view open.cpp @ 405:ef4792df8f93 api-inversion

invert audioDB::insert / audiodb_insert().

Start off by removing audioDB::insertDatum, and essentially reusing it
as audiodb_insert.  We now ignore the fact that the command-line parsing
code has "helpfully" opened a std::ifstream for the times file and an fd
for the power file, and simply go ahead and do our own dirty work.

We can delete audioDB::insertDatum entirely, but unfortunately we can't
delete audioDB::insertPowerData and audioDB::insertTimestamps, because
the index and query code respectively use them.  Instead, move the two
methods closer to their single uses.

audiodb_insert() is perhaps not as short and simple as it might have
been hoped given the existence of audiodb_insert_datum(); some of that
is C and its terribly way of making you pay every time you use dynamic
memory; some of it is the fact that the three different files (feature,
times, power) each requires slightly different treatment.  Hey ho.

We can implement audiodb_batchinsert() in terms of audiodb_insert(); the
function is pleasingly small.  We can't quite use it for
audioDB::batchinsert yet, as we have to deal with the O2_FLAG_LARGE_ADB
case (which codepath is untested in libtests/).

This means that we can delete whole swathes of hideous code from
audioDB.cpp, including not just the versions of audiodb_insert() and
audiodb_batchinsert() but also an entire audioDB constructor.  Yay.
(audioDB::unitNormAndInsertL2 has also died a deserved death).

#include "audioDB.h"
extern "C" {
#include "audioDB_API.h"
#include "audioDB-internals.h"
}

static bool audiodb_check_header(adb_header_t *header) {
  /* FIXME: use syslog() or write to stderr or something to give the
     poor user some diagnostics. */
  if(header->magic == O2_OLD_MAGIC) {
    return false;
  }
  if(header->magic != O2_MAGIC) {
    return false;
  }
  if(header->version != O2_FORMAT_VERSION) {
    return false;
  }
  if(header->headerSize != O2_HEADERSIZE) {
    return false;
  }
  return true;
}

static int audiodb_collect_keys(adb_t *adb) {
  char *key_table = 0;
  size_t key_table_length = 0;

  if(adb->header->length > 0) {
    unsigned nfiles = adb->header->numFiles;
    key_table_length = ALIGN_PAGE_UP(nfiles * O2_FILETABLE_ENTRY_SIZE);
    mmap_or_goto_error(char *, key_table, adb->header->fileTableOffset, key_table_length);
    for (unsigned i = 0; i < nfiles; i++) {
      adb->keys->insert(key_table + i*O2_FILETABLE_ENTRY_SIZE);
    }
    munmap(key_table, key_table_length);
  }

  return 0;

 error:
  maybe_munmap(key_table, key_table_length);
  return 1;
}

adb_t *audiodb_open(const char *path, int flags) {
  adb_t *adb = 0;
  int fd = -1;

  flags &= (O_RDONLY|O_RDWR);
  fd = open(path, flags);
  if(fd == -1) {
    goto error;
  }
  if(acquire_lock(fd, flags == O_RDWR)) {
    goto error;
  }

  adb = (adb_t *) malloc(sizeof(adb_t));
  if(!adb) {
    goto error;
  }
  adb->fd = fd;
  adb->flags = flags;
  adb->path = (char *) malloc(1+strlen(path));
  if(!(adb->path)) {
    goto error;
  }
  strcpy(adb->path, path);

  adb->header = (adb_header_t *) malloc(sizeof(adb_header_t));
  if(!(adb->header)) {
    goto error;
  }
  if(read(fd, (char *) adb->header, O2_HEADERSIZE) != O2_HEADERSIZE) {
    goto error;
  }
  if(!audiodb_check_header(adb->header)) {
    goto error;
  }

  adb->keys = new std::set<std::string>;
  if(!adb->keys) {
    goto error;
  }
  if(audiodb_collect_keys(adb)) {
    goto error;
  }
  return adb;

 error:
  if(adb) {
    if(adb->header) {
      free(adb->header);
    }
    if(adb->path) {
      free(adb->path);
    }
    if(adb->keys) {
      delete adb->keys;
    }
    free(adb);
  }
  if(fd != -1) {
    close(fd);
  }
  return NULL;
}