11:34 p.m.
I'm in the middle of writing a patch series for virDomainListAllSnapshots;
this series is preliminary to that, and I'd like to get the review
started now.
The end result of this series is a net gain in lines of code, but a
much nicer framework for changing just one point in the code to use
new APIs and having everything else continue to work as before.
Eric Blake (6):
buf: support peeking at string contents
virsh: remove limits on tree listing
virsh: make tree listing more flexible
snapshot: virsh indentation cleanup
snapshot: new virsh function factored from snapshot-list
snapshot: use new virsh function for snapshot-list
src/libvirt_private.syms | 1 +
src/util/buf.c | 22 +-
src/util/buf.h | 1 +
tests/virbuftest.c | 8 +
tools/virsh.c | 735 +++++++++++++++++++++++++++-------------------
5 files changed, 466 insertions(+), 301 deletions(-)
--
1.7.10.2
11:34 p.m.
New subject: [libvirt] [PATCH 1/6] buf: support peeking at string contents
Right now, the only way to get at the contents of a virBuffer is
to destroy it. But there are cases in my upcoming patches where
peeking at the contents makes life easier. I suppose this does
open up the potential for bad code to dereference a stale pointer,
by disregarding the docs that the return value is invalid on the
next virBuf operation, but such is life.
* src/util/buf.h (virBufferCurrentContent): New declaration.
* src/util/buf.c (virBufferCurrentContent): Implement it.
* src/libvirt_private.syms (buf.h): Export it.
* tests/virbuftest.c (testBufAutoIndent): Test it.
---
src/libvirt_private.syms | 1 +
src/util/buf.c | 22 +++++++++++++++++++++-
src/util/buf.h | 1 +
tests/virbuftest.c | 8 ++++++++
4 files changed, 31 insertions(+), 1 deletion(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index fdf2186..ef8047d 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -20,6 +20,7 @@ virBufferAddChar;
virBufferAdjustIndent;
virBufferAsprintf;
virBufferContentAndReset;
+virBufferCurrentContent;
virBufferError;
virBufferEscape;
virBufferEscapeSexpr;
diff --git a/src/util/buf.c b/src/util/buf.c
index 630e4c9..6c7c501 100644
--- a/src/util/buf.c
+++ b/src/util/buf.c
@@ -175,12 +175,32 @@ virBufferAddChar(virBufferPtr buf, char c)
}
/**
+ * virBufferCurrentContent:
+ * @buf: Buffer
+ *
+ * Get the current content from the buffer. The content is only valid
+ * until the next operation on @buf, and an empty string is returned if
+ * no content is present yet.
+ *
+ * Returns the buffer content or NULL in case of error.
+ */
+const char *
+virBufferCurrentContent(virBufferPtr buf)
+{
+ if (!buf || buf->error)
+ return NULL;
+ return buf->use ? buf->content : "";
+}
+
+/**
* virBufferContentAndReset:
* @buf: Buffer
*
* Get the content from the buffer and free (only) the buffer structure.
* The caller owns the returned string & should free it when no longer
- * required. The buffer object is reset to its initial state.
+ * required. The buffer object is reset to its initial state. This
+ * interface intentionally returns NULL instead of an empty string if
+ * there is no content.
*
* Returns the buffer content or NULL in case of error.
*/
diff --git a/src/util/buf.h b/src/util/buf.h
index a8e2eb5..2750b17 100644
--- a/src/util/buf.h
+++ b/src/util/buf.h
@@ -37,6 +37,7 @@ struct _virBuffer {
};
# endif
+const char *virBufferCurrentContent(virBufferPtr buf);
char *virBufferContentAndReset(virBufferPtr buf);
void virBufferFreeAndReset(virBufferPtr buf);
int virBufferError(const virBufferPtr buf);
diff --git a/tests/virbuftest.c b/tests/virbuftest.c
index cd02db1..7af679c 100644
--- a/tests/virbuftest.c
+++ b/tests/virbuftest.c
@@ -73,6 +73,10 @@ static int testBufAutoIndent(const void *data ATTRIBUTE_UNUSED)
ret = -1;
}
virBufferAdjustIndent(buf, 3);
+ if (STRNEQ_NULLABLE(virBufferCurrentContent(buf), "")) {
+ TEST_ERROR("Wrong content");
+ ret = -1;
+ }
if (virBufferGetIndent(buf, false) != 3 ||
virBufferGetIndent(buf, true) != 3 ||
virBufferError(buf)) {
@@ -102,6 +106,10 @@ static int testBufAutoIndent(const void *data ATTRIBUTE_UNUSED)
}
virBufferAdjustIndent(buf, 2);
virBufferAddLit(buf, "1");
+ if (STRNEQ_NULLABLE(virBufferCurrentContent(buf), " 1")) {
+ TEST_ERROR("Wrong content");
+ ret = -1;
+ }
if (virBufferGetIndent(buf, false) != 2 ||
virBufferGetIndent(buf, true) != 0) {
TEST_ERROR("Wrong indentation");
--
1.7.10.2
7:05 a.m.
New subject: [libvirt] [PATCH 1/6] buf: support peeking at string contents
On 06/09/12 06:34, Eric Blake wrote:
Right now, the only way to get at the contents of a virBuffer is
to destroy it. But there are cases in my upcoming patches where
peeking at the contents makes life easier. I suppose this does
open up the potential for bad code to dereference a stale pointer,
by disregarding the docs that the return value is invalid on the
next virBuf operation, but such is life.
* src/util/buf.h (virBufferCurrentContent): New declaration.
* src/util/buf.c (virBufferCurrentContent): Implement it.
* src/libvirt_private.syms (buf.h): Export it.
* tests/virbuftest.c (testBufAutoIndent): Test it.
---
ACK. Might be useful sometimes. I looked for something like this once.
Peter
10:07 a.m.
New subject: [libvirt] [PATCH 1/6] buf: support peeking at string contents
On 06/11/2012 06:05 AM, Peter Krempa wrote:
On 06/09/12 06:34, Eric Blake wrote:
> Right now, the only way to get at the contents of a virBuffer is
> to destroy it. But there are cases in my upcoming patches where
> peeking at the contents makes life easier. I suppose this does
> open up the potential for bad code to dereference a stale pointer,
> by disregarding the docs that the return value is invalid on the
> next virBuf operation, but such is life.
>
> * src/util/buf.h (virBufferCurrentContent): New declaration.
> * src/util/buf.c (virBufferCurrentContent): Implement it.
> * src/libvirt_private.syms (buf.h): Export it.
> * tests/virbuftest.c (testBufAutoIndent): Test it.
> ---
ACK. Might be useful sometimes. I looked for something like this once.
Thanks; pushed.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
11:34 p.m.
New subject: [libvirt] [PATCH 2/6] virsh: remove limits on tree listing
I am not a fan of fixed-width buffers. All it takes is a
linear chain of more than 100 snapshots to mess up 'virsh
snapshot-list --tree'. Now that virBuffer is more powerful,
we might as well exploit its power.
* tools/virsh.c (cmdNodeListDevicesPrint): Simplify to use a
virBuffer instead of fixed-width prefix, factor guts, and rename...
(vshTreePrint, vshTreePrintInternal): ...along with new helper.
(cmdNodeListDevices, cmdSnapshotList): Update callers.
