view create.cpp @ 251:a6c9a1c68646

Detect when we've run out of per-file space on insert() and
batchinsert().

Exposed by Lute Music/frames1 dataset, we previously corrupted the
trackTable and then got a segfault.  This happened because the fileTable
and trackTable were mmap()ed next to each other, by coincidence, and the
lack of overflow checking on the fileTable meant that continued
insertion scribbled over the trackTable, which was twice as big (because
it has to be at least one memory page in size).

The root cause of all this is the --size creation argument, which needs
to be split into --nfiles, --datasize and --dimensions, so that the size
of all the tables can be computed accurately.

No test case yet, because my /bin/sh is currently pointing to dash,
which gets about as far as line 6 of run-tests.sh before giving up.
(We need either to fix bashisms or to run /bin/bash explicitly.)

#include "audioDB.h"

/* Make a new database.

   The database consists of:

   * a header (see dbTableHeader struct definition);
   * keyTable: list of keys of tracks;
   * trackTable: Maps implicit feature index to a feature vector
     matrix (sizes of tracks)
   * featureTable: Lots of doubles;
   * timesTable: (start,end) time points for each feature vector;
   * powerTable: associated power for each feature vector;
   * l2normTable: squared l2norms for each feature vector.
*/

void audioDB::create(const char* dbName){
  if ((dbfid = open (dbName, O_RDWR|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)) < 0)
    error("Can't create database file", dbName, "open");
  get_lock(dbfid, 1);

  VERB_LOG(0, "header size: %ju\n", (intmax_t) O2_HEADERSIZE);
  
  dbH = new dbTableHeaderT();
  assert(dbH);

  unsigned int maxfiles = (unsigned int) rint((double) O2_MAXFILES * (double) size / (double) O2_DEFAULTDBSIZE);

  // Initialize header
  dbH->magic = O2_MAGIC;
  dbH->version = O2_FORMAT_VERSION;
  dbH->numFiles = 0;
  dbH->dim = 0;
  dbH->flags = 0;
  dbH->headerSize = O2_HEADERSIZE;
  dbH->length = 0;
  dbH->fileTableOffset = ALIGN_PAGE_UP(O2_HEADERSIZE);
  dbH->trackTableOffset = ALIGN_PAGE_UP(dbH->fileTableOffset + O2_FILETABLESIZE*maxfiles);
  dbH->dataOffset = ALIGN_PAGE_UP(dbH->trackTableOffset + O2_TRACKTABLESIZE*maxfiles);
  dbH->l2normTableOffset = ALIGN_PAGE_DOWN(size - maxfiles*O2_MEANNUMVECTORS*sizeof(double));
  dbH->powerTableOffset = ALIGN_PAGE_DOWN(dbH->l2normTableOffset - maxfiles*O2_MEANNUMVECTORS*sizeof(double));
  dbH->timesTableOffset = ALIGN_PAGE_DOWN(dbH->powerTableOffset - 2*maxfiles*O2_MEANNUMVECTORS*sizeof(double));
  dbH->dbSize = size;

  write(dbfid, dbH, O2_HEADERSIZE);

  // go to the location corresponding to the last byte
  if (lseek (dbfid, size - 1, SEEK_SET) == -1)
    error("lseek error in db file", "", "lseek");

  // write a dummy byte at the last location
  if (write (dbfid, "", 1) != 1)
    error("write error", "", "write");

  VERB_LOG(0, "%s %s\n", COM_CREATE, dbName);
}

void audioDB::drop(){
  // FIXME: drop something?  Should we even allow this?
}