producer_result_t device_read_producer(gpointer devicep,
queue_buffer_t *buffer,
size_t hint_size G_GNUC_UNUSED) {
Device* device;
device = (Device*) devicep;
g_assert(IS_DEVICE(device));
buffer->offset = 0;
for (;;) {
int result, read_size;
read_size = buffer->alloc_size;
result = device_read_block(device, buffer->data, &read_size);
if (result > 0) {
buffer->data_size = read_size;
return PRODUCER_MORE;
} else if (result == 0) {
/* unfortunately, the best "memory" we have of needing a larger
* block size is the next time this buffer comes around, and even
* this is incomplete as buffers may be resized periodically. So
* we'll end up calling read_block with small buffers more often
* than strictly necessary. */
buffer->data = realloc(buffer->data, read_size);
buffer->alloc_size = read_size;
} else if (device->is_eof) {
return PRODUCER_FINISHED;
} else {
buffer->data_size = 0;
return PRODUCER_ERROR;
}
}
}
static gpointer
pull_buffer_impl(
XferElement *elt,
size_t *size)
{
XferSourceDevice *self = (XferSourceDevice *)elt;
gpointer buf = NULL;
int result;
int devsize;
int max_block;
/* indicate EOF on an cancel */
if (elt->cancelled) {
*size = 0;
return NULL;
}
/* get the device block size */
if (self->block_size == 0) {
self->block_size = self->device->block_size;
}
do {
buf = g_try_malloc(self->block_size);
if (buf == NULL) {
xfer_cancel_with_error(elt,
_("%s: cannot allocate memory"),
self->device->device_name);
wait_until_xfer_cancelled(elt->xfer);
return NULL;
}
devsize = (int)self->block_size;
if (elt->size < 0)
max_block = -1;
else
max_block = (elt->size+self->block_size-1)/self->block_size;
result = device_read_block(self->device, buf, &devsize, max_block);
*size = devsize;
/* if the buffer was too small, loop around again */
if (result == 0) {
g_assert(*size > self->block_size);
self->block_size = devsize;
amfree(buf);
}
} while (result == 0);
if (result < 0) {
amfree(buf);
/* if we're not at EOF, it's an error */
if (!self->device->is_eof) {
xfer_cancel_with_error(elt,
_("error reading from %s: %s"),
self->device->device_name,
device_error_or_status(self->device));
wait_until_xfer_cancelled(elt->xfer);
}
*size = 0;
return NULL;
}
return buf;
}
static gpointer
pull_buffer_impl(
XferElement *elt,
size_t *size)
{
XferSourceRecovery *self = XFER_SOURCE_RECOVERY(elt);
gpointer buf = NULL;
int result;
int devsize;
XMsg *msg;
g_assert(elt->output_mech == XFER_MECH_PULL_BUFFER);
g_mutex_lock(self->start_part_mutex);
if (elt->size == 0) {
if (elt->offset == 0 && elt->orig_size == 0) {
self->paused = TRUE;
} else {
DBG(2, "xfer-source-recovery sending XMSG_CRC message");
DBG(2, "xfer-source-recovery CRC: %08x size %lld",
crc32_finish(&elt->crc), (long long)elt->crc.size);
msg = xmsg_new(XFER_ELEMENT(self), XMSG_CRC, 0);
msg->crc = crc32_finish(&elt->crc);
msg->size = elt->crc.size;
xfer_queue_message(elt->xfer, msg);
/* the device has signalled EOF (really end-of-part), so clean up instance
* variables and report the EOP to the caller in the form of an xmsg */
DBG(2, "pull_buffer hit EOF; sending XMSG_SEGMENT_DONE");
msg = xmsg_new(XFER_ELEMENT(self), XMSG_SEGMENT_DONE, 0);
msg->size = self->part_size;
if (self->part_timer) {
msg->duration = g_timer_elapsed(self->part_timer, NULL);
g_timer_destroy(self->part_timer);
self->part_timer = NULL;
}
msg->partnum = 0;
msg->fileno = self->device->file;
msg->successful = TRUE;
msg->eof = FALSE;
self->paused = TRUE;
device_clear_bytes_read(self->device);
self->bytes_read += self->part_size;
self->part_size = 0;
self->block_size = 0;
/* don't queue the XMSG_PART_DONE until we've adjusted all of our
* instance variables appropriately */
xfer_queue_message(elt->xfer, msg);
if (self->device->is_eof) {
DBG(2, "pull_buffer hit EOF; sending XMSG_PART_DONE");
msg = xmsg_new(XFER_ELEMENT(self), XMSG_PART_DONE, 0);
msg->size = self->part_size;
if (self->part_timer) {
