odyssey/lib/mm_read_sync.c

141 lines
3.1 KiB
C

/*
* machinarium.
*
* Cooperative multitasking engine.
*/
#include <machinarium_private.h>
#include <machinarium.h>
static void
mm_io_read_timeout_cb(uv_timer_t *handle)
{
mmio *io = handle->data;
uv_read_stop((uv_stream_t*)&io->handle);
io->read_timeout = 1;
io->read_status = -ETIMEDOUT;
mm_wakeup(io->f, io->read_fiber);
}
static void
mm_io_read_cancel_cb(mmfiber *fiber, void *arg)
{
mmio *io = arg;
mm_io_timer_stop(io, &io->read_timer);
uv_read_stop((uv_stream_t*)&io->handle);
io->read_timeout = 0;
io->read_status = -ECANCELED;
mm_wakeup(io->f, io->read_fiber);
}
static void
mm_io_read_alloc_cb(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf)
{
mmio *io = handle->data;
int rc;
rc = mm_bufensure(&io->read_ahead, io->read_ahead_size);
if (rc == -1)
return;
buf->base = io->read_ahead.p;
buf->len = io->read_ahead_size;
}
static void
mm_io_read_cb(uv_stream_t *handle, ssize_t size, const uv_buf_t *buf)
{
mmio *io = handle->data;
assert(! io->read_timeout);
if (size >= 0) {
mm_bufadvance(&io->read_ahead, size);
if (mm_bufused(&io->read_ahead) < io->read_size) {
/* expect more data */
return;
}
/* readahead buffer now has atleast as minum
* size required by read operation */
assert(mm_bufused(&io->read_ahead) >= io->read_size);
} else {
/* connection closed */
if (size == UV_EOF) {
io->connected = 0;
}
io->read_status = size;
}
mm_io_timer_stop(io, &io->read_timer);
uv_read_stop(handle);
mm_wakeup(io->f, io->read_fiber);
}
MM_API int
mm_read(mm_io_t iop, int size, uint64_t time_ms)
{
mmio *io = iop;
mmfiber *current = mm_current(io->f);
if (mm_fiber_is_cancel(current))
return -ECANCELED;
if (io->read_fiber)
return -1;
if (size > io->read_ahead_size)
return -EINVAL;
io->read_status = 0;
io->read_timeout = 0;
io->read_size = 0;
io->read_fiber = NULL;
/* readhead */
int ra_left = mm_bufused(&io->read_ahead) - io->read_ahead_pos;
if (ra_left >= size) {
io->read_ahead_pos_data = io->read_ahead_pos;
io->read_ahead_pos += size;
return 0;
}
/* ra_left < size */
if (ra_left > 0) {
memmove(io->read_ahead.s,
io->read_ahead.s + io->read_ahead_pos, ra_left);
mm_bufreset(&io->read_ahead);
mm_bufadvance(&io->read_ahead, ra_left);
} else {
mm_bufreset(&io->read_ahead);
}
io->read_size = size - ra_left;
io->read_fiber = current;
io->read_ahead_pos_data = 0;
io->read_ahead_pos = ra_left + io->read_size;
mm_io_timer_start(io, &io->read_timer, mm_io_read_timeout_cb,
time_ms);
int rc;
rc = uv_read_start((uv_stream_t*)&io->handle,
mm_io_read_alloc_cb,
mm_io_read_cb);
if (rc < 0) {
mm_io_timer_stop(io, &io->read_timer);
io->read_fiber = NULL;
return rc;
}
mm_fiber_op_begin(io->read_fiber, mm_io_read_cancel_cb, io);
mm_scheduler_yield(&io->f->scheduler);
mm_fiber_op_end(io->read_fiber);
rc = io->read_status;
io->read_fiber = NULL;
if (rc < 0)
return rc;
return 0;
}
MM_API int
mm_read_is_timeout(mm_io_t iop)
{
mmio *io = iop;
return io->read_timeout;
}
MM_API char*
mm_read_buf(mm_io_t iop)
{
mmio *io = iop;
return io->read_ahead.s + io->read_ahead_pos_data;
}