view create.cpp @ 401:a8a5f2ca5380 api-inversion

Invert audioDB::l2norm / audiodb_l2norm()

We now have some functions that shouldn't be exported to the user of the
library, but are used in more than one source file; case in point:
audiodb_sync_header().  Make a new audioDB-internals.h file for them,
and while we're at it put the scary mmap()-related macros in there too.

We can't delete audioDB::unitNormAndInsertL2() quite yet, because it's
used in insertion too, but we can delete the non-append branches.
That's not very much code to lose, but every little helps.

#include "audioDB.h"
extern "C" {
#include "audioDB_API.h"
}
/* Make a new database.

IF size(featuredata) < O2_LARGE_ADB_SIZE 
   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.
   
ELSE the database consists of:
   
   * a header (see dbTableHeader struct definition);
   * keyTable: list of keys of tracks
   * trackTable: sizes of tracks
   * featureTable: list of feature file names
   * timesTable: list of times file names
   * powerTable: list of power file names

*/

extern "C" {
  adb_t *audiodb_create(const char *path, unsigned datasize, unsigned ntracks, unsigned datadim) {
    int fd;
    adb_header_t *header = 0;
    off_t databytes, auxbytes;
    if(datasize == 0) {
      datasize = O2_DEFAULT_DATASIZE;
    }
    if(ntracks == 0) {
      ntracks = O2_DEFAULT_NTRACKS;
    }
    if(datadim == 0) {
      datadim = O2_DEFAULT_DATADIM;
    }

    if ((fd = open(path, O_RDWR|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)) < 0) {
      goto error;
    }
    if (acquire_lock(fd, true)) {
      goto error;
    }

    header = (adb_header_t *) malloc(sizeof(adb_header_t));
    if(!header) {
      goto error;
    }
    
    // Initialize header
    header->magic = O2_MAGIC;
    header->version = O2_FORMAT_VERSION;
    header->numFiles = 0;
    header->dim = 0;
    header->flags = 0;
    header->headerSize = O2_HEADERSIZE;
    header->length = 0;
    header->fileTableOffset = ALIGN_PAGE_UP(O2_HEADERSIZE);
    header->trackTableOffset = ALIGN_PAGE_UP(header->fileTableOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
    header->dataOffset = ALIGN_PAGE_UP(header->trackTableOffset + O2_TRACKTABLE_ENTRY_SIZE*ntracks);
    
    databytes = ((off_t) datasize) * 1024 * 1024;
    auxbytes = databytes / datadim;

    /* FIXME: what's going on here?  There are two distinct
       preprocessor constants (O2_LSH_N_POINT_BITS, LSH_N_POINT_BITS);
       a third is presumably some default
       (O2_DEFAULT_LSH_N_POINT_BITS), and then there's this magic 28
       bits.  Should this really be part of the flags structure at
       all?  Putting it elsewhere will of course break backwards
       compatibility, unless 14 is the only value that's been used
       anywhere... */
    
    // For backward-compatibility, Record the point-encoding parameter for LSH indexing in the adb header
    // If this value is 0 then it will be set to 14
    
#if O2_LSH_N_POINT_BITS > 15
#error "AudioDB Compile ERROR: consistency check of O2_LSH_POINT_BITS failed (>15)"
#endif
    
    header->flags |= LSH_N_POINT_BITS << 28;
    
    // If database will fit in a single file the vectors are copied into the AudioDB instance
    // Else all the vectors are left on the FileSystem and we use the dataOffset as storage
    // for the location of the features, powers and times files (assuming that arbitrary keys are used for the fileTable)
    if(ntracks<O2_LARGE_ADB_NTRACKS && datasize<O2_LARGE_ADB_SIZE){
      header->timesTableOffset = ALIGN_PAGE_UP(header->dataOffset + databytes);
      header->powerTableOffset = ALIGN_PAGE_UP(header->timesTableOffset + 2*auxbytes);
      header->l2normTableOffset = ALIGN_PAGE_UP(header->powerTableOffset + auxbytes);
      header->dbSize = ALIGN_PAGE_UP(header->l2normTableOffset + auxbytes);
    } else { // Create LARGE_ADB, features and powers kept on filesystem 
      header->flags |= O2_FLAG_LARGE_ADB;
      header->timesTableOffset = ALIGN_PAGE_UP(header->dataOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
      header->powerTableOffset = ALIGN_PAGE_UP(header->timesTableOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
      header->l2normTableOffset = ALIGN_PAGE_UP(header->powerTableOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
      header->dbSize = header->l2normTableOffset;
    } 
    
    if (write(fd, header, O2_HEADERSIZE) != O2_HEADERSIZE) {
      goto error;
    }
    
    // go to the location corresponding to the last byte
    if (lseek (fd, header->dbSize - 1, SEEK_SET) == -1) {
      goto error;
    }

    // write a dummy byte at the last location
    if (write (fd, "", 1) != 1) {
      goto error;
    }

    free(header);
    return audiodb_open(path, O_RDWR);

  error:
    if(header) {
      free(header);
    }
    return NULL;
  }
}