// Callback invoked by libuv after it copies the data into the buffer provided
// by `alloc_cb`. This is also called on EOF or when `alloc_cb` returns a
// 0-length buffer.
static void read_cb(uv_stream_t *stream, ssize_t cnt, const uv_buf_t *buf)
{
RStream *rstream = stream->data;
if (cnt <= 0) {
if (cnt != UV_ENOBUFS) {
// Read error or EOF, either way stop the stream and invoke the callback
// with eof == true
uv_read_stop(stream);
emit_read_event(rstream, true);
}
return;
}
// at this point we're sure that cnt is positive, no error occurred
size_t nread = (size_t) cnt;
// Data was already written, so all we need is to update 'wpos' to reflect
// the space actually used in the buffer.
rstream->wpos += nread;
if (rstream->wpos == rstream->buffer_size) {
// The last read filled the buffer, stop reading for now
rstream_stop(rstream);
}
rstream->reading = false;
emit_read_event(rstream, false);
}
// Called by the by the 'idle' handle to emulate a reading event
static void fread_idle_cb(uv_idle_t *handle)
{
uv_fs_t req;
RStream *rstream = handle->data;
rstream->uvbuf.base = rstream->buffer + rstream->wpos;
rstream->uvbuf.len = rstream->buffer_size - rstream->wpos;
// the offset argument to uv_fs_read is int64_t, could someone really try
// to read more than 9 quintillion (9e18) bytes?
// upcast is meant to avoid tautological condition warning on 32 bits
uintmax_t fpos_intmax = rstream->fpos;
assert(fpos_intmax <= INT64_MAX);
// Synchronous read
uv_fs_read(
uv_default_loop(),
&req,
rstream->fd,
&rstream->uvbuf,
1,
(int64_t) rstream->fpos,
NULL);
uv_fs_req_cleanup(&req);
if (req.result <= 0) {
uv_idle_stop(rstream->fread_idle);
emit_read_event(rstream, true);
return;
}
// no errors (req.result (ssize_t) is positive), it's safe to cast.
size_t nread = (size_t) req.result;
rstream->wpos += nread;
rstream->fpos += nread;
if (rstream->wpos == rstream->buffer_size) {
// The last read filled the buffer, stop reading for now
rstream_stop(rstream);
}
emit_read_event(rstream, false);
}
// Called by the by the 'idle' handle to emulate a reading event
static void fread_idle_cb(uv_idle_t *handle)
{
uv_fs_t req;
RStream *rstream = handle->data;
rstream->uvbuf.base = rstream->buffer + rstream->wpos;
rstream->uvbuf.len = rstream->buffer_size - rstream->wpos;
// the offset argument to uv_fs_read is int64_t, could someone really try
// to read more than 9 quintillion (9e18) bytes?
// DISABLED TO FIX BROKEN BUILD ON 32bit
// TODO(elmart): Review types to allow assertion
// assert(rstream->fpos <= INT64_MAX);
// Synchronous read
uv_fs_read(
uv_default_loop(),
&req,
rstream->fd,
&rstream->uvbuf,
1,
(int64_t) rstream->fpos,
NULL);
uv_fs_req_cleanup(&req);
if (req.result <= 0) {
uv_idle_stop(rstream->fread_idle);
emit_read_event(rstream, true);
return;
}
// no errors (req.result (ssize_t) is positive), it's safe to cast.
size_t nread = (size_t) req.result;
rstream->wpos += nread;
rstream->fpos += nread;
if (rstream->wpos == rstream->buffer_size) {
// The last read filled the buffer, stop reading for now
rstream_stop(rstream);
}
emit_read_event(rstream, false);
}
