time;
 227
 228 #ifdef DEBUG_HEAVY_FILE_OPS
 229   if (currfile->_time == file_time(time_t(0)))
 230     LOG(astring("failed for ") + currfile->raw() + " -- has zero file time");
 231 #endif
 232
 233   last_action._byte_start = 0;
 234   last_action._length = 0;
 235   return OKAY;
 236 }
 237
 238 outcome heavy_file_operations::buffer_files(const astring &source_root,
 239     const filename_list &to_transfer, file_transfer_header &last_action,
 240     byte_array &storage, int maximum_bytes)
 241 {
 242   FUNCDEF("buffer_files");
 243   storage.reset();  // clear out the current contents.
 244
 245   if (!to_transfer.elements()) {
 246     // we seem to be done.
 247     return FINISHED;
 248   }
 249
 250   outcome to_return = OKAY;
 251
 252   // this records if we're working on a new file.
 253   bool fresh_file = false;
 254
 255   // start filling the array with bytes from the files.
 256   while (storage.length() < maximum_bytes) {
 257     double remaining_in_array = maximum_bytes - storage.length()
 258         - last_action.packed_size();
 259     if (remaining_in_array < MINIMUM_ARRAY_SIZE) {
 260       // ensure that we at least have a reasonable amount of space left
 261       // for storing into the array.
 262       break;
 263     }
 264
 265     // find the current file we're at, as provided in record.
 266     if (!last_action._filename) {
 267       // no filename yet.  assume this is the first thing we've done.
 268       const file_info *currfile = to_transfer.get(0);
 269       last_action._filename = currfile->raw();
 270       last_action._time = currfile->_time;
 271       last_action._byte_start = 0;
 272       last_action._length = 0;
 273       fresh_file = true;
 274     }
 275
 276     const file_info *found = to_transfer.find(last_action._filename);
 277     if (!found) {
 278       // they have referenced a file that we don't have.  that's bad news.
 279       LOG(astring("unknown last file requested in transfer: ") + last_action._filename);
 280       return BAD_INPUT;
 281     }
 282
 283     astring full_file = source_root + "/" + last_action._filename;
 284     huge_file current(full_file, "rb");
 285     if (!current.good()) {
 286       // we need to skip this file.
 287       LOG(astring("skipping bad file: ") + full_file);
 288       fresh_file = true;
 289       to_return = advance(to_transfer, last_action);
 290       if (to_return != OKAY) break;
 291       continue;
 292     }
 293 //LOG(astring("working on file: ") + current.name());
 294
 295     // we don't try to check done if we just started this file.
 296     if (!fresh_file && (last_action._byte_start + last_action._length >= current.length())) {
 297       // this file is done now.  go to the next one.
 298 #ifdef DEBUG_HEAVY_FILE_OPS
 299       LOG(astring("finished stuffing file: ") + full_file);
 300 #endif
 301       fresh_file = true;
 302       to_return = advance(to_transfer, last_action);
 303       if (to_return != OKAY) break;
 304       continue;
 305     }
 306     // now that we tested if the file was fresh in our 'finished' check above, we
 307     // consider the file not to be fresh until told otherwise.
 308     fresh_file = false;
 309
 310     // calculate the largest piece remaining of that file that will fit in the
 311     // allotted space.
 312     double new_start = last_action._byte_start + last_action._length;
 313     double remaining_in_file = current.length() - new_start;
 314     if (remaining_in_file < 0) remaining_in_file = 0;
 315     double new_len = minimum(remaining_in_file, remaining_in_array);
 316
 317     // pack this new piece of the file.
 318     current.seek(new_start, byte_filer::FROM_START);
 319     byte_array new_chunk;
 320     int bytes_read = 0;
 321     outcome ret = current.read(new_chunk, int(new_len), bytes_read);
 322     if (bytes_read != new_len) {
 323       if (!bytes_read) {
 324         // some kind of problem reading the file.
 325         fresh_file = true;
 326         to_return = advance(to_transfer, last_action);
 327         if (to_return != OKAY) break;
 328         continue;
 329       }
 330 //why would this happen?  just complain, i guess.
 331     }
 332
 333     // update the record since it seems we're successful here.
 334     last_action._byte_start = new_start;
 335     last_action._length = int(new_len);
 336
 337     // add in this next new chunk of file.
 338     last_action.pack(storage);  // add the header.
 339     storage += new_chunk;  // add the new stuff.
 340
 341     if (!current.length()) {
 342       // ensure we don't get stuck redoing zero length files, which we allowed
 343       // to go past their end above (since otherwise we'd never see them).
 344       fresh_file = true;
 345       to_return = advance(to_transfer, last_action);
 346       if (to_return != OKAY) break;
 347       continue;
 348     }
 349
 350     // just keep going, if there's space...
 351   }
 352
 353   return to_return;
 354 }
 355
 356 } //namespace.
 357