view create.cpp @ 284:cacad987d785

Really finish with the sampling branch, this time merging all of it,
yes, even the last revision.  (The last revision was one that seeded the
RNG with the current time, which is helpful when trying to get multiple
independent-ish samples from the same database...)

#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_FILETABLE_ENTRY_SIZE*ntracks);
  dbH->dataOffset = ALIGN_PAGE_UP(dbH->trackTableOffset + O2_TRACKTABLE_ENTRY_SIZE*ntracks);

  off_t databytes = ((off_t) datasize) * 1024 * 1024;
  off_t auxbytes = databytes / datadim;

  dbH->timesTableOffset = ALIGN_PAGE_UP(dbH->dataOffset + databytes);
  dbH->powerTableOffset = ALIGN_PAGE_UP(dbH->timesTableOffset + 2*auxbytes);
  dbH->l2normTableOffset = ALIGN_PAGE_UP(dbH->powerTableOffset + auxbytes);
  dbH->dbSize = ALIGN_PAGE_UP(dbH->l2normTableOffset + auxbytes);

  write(dbfid, dbH, O2_HEADERSIZE);

  // go to the location corresponding to the last byte
  if (lseek (dbfid, dbH->dbSize - 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?
}