---
tools/virsh.c | 172 ++++++++++++++++++++++++++-------------------------------
1 file changed, 78 insertions(+), 94 deletions(-)
diff --git a/tools/virsh.c b/tools/virsh.c
index b28dc49..0d67f4b 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -13165,60 +13165,34 @@ cmdVersion(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
return true;
}
-/*
- * "nodedev-list" command
- */
-static const vshCmdInfo info_node_list_devices[] = {
- {"help", N_("enumerate devices on this host")},
- {"desc", ""},
- {NULL, NULL}
-};
-
-static const vshCmdOptDef opts_node_list_devices[] = {
- {"tree", VSH_OT_BOOL, 0, N_("list devices in a tree")},
- {"cap", VSH_OT_STRING, VSH_OFLAG_NONE, N_("capability name")},
- {NULL, 0, 0, NULL}
-};
-
-#define MAX_DEPTH 100
-#define INDENT_SIZE 4
-#define INDENT_BUFLEN ((MAX_DEPTH * INDENT_SIZE) + 1)
-
-static void
-cmdNodeListDevicesPrint(vshControl *ctl,
- char **devices,
- char **parents,
- int num_devices,
- int devid,
- int lastdev,
- unsigned int depth,
- unsigned int indentIdx,
- char *indentBuf)
+/* Tree listing helpers. */
+static int
+vshTreePrintInternal(vshControl *ctl,
+ char **devices,
+ char **parents,
+ int num_devices,
+ int devid,
+ int lastdev,
+ bool root,
+ virBufferPtr indent)
{
int i;
int nextlastdev = -1;
+ int ret = -1;
- /* Prepare indent for this device, but not if at root */
- if (depth && depth < MAX_DEPTH) {
- indentBuf[indentIdx] = '+';
- indentBuf[indentIdx+1] = '-';
- indentBuf[indentIdx+2] = ' ';
- indentBuf[indentIdx+3] = '\0';
- }
-
- /* Print this device */
- vshPrint(ctl, "%s", indentBuf);
- vshPrint(ctl, "%s\n", devices[devid]);
+ if (virBufferError(indent))
+ goto cleanup;
+ /* Print this device, with indent if not at root */
+ vshPrint(ctl, "%s%s%s\n", virBufferCurrentContent(indent),
+ root ? "" : "+- ", devices[devid]);
/* Update indent to show '|' or ' ' for child devices */
- if (depth && depth < MAX_DEPTH) {
- if (devid == lastdev)
- indentBuf[indentIdx] = ' ';
- else
- indentBuf[indentIdx] = '|';
- indentBuf[indentIdx+1] = ' ';
- indentIdx+=2;
+ if (!root) {
+ virBufferAddChar(indent, devid == lastdev ? ' ' : '|');
+ virBufferAddChar(indent, ' ');
+ if (virBufferError(indent))
+ goto cleanup;
}
/* Determine the index of the last child device */
@@ -13230,43 +13204,70 @@ cmdNodeListDevicesPrint(vshControl *ctl,
}
/* If there is a child device, then print another blank line */
- if (nextlastdev != -1) {
- vshPrint(ctl, "%s", indentBuf);
- vshPrint(ctl, " |\n");
- }
+ if (nextlastdev != -1)
+ vshPrint(ctl, "%s |\n", virBufferCurrentContent(indent));
/* Finally print all children */
- if (depth < MAX_DEPTH)
- indentBuf[indentIdx] = ' ';
+ virBufferAddLit(indent, " ");
for (i = 0 ; i < num_devices ; i++) {
- if (depth < MAX_DEPTH) {
- indentBuf[indentIdx] = ' ';
- indentBuf[indentIdx+1] = ' ';
- }
- if (parents[i] &&
- STREQ(parents[i], devices[devid]))
- cmdNodeListDevicesPrint(ctl, devices, parents,
- num_devices, i, nextlastdev,
- depth + 1, indentIdx + 2, indentBuf);
- if (depth < MAX_DEPTH)
- indentBuf[indentIdx] = '\0';
+ if (parents[i] && STREQ(parents[i], devices[devid]) &&
+ vshTreePrintInternal(ctl, devices, parents,
+ num_devices, i, nextlastdev,
+ false, indent) < 0)
+ goto cleanup;
}
+ virBufferTrim(indent, " ", -1);
/* If there was no child device, and we're the last in
* a list of devices, then print another blank line */
- if (nextlastdev == -1 && devid == lastdev) {
- vshPrint(ctl, "%s", indentBuf);
- vshPrint(ctl, "\n");
- }
+ if (nextlastdev == -1 && devid == lastdev)
+ vshPrint(ctl, "%s\n", virBufferCurrentContent(indent));
+
+ if (!root)
+ virBufferTrim(indent, NULL, 2);
+ ret = 0;
+cleanup:
+ return ret;
+}
+
+static int
+vshTreePrint(vshControl *ctl, char **devices, char **parents,
+ int num_devices, int devid)
+{
+ int ret;
+ virBuffer indent = VIR_BUFFER_INITIALIZER;
+
+ ret = vshTreePrintInternal(ctl, devices, parents, num_devices,
+ devid, devid, true, &indent);
+ if (ret < 0)
+ vshError(ctl, "%s", _("Failed to complete tree listing"));
+ virBufferFreeAndReset(&indent);
+ return ret;
}
+/*
+ * "nodedev-list" command
+ */
+static const vshCmdInfo info_node_list_devices[] = {
+ {"help", N_("enumerate devices on this host")},
+ {"desc", ""},
+ {NULL, NULL}
+};
+
+static const vshCmdOptDef opts_node_list_devices[] = {
+ {"tree", VSH_OT_BOOL, 0, N_("list devices in a tree")},
+ {"cap", VSH_OT_STRING, VSH_OFLAG_NONE, N_("capability name")},
+ {NULL, 0, 0, NULL}
+};
+
static bool
-cmdNodeListDevices (vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
+cmdNodeListDevices(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
{
const char *cap = NULL;
char **devices;
int num_devices, i;
bool tree = vshCommandOptBool(cmd, "tree");
+ bool ret = true;
if (!vshConnectionUsability(ctl, ctl->conn))
return false;
@@ -13292,8 +13293,8 @@ cmdNodeListDevices (vshControl *ctl, const vshCmd *cmd
ATTRIBUTE_UNUSED)
}
qsort(&devices[0], num_devices, sizeof(char*), namesorter);
if (tree) {
- char indentBuf[INDENT_BUFLEN];
char **parents = vshMalloc(ctl, sizeof(char *) * num_devices);
+
for (i = 0; i < num_devices; i++) {
virNodeDevicePtr dev = virNodeDeviceLookupByName(ctl->conn, devices[i]);
if (dev && STRNEQ(devices[i], "computer")) {
@@ -13305,17 +13306,9 @@ cmdNodeListDevices (vshControl *ctl, const vshCmd *cmd
ATTRIBUTE_UNUSED)
virNodeDeviceFree(dev);
}
for (i = 0 ; i < num_devices ; i++) {
- memset(indentBuf, '\0', sizeof(indentBuf));
- if (parents[i] == NULL)
- cmdNodeListDevicesPrint(ctl,
- devices,
- parents,
- num_devices,
- i,
- i,
- 0,
- 0,
- indentBuf);
+ if (parents[i] == NULL &&
+ vshTreePrint(ctl, devices, parents, num_devices, i) < 0)
+ ret = false;
}
for (i = 0 ; i < num_devices ; i++) {
VIR_FREE(devices[i]);
@@ -13329,7 +13322,7 @@ cmdNodeListDevices (vshControl *ctl, const vshCmd *cmd
ATTRIBUTE_UNUSED)
}
}
VIR_FREE(devices);
- return true;
+ return ret;
}
/*
@@ -16763,20 +16756,11 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
}
}
if (tree) {
- char indentBuf[INDENT_BUFLEN];
for (i = 0 ; i < actual ; i++) {
- memset(indentBuf, '\0', sizeof(indentBuf));
if ((from && ctl->useSnapshotOld) ? STREQ(names[i], from) :
- !parents[i])
- cmdNodeListDevicesPrint(ctl,
- names,
- parents,
- actual,
- i,
- i,
- 0,
- 0,
- indentBuf);
+ !parents[i] &&
+ vshTreePrint(ctl, names, parents, actual, i) < 0)
+ goto cleanup;
}
ret = true;
--
1.7.10.2
7:31 a.m.
New subject: [libvirt] [PATCH 2/6] virsh: remove limits on tree listing
On 06/09/12 06:34, Eric Blake wrote:
I am not a fan of fixed-width buffers. All it takes is a
linear chain of more than 100 snapshots to mess up 'virsh
snapshot-list --tree'. Now that virBuffer is more powerful,
we might as well exploit its power.
* tools/virsh.c (cmdNodeListDevicesPrint): Simplify to use a
virBuffer instead of fixed-width prefix, factor guts, and rename...
(vshTreePrint, vshTreePrintInternal): ...along with new helper.
(cmdNodeListDevices, cmdSnapshotList): Update callers.
---
ACK, great improvement in code understandability.
Peter
11:20 a.m.
New subject: [libvirt] [PATCH 2/6] virsh: remove limits on tree listing
On 06/11/2012 06:31 AM, Peter Krempa wrote:
On 06/09/12 06:34, Eric Blake wrote:
> I am not a fan of fixed-width buffers. All it takes is a
> linear chain of more than 100 snapshots to mess up 'virsh
> snapshot-list --tree'. Now that virBuffer is more powerful,
> we might as well exploit its power.
>
> * tools/virsh.c (cmdNodeListDevicesPrint): Simplify to use a
> virBuffer instead of fixed-width prefix, factor guts, and rename...
> (vshTreePrint, vshTreePrintInternal): ...along with new helper.
> (cmdNodeListDevices, cmdSnapshotList): Update callers.
> ---
ACK, great improvement in code understandability.
Thanks; pushed.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
11:34 p.m.
New subject: [libvirt] [PATCH 3/6] virsh: make tree listing more flexible
Requiring the user to pass in parallel arrays of names and parents
is annoying; it means that you can't qsort one of the arrays without
invalidating the ordering of the other. By refactoring this function
to use callbacks, we isolate the layout to be independent of the
printing, and a future patch can exploit that to improve layout.
* tools/virsh.c (vshTreePrintInternal): Use callbacks rather than
requiring a char** array.
(vshTreeArrayLookup): New helper function.
(vshTreePrint, cmdNodeListDevices, cmdSnapshotList): Update callers.
