Sys::Virt::virStream->send_all() uses virStreamSendAll() under the hood. This function takes one callback to fill the send buffer with stream data. We have a C glue callback that eventually calls the perl one. However, there's a problem with the glue callback mangling the data as it mistakenly uses strcpy() instead of memcpy(). Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- Changes | 1 + Virt.xs | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/Changes b/Changes index 2e5bfe4..2e4a99e 100644 --- a/Changes +++ b/Changes @@ -3,6 +3,7 @@ Revision history for perl module Sys::Virt 3.4.0 2017-06-00 - Add LIST_CAP_MDEV & LIST_CAP_MDEV_TYPES constants + - Fix send_all() callback helper 3.3.0 2017-05-08 diff --git a/Virt.xs b/Virt.xs index 9ccdc1f..a041c95 100644 --- a/Virt.xs +++ b/Virt.xs @@ -1948,7 +1948,7 @@ _stream_send_all_source(virStreamPtr st, const char *newdata = SvPV_nolen(datasv); if (ret > nbytes) ret = nbytes; - strncpy(data, newdata, nbytes); + memcpy(data, newdata, nbytes); } FREETMPS; -- 2.13.0

Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- Changes | 1 + Virt.xs | 28 ++++++++++++++++++++++++++++ lib/Sys/Virt/Stream.pm | 17 +++++++++++++++++ 3 files changed, 46 insertions(+) diff --git a/Changes b/Changes index b4a493c..c92c271 100644 --- a/Changes +++ b/Changes @@ -6,6 +6,7 @@ Revision history for perl module Sys::Virt - Fix send_all() callback helper - Introduce flags to Stream::recv() and register RECV_STOP_AT_HOLE constant + - Introduce Stream::recvHole() and Stream::sendHole() 3.3.0 2017-05-08 diff --git a/Virt.xs b/Virt.xs index 498e711..d112708 100644 --- a/Virt.xs +++ b/Virt.xs @@ -7900,6 +7900,34 @@ recv(st, data, nbytes, flags=0) RETVAL +SV * +recvHole(st, flags=0) + virStreamPtr st; + unsigned int flags; + PREINIT: + long long length; + CODE: + if (virStreamRecvHole(st, &length, flags) < 0) + _croak_error(); + + RETVAL = virt_newSVll(length); + OUTPUT: + RETVAL + + +void +sendHole(st, lengthSV, flags=0) + virStreamPtr st; + SV *lengthSV; + unsigned int flags; + PREINIT: + long long length; + PPCODE: + length = virt_SvIVll(lengthSV); + if (virStreamSendHole(st, length, flags) < 0) + _croak_error(); + + void send_all(stref, handler) SV *stref; diff --git a/lib/Sys/Virt/Stream.pm b/lib/Sys/Virt/Stream.pm index 069895e..5984fb6 100644 --- a/lib/Sys/Virt/Stream.pm +++ b/lib/Sys/Virt/Stream.pm @@ -93,6 +93,23 @@ Send upto C<$nbytes> worth of data, copying from C<$data>. Returns the number of bytes sent, or -2 if I/O would block, or -1 on error. +=item $rv = $st->recvHole($flags=0) + +Determine the amount of the empty space (in bytes) to be created +in a stream's target file when uploading or downloading sparsely +populated files. This is the counterpart to C<sendHole>. The +optional C<$flags> parameter is currently unused and defaults to +zero if omitted. + +=item $st->sendHole($length, $flags=0) + +Rather than transmitting empty file space, this method directs +the stream target to create C<$length> bytes of empty space. +This method would be used when uploading or downloading sparsely +populated files to avoid the needless copy of empty file space. +The optional C<$flags> parameter is currently unused and defaults +to zero if omitted. + =item $st->recv_all($handler) Receive all data available from the stream, invoking -- 2.13.0

Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- Changes | 1 + Virt.xs | 70 ++++++++++++++++++++++++++++++++++++++++++++++++++ lib/Sys/Virt/Stream.pm | 14 ++++++++++ t/030-api-coverage.t | 1 + 4 files changed, 86 insertions(+) diff --git a/Changes b/Changes index c92c271..4c1e071 100644 --- a/Changes +++ b/Changes @@ -7,6 +7,7 @@ Revision history for perl module Sys::Virt - Introduce flags to Stream::recv() and register RECV_STOP_AT_HOLE constant - Introduce Stream::recvHole() and Stream::sendHole() + - Introduce Stream::sparse_recv_all() 3.3.0 2017-05-08 diff --git a/Virt.xs b/Virt.xs index d112708..002bd6a 100644 --- a/Virt.xs +++ b/Virt.xs @@ -2008,6 +2008,48 @@ _stream_recv_all_sink(virStreamPtr st, } +static int +_stream_sparse_recv_holeHandler(virStreamPtr st, + long long offset, + void *opaque) +{ + AV *av = opaque; + SV **self; + SV **holeHandler; + int rv; + int ret; + dSP; + + self = av_fetch(av, 0, 0); + holeHandler = av_fetch(av, 2, 0); + + SvREFCNT_inc(*self); + + ENTER; + SAVETMPS; + + PUSHMARK(SP); + XPUSHs(*self); + XPUSHs(sv_2mortal(virt_newSVll(offset))); + PUTBACK; + + rv = call_sv((SV*)*holeHandler, G_SCALAR); + + SPAGAIN; + + if (rv == 1) { + ret = POPi; + } else { + ret = -1; + } + + FREETMPS; + LEAVE; + + return ret; +} + + MODULE = Sys::Virt PACKAGE = Sys::Virt PROTOTYPES: ENABLE @@ -7972,6 +8014,34 @@ recv_all(stref, handler) SvREFCNT_dec(opaque); +void +sparse_recv_all(stref, handler, holeHandler) + SV *stref; + SV *handler; + SV *holeHandler; + PREINIT: + AV *opaque; + virStreamPtr st; + CODE: + st = (virStreamPtr)SvIV((SV*)SvRV(stref)); + + opaque = newAV(); + SvREFCNT_inc(stref); + SvREFCNT_inc(handler); + SvREFCNT_inc(holeHandler); + av_push(opaque, stref); + av_push(opaque, handler); + av_push(opaque, holeHandler); + + if (virStreamSparseRecvAll(st, + _stream_recv_all_sink, + _stream_sparse_recv_holeHandler, + opaque) < 0) + _croak_error(); + + SvREFCNT_dec(opaque); + + void add_callback(stref, events, cb) SV* stref; diff --git a/lib/Sys/Virt/Stream.pm b/lib/Sys/Virt/Stream.pm index 5984fb6..c32b957 100644 --- a/lib/Sys/Virt/Stream.pm +++ b/lib/Sys/Virt/Stream.pm @@ -130,6 +130,20 @@ data byte count desired. The function should return the number of bytes filled, 0 on end of file, or -1 upon error +=item $st->sparse_recv_all($handler, $holeHandler) + +Receive all data available from the sparse stream, invoking +C<$handler> to process the data. The C<$handler> parameter must +be a function which expects three arguments, the C<$st> stream +object, a scalar containing the data received and a data byte +count. The function should return the number of bytes processed, +or -1 upon error. The second argument C<$holeHandler> is a +function which expects two arguments: the C<$st> stream and a +scalar, number describing the size of the hole in the stream (in +bytes). The C<$holeHandler> is expected to return a non-negative +number on success (usually 0) and a negative number (usually -1) +otherwise. + =item $st->add_callback($events, $coderef) Register a callback to be invoked whenever the stream has diff --git a/t/030-api-coverage.t b/t/030-api-coverage.t index 3049713..6a281ba 100644 --- a/t/030-api-coverage.t +++ b/t/030-api-coverage.t @@ -114,6 +114,7 @@ virEventUpdateTimeoutFunc virStreamEventCallback virStreamSinkFunc +virStreamSinkHoleFunc virStreamSourceFunc virConnectCloseFunc -- 2.13.0

Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- Changes | 1 + examples/vol-sparse.pl | 142 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 143 insertions(+) create mode 100755 examples/vol-sparse.pl diff --git a/Changes b/Changes index 6c671c0..3742a8c 100644 --- a/Changes +++ b/Changes @@ -11,6 +11,7 @@ Revision history for perl module Sys::Virt - Introduce Stream::sparse_send_all() - Register VOL_DOWNLOAD_SPARSE_STREAM & VOL_UPLOAD_SPARSE_STREAM constants + - Add vol-sparse.pl example 3.3.0 2017-05-08 diff --git a/examples/vol-sparse.pl b/examples/vol-sparse.pl new file mode 100755 index 0000000..b99b57f --- /dev/null +++ b/examples/vol-sparse.pl @@ -0,0 +1,142 @@ +#!/usr/bin/perl + +use strict; +use warnings; + +use Sys::Virt; +use Fcntl; + +my $FILE; + +sub downloadHandler { + my $st = shift; + my $data = shift; + my $nbytes = shift; + return syswrite FILE, $data, $nbytes; +} + +sub downloadHoleHandler { + my $st = shift; + my $offset = shift; + my $pos = sysseek FILE, $offset, Fcntl::SEEK_CUR or die "Unable to seek in $FILE: $!"; + truncate FILE, $pos; +} + + +sub download { + my $vol = shift; + my $st = shift; + my $filename = shift; + my $offset = 0; + my $length = 0; + + open FILE, ">$filename" or die "unable to create $filename: $!"; + eval { + $vol->download($st, $offset, $length, Sys::Virt::StorageVol::VOL_DOWNLOAD_SPARSE_STREAM); + $st->sparse_recv_all(\&downloadHandler, \&downloadHoleHandler); + $st->finish(); + }; + if ($@) { + unlink $filename if $@; + close FILE; + die $@; + } + + close FILE or die "cannot save $filename: $!" +} + +sub uploadHandler { + my $st = $_[0]; + my $nbytes = $_[2]; + return sysread FILE, $_[1], $nbytes; +} + +sub uploadHoleHandler { + my $st = shift; + my $inData; + my $sectionLen; + + # HACK, Perl lacks SEEK_DATA and SEEK_HOLE. + my $SEEK_DATA = 3; + my $SEEK_HOLE = 4; + + my $cur = sysseek FILE, 0, Fcntl::SEEK_CUR; + eval { + my $data = sysseek FILE, $cur, $SEEK_DATA; + # There are three options: + # 1) $data == $cur; $cur is in data + # 2) $data > $cur; $cur is in a hole, next data at $data + # 3) $data < 0; either $cur is in trailing hole, or $cur is beyond EOF. + + if (!defined($data)) { + # case 3 + $inData = 0; + my $end = sysseek FILE, 0, Fcntl::SEEK_END or die "Unable to get EOF position: $!"; + $sectionLen = $end - $cur; + } elsif ($data > $cur) { + #case 2 + $inData = 0; + $sectionLen = $data - $cur; + } else { + #case 1 + my $hole = sysseek FILE, $data, $SEEK_HOLE; + if (!defined($hole) or $hole eq $data) { + die "Blah"; + } + $inData = 1; + $sectionLen = $hole - $data; + } + }; + + # reposition file back + sysseek FILE, $cur, Fcntl::SEEK_SET; + + return ($inData, $sectionLen); +} + +sub uploadSkipHandler { + my $st = shift; + my $offset = shift; + print("uploadSkipHandler: $offset\n"); + sysseek FILE, $offset, Fcntl::SEEK_CUR or die "Unable to seek in $FILE"; +} + +sub upload { + my $vol = shift; + my $st = shift; + my $filename = shift; + my $offset = 0; + my $length = 0; + + open FILE, "<$filename" or die "unable to open $filename: $!"; + eval { + $vol->upload($st, $offset, $length, Sys::Virt::StorageVol::VOL_UPLOAD_SPARSE_STREAM); + $st->sparse_send_all(\&uploadHandler, \&uploadHoleHandler, \&uploadSkipHandler); + $st->finish(); + }; + if ($@) { + close FILE; + die $@; + } + + close FILE or die "cannot close $filename: $!" +} + +die "syntax: $0 URI --download/--upload VOLUME FILE" unless int(@ARGV) == 4; + +my $uri = shift @ARGV; +my $action = shift @ARGV; +my $volpath = shift @ARGV; +my $filename = shift @ARGV; + +my $c = Sys::Virt->new(uri => $uri) or die "Unable to connect to $uri"; +my $vol = $c->get_storage_volume_by_key($volpath) or die "No such volume"; +my $st = $c->new_stream(); + +if ($action eq "--download") { + download($vol, $st, $filename); +} elsif ($action eq "--upload") { + upload($vol, $st, $filename); +} else { + die "unknown action $action"; +} -- 2.13.0