string * csdbg::filebuf::unique_id ( const i8 *  fmt )

static

Create a unique ID based on process identifiers arranged as indicated by a printf-style format string.

Parameters

[in]

fmt

the format string

Returns

the ID (heap allocated)

Exceptions

std::bad_alloc
csdbg::exception

Note

The ID can be used to name files in an unambiguous way. The specifiers are:

• %e - executable name
• %a - executable absolute path
• %p - process ID
• %t - thread ID
• %s - timestamp (in microseconds)

Attention

If fmt is NULL or an empty string then the default format %e_%p_%t_%s is used. All numeric values are hexadecimal

Definition at line 355 of file filebuf.cpp.

References __D_ASSERT, csdbg::string::append(), csdbg::util::exec_path(), likely, path(), csdbg::string::string(), and unlikely.

{
  __D_ASSERT(fmt != NULL);
  if ( unlikely(fmt == NULL || strlen(fmt) == 0) )
    fmt = "%e_%p_%t_%s";

  struct timeval now;
  gettimeofday(&now, NULL);
  u64 tstamp = static_cast<u64> (now.tv_sec) * 10e+5 + now.tv_usec;

  const i8 *path = util::exec_path();
  string *retval = NULL;

  /* If an exception occurs, release resources and rethrow it */
  try {
    retval = new string();

    for (u32 i = 0, len = strlen(fmt); likely(i < len); i++) {
      i8 ch = fmt[i];
      if ( likely(ch != '%') ) {
        retval->append(ch);
        continue;
      }

      if ( unlikely(i == len - 1) )
        throw exception("invalid format '%s' (at %d: no specifier)", fmt, ++i);

      ch = fmt[++i];
      switch (ch) {
      case '%':
        retval->append(ch);
        break;

      case 'a':
        retval->append(path);
        break;

      case 'e':
        retval->append(basename(path));
        break;

      case 'p':
        retval->append("%x", getpid());
        break;

      case 't':
        retval->append("%lx", pthread_self());
        break;

      case 's':
        retval->append("%lx", tstamp);
        break;

      default: {
        const i8 err[] = "invalid format '%s' (at %d: unknown specifier '%c')";
        throw exception(err, fmt, i, ch);
      }}
    }

    delete[] path;
    return retval;
  }

  catch (...) {
    delete[] path;
    delete retval;
    throw;
  }
}

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