[libvirt] [PATCH RFC 29/48] fdstream: Implement seek
Implement virStreamSkip and virStreamInData callbacks. These
callbacks do no magic, just skip a hole or detect whether we are
in a data section of a file or in a hole and how much bytes can
we read until section changes.
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/fdstream.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/src/fdstream.c b/src/fdstream.c
index bebeac3..be94325 100644
--- a/src/fdstream.c
+++ b/src/fdstream.c
@@ -504,11 +504,59 @@ static int virFDStreamRead(virStreamPtr st, char *bytes, size_t
nbytes)
}
+static int
+virFDStreamSkip(virStreamPtr st,
+ unsigned long long length)
+{
+ virFDStreamDataPtr fdst = st->privateData;
+ off_t off;
+ int ret = -1;
+
+ virObjectLock(fdst);
+ if (fdst->length) {
+ if (fdst->offset + length > fdst->length) {
+ virReportSystemError(ENOSPC, "%s",
+ _("cannot write to stream"));
+ goto cleanup;
+ }
+ fdst->offset += length;
+ }
+
+ off = lseek(fdst->fd, length, SEEK_CUR);
+ if (off == (off_t) -1) {
+ virReportSystemError(errno, "%s",
+ _("unable to seek"));
+ goto cleanup;
+ }
+ ret = 0;
+ cleanup:
+ virObjectUnlock(fdst);
+ return ret;
+}
+
+
+static int
+virFDStreamInData(virStreamPtr st,
+ int *inData,
+ unsigned long long *length)
+{
+ virFDStreamDataPtr fdst = st->privateData;
+ int ret = -1;
+
+ virObjectLock(fdst);
+ ret = virFileInData(fdst->fd, inData, length);
+ virObjectUnlock(fdst);
+ return ret;
+}
+
+
static virStreamDriver virFDStreamDrv = {
.streamSend = virFDStreamWrite,
.streamRecv = virFDStreamRead,
.streamFinish = virFDStreamClose,
.streamAbort = virFDStreamAbort,
+ .streamSkip = virFDStreamSkip,
+ .streamInData = virFDStreamInData,
.streamEventAddCallback = virFDStreamAddCallback,
.streamEventUpdateCallback = virFDStreamUpdateCallback,
.streamEventRemoveCallback = virFDStreamRemoveCallback
--
2.8.4