msg->duration = g_timer_elapsed(self->part_timer, NULL);
g_timer_destroy(self->part_timer);
self->part_timer = NULL;
}
msg->partnum = 0;
msg->fileno = self->device->file;
msg->successful = TRUE;
msg->eof = FALSE;
xfer_queue_message(elt->xfer, msg);
}
}
}
while (1) {
/* make sure we have a device */
while (self->paused && !elt->cancelled)
g_cond_wait(self->start_part_cond, self->start_part_mutex);
/* indicate EOF on an cancel or when there are no more parts */
if (elt->cancelled) {
goto error;
}
if (self->done)
goto error;
/* start the timer if this is the first pull_buffer of this part */
if (!self->part_timer) {
DBG(2, "first pull_buffer of new part");
self->part_timer = g_timer_new();
}
if (elt->size == 0) {
result = -1;
} else {
/* loop until we read a full block, in case the blocks are larger
* than expected */
if (self->block_size == 0)
self->block_size = (size_t)self->device->block_size;
do {
int max_block;
buf = g_malloc(self->block_size);
if (buf == NULL) {
xfer_cancel_with_error(elt,
_("%s: cannot allocate memory"),
self->device->device_name);
g_mutex_unlock(self->start_part_mutex);
wait_until_xfer_cancelled(elt->xfer);
goto error_unlocked;
}
devsize = (int)self->block_size;
if (elt->size < 0)
max_block = -1;
else
max_block = (elt->size+self->block_size-1)/self->block_size;
result = device_read_block(self->device, buf, &devsize, max_block);
*size = devsize;
if (result == 0) {
g_assert(*size > self->block_size);
self->block_size = devsize;
amfree(buf);
}
} while (result == 0);
if (result > 0 &&
(elt->offset ||
(elt->size > 0 && (long long unsigned)elt->size < *size))) {
gpointer buf1 = g_malloc(self->block_size);
if ((long long unsigned)elt->offset > *size) {
g_debug("offset > *size");
} else if ((long long unsigned)elt->offset == *size) {
g_debug("offset == *size");
}
*size -= elt->offset;
if (elt->size > 0 && (size_t)elt->size < *size)
*size = elt->size;
memmove(buf1, buf + elt->offset, *size);
elt->offset = 0;
g_free(buf);
buf = buf1;
}
if (result > 0)
elt->size -= *size;
}
/* if this block was successful, return it */
if (result > 0) {
self->part_size += *size;
break;
}
if (result < 0) {
amfree(buf);
/* if we're not at EOF, it's an error */
if (!self->device->is_eof && elt->size != 0) {
xfer_cancel_with_error(elt,
_("error reading from %s: %s"),
self->device->device_name,
device_error_or_status(self->device));
g_mutex_unlock(self->start_part_mutex);
wait_until_xfer_cancelled(elt->xfer);
goto error_unlocked;
}
DBG(2, "xfer-source-recovery sending XMSG_CRC message");
DBG(2, "xfer-source-recovery CRC: %08x size %lld",
crc32_finish(&elt->crc), (long long)elt->crc.size);
msg = xmsg_new(XFER_ELEMENT(self), XMSG_CRC, 0);
msg->crc = crc32_finish(&elt->crc);
msg->size = elt->crc.size;
xfer_queue_message(elt->xfer, msg);
/* the device has signalled EOF (really end-of-part), so clean up instance
* variables and report the EOP to the caller in the form of an xmsg */
DBG(2, "pull_buffer hit EOF; sending XMSG_PART_DONE");
msg = xmsg_new(XFER_ELEMENT(self), XMSG_PART_DONE, 0);
msg->size = self->part_size;
msg->duration = g_timer_elapsed(self->part_timer, NULL);
msg->partnum = 0;
msg->fileno = self->device->file;
msg->successful = TRUE;
msg->eof = FALSE;
self->paused = TRUE;
self->bytes_read += self->part_size;
device_clear_bytes_read(self->device);
self->part_size = 0;
self->block_size = 0;
if (self->part_timer) {
g_timer_destroy(self->part_timer);
self->part_timer = NULL;
}
/* don't queue the XMSG_PART_DONE until we've adjusted all of our
* instance variables appropriately */
xfer_queue_message(elt->xfer, msg);
if (elt->size == 0) {
g_mutex_unlock(self->start_part_mutex);
return NULL;
}
}
}
g_mutex_unlock(self->start_part_mutex);
if (buf) {
crc32_add(buf, *size, &elt->crc);
}
return buf;
error:
g_mutex_unlock(self->start_part_mutex);
error_unlocked:
*size = 0;
return NULL;
}