---
tools/virsh.c | 50 ++++++++++++++++++++++++++++++++++++++------------
1 file changed, 38 insertions(+), 12 deletions(-)
diff --git a/tools/virsh.c b/tools/virsh.c
index 0d67f4b..85e618c 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -13166,10 +13166,15 @@ cmdVersion(vshControl *ctl, const vshCmd *cmd ATTRIBUTE_UNUSED)
}
/* Tree listing helpers. */
+
+/* Given an index, return either the name of that device (non-NULL) or
+ * of its parent (NULL if a root). */
+typedef const char * (*vshTreeLookup)(int devid, bool parent, void *opaque);
+
static int
vshTreePrintInternal(vshControl *ctl,
- char **devices,
- char **parents,
+ vshTreeLookup lookup,
+ void *opaque,
int num_devices,
int devid,
int lastdev,
@@ -13179,13 +13184,14 @@ vshTreePrintInternal(vshControl *ctl,
int i;
int nextlastdev = -1;
int ret = -1;
+ const char *dev = (lookup)(devid, false, opaque);
if (virBufferError(indent))
goto cleanup;
/* Print this device, with indent if not at root */
vshPrint(ctl, "%s%s%s\n", virBufferCurrentContent(indent),
- root ? "" : "+- ", devices[devid]);
+ root ? "" : "+- ", dev);
/* Update indent to show '|' or ' ' for child devices */
if (!root) {
@@ -13197,10 +13203,10 @@ vshTreePrintInternal(vshControl *ctl,
/* Determine the index of the last child device */
for (i = 0 ; i < num_devices ; i++) {
- if (parents[i] &&
- STREQ(parents[i], devices[devid])) {
+ const char *parent = (lookup)(i, true, opaque);
+
+ if (parent && STREQ(parent, dev))
nextlastdev = i;
- }
}
/* If there is a child device, then print another blank line */
@@ -13210,8 +13216,10 @@ vshTreePrintInternal(vshControl *ctl,
/* Finally print all children */
virBufferAddLit(indent, " ");
for (i = 0 ; i < num_devices ; i++) {
- if (parents[i] && STREQ(parents[i], devices[devid]) &&
- vshTreePrintInternal(ctl, devices, parents,
+ const char *parent = (lookup)(i, true, opaque);
+
+ if (parent && STREQ(parent, dev) &&
+ vshTreePrintInternal(ctl, lookup, opaque,
num_devices, i, nextlastdev,
false, indent) < 0)
goto cleanup;
@@ -13231,13 +13239,13 @@ cleanup:
}
static int
-vshTreePrint(vshControl *ctl, char **devices, char **parents,
+vshTreePrint(vshControl *ctl, vshTreeLookup lookup, void *opaque,
int num_devices, int devid)
{
int ret;
virBuffer indent = VIR_BUFFER_INITIALIZER;
- ret = vshTreePrintInternal(ctl, devices, parents, num_devices,
+ ret = vshTreePrintInternal(ctl, lookup, opaque, num_devices,
devid, devid, true, &indent);
if (ret < 0)
vshError(ctl, "%s", _("Failed to complete tree listing"));
@@ -13245,6 +13253,20 @@ vshTreePrint(vshControl *ctl, char **devices, char **parents,
return ret;
}
+struct vshTreeArray {
+ char **names;
+ char **parents;
+};
+
+static const char *
+vshTreeArrayLookup(int devid, bool parent, void *opaque)
+{
+ struct vshTreeArray *arrays = opaque;
+ if (parent)
+ return arrays->parents[devid];
+ return arrays->names[devid];
+}
+
/*
* "nodedev-list" command
*/
@@ -13294,6 +13316,7 @@ cmdNodeListDevices(vshControl *ctl, const vshCmd *cmd
ATTRIBUTE_UNUSED)
qsort(&devices[0], num_devices, sizeof(char*), namesorter);
if (tree) {
char **parents = vshMalloc(ctl, sizeof(char *) * num_devices);
+ struct vshTreeArray arrays = { devices, parents };
for (i = 0; i < num_devices; i++) {
virNodeDevicePtr dev = virNodeDeviceLookupByName(ctl->conn, devices[i]);
@@ -13307,7 +13330,8 @@ cmdNodeListDevices(vshControl *ctl, const vshCmd *cmd
ATTRIBUTE_UNUSED)
}
for (i = 0 ; i < num_devices ; i++) {
if (parents[i] == NULL &&
- vshTreePrint(ctl, devices, parents, num_devices, i) < 0)
+ vshTreePrint(ctl, vshTreeArrayLookup, &arrays, num_devices,
+ i) < 0)
ret = false;
}
for (i = 0 ; i < num_devices ; i++) {
@@ -16756,10 +16780,12 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
}
}
if (tree) {
+ struct vshTreeArray arrays = { names, parents };
+
for (i = 0 ; i < actual ; i++) {
if ((from && ctl->useSnapshotOld) ? STREQ(names[i], from) :
!parents[i] &&
- vshTreePrint(ctl, names, parents, actual, i) < 0)
+ vshTreePrint(ctl, vshTreeArrayLookup, &arrays, actual, i) < 0)
goto cleanup;
}
--
1.7.10.2
8:13 a.m.
New subject: [libvirt] [PATCH 3/6] virsh: make tree listing more flexible
On 06/09/12 06:34, Eric Blake wrote:
Requiring the user to pass in parallel arrays of names and parents
is annoying; it means that you can't qsort one of the arrays without
invalidating the ordering of the other. By refactoring this function
to use callbacks, we isolate the layout to be independent of the
printing, and a future patch can exploit that to improve layout.
* tools/virsh.c (vshTreePrintInternal): Use callbacks rather than
requiring a char** array.
(vshTreeArrayLookup): New helper function.
(vshTreePrint, cmdNodeListDevices, cmdSnapshotList): Update callers.
---
tools/virsh.c | 50 ++++++++++++++++++++++++++++++++++++++------------
@@ -13245,6 +13253,20 @@ vshTreePrint(vshControl *ctl, char **devices, char **parents,
return ret;
}
+struct vshTreeArray {
+ char **names;
+ char **parents;
+};
+
+static const char *
+vshTreeArrayLookup(int devid, bool parent, void *opaque)
+{
+ struct vshTreeArray *arrays = opaque;
+ if (parent)
+ return arrays->parents[devid];
+ return arrays->names[devid];
+}
+
This is used just for listing node devices IIUC. Wouln't it be better to
explicitly name the helper and struct that it's meant for node devices?
vshNodeDeviceTree ... ?
/*
* "nodedev-list" command
*/
ACK. The name doesn't matter that much, making the tree printer more
universal does.
Peter
8:43 a.m.
New subject: [libvirt] [PATCH 3/6] virsh: make tree listing more flexible
On 06/11/2012 07:13 AM, Peter Krempa wrote:
On 06/09/12 06:34, Eric Blake wrote:
> Requiring the user to pass in parallel arrays of names and parents
> is annoying; it means that you can't qsort one of the arrays without
> invalidating the ordering of the other. By refactoring this function
> to use callbacks, we isolate the layout to be independent of the
> printing, and a future patch can exploit that to improve layout.
>
> * tools/virsh.c (vshTreePrintInternal): Use callbacks rather than
> requiring a char** array.
> (vshTreeArrayLookup): New helper function.
> (vshTreePrint, cmdNodeListDevices, cmdSnapshotList): Update callers.
> +static const char *
> +vshTreeArrayLookup(int devid, bool parent, void *opaque)
> +{
> + struct vshTreeArray *arrays = opaque;
> + if (parent)
> + return arrays->parents[devid];
> + return arrays->names[devid];
> +}
> +
This is used just for listing node devices IIUC. Wouln't it be better to
explicitly name the helper and struct that it's meant for node devices?
vshNodeDeviceTree ... ?
In _this_ patch, it's used by both node devices and snapshots. Later,
in patch 6/6, I switch snapshots over to using a different callback.
Maybe I should rename this function as part of that later split into two
different callbacks, but for this patch, since it really is used twice,
I think it makes sense as-is.
ACK. The name doesn't matter that much, making the tree printer more
universal does.
Peter
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
11:21 a.m.
New subject: [libvirt] [PATCH 3/6] virsh: make tree listing more flexible
On 06/11/2012 07:43 AM, Eric Blake wrote:
On 06/11/2012 07:13 AM, Peter Krempa wrote:
> On 06/09/12 06:34, Eric Blake wrote:
>> Requiring the user to pass in parallel arrays of names and parents
>> is annoying; it means that you can't qsort one of the arrays without
>> invalidating the ordering of the other. By refactoring this function
>> to use callbacks, we isolate the layout to be independent of the
>> printing, and a future patch can exploit that to improve layout.
>>
>> +static const char *
>> +vshTreeArrayLookup(int devid, bool parent, void *opaque)
>
> This is used just for listing node devices IIUC. Wouln't it be better to
> explicitly name the helper and struct that it's meant for node devices?
> vshNodeDeviceTree ... ?
In _this_ patch, it's used by both node devices and snapshots. Later,
in patch 6/6, I switch snapshots over to using a different callback.
Maybe I should rename this function as part of that later split into two
different callbacks, but for this patch, since it really is used twice,
I think it makes sense as-is.
>
> ACK. The name doesn't matter that much, making the tree printer more
> universal does.
I've pushed this now, but will remain open to the idea of reworking 6/6
to adjust naming.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
11:34 p.m.
New subject: [libvirt] [PATCH 4/6] snapshot: virsh indentation cleanup
No semantic change; this will make it easier to refactor code.
* tools/virsh.c (cmdSnapshotList): Drop level of indentation, and
rename a variable.
---
tools/virsh.c | 238 ++++++++++++++++++++++++++++-----------------------------
1 file changed, 118 insertions(+), 120 deletions(-)
diff --git a/tools/virsh.c b/tools/virsh.c
index 85e618c..de7b282 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -16600,10 +16600,9 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
unsigned int flags = 0;
int parent_filter = 0; /* -1 for roots filtering, 0 for no parent
information needed, 1 for parent column */
- int numsnaps;
char **names = NULL;
char **parents = NULL;
- int actual = 0;
+ int count = 0;
int i;
xmlDocPtr xml = NULL;
xmlXPathContextPtr ctxt = NULL;
@@ -16677,9 +16676,9 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (descendants || tree) {
flags |= VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
}
- numsnaps = ctl->useSnapshotOld ? -1 :
+ count = ctl->useSnapshotOld ? -1 :
virDomainSnapshotNumChildren(start, flags);
- if (numsnaps < 0) {
+ if (count < 0) {
if (ctl->useSnapshotOld ||
last_error->code == VIR_ERR_NO_SUPPORT) {
/* We can emulate --from. */
@@ -16688,27 +16687,27 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
last_error = NULL;
ctl->useSnapshotOld = true;
flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
- numsnaps = virDomainSnapshotNum(dom, flags);
+ count = virDomainSnapshotNum(dom, flags);
}
} else if (tree) {
- numsnaps++;
+ count++;
}
} else {
- numsnaps = virDomainSnapshotNum(dom, flags);
+ count = virDomainSnapshotNum(dom, flags);
/* Fall back to simulation if --roots was unsupported. */
/* XXX can we also emulate --leaves? */
- if (numsnaps < 0 && last_error->code == VIR_ERR_INVALID_ARG
&&
+ if (count < 0 && last_error->code == VIR_ERR_INVALID_ARG
&&
(flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
virFreeError(last_error);
last_error = NULL;
parent_filter = -1;
flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
- numsnaps = virDomainSnapshotNum(dom, flags);
+ count = virDomainSnapshotNum(dom, flags);
}
}
- if (numsnaps < 0) {
+ if (count < 0) {
if (!last_error)
vshError(ctl, _("missing support"));
goto cleanup;
@@ -16726,41 +16725,40 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
"------------------------------------------------------------\n");
}
- if (!numsnaps) {
+ if (!count) {
ret = true;
goto cleanup;
}
- if (VIR_ALLOC_N(names, numsnaps) < 0)
+ if (VIR_ALLOC_N(names, count) < 0)
goto cleanup;
if (from && !ctl->useSnapshotOld) {
/* When mixing --from and --tree, we want to start the tree at the
* given snapshot. Without --tree, only list the children. */
if (tree) {
- if (numsnaps)
- actual = virDomainSnapshotListChildrenNames(start, names + 1,
- numsnaps - 1,
- flags);
- if (actual >= 0) {
- actual++;
+ if (count)
+ count = virDomainSnapshotListChildrenNames(start, names + 1,
+ count - 1, flags);
+ if (count >= 0) {
+ count++;
names[0] = vshStrdup(ctl, from);
}
} else {
- actual = virDomainSnapshotListChildrenNames(start, names,
- numsnaps, flags);
+ count = virDomainSnapshotListChildrenNames(start, names,
+ count, flags);
}
} else {
- actual = virDomainSnapshotListNames(dom, names, numsnaps, flags);
+ count = virDomainSnapshotListNames(dom, names, count, flags);
}
- if (actual < 0)
+ if (count < 0)
goto cleanup;
- qsort(&names[0], actual, sizeof(char*), namesorter);
+ qsort(&names[0], count, sizeof(char*), namesorter);
if (tree || (from && ctl->useSnapshotOld)) {
- parents = vshCalloc(ctl, sizeof(char *), actual);
- for (i = (from && !ctl->useSnapshotOld); i < actual; i++) {
+ parents = vshCalloc(ctl, sizeof(char *), count);
+ for (i = (from && !ctl->useSnapshotOld); i < count; i++) {
if (from && ctl->useSnapshotOld && STREQ(names[i], from))
{
start_index = i;
continue;
@@ -16782,123 +16780,123 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (tree) {
struct vshTreeArray arrays = { names, parents };
- for (i = 0 ; i < actual ; i++) {
+ for (i = 0 ; i < count ; i++) {
if ((from && ctl->useSnapshotOld) ? STREQ(names[i], from) :
!parents[i] &&
- vshTreePrint(ctl, vshTreeArrayLookup, &arrays, actual, i) < 0)
+ vshTreePrint(ctl, vshTreeArrayLookup, &arrays, count, i) < 0)
goto cleanup;
}
ret = true;
goto cleanup;
- } else {
- if (ctl->useSnapshotOld && descendants) {
- bool changed = false;
-
- /* Make multiple passes over the list - first pass NULLs
- * out all roots except start, remaining passes NULL out
- * any entry whose parent is not still in list. Also, we
- * NULL out parent when name is known to be in list.
- * Sorry, this is O(n^3) - hope your hierarchy isn't huge. */
- if (start_index < 0) {
- vshError(ctl, _("snapshot %s disappeared from list"), from);
- goto cleanup;
- }
- for (i = 0; i < actual; i++) {
- if (i == start_index)
- continue;
- if (!parents[i]) {
- VIR_FREE(names[i]);
- } else if (STREQ(parents[i], from)) {
- VIR_FREE(parents[i]);
- changed = true;
- }
- }
- if (!changed) {
- ret = true;
- goto cleanup;
+ }
+
+ if (ctl->useSnapshotOld && descendants) {
+ bool changed = false;
+
+ /* Make multiple passes over the list - first pass NULLs out
+ * all roots except start, remaining passes NULL out any entry
+ * whose parent is not still in list. Also, we NULL out
+ * parent when name is known to be in list. Sorry, this is
+ * O(n^3) - hope your hierarchy isn't huge. */
+ if (start_index < 0) {
+ vshError(ctl, _("snapshot %s disappeared from list"), from);
+ goto cleanup;
+ }
+ for (i = 0; i < count; i++) {
+ if (i == start_index)
+ continue;
+ if (!parents[i]) {
+ VIR_FREE(names[i]);
+ } else if (STREQ(parents[i], from)) {
+ VIR_FREE(parents[i]);
+ changed = true;
}
- while (changed) {
- changed = false;
- for (i = 0; i < actual; i++) {
- bool found = false;
- int j;
+ }
+ if (!changed) {
+ ret = true;
+ goto cleanup;
+ }
+ while (changed) {
+ changed = false;
+ for (i = 0; i < count; i++) {
+ bool found = false;
+ int j;
- if (!names[i] || !parents[i])
+ if (!names[i] || !parents[i])
+ continue;
+ for (j = 0; j < count; j++) {
+ if (!names[j] || i == j)
continue;
- for (j = 0; j < actual; j++) {
- if (!names[j] || i == j)
- continue;
- if (STREQ(parents[i], names[j])) {
- found = true;
- if (!parents[j])
- VIR_FREE(parents[i]);
- break;
- }
- }
- if (!found) {
- changed = true;
- VIR_FREE(names[i]);
+ if (STREQ(parents[i], names[j])) {
+ found = true;
+ if (!parents[j])
+ VIR_FREE(parents[i]);
+ break;
}
}
+ if (!found) {
+ changed = true;
+ VIR_FREE(names[i]);
+ }
}
- VIR_FREE(names[start_index]);
}
+ VIR_FREE(names[start_index]);
+ }
- for (i = 0; i < actual; i++) {
- if (from && ctl->useSnapshotOld &&
- (descendants ? !names[i] : STRNEQ_NULLABLE(parents[i], from)))
- continue;
-
- /* free up memory from previous iterations of the loop */
- VIR_FREE(parent);
- VIR_FREE(state);
- if (snapshot)
- virDomainSnapshotFree(snapshot);
- xmlXPathFreeContext(ctxt);
- xmlFreeDoc(xml);
- VIR_FREE(doc);
+ for (i = 0; i < count; i++) {
+ if (from && ctl->useSnapshotOld &&
+ (descendants ? !names[i] : STRNEQ_NULLABLE(parents[i], from)))
+ continue;
- snapshot = virDomainSnapshotLookupByName(dom, names[i], 0);
- if (snapshot == NULL)
- continue;
+ /* free up memory from previous iterations of the loop */
+ VIR_FREE(parent);
+ VIR_FREE(state);
+ if (snapshot)
+ virDomainSnapshotFree(snapshot);
+ xmlXPathFreeContext(ctxt);
+ xmlFreeDoc(xml);
+ VIR_FREE(doc);
- doc = virDomainSnapshotGetXMLDesc(snapshot, 0);
- if (!doc)
- continue;
+ snapshot = virDomainSnapshotLookupByName(dom, names[i], 0);
+ if (snapshot == NULL)
+ continue;
- xml = virXMLParseStringCtxt(doc, _("(domain_snapshot)"),
&ctxt);
- if (!xml)
- continue;
+ doc = virDomainSnapshotGetXMLDesc(snapshot, 0);
+ if (!doc)
+ continue;
- if (parent_filter) {
- parent = virXPathString("string(/domainsnapshot/parent/name)",
- ctxt);
- if (!parent && parent_filter < 0)
- continue;
- }
+ xml = virXMLParseStringCtxt(doc, _("(domain_snapshot)"), &ctxt);
+ if (!xml)
+ continue;
- state = virXPathString("string(/domainsnapshot/state)", ctxt);
- if (state == NULL)
- continue;
- if (virXPathLongLong("string(/domainsnapshot/creationTime)", ctxt,
- &creation_longlong) < 0)
+ if (parent_filter) {
+ parent = virXPathString("string(/domainsnapshot/parent/name)",
+ ctxt);
+ if (!parent && parent_filter < 0)
continue;
- creation_time_t = creation_longlong;
- if (creation_time_t != creation_longlong) {
- vshError(ctl, "%s", _("time_t overflow"));
- continue;
- }
- localtime_r(&creation_time_t, &time_info);
- strftime(timestr, sizeof(timestr), "%Y-%m-%d %H:%M:%S %z",
- &time_info);
+ }
- if (parent)
- vshPrint(ctl, " %-20s %-25s %-15s %s\n",
- names[i], timestr, state, parent);
- else
- vshPrint(ctl, " %-20s %-25s %s\n", names[i], timestr, state);
+ state = virXPathString("string(/domainsnapshot/state)", ctxt);
+ if (state == NULL)
+ continue;
+ if (virXPathLongLong("string(/domainsnapshot/creationTime)", ctxt,
+ &creation_longlong) < 0)
+ continue;
+ creation_time_t = creation_longlong;
+ if (creation_time_t != creation_longlong) {
+ vshError(ctl, "%s", _("time_t overflow"));
+ continue;
}
+ localtime_r(&creation_time_t, &time_info);
+ strftime(timestr, sizeof(timestr), "%Y-%m-%d %H:%M:%S %z",
+ &time_info);
+
+ if (parent)
+ vshPrint(ctl, " %-20s %-25s %-15s %s\n",
+ names[i], timestr, state, parent);
+ else
+ vshPrint(ctl, " %-20s %-25s %s\n", names[i], timestr, state);
}
ret = true;
@@ -16914,7 +16912,7 @@ cleanup:
xmlXPathFreeContext(ctxt);
xmlFreeDoc(xml);
VIR_FREE(doc);
- for (i = 0; i < actual; i++) {
+ for (i = 0; i < count; i++) {
VIR_FREE(names[i]);
if (parents)
VIR_FREE(parents[i]);
--
1.7.10.2
8:52 a.m.
New subject: [libvirt] [PATCH 4/6] snapshot: virsh indentation cleanup
On 06/09/12 06:34, Eric Blake wrote:
No semantic change; this will make it easier to refactor code.
* tools/virsh.c (cmdSnapshotList): Drop level of indentation, and
rename a variable.
---
git show -b is the magic formula to help with indentation patch review :)
ACK
Peter
11:36 a.m.
New subject: [libvirt] [PATCH 4/6] snapshot: virsh indentation cleanup
On 06/11/2012 07:52 AM, Peter Krempa wrote:
On 06/09/12 06:34, Eric Blake wrote:
> No semantic change; this will make it easier to refactor code.
>
> * tools/virsh.c (cmdSnapshotList): Drop level of indentation, and
> rename a variable.
> ---
git show -b is the magic formula to help with indentation patch review :)
ACK
Thanks; pushed.
When reviewing 5/6 myself before posting, I found it easiest to compare
the new code in one window side-by-side with the existing
cmdSnapshotList code in another window. Now that the indentation and
naming is similar, the differences boil down to a different
representation (single struct instead of parallel arrays) and deleting
entries from that array.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
11:34 p.m.
New subject: [libvirt] [PATCH 5/6] snapshot: new virsh function factored from snapshot-list
This patch copies just the fallback code out of cmdSnapshotList,
and keeps the snapshot objects around rather than just their
name for easier manipulation. It looks forward to a future
patch when we add a way to list all snapshot objects at once,
and the next patch will simplify cmdSnapshotList to take
advantage of this factorization.
* tools/virsh.c (vshSnapshotList, vshSnapshotListFree): New functions.
---
tools/virsh.c | 272 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 272 insertions(+)
diff --git a/tools/virsh.c b/tools/virsh.c
index de7b282..62546b2 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -16568,6 +16568,278 @@ cleanup:
return ret;
}
+/* Helpers for collecting a list of snapshots. */
+struct vshSnap {
+ virDomainSnapshotPtr snap;
+ char *parent;
+};
+struct vshSnapshotList {
+ struct vshSnap *snaps;
+ int nsnaps;
+};
+typedef struct vshSnapshotList *vshSnapshotListPtr;
+
+static void
+vshSnapshotListFree(vshSnapshotListPtr snaplist)
+{
+ int i;
+
+ if (!snaplist)
+ return;
+ if (snaplist->snaps) {
+ for (i = 0; i < snaplist->nsnaps; i++) {
+ if (snaplist->snaps[i].snap)
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ VIR_FREE(snaplist->snaps[i].parent);
+ }
+ VIR_FREE(snaplist->snaps);
+ }
+ VIR_FREE(snaplist);
+}
+
+static int
+vshSnapSorter(const void *a, const void *b)
+{
+ const struct vshSnap *sa = a;
+ const struct vshSnap *sb = b;
+
+ if (sa->snap && !sb->snap)
+ return 1;
+ if (!sa->snap && sb->snap)
+ return -1;
+ if (!sa->snap)
+ return 0;
+
+ /* User visible sort, so we want locale-specific case comparison. */
+ return strcasecmp(virDomainSnapshotGetName(sa->snap),
+ virDomainSnapshotGetName(sb->snap));
+}
+
+/* Compute a list of snapshots from DOM. If FROM is provided, the
+ * list is limited to descendants of the given snapshot. If FLAGS is
+ * given, the list is filtered. If TREE is specified, then the
+ * parents array of SNAPLIST will also be set in a manner usable by
+ * tree listings (note that parents may also be set when getting
+ * descendants using older servers). */
+static vshSnapshotListPtr ATTRIBUTE_UNUSED
+vshSnapshotListCollect(vshControl *ctl, virDomainPtr dom,
+ virDomainSnapshotPtr from,
+ unsigned int flags, bool tree)
+{
+ int i;
+ char **names = NULL;
+ int count = 0;
+ bool descendants = false;
+ bool roots = false;
+ vshSnapshotListPtr snaplist = vshMalloc(ctl, sizeof(*snaplist));
+ vshSnapshotListPtr ret = NULL;
+ const char *fromname = NULL;
+ int start_index = -1;
+ int deleted = 0;
+
+ /* 0.9.13 will be adding a new listing API. */
+
+ /* This is the interface available in 0.9.12 and earlier,
+ * including fallbacks to 0.9.4 and earlier. */
+ if (from) {
+ fromname = virDomainSnapshotGetName(from);
+ if (!fromname) {
+ vshError(ctl, "%s", _("Could not get snapshot name"));
+ goto cleanup;
+ }
+ descendants = (flags & VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS) != 0;
+ if (tree)
+ flags |= VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
+ count = ctl->useSnapshotOld ? -1 :
+ virDomainSnapshotNumChildren(from, flags);
+ if (count < 0) {
+ if (ctl->useSnapshotOld ||
+ last_error->code == VIR_ERR_NO_SUPPORT) {
+ /* We can emulate --from. */
+ /* XXX can we also emulate --leaves? */
+ virFreeError(last_error);
+ last_error = NULL;
+ ctl->useSnapshotOld = true;
+ flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
+ count = virDomainSnapshotNum(dom, flags);
+ }
+ } else if (tree) {
+ count++;
+ }
+ } else {
+ count = virDomainSnapshotNum(dom, flags);
+
+ /* Fall back to simulation if --roots was unsupported. */
+ /* XXX can we also emulate --leaves? */
+ if (count < 0 && last_error->code == VIR_ERR_INVALID_ARG
&&
+ (flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
+ virFreeError(last_error);
+ last_error = NULL;
+ roots = true;
+ flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
+ count = virDomainSnapshotNum(dom, flags);
+ }
+ }
+
+ if (count < 0) {
+ if (!last_error)
+ vshError(ctl, _("missing support"));
+ goto cleanup;
+ }
+
+ if (!count)
+ goto success;
+
+ names = vshCalloc(ctl, sizeof(*names), count);
+
+ if (from && !ctl->useSnapshotOld) {
+ if (tree) {
+ if (count)
+ count = virDomainSnapshotListChildrenNames(from, names + 1,
+ count - 1, flags);
+ if (count >= 0) {
+ count++;
+ names[0] = vshStrdup(ctl, fromname);
+ }
+ } else {
+ count = virDomainSnapshotListChildrenNames(from, names,
+ count, flags);
+ }
+ } else {
+ count = virDomainSnapshotListNames(dom, names, count, flags);
+ }
+ if (count < 0)
+ goto cleanup;
+
+ snaplist->snaps = vshCalloc(ctl, sizeof(*snaplist->snaps), count);
+ snaplist->nsnaps = count;
+ for (i = 0; i < count; i++) {
+ snaplist->snaps[i].snap = virDomainSnapshotLookupByName(dom,
+ names[i], 0);
+ if (!snaplist->snaps[i].snap)
+ goto cleanup;
+ }
+
+ if (tree || (from && ctl->useSnapshotOld)) {
+ for (i = (from && !ctl->useSnapshotOld); i < count; i++) {
+ if (from && ctl->useSnapshotOld && STREQ(names[i],
fromname)) {
+ start_index = i;
+ continue;
+ }
+ if (vshGetSnapshotParent(ctl, snaplist->snaps[i].snap,
+ &snaplist->snaps[i].parent) < 0)
+ goto cleanup;
+ }
+ }
+ if (tree) {
+ if (from && ctl->useSnapshotOld) {
+ /* Leave things so that the only entry without a parent is
+ * 'from'. */
+ for (i = 0; i < count; i++) {
+ if (STREQ(virDomainSnapshotGetName(snaplist->snaps[i].snap),
+ fromname)) {
+ VIR_FREE(snaplist->snaps[i].parent);
+ } else if (!snaplist->snaps[i].parent) {
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ deleted++;
+ }
+ }
+ }
+ goto success;
+ }
+
+ if (ctl->useSnapshotOld && descendants) {
+ bool changed = false;
+
+ /* Make multiple passes over the list - first pass NULLs out
+ * all roots except start, remaining passes NULL out any entry
+ * whose parent is not still in list. Also, we NULL out
+ * parent when name is known to be in list. Sorry, this is
+ * O(n^3) - hope your hierarchy isn't huge. */
+ if (start_index < 0) {
+ vshError(ctl, _("snapshot %s disappeared from list"), fromname);
+ goto cleanup;
+ }
+ for (i = 0; i < count; i++) {
+ if (i == start_index)
+ continue;
+ if (!snaplist->snaps[i].parent) {
+ VIR_FREE(names[i]);
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ VIR_FREE(snaplist->snaps[i].parent);
+ deleted++;
+ } else if (STREQ(snaplist->snaps[i].parent, fromname)) {
+ VIR_FREE(snaplist->snaps[i].parent);
+ changed = true;
+ }
+ }
+ if (!changed)
+ goto success;
+ while (changed) {
+ changed = false;
+ for (i = 0; i < count; i++) {
+ bool found = false;
+ int j;
+
+ if (!names[i] || !snaplist->snaps[i].parent)
+ continue;
+ for (j = 0; j < count; j++) {
+ if (!names[j] || i == j)
+ continue;
+ if (STREQ(snaplist->snaps[i].parent, names[j])) {
+ found = true;
+ if (!snaplist->snaps[j].parent)
+ VIR_FREE(snaplist->snaps[i].parent);
+ break;
+ }
+ }
+ if (!found) {
+ changed = true;
+ VIR_FREE(names[i]);
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ VIR_FREE(snaplist->snaps[i].parent);
+ deleted++;
+ }
+ }
+ }
+ VIR_FREE(names[start_index]);
+ virDomainSnapshotFree(snaplist->snaps[start_index].snap);
+ snaplist->snaps[start_index].snap = NULL;
+ VIR_FREE(snaplist->snaps[start_index].parent);
+ deleted++;
+ }
+ if (roots) {
+ for (i = 0; i < count; i++) {
+ if (snaplist->snaps[i].parent) {
+ VIR_FREE(names[i]);
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ VIR_FREE(snaplist->snaps[i].parent);
+ deleted++;
+ }
+ }
+ }
+
+success:
+ qsort(snaplist->snaps, count, sizeof(*snaplist->snaps), vshSnapSorter);
+
+ snaplist->nsnaps -= deleted;
+
+ ret = snaplist;
+ snaplist = NULL;
+
+cleanup:
+ vshSnapshotListFree(snaplist);
+ if (names)
+ for (i = 0; i < count; i++)
+ VIR_FREE(names[i]);
+ VIR_FREE(names);
+ return ret;
+}
+
/*
* "snapshot-list" command
*/
--
1.7.10.2
7:54 a.m.
New subject: [libvirt] [PATCH 5/6] snapshot: new virsh function factored from snapshot-list
On 06/09/12 06:34, Eric Blake wrote:
This patch copies just the fallback code out of cmdSnapshotList,
and keeps the snapshot objects around rather than just their
name for easier manipulation. It looks forward to a future
patch when we add a way to list all snapshot objects at once,
and the next patch will simplify cmdSnapshotList to take
advantage of this factorization.
* tools/virsh.c (vshSnapshotList, vshSnapshotListFree): New functions.
---
tools/virsh.c | 272 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 272 insertions(+)
diff --git a/tools/virsh.c b/tools/virsh.c
index de7b282..62546b2 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
+
+/* Compute a list of snapshots from DOM. If FROM is provided, the
+ * list is limited to descendants of the given snapshot. If FLAGS is
+ * given, the list is filtered. If TREE is specified, then the
+ * parents array of SNAPLIST will also be set in a manner usable by
+ * tree listings (note that parents may also be set when getting
+ * descendants using older servers). */
+static vshSnapshotListPtr ATTRIBUTE_UNUSED
+vshSnapshotListCollect(vshControl *ctl, virDomainPtr dom,
+ virDomainSnapshotPtr from,
+ unsigned int flags, bool tree)
+{
+ int i;
+ char **names = NULL;
+ int count = 0;
+ bool descendants = false;
+ bool roots = false;
+ vshSnapshotListPtr snaplist = vshMalloc(ctl, sizeof(*snaplist));
+ vshSnapshotListPtr ret = NULL;
+ const char *fromname = NULL;
+ int start_index = -1;
+ int deleted = 0;
+
+ /* 0.9.13 will be adding a new listing API. */
+
+ /* This is the interface available in 0.9.12 and earlier,
+ * including fallbacks to 0.9.4 and earlier. */
+ if (from) {
+ fromname = virDomainSnapshotGetName(from);
+ if (!fromname) {
+ vshError(ctl, "%s", _("Could not get snapshot name"));
+ goto cleanup;
+ }
+ descendants = (flags & VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS) != 0;
+ if (tree)
+ flags |= VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
+ count = ctl->useSnapshotOld ? -1 :
+ virDomainSnapshotNumChildren(from, flags);
I'd prefer this to use an if statement instead from the ternary operator, this looks
really messy. I tried reworking this block, please look below.
+ if (count < 0) {
+ if (ctl->useSnapshotOld ||
+ last_error->code == VIR_ERR_NO_SUPPORT) {
Those two lines also aren't intuitive on the first read. last_error will be filled as
virDomainSnapshotNumChildren has to fail or never be called.
+ /* We can emulate --from. */
+ /* XXX can we also emulate --leaves? */
+ virFreeError(last_error);
+ last_error = NULL;
+ ctl->useSnapshotOld = true;
+ flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
+ count = virDomainSnapshotNum(dom, flags);
+ }
+ } else if (tree) {
+ count++;
+ }
+ } else {
+ count = virDomainSnapshotNum(dom, flags);
+
+ /* Fall back to simulation if --roots was unsupported. */
+ /* XXX can we also emulate --leaves? */
+ if (count < 0 && last_error->code == VIR_ERR_INVALID_ARG
&&
+ (flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
+ virFreeError(last_error);
+ last_error = NULL;
+ roots = true;
+ flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
+ count = virDomainSnapshotNum(dom, flags);
+ }
+ }
+
+ if (count < 0) {
+ if (!last_error)
+ vshError(ctl, _("missing support"));
I know it's copied code, but this error message doesn't look helpful. I think
it's worth improving: "Failed to collect snapshot list" perhaps?
+ goto cleanup;
+ }
I had a very hard time parsing the code flow in this block, I'd rewrite this block as
follows:
/* This is the interface available in 0.9.12 and earlier,
* including fallbacks to 0.9.4 and earlier. */
if (from) {
if (!(fromname = virDomainSnapshotGetName(from))) {
vshError(ctl, "%s", _("Could not get snapshot name"));
goto cleanup;
}
descendants = (flags & VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS) != 0;
if (tree)
flags |= VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
/* try new API at first */
if (!ctl->useSnapshotOld &&
(count = virDomainSnapshotNumChildren(from, flags)) < 0 &&
last_error && last_error->code == VIR_ERR_NO_SUPPORT) {
/* We can emulate --from. */
/* XXX can we also emulate --leaves? */
virFreeError(last_error);
lastError = NULL;
ctl->useSnapshotOld = true;
flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
}
if (tree && count >= 0)
count++;
}
/* fallback to old API */
if (count < 0) {
count = virDomainSnapshotNum(dom, flags);
/* Fall back to simulation if --roots was unsupported. */
/* XXX can we also emulate --leaves? */
if (!from && count < 0 &&
last_error->code == VIR_ERR_INVALID_ARG &&
(flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
virFreeError(last_error);
last_error = NULL;
roots = true;
flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
count = virDomainSnapshotNum(dom, flags);
}
}
if (count < 0) {
if (!last_error)
vshError(ctl, _("Failed to collect snapshot list"));
goto cleanup;
}
if (!count)
goto success;
+
+ if (!count)
+ goto success;
+
+ names = vshCalloc(ctl, sizeof(*names), count);
+
+ if (from && !ctl->useSnapshotOld) {
+ if (tree) {
+ if (count)
+ count = virDomainSnapshotListChildrenNames(from, names + 1,
+ count - 1, flags);
+ if (count >= 0) {
+ count++;
+ names[0] = vshStrdup(ctl, fromname);
+ }
+ } else {
+ count = virDomainSnapshotListChildrenNames(from, names,
+ count, flags);
+ }
+ } else {
+ count = virDomainSnapshotListNames(dom, names, count, flags);
+ }
+ if (count < 0)
+ goto cleanup;
+
+ snaplist->snaps = vshCalloc(ctl, sizeof(*snaplist->snaps), count);
+ snaplist->nsnaps = count;
+ for (i = 0; i < count; i++) {
+ snaplist->snaps[i].snap = virDomainSnapshotLookupByName(dom,
+ names[i], 0);
+ if (!snaplist->snaps[i].snap)
+ goto cleanup;
+ }
+
+ if (tree || (from && ctl->useSnapshotOld)) {
+ for (i = (from && !ctl->useSnapshotOld); i < count; i++) {
+ if (from && ctl->useSnapshotOld && STREQ(names[i],
fromname)) {
+ start_index = i;
+ continue;
+ }
+ if (vshGetSnapshotParent(ctl, snaplist->snaps[i].snap,
+ &snaplist->snaps[i].parent) < 0)
+ goto cleanup;
+ }
+ }
+ if (tree) {
+ if (from && ctl->useSnapshotOld) {
+ /* Leave things so that the only entry without a parent is
+ * 'from'. */
+ for (i = 0; i < count; i++) {
+ if (STREQ(virDomainSnapshotGetName(snaplist->snaps[i].snap),
+ fromname)) {
+ VIR_FREE(snaplist->snaps[i].parent);
+ } else if (!snaplist->snaps[i].parent) {
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ deleted++;
+ }
+ }
+ }
+ goto success;
+ }
+
+ if (ctl->useSnapshotOld && descendants) {
+ bool changed = false;
+
+ /* Make multiple passes over the list - first pass NULLs out
+ * all roots except start, remaining passes NULL out any entry
+ * whose parent is not still in list. Also, we NULL out
+ * parent when name is known to be in list. Sorry, this is
+ * O(n^3) - hope your hierarchy isn't huge. */
+ if (start_index < 0) {
+ vshError(ctl, _("snapshot %s disappeared from list"), fromname);
+ goto cleanup;
+ }
+ for (i = 0; i < count; i++) {
+ if (i == start_index)
+ continue;
+ if (!snaplist->snaps[i].parent) {
+ VIR_FREE(names[i]);
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ VIR_FREE(snaplist->snaps[i].parent);
+ deleted++;
+ } else if (STREQ(snaplist->snaps[i].parent, fromname)) {
+ VIR_FREE(snaplist->snaps[i].parent);
+ changed = true;
+ }
+ }
+ if (!changed)
+ goto success;
+ while (changed) {
+ changed = false;
+ for (i = 0; i < count; i++) {
+ bool found = false;
+ int j;
+
+ if (!names[i] || !snaplist->snaps[i].parent)
+ continue;
+ for (j = 0; j < count; j++) {
+ if (!names[j] || i == j)
+ continue;
+ if (STREQ(snaplist->snaps[i].parent, names[j])) {
+ found = true;
+ if (!snaplist->snaps[j].parent)
+ VIR_FREE(snaplist->snaps[i].parent);
+ break;
+ }
+ }
+ if (!found) {
+ changed = true;
+ VIR_FREE(names[i]);
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ VIR_FREE(snaplist->snaps[i].parent);
+ deleted++;
+ }
+ }
+ }
+ VIR_FREE(names[start_index]);
+ virDomainSnapshotFree(snaplist->snaps[start_index].snap);
+ snaplist->snaps[start_index].snap = NULL;
+ VIR_FREE(snaplist->snaps[start_index].parent);
+ deleted++;
+ }
+ if (roots) {
+ for (i = 0; i < count; i++) {
+ if (snaplist->snaps[i].parent) {
+ VIR_FREE(names[i]);
+ virDomainSnapshotFree(snaplist->snaps[i].snap);
+ snaplist->snaps[i].snap = NULL;
+ VIR_FREE(snaplist->snaps[i].parent);
+ deleted++;
+ }
+ }
+ }
+
+success:
+ qsort(snaplist->snaps, count, sizeof(*snaplist->snaps), vshSnapSorter);
+
+ snaplist->nsnaps -= deleted;
+
+ ret = snaplist;
+ snaplist = NULL;
+
+cleanup:
+ vshSnapshotListFree(snaplist);
+ if (names)
+ for (i = 0; i < count; i++)
+ VIR_FREE(names[i]);
+ VIR_FREE(names);
+ return ret;
+}
+
This one was really though to review. As this is just code movement and your tweaks to use
the new structs
look correct I'm fine if you push it without change.
Peter
7:59 a.m.
New subject: [libvirt] [PATCH 5/6] snapshot: new virsh function factored from snapshot-list
On 06/12/12 14:54, Peter Krempa wrote:
On 06/09/12 06:34, Eric Blake wrote:
> This patch copies just the fallback code out of cmdSnapshotList,
> and keeps the snapshot objects around rather than just their
> name for easier manipulation. It looks forward to a future
> patch when we add a way to list all snapshot objects at once,
> and the next patch will simplify cmdSnapshotList to take
> advantage of this factorization.
>
I know it's copied code, but this error message doesn't look
helpful. I think it's worth improving: "Failed to collect snapshot list"
perhaps?
> + goto cleanup;
> + }
I had a very hard time parsing the code flow in this block, I'd rewrite this block as
follows:
I forgot to attach the patch for the rewrite.
Peter
6:27 p.m.
New subject: [libvirt] [PATCH 5/6] snapshot: new virsh function factored from snapshot-list
On 06/12/2012 06:59 AM, Peter Krempa wrote:
On 06/12/12 14:54, Peter Krempa wrote:
> On 06/09/12 06:34, Eric Blake wrote:
>> This patch copies just the fallback code out of cmdSnapshotList,
>> and keeps the snapshot objects around rather than just their
>> name for easier manipulation. It looks forward to a future
>> patch when we add a way to list all snapshot objects at once,
>> and the next patch will simplify cmdSnapshotList to take
>> advantage of this factorization.
>>
> I know it's copied code, but this error message doesn't look helpful.
> I think it's worth improving: "Failed to collect snapshot list"
perhaps?
>
>> + goto cleanup;
>> + }
>
> I had a very hard time parsing the code flow in this block, I'd
> rewrite this block as follows:
I forgot to attach the patch for the rewrite.
Thanks; that helps.
@@ -16641,36 +16641,40 @@ vshSnapshotListCollect(vshControl *ctl,
virDomainPtr dom,
/* This is the interface available in 0.9.12 and earlier,
* including fallbacks to 0.9.4 and earlier. */
I'm off on my versioning - this was 0.9.6 and earlier.
if (from) {
There's multiple things going on here:
First, the valid combinations:
list (all snapshots, no parent info needed)
list --roots (only root snapshots)
list --from (only direct children of --from)
list --from --descendants (recursive children of --from)
list --tree (all snapshots, parent info needed)
list --tree --from (recursive children of --from, but also list from)
Then the API that satisfy those combinations:
'new' API (aka 0.9.7-0.9.12) with --from (regardless of --descendants)
-> use virDomainSnapshotNumChildren in its entirety
new API without --from (regardless of -roots) -> use
virDomainSnapshotNum in its entirety
'old' API (aka 0.8.0-0.9.6) without --from or --roots -> use
virDomainSnapshotNum in its entirety
old API without --from but with --roots -> use virDomainSnapshotNum, but
then manually filter to just roots
old with --from (regardless of --descendants) -> use
virDomainSnapshotNum to get a global list, then manually filter to just
the snapshot's children
Additionally, if both --from and --tree are present, then we want --from
to be included in the list.
I really need to list this as a comment. I'll post a v2, adding
comments and including your improvements.
+ /* fallback to old API */
+ if (count < 0) {
count = virDomainSnapshotNum(dom, flags);
More like: fall back to old API when doing children listing, or do
initial probe when doing global listing.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
7:42 p.m.
New subject: [libvirt] [PATCH 5/6] snapshot: new virsh function factored from snapshot-list
On 06/12/2012 05:27 PM, Eric Blake wrote:
I'm off on my versioning - this was 0.9.6 and earlier.
> if (from) {
There's multiple things going on here:
First, the valid combinations:
Then the API that satisfy those combinations:
I really need to list this as a comment. I'll post a v2, adding
comments and including your improvements.
Here's what I'll squash for my v2:
diff --git i/tools/virsh.c w/tools/virsh.c
index 768d189..537496f 100644
--- i/tools/virsh.c
+++ w/tools/virsh.c
@@ -16848,7 +16848,7 @@ vshSnapshotListCollect(vshControl *ctl,
virDomainPtr dom,
{
int i;
char **names = NULL;
- int count = 0;
+ int count = -1;
bool descendants = false;
bool roots = false;
vshSnapshotListPtr snaplist = vshMalloc(ctl, sizeof(*snaplist));
@@ -16859,8 +16859,24 @@ vshSnapshotListCollect(vshControl *ctl,
virDomainPtr dom,
/* 0.9.13 will be adding a new listing API. */
- /* This is the interface available in 0.9.12 and earlier,
- * including fallbacks to 0.9.4 and earlier. */
+ /* This uses the interfaces available in 0.8.0-0.9.6
+ * (virDomainSnapshotListNames, global list only) and in
+ * 0.9.7-0.9.12 (addition of virDomainSnapshotListChildrenNames
+ * for child listing, and new flags), as follows, with [*] by the
+ * combinations that need parent info (either for filtering
+ * purposes or for the resulting tree listing):
+ * old new
+ * list global as-is global as-is
+ * list --roots *global + filter global + flags
+ * list --from *global + filter child + flags
+ * list --from --descendants *global + filter child + flags
+ * list --tree *global as-is *global as-is
+ * list --tree --from *global + filter *child + flags
+ *
+ * Additionally, when --tree and --from are both used, from is
+ * added to the final list as the only element without a parent.
+ * Otherwise, --from does not appear in the final list.
+ */
if (from) {
fromname = virDomainSnapshotGetName(from);
if (!fromname) {
@@ -16870,28 +16886,30 @@ vshSnapshotListCollect(vshControl *ctl,
virDomainPtr dom,
descendants = (flags & VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS) != 0;
if (tree)
flags |= VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
- count = ctl->useSnapshotOld ? -1 :
- virDomainSnapshotNumChildren(from, flags);
- if (count < 0) {
- if (ctl->useSnapshotOld ||
- last_error->code == VIR_ERR_NO_SUPPORT) {
- /* We can emulate --from. */
- /* XXX can we also emulate --leaves? */
- virFreeError(last_error);
- last_error = NULL;
- ctl->useSnapshotOld = true;
- flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
- count = virDomainSnapshotNum(dom, flags);
- }
- } else if (tree) {
- count++;
+
+ /* First, determine if we can use the new child listing API. */
+ if (!ctl->useSnapshotOld &&
+ (count = virDomainSnapshotNumChildren(from, flags) < 0) &&
+ last_error->code == VIR_ERR_NO_SUPPORT) {
+ /* We can emulate --from. */
+ /* XXX can we also emulate --leaves? */
+ virFreeError(last_error);
+ last_error = NULL;
+ ctl->useSnapshotOld = true;
+ flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
}
- } else {
+ if (tree && count >= 0)
+ count++;
+ }
+
+ /* Global listing (including fallback when --from failed with
+ * child listing). */
+ if (count < 0) {
count = virDomainSnapshotNum(dom, flags);
/* Fall back to simulation if --roots was unsupported. */
/* XXX can we also emulate --leaves? */
- if (count < 0 && last_error->code == VIR_ERR_INVALID_ARG
&&
+ if (!from && count < 0 && last_error->code ==
VIR_ERR_INVALID_ARG &&
(flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
virFreeError(last_error);
last_error = NULL;
@@ -16903,7 +16921,7 @@ vshSnapshotListCollect(vshControl *ctl,
virDomainPtr dom,
if (count < 0) {
if (!last_error)
- vshError(ctl, _("missing support"));
+ vshError(ctl, _("failed to collect snapshot list"));
goto cleanup;
}
@@ -16912,6 +16930,7 @@ vshSnapshotListCollect(vshControl *ctl,
virDomainPtr dom,
names = vshCalloc(ctl, sizeof(*names), count);
+ /* Now that we have a count, collect the list. */
if (from && !ctl->useSnapshotOld) {
if (tree) {
if (count)
@@ -16940,6 +16959,10 @@ vshSnapshotListCollect(vshControl *ctl,
virDomainPtr dom,
goto cleanup;
}
+ /* Collect parents when needed. With the new API, --tree and
+ * --from together put from as the first element without a parent;
+ * with the old API we still need to do a post-process filtering
+ * based on all parent information. */
if (tree || (from && ctl->useSnapshotOld)) {
for (i = (from && !ctl->useSnapshotOld); i < count; i++) {
if (from && ctl->useSnapshotOld && STREQ(names[i],
fromname)) {
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
5:33 p.m.
New subject: [libvirt] [PATCH 5/6] snapshot: new virsh function factored from snapshot-list
On 06/12/2012 06:42 PM, Eric Blake wrote:
> I really need to list this as a comment. I'll post a v2,
adding
> comments and including your improvements.
Here's what I'll squash for my v2:
+ /* First, determine if we can use the new child listing API.
*/
+ if (!ctl->useSnapshotOld &&
+ (count = virDomainSnapshotNumChildren(from, flags) < 0) &&
Ouch - nasty typo on my part in transcribing Peter's suggestions (hint -
')' in the wrong place). All the more reason for me to post a corrected v2.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
11:34 p.m.
New subject: [libvirt] [PATCH 6/6] snapshot: use new virsh function for snapshot-list
Operating on a list of snapshot objects looks so much simpler.
In particular, since the helper function already trimmed out
irrelevant entries, we no longer have quite so many special cases
on finding the first snapshot to operate on.
* tools/virsh.c (cmdSnapshotList): Use previous patches.
---
tools/virsh.c | 207 +++++++++------------------------------------------------
1 file changed, 31 insertions(+), 176 deletions(-)
diff --git a/tools/virsh.c b/tools/virsh.c
index 62546b2..dc098f5 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -16621,7 +16621,7 @@ vshSnapSorter(const void *a, const void *b)
* parents array of SNAPLIST will also be set in a manner usable by
* tree listings (note that parents may also be set when getting
* descendants using older servers). */
-static vshSnapshotListPtr ATTRIBUTE_UNUSED
+static vshSnapshotListPtr
vshSnapshotListCollect(vshControl *ctl, virDomainPtr dom,
virDomainSnapshotPtr from,
unsigned int flags, bool tree)
@@ -16840,6 +16840,15 @@ cleanup:
return ret;
}
+static const char *
+vshSnapshotListLookup(int id, bool parent, void *opaque)
+{
+ vshSnapshotListPtr snaplist = opaque;
+ if (parent)
+ return snaplist->snaps[id].parent;
+ return virDomainSnapshotGetName(snaplist->snaps[id].snap);
+}
+
/*
* "snapshot-list" command
*/
@@ -16870,11 +16879,7 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
virDomainPtr dom = NULL;
bool ret = false;
unsigned int flags = 0;
- int parent_filter = 0; /* -1 for roots filtering, 0 for no parent
- information needed, 1 for parent column */
- char **names = NULL;
- char **parents = NULL;
- int count = 0;
+ bool show_parent = false;
int i;
xmlDocPtr xml = NULL;
xmlXPathContextPtr ctxt = NULL;
@@ -16890,8 +16895,8 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
bool leaves = vshCommandOptBool(cmd, "leaves");
const char *from = NULL;
virDomainSnapshotPtr start = NULL;
- int start_index = -1;
bool descendants = false;
+ vshSnapshotListPtr snaplist = NULL;
if (!vshConnectionUsability(ctl, ctl->conn))
goto cleanup;
@@ -16916,7 +16921,7 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
_("--parent and --tree are mutually exclusive"));
goto cleanup;
}
- parent_filter = 1;
+ show_parent = true;
} else if (vshCommandOptBool(cmd, "roots")) {
if (tree) {
vshError(ctl, "%s",
@@ -16945,48 +16950,16 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (from) {
descendants = vshCommandOptBool(cmd, "descendants");
- if (descendants || tree) {
+ if (descendants)
flags |= VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
- }
- count = ctl->useSnapshotOld ? -1 :
- virDomainSnapshotNumChildren(start, flags);
- if (count < 0) {
- if (ctl->useSnapshotOld ||
- last_error->code == VIR_ERR_NO_SUPPORT) {
- /* We can emulate --from. */
- /* XXX can we also emulate --leaves? */
- virFreeError(last_error);
- last_error = NULL;
- ctl->useSnapshotOld = true;
- flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
- count = virDomainSnapshotNum(dom, flags);
- }
- } else if (tree) {
- count++;
- }
- } else {
- count = virDomainSnapshotNum(dom, flags);
-
- /* Fall back to simulation if --roots was unsupported. */
- /* XXX can we also emulate --leaves? */
- if (count < 0 && last_error->code == VIR_ERR_INVALID_ARG
&&
- (flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
- virFreeError(last_error);
- last_error = NULL;
- parent_filter = -1;
- flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
- count = virDomainSnapshotNum(dom, flags);
- }
}
- if (count < 0) {
- if (!last_error)
- vshError(ctl, _("missing support"));
+ if ((snaplist = vshSnapshotListCollect(ctl, dom, start, flags,
+ tree)) == NULL)
goto cleanup;
- }
if (!tree) {
- if (parent_filter > 0)
+ if (show_parent)
vshPrintExtra(ctl, " %-20s %-25s %-15s %s",
_("Name"), _("Creation Time"),
_("State"),
_("Parent"));
@@ -16997,142 +16970,35 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
"------------------------------------------------------------\n");
}
- if (!count) {
+ if (!snaplist->nsnaps) {
ret = true;
goto cleanup;
}
- if (VIR_ALLOC_N(names, count) < 0)
- goto cleanup;
-
- if (from && !ctl->useSnapshotOld) {
- /* When mixing --from and --tree, we want to start the tree at the
- * given snapshot. Without --tree, only list the children. */
- if (tree) {
- if (count)
- count = virDomainSnapshotListChildrenNames(start, names + 1,
- count - 1, flags);
- if (count >= 0) {
- count++;
- names[0] = vshStrdup(ctl, from);
- }
- } else {
- count = virDomainSnapshotListChildrenNames(start, names,
- count, flags);
- }
- } else {
- count = virDomainSnapshotListNames(dom, names, count, flags);
- }
- if (count < 0)
- goto cleanup;
-
- qsort(&names[0], count, sizeof(char*), namesorter);
-
- if (tree || (from && ctl->useSnapshotOld)) {
- parents = vshCalloc(ctl, sizeof(char *), count);
- for (i = (from && !ctl->useSnapshotOld); i < count; i++) {
- if (from && ctl->useSnapshotOld && STREQ(names[i], from))
{
- start_index = i;
- continue;
- }
-
- /* free up memory from previous iterations of the loop */
- if (snapshot)
- virDomainSnapshotFree(snapshot);
- snapshot = virDomainSnapshotLookupByName(dom, names[i], 0);
- if (!snapshot ||
- vshGetSnapshotParent(ctl, snapshot, &parents[i]) < 0) {
- while (--i >= 0)
- VIR_FREE(parents[i]);
- VIR_FREE(parents);
- goto cleanup;
- }
- }
- }
if (tree) {
- struct vshTreeArray arrays = { names, parents };
-
- for (i = 0 ; i < count ; i++) {
- if ((from && ctl->useSnapshotOld) ? STREQ(names[i], from) :
- !parents[i] &&
- vshTreePrint(ctl, vshTreeArrayLookup, &arrays, count, i) < 0)
+ for (i = 0 ; i < snaplist->nsnaps ; i++) {
+ if (!snaplist->snaps[i].parent &&
+ vshTreePrint(ctl, vshSnapshotListLookup, snaplist,
+ snaplist->nsnaps, i) < 0)
goto cleanup;
}
-
ret = true;
goto cleanup;
}
- if (ctl->useSnapshotOld && descendants) {
- bool changed = false;
-
- /* Make multiple passes over the list - first pass NULLs out
- * all roots except start, remaining passes NULL out any entry
- * whose parent is not still in list. Also, we NULL out
- * parent when name is known to be in list. Sorry, this is
- * O(n^3) - hope your hierarchy isn't huge. */
- if (start_index < 0) {
- vshError(ctl, _("snapshot %s disappeared from list"), from);
- goto cleanup;
- }
- for (i = 0; i < count; i++) {
- if (i == start_index)
- continue;
- if (!parents[i]) {
- VIR_FREE(names[i]);
- } else if (STREQ(parents[i], from)) {
- VIR_FREE(parents[i]);
- changed = true;
- }
- }
- if (!changed) {
- ret = true;
- goto cleanup;
- }
- while (changed) {
- changed = false;
- for (i = 0; i < count; i++) {
- bool found = false;
- int j;
-
- if (!names[i] || !parents[i])
- continue;
- for (j = 0; j < count; j++) {
- if (!names[j] || i == j)
- continue;
- if (STREQ(parents[i], names[j])) {
- found = true;
- if (!parents[j])
- VIR_FREE(parents[i]);
- break;
- }
- }
- if (!found) {
- changed = true;
- VIR_FREE(names[i]);
- }
- }
- }
- VIR_FREE(names[start_index]);
- }
-
- for (i = 0; i < count; i++) {
- if (from && ctl->useSnapshotOld &&
- (descendants ? !names[i] : STRNEQ_NULLABLE(parents[i], from)))
- continue;
+ for (i = 0; i < snaplist->nsnaps; i++) {
+ const char *name;
/* free up memory from previous iterations of the loop */
VIR_FREE(parent);
VIR_FREE(state);
- if (snapshot)
- virDomainSnapshotFree(snapshot);
xmlXPathFreeContext(ctxt);
xmlFreeDoc(xml);
VIR_FREE(doc);
- snapshot = virDomainSnapshotLookupByName(dom, names[i], 0);
- if (snapshot == NULL)
- continue;
+ snapshot = snaplist->snaps[i].snap;
+ name = virDomainSnapshotGetName(snapshot);
+ assert(name);
doc = virDomainSnapshotGetXMLDesc(snapshot, 0);
if (!doc)
@@ -17142,12 +17008,9 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (!xml)
continue;
- if (parent_filter) {
+ if (show_parent)
parent = virXPathString("string(/domainsnapshot/parent/name)",
ctxt);
- if (!parent && parent_filter < 0)
- continue;
- }
state = virXPathString("string(/domainsnapshot/state)", ctxt);
if (state == NULL)
@@ -17166,31 +17029,23 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (parent)
vshPrint(ctl, " %-20s %-25s %-15s %s\n",
- names[i], timestr, state, parent);
+ name, timestr, state, parent);
else
- vshPrint(ctl, " %-20s %-25s %s\n", names[i], timestr, state);
+ vshPrint(ctl, " %-20s %-25s %s\n", name, timestr, state);
}
ret = true;
cleanup:
/* this frees up memory from the last iteration of the loop */
+ vshSnapshotListFree(snaplist);
VIR_FREE(parent);
VIR_FREE(state);
- if (snapshot)
- virDomainSnapshotFree(snapshