8:31 a.m.
This is just a wrapper over new function that have been just
introduced: virStreamSkip() . It's very similar to
virStreamSendAll() except it handles sparse streams well.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
include/libvirt/libvirt-stream.h | 43 ++++++++++++++--
src/libvirt-stream.c | 104 +++++++++++++++++++++++++++++++++++++++
src/libvirt_public.syms | 1 +
3 files changed, 145 insertions(+), 3 deletions(-)
diff --git a/include/libvirt/libvirt-stream.h b/include/libvirt/libvirt-stream.h
index e5f5126..9aa728e 100644
--- a/include/libvirt/libvirt-stream.h
+++ b/include/libvirt/libvirt-stream.h
@@ -69,9 +69,9 @@ int virStreamHoleSize(virStreamPtr,
* @nbytes: size of the data array
* @opaque: optional application provided data
*
- * The virStreamSourceFunc callback is used together
- * with the virStreamSendAll function for libvirt to
- * obtain the data that is to be sent.
+ * The virStreamSourceFunc callback is used together with
+ * the virStreamSendAll and virStreamSparseSendAll functions
+ * for libvirt to obtain the data that is to be sent.
*
* The callback will be invoked multiple times,
* fetching data in small chunks. The application
@@ -95,6 +95,43 @@ int virStreamSendAll(virStreamPtr st,
void *opaque);
/**
+ * virStreamSourceHoleFunc:
+ * @st: the stream object
+ * @inData: are we in data section
+ * @length: how long is the section we are currently in
+ * @opaque: optional application provided data
+ *
+ * The virStreamSourceHoleFunc callback is used together
+ * with the virStreamSparseSendAll function for libvirt to
+ * obtain the length of section stream is currently in.
+ *
+ * Moreover, upon successful return, @length should be
+ * updated with how much bytes are there left until current
+ * section ends (be it data section or hole section) and if
+ * the stream is currently in data section, @inData should
+ * be set to a non-zero value and vice versa.
+ * As a corner case, there's an implicit hole at the end of
+ * each file. If that's the case, @inData should be set to 0
+ * as well as @length.
+ * Moreover, this function should always leave the stream in
+ * data section. Either the one that we have been to prior
+ * calling this function, or the one that follows the hole
+ * we are in.
+ *
+ * Returns 0 on success,
+ * -1 upon error
+ */
+typedef int (*virStreamSourceHoleFunc)(virStreamPtr st,
+ int *inData,
+ unsigned long long *length,
+ void *opaque);
+
+int virStreamSparseSendAll(virStreamPtr st,
+ virStreamSourceFunc handler,
+ virStreamSourceHoleFunc holeHandler,
+ void *opaque);
+
+/**
* virStreamSinkFunc:
*
* @st: the stream object
diff --git a/src/libvirt-stream.c b/src/libvirt-stream.c
index 81190cc..3a9edcd 100644
--- a/src/libvirt-stream.c
+++ b/src/libvirt-stream.c
@@ -565,7 +565,111 @@ virStreamSendAll(virStreamPtr stream,
}
+
/**
+ * virStreamSparseSendAll:
+ * @stream: pointer to the stream object
+ * @handler: source callback for reading data from application
+ * @holeHandler: source callback for determining holes
+ * @opaque: application defined data
+ *
+ * Some dummy description here.
+ *
+ * Opaque data in @opaque are shared between @handler and @holeHandler.
+ *
+ * Returns 0 if all the data was successfully sent. The caller
+ * should invoke virStreamFinish(st) to flush the stream upon
+ * success and then virStreamFree
+ *
+ * Returns -1 upon any error, with virStreamAbort() already
+ * having been called, so the caller need only call
+ * virStreamFree()
+ */
+int virStreamSparseSendAll(virStreamPtr stream,
+ virStreamSourceFunc handler,
+ virStreamSourceHoleFunc holeHandler,
+ void *opaque)
+{
+ char *bytes = NULL;
+ size_t want = VIR_NET_MESSAGE_LEGACY_PAYLOAD_MAX;
+ int ret = -1;
+ unsigned long long dataLen = 0;
+
+ VIR_DEBUG("stream=%p handler=%p holeHandler=%p opaque=%p",
+ stream, handler, holeHandler, opaque);
+
+ virResetLastError();
+
+ virCheckStreamReturn(stream, -1);
+ virCheckNonNullArgGoto(handler, cleanup);
+ virCheckNonNullArgGoto(holeHandler, cleanup);
+
+ if (stream->flags & VIR_STREAM_NONBLOCK) {
+ virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+ _("data sources cannot be used for non-blocking
streams"));
+ goto cleanup;
+ }
+
+ if (VIR_ALLOC_N(bytes, want) < 0)
+ goto cleanup;
+
+ for (;;) {
+ int inData, got, offset = 0;
+ unsigned long long sectionLen;
+
+ if (!dataLen) {
+ if (holeHandler(stream, &inData, §ionLen, opaque) < 0) {
+ virStreamAbort(stream);
+ goto cleanup;
+ }
+
+ if (!inData) {
+ if (sectionLen && virStreamSkip(stream, sectionLen) < 0) {
+ virStreamAbort(stream);
+ goto cleanup;
+ }
+
+ if (sectionLen)
+ continue;
+
+ /* Here inData == 0 and sectionLen == 0 as well.
+ * This means, we are in the trailing hole. Don't
+ * start new iteration but let virStreamSend()
+ * close the stream gracefully. */
+ } else {
+ dataLen = sectionLen;
+ }
+ }
+
+ if (want > dataLen)
+ want = dataLen;
+
+ got = (handler)(stream, bytes, want, opaque);
+ if (got < 0) {
+ virStreamAbort(stream);
+ goto cleanup;
+ }
+ if (got == 0)
+ break;
+ while (offset < got) {
+ int done;
+ done = virStreamSend(stream, bytes + offset, got - offset);
+ if (done < 0)
+ goto cleanup;
+ offset += done;
+ dataLen -= done;
+ }
+ }
+ ret = 0;
+
+ cleanup:
+ VIR_FREE(bytes);
+
+ if (ret != 0)
+ virDispatchError(stream->conn);
+
+ return ret;
+}/**
* virStreamRecvAll:
* @stream: pointer to the stream object
* @handler: sink callback for writing data to application
diff --git a/src/libvirt_public.syms b/src/libvirt_public.syms
index 008dc59..ea4ddd5 100644
--- a/src/libvirt_public.syms
+++ b/src/libvirt_public.syms
@@ -765,6 +765,7 @@ LIBVIRT_3.3.0 {
virStreamRecvFlags;
virStreamSkip;
virStreamSparseRecvAll;
+ virStreamSparseSendAll;
} LIBVIRT_3.1.0;
# .... define new API here using predicted next version number ....
--
2.10.2