mirror of https://gitee.com/openkylin/libvirt.git
Introduce virStreamSparseSendAll
This is just a wrapper over new function that have been just introduced: virStreamSendHole() . It's very similar to virStreamSendAll() except it handles sparse streams well. Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
This commit is contained in:
Michal Privoznik
parent
3a1e2e920e
commit
a524951091
|
|
@ -71,9 +71,9 @@ int virStreamRecvHole(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
|
||||
|
|
@ -96,6 +96,65 @@ int virStreamSendAll(virStreamPtr st,
|
|||
virStreamSourceFunc handler,
|
||||
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 many bytes are left until the current section ends
|
||||
* (either data section or hole section). Also the stream is
|
||||
* currently in data section, @inData should be set to a non-zero
|
||||
* value and vice versa.
|
||||
*
|
||||
* NB: there's an implicit hole at the end of each file. If
|
||||
* that's the case, @inData and @length should be both set to 0.
|
||||
*
|
||||
* This function should not adjust the current position within
|
||||
* the file.
|
||||
*
|
||||
* Returns 0 on success,
|
||||
* -1 upon error
|
||||
*/
|
||||
typedef int (*virStreamSourceHoleFunc)(virStreamPtr st,
|
||||
int *inData,
|
||||
long long *length,
|
||||
void *opaque);
|
||||
|
||||
/**
|
||||
* virStreamSourceSkipFunc:
|
||||
* @st: the stream object
|
||||
* @length: stream hole size
|
||||
* @opaque: optional application provided data
|
||||
*
|
||||
* This callback is used together with the virStreamSparseSendAll
|
||||
* to skip holes in the underlying file as reported by
|
||||
* virStreamSourceHoleFunc.
|
||||
*
|
||||
* The callback may be invoked multiple times as holes are found
|
||||
* during processing a stream. The application should skip
|
||||
* processing the hole in the stream source and then return.
|
||||
* A return value of -1 at any time will abort the send operation.
|
||||
*
|
||||
* Returns 0 on success,
|
||||
* -1 upon error.
|
||||
*/
|
||||
typedef int (*virStreamSourceSkipFunc)(virStreamPtr st,
|
||||
long long length,
|
||||
void *opaque);
|
||||
|
||||
int virStreamSparseSendAll(virStreamPtr st,
|
||||
virStreamSourceFunc handler,
|
||||
virStreamSourceHoleFunc holeHandler,
|
||||
virStreamSourceSkipFunc skipHandler,
|
||||
void *opaque);
|
||||
|
||||
/**
|
||||
* virStreamSinkFunc:
|
||||
*
|
||||
|
|
|
|||
|
|
@ -574,6 +574,165 @@ virStreamSendAll(virStreamPtr stream,
|
|||
}
|
||||
|
||||
|
||||
/**
|
||||
* virStreamSparseSendAll:
|
||||
* @stream: pointer to the stream object
|
||||
* @handler: source callback for reading data from application
|
||||
* @holeHandler: source callback for determining holes
|
||||
* @skipHandler: skip holes as reported by @holeHandler
|
||||
* @opaque: application defined data
|
||||
*
|
||||
* Send the entire data stream, reading the data from the
|
||||
* requested data source. This is simply a convenient alternative
|
||||
* to virStreamSend, for apps that do blocking-I/O.
|
||||
*
|
||||
* An example using this with a hypothetical file upload
|
||||
* API looks like
|
||||
*
|
||||
* int mysource(virStreamPtr st, char *buf, int nbytes, void *opaque) {
|
||||
* int *fd = opaque;
|
||||
*
|
||||
* return read(*fd, buf, nbytes);
|
||||
* }
|
||||
*
|
||||
* int myskip(virStreamPtr st, long long offset, void *opaque) {
|
||||
* int *fd = opaque;
|
||||
*
|
||||
* return lseek(*fd, offset, SEEK_CUR) == (off_t) -1 ? -1 : 0;
|
||||
* }
|
||||
*
|
||||
* int myindata(virStreamPtr st, int *inData,
|
||||
* long long *offset, void *opaque) {
|
||||
* int *fd = opaque;
|
||||
*
|
||||
* if (@fd in hole) {
|
||||
* *inData = 0;
|
||||
* *offset = holeSize;
|
||||
* } else {
|
||||
* *inData = 1;
|
||||
* *offset = dataSize;
|
||||
* }
|
||||
*
|
||||
* return 0;
|
||||
* }
|
||||
*
|
||||
* virStreamPtr st = virStreamNew(conn, 0);
|
||||
* int fd = open("demo.iso", O_RDONLY);
|
||||
*
|
||||
* virConnectUploadSparseFile(conn, st);
|
||||
* if (virStreamSparseSendAll(st,
|
||||
* mysource,
|
||||
* myindata,
|
||||
* myskip,
|
||||
* &fd) < 0) {
|
||||
* ...report an error ...
|
||||
* goto done;
|
||||
* }
|
||||
* if (virStreamFinish(st) < 0)
|
||||
* ...report an error...
|
||||
* virStreamFree(st);
|
||||
* close(fd);
|
||||
*
|
||||
* Note that @opaque data are shared between @handler, @holeHandler and @skipHandler.
|
||||
*
|
||||
* 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,
|
||||
virStreamSourceSkipFunc skipHandler,
|
||||
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);
|
||||
virCheckNonNullArgGoto(skipHandler, 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;
|
||||
long long sectionLen;
|
||||
const unsigned int skipFlags = 0;
|
||||
|
||||
if (!dataLen) {
|
||||
if (holeHandler(stream, &inData, §ionLen, opaque) < 0) {
|
||||
virStreamAbort(stream);
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
if (!inData && sectionLen) {
|
||||
if (virStreamSendHole(stream, sectionLen, skipFlags) < 0) {
|
||||
virStreamAbort(stream);
|
||||
goto cleanup;
|
||||
}
|
||||
|
||||
if (skipHandler(stream, sectionLen, opaque) < 0) {
|
||||
virReportSystemError(errno, "%s",
|
||||
_("unable to skip hole"));
|
||||
virStreamAbort(stream);
|
||||
goto cleanup;
|
||||
}
|
||||
continue;
|
||||
} 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
|
||||
|
|
|
|||
|
|
@ -765,6 +765,7 @@ LIBVIRT_3.4.0 {
|
|||
virStreamRecvHole;
|
||||
virStreamSendHole;
|
||||
virStreamSparseRecvAll;
|
||||
virStreamSparseSendAll;
|
||||
} LIBVIRT_3.1.0;
|
||||
|
||||
# .... define new API here using predicted next version number ....
|
||||
|
|
|
|||
Loading…
Reference in New Issue