static bool
preallocate_file_sparse (tr_sys_file_t fd, uint64_t length, tr_error ** error)
{
tr_error * my_error = NULL;
if (length == 0)
return true;
if (tr_sys_file_preallocate (fd, length, TR_SYS_FILE_PREALLOC_SPARSE, &my_error))
return true;
dbgmsg ("Preallocating (sparse, normal) failed (%d): %s", my_error->code, my_error->message);
if (!TR_ERROR_IS_ENOSPC (my_error->code))
{
const char zero = '\0';
tr_error_clear (&my_error);
/* fallback: the old-style seek-and-write */
if (tr_sys_file_write_at (fd, &zero, 1, length - 1, NULL, &my_error) &&
tr_sys_file_truncate (fd, length, &my_error))
return true;
dbgmsg ("Preallocating (sparse, fallback) failed (%d): %s", my_error->code, my_error->message);
}
tr_error_propagate (error, &my_error);
return false;
}
/* returns 0 on success, or an errno on failure */
static int
readOrWriteBytes (tr_session * session,
tr_torrent * tor,
int ioMode,
tr_file_index_t fileIndex,
uint64_t fileOffset,
void * buf,
size_t buflen)
{
tr_sys_file_t fd;
int err = 0;
const bool doWrite = ioMode >= TR_IO_WRITE;
const tr_info * const info = &tor->info;
const tr_file * const file = &info->files[fileIndex];
assert (fileIndex < info->fileCount);
assert (!file->length || (fileOffset < file->length));
assert (fileOffset + buflen <= file->length);
if (!file->length)
return 0;
/***
**** Find the fd
***/
fd = tr_fdFileGetCached (session, tr_torrentId (tor), fileIndex, doWrite);
if (fd == TR_BAD_SYS_FILE)
{
/* it's not cached, so open/create it now */
char * subpath;
const char * base;
/* see if the file exists... */
if (!tr_torrentFindFile2 (tor, fileIndex, &base, &subpath, NULL))
{
/* we can't read a file that doesn't exist... */
if (!doWrite)
err = ENOENT;
/* figure out where the file should go, so we can create it */
base = tr_torrentGetCurrentDir (tor);
subpath = tr_sessionIsIncompleteFileNamingEnabled (tor->session)
? tr_torrentBuildPartial (tor, fileIndex)
: tr_strdup (file->name);
}
if (!err)
{
/* open (and maybe create) the file */
char * filename = tr_buildPath (base, subpath, NULL);
const int prealloc = file->dnd || !doWrite
? TR_PREALLOCATE_NONE
: tor->session->preallocationMode;
if (((fd = tr_fdFileCheckout (session, tor->uniqueId, fileIndex,
filename, doWrite,
prealloc, file->length))) == TR_BAD_SYS_FILE)
{
err = errno;
tr_logAddTorErr (tor, "tr_fdFileCheckout failed for \"%s\": %s",
filename, tr_strerror (err));
}
else if (doWrite)
{
/* make a note that we just created a file */
tr_statsFileCreated (tor->session);
}
tr_free (filename);
}
tr_free (subpath);
}
/***
**** Use the fd
***/
if (!err)
{
tr_error * error = NULL;
if (ioMode == TR_IO_READ)
{
if (!tr_sys_file_read_at (fd, buf, buflen, fileOffset, NULL, &error))
{
err = error->code;
tr_logAddTorErr (tor, "read failed for \"%s\": %s", file->name, error->message);
tr_error_free (error);
}
}
else if (ioMode == TR_IO_WRITE)
{
if (!tr_sys_file_write_at (fd, buf, buflen, fileOffset, NULL, &error))
{
err = error->code;
tr_logAddTorErr (tor, "write failed for \"%s\": %s", file->name, error->message);
tr_error_free (error);
}
}
else if (ioMode == TR_IO_PREFETCH)
{
tr_sys_file_prefetch (fd, fileOffset, buflen, NULL);
}
else
{
abort ();
}
}
return err;
}
