Re: [libvirt] [PATCH v2 16/38] Introduce virStreamInData

This is just an internal API, that calls corresponding function

in stream driver. This function will set @data=1 if the

underlying file is in data section, or @data=0 if it is in a hole. At any rate, @length is set to number of bytes remaining in the section the file currently is.

Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/driver-stream.h | 6 ++++++ src/libvirt-stream.c | 43 +++++++++++++++++++++++++++++++++++++++++++ src/libvirt_internal.h | 3 +++ src/libvirt_private.syms | 1 + 4 files changed, 53 insertions(+) diff --git a/src/driver-stream.h b/src/driver-stream.h index e196b6d..5d84b9a 100644 --- a/src/driver-stream.h +++ b/src/driver-stream.h @@ -50,6 +50,11 @@ typedef int unsigned long long *length); typedef int +(*virDrvStreamInData)(virStreamPtr st, + int *data, + unsigned long long *length); + +typedef int (*virDrvStreamEventAddCallback)(virStreamPtr stream, int events, virStreamEventCallback cb, @@ -78,6 +83,7 @@ struct _virStreamDriver { virDrvStreamRecvFlags streamRecvFlags; virDrvStreamSkip streamSkip; virDrvStreamHoleSize streamHoleSize; + virDrvStreamInData streamInData; virDrvStreamEventAddCallback streamEventAddCallback; virDrvStreamEventUpdateCallback streamEventUpdateCallback; virDrvStreamEventRemoveCallback streamEventRemoveCallback; diff --git a/src/libvirt-stream.c b/src/libvirt-stream.c index 7ad5a38..975315e 100644 --- a/src/libvirt-stream.c +++ b/src/libvirt-stream.c @@ -473,6 +473,49 @@ virStreamHoleSize(virStreamPtr stream, /** + * virStreamInData: + * @stream: stream + * @data: are we in data or hole + * @length: length to next section + * + * This function checks the underlying stream (typically a file) + * to learn whether the current stream position lies within a + * data section or a hold. Upon return @data is set to a nonzero

+ * value if former is the case, or to zero if @stream is in a + * hole. Moreover, @length is updated to tell caller how many + * bytes can be read from @stream until current section changes + * (from data to a hole or vice versa). + * + * As a special case, there's an implicit hole at EOF. In this

+ * situation this function should set @data = false, @length = 0 + * and return 0.

+ * + * Returns 0 on success, + * -1 otherwise + */ +int +virStreamInData(virStreamPtr stream, + int *data,

+ unsigned long long *length) +{ + VIR_DEBUG("stream=%p, data=%p, length=%p", stream, data, length); + + /* No checks of arguments or error resetting. This is an + * internal function that just happen to live next to some + * public functions of ours. */ + + if (stream->driver->streamInData) { + int ret; + ret = (stream->driver->streamInData)(stream, data, length); + return ret; + } + + virReportUnsupportedError(); + return -1; +} + + +/** * virStreamSendAll: * @stream: pointer to the stream object * @handler: source callback for reading data from application diff --git a/src/libvirt_internal.h b/src/libvirt_internal.h index 96439d8..0e945aa 100644 --- a/src/libvirt_internal.h +++ b/src/libvirt_internal.h @@ -294,4 +294,7 @@ virTypedParameterValidateSet(virConnectPtr conn, virTypedParameterPtr params, int nparams); +int virStreamInData(virStreamPtr stream, + int *data, + unsigned long long *lengtht);

#endif diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 7132b3a..07633f2 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -1117,6 +1117,7 @@ virStateCleanup; virStateInitialize; virStateReload; virStateStop; +virStreamInData; # locking/domain_lock.h