Function duk_trans_socket_read_cb

Source/Utils/duk_trans_socket_unix.c:145–206

Duktape debug transport callback: (possibly partial) read. */

/* Duktape debug transport callback: (possibly partial) read. */
duk_size_t duk_trans_socket_read_cb(void *udata, char *buffer, duk_size_t length) {
	ssize_t ret;

	(void) udata;  /* not needed by the example */

#if defined(DEBUG_PRINTS)
	fprintf(stderr, "%s: udata=%p, buffer=%p, length=%ld\n",
	        __func__, (void *) udata, (void *) buffer, (long) length);
	fflush(stderr);
#endif

	if (client_sock < 0) {
		return 0;
	}

	if (length == 0) {
		/* This shouldn't happen. */
		fprintf(stderr, "%s: read request length == 0, closing connection\n",
		        __FILE__);
		fflush(stderr);
		goto fail;
	}

	if (buffer == NULL) {
		/* This shouldn't happen. */
		fprintf(stderr, "%s: read request buffer == NULL, closing connection\n",
		        __FILE__);
		fflush(stderr);
		goto fail;
	}

	/* In a production quality implementation there would be a sanity
	 * timeout here to recover from "black hole" disconnects.
	 */

	ret = read(client_sock, (void *) buffer, (size_t) length);
	if (ret < 0) {
		fprintf(stderr, "%s: debug read failed, closing connection: %s\n",
		        __FILE__, strerror(errno));
		fflush(stderr);
		goto fail;
	} else if (ret == 0) {
		fprintf(stderr, "%s: debug read failed, ret == 0 (EOF), closing connection\n",
		        __FILE__);
		fflush(stderr);
		goto fail;
	} else if (ret > (ssize_t) length) {
		fprintf(stderr, "%s: debug read failed, ret too large (%ld > %ld), closing connection\n",
		        __FILE__, (long) ret, (long) length);
		fflush(stderr);
		goto fail;
	}

	return (duk_size_t) ret;

 fail:
	if (client_sock >= 0) {
		(void) close(client_sock);