[libvirt] [PATCH RFC 12/48] 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>
---
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 707c0ed..2632d55 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 f476eae..f2983e0 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1030,6 +1030,7 @@ virStateCleanup;
virStateInitialize;
virStateReload;
virStateStop;
+virStreamInData;
# locking/domain_lock.h
--
2.8.4