On 04/20/2017 06:01 AM, Michal Privoznik wrote:
> 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.
You could have some changes here due to previous API name changes.
Still the commit msg is a bit terse needs some cleanup anyway.
>
> Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
> ---
> include/libvirt/libvirt-stream.h | 59 +++++++++++++++++++--
> src/libvirt-stream.c | 107 +++++++++++++++++++++++++++++++++++++++
> src/libvirt_public.syms | 1 +
> 3 files changed, 164 insertions(+), 3 deletions(-)
>
> diff --git a/include/libvirt/libvirt-stream.h b/include/libvirt/libvirt-stream.h
> index e5f5126..3e9ff11 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 +95,59 @@ 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
s/much/many
s/there//
s/until/until the/
> + * section ends (be it data section or hole section) and if
s/be it/either/
s/) and if/). Also if/
> + * the stream is currently in data section, @inData should
> + * be set to a non-zero value and vice versa.
Need extra line between paragraphs
> + * As a corner case, there's an implicit hole at the end of
s/As a corner case,/NB:/
> + * each file. If that's the case, @inData should be set to 0
> + * as well as @length.
... @inData and @length should both be set to 0. (reads better to me)
Need extra line between paragraphs
> + * Moreover, this function should upon its return leave the
> + * file in the position it was called with.
Consider instead:
This function is not expected to adjust the current position within the
file.
(or more explicitly - should not adjust!)
> + *
> + * Returns 0 on success,
> + * -1 upon error
> + */
> +typedef int (*virStreamSourceHoleFunc)(virStreamPtr st,
> + int *inData,
> + unsigned 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,
> + unsigned long long length,
> + void *opaque);
> +
> +int virStreamSparseSendAll(virStreamPtr st,
> + virStreamSourceFunc handler,
> + virStreamSourceHoleFunc holeHandler,
> + virStreamSourceSkipFunc skipHandler,
> + void *opaque);
> +
> +/**
> * virStreamSinkFunc:
> *
> * @st: the stream object
> diff --git a/src/libvirt-stream.c b/src/libvirt-stream.c
> index 81190cc..7ad5a38 100644
> --- a/src/libvirt-stream.c
> +++ b/src/libvirt-stream.c
> @@ -565,7 +565,114 @@ virStreamSendAll(virStreamPtr stream,
> }
>
>
> +
Spurious extra line... Now there's 3 between functions.
> /**
> + * 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
> + *
> + * Some dummy description here.
Some smart-aleck comment here ;-)
> + *
> + * Opaque data in @opaque 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;
> + unsigned long long sectionLen;
> +
> + if (!dataLen) {
> + if (holeHandler(stream, &inData, §ionLen, opaque) < 0) {
> + virStreamAbort(stream);
> + goto cleanup;
> + }
> +
> + if (!inData && sectionLen) {
So if !inData and sectionLen == 0, we don't go here, but
> + if (virStreamSkip(stream, sectionLen) < 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;
We go here indicating 'dataLen = 0' which is a misnomer since we're not
inData, rather we at EOF, right? Or did I miss something a bit subtle.
> + }
> + }
> +
> + 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;
> +}/**
Need to clean up the spacing here... e.g.
}
/**
Another one close for an ACK - some cleanup here as well as seeing the
fallout from previous patches.
John
> * 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 ....
>
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