2014-03-31 15:46 GMT+02:00 Michal Privoznik <mprivozn@redhat.com>:
On 30.03.2014 21:03, Matthias Bolte wrote:
This allows to implement libvirt functions that use streams, such as virDoaminScreenshot, without the need to store the downloaded data in a temporary file first. The stream driver directly interacts with libcurl to send and receive data.
The driver uses the libcurl multi interface that allows to do a transfer in multiple curl_multi_perform() calls. The easy interface would do the whole transfer in a single curl_easy_perform() call. This doesn't work with the libvirt stream API that is driven by multiple calls to the virStreamSend() and virStreamRecv() functions.
The curl_multi_wait() function is used to do blocking operations. But it was added in libcurl 7.28.0. For older versions it is emulated using the socket callback of the multi interface.
The current driver only supports blocking operations. There is already some code in place for non-blocking mode but it's incomplete. As you can tell from the copyright date I implemeted this in 2012, but never came around to publish it then. I did some work in 2013 and now it's 2014 and I don't want to hold it back any longer. --- po/POTFILES.in | 1 + src/Makefile.am | 1 + src/esx/esx_stream.c | 478 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/esx/esx_stream.h | 32 ++++ src/esx/esx_vi.c | 222 +++++++++++++++++++++++- src/esx/esx_vi.h | 19 +- 6 files changed, 749 insertions(+), 4 deletions(-) create mode 100644 src/esx/esx_stream.c create mode 100644 src/esx/esx_stream.h
+static int +esxStreamClose(virStreamPtr stream, bool finish) +{ + int result = 0; + esxStreamPrivate *priv = stream->privateData; + + if (!priv) + return 0; + + virMutexLock(&priv->curl->lock); + + if (finish && priv->backlog_used > 0) {
I think you want to unlock the curl lock here.
No, because there is no return statement in the if block, so the unlock call after the if block is sufficient.
+ virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Stream has untransferred data left")); + result = -1; + } + + stream->privateData = NULL; + + virMutexUnlock(&priv->curl->lock); + + esxFreeStreamPrivate(&priv); + + return result; +} +
diff --git a/src/esx/esx_vi.c b/src/esx/esx_vi.c index 6188139..ba34bfd 100644 --- a/src/esx/esx_vi.c +++ b/src/esx/esx_vi.c @@ -2,7 +2,7 @@ * esx_vi.c: client for the VMware VI API 2.5 to manage ESX hosts * * Copyright (C) 2010-2012 Red Hat, Inc. - * Copyright (C) 2009-2012 Matthias Bolte <matthias.bolte@googlemail.com> + * Copyright (C) 2009-2012, 2014 Matthias Bolte <matthias.bolte@googlemail.com> * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -22,6 +22,7 @@
#include <config.h>
+#include <poll.h> #include <libxml/parser.h> #include <libxml/xpathInternals.h>
@@ -662,6 +663,68 @@ esxVI_SharedCURL_Remove(esxVI_SharedCURL *shared, esxVI_CURL *curl) * MultiCURL */
+#if ESX_EMULATE_CURL_MULTI_WAIT + +static int +esxVI_MultiCURL_SocketCallback(CURL *handle ATTRIBUTE_UNUSED, + curl_socket_t fd, int action, + void *callback_opaque, + void *socket_opaque ATTRIBUTE_UNUSED) +{ + esxVI_MultiCURL *multi = callback_opaque; + size_t i; + struct pollfd *pollfd = NULL; + struct pollfd dummy; + + if (action & CURL_POLL_REMOVE) { + for (i = 0; i < multi->npollfds; ++i) { + if (multi->pollfds[i].fd == fd) { + VIR_DELETE_ELEMENT(multi->pollfds, i, multi->npollfds); + break; + } + } + } else { + for (i = 0; i < multi->npollfds; ++i) { + if (multi->pollfds[i].fd == fd) { + pollfd = &multi->pollfds[i]; + break; + } + } + + if (pollfd == NULL) { + if (VIR_APPEND_ELEMENT(multi->pollfds, multi->npollfds, dummy) < 0) { + return 0;
Okay, this is strange. But I see why you can't return -1. From the curl_multi_socket() documentation:
"The callback MUST return 0."
I added a comment about this now.
+ } + + pollfd = &multi->pollfds[multi->npollfds - 1]; + } + + pollfd->fd = fd; + pollfd->events = 0; + + if (action & CURL_POLL_IN) + pollfd->events |= POLLIN; + + if (action & CURL_POLL_OUT) + pollfd->events |= POLLOUT; + } + + return 0; +} +
ACK with the nits fixed.
Michal
Thanks, pushed... finally :) -- Matthias Bolte http://photron.blogspot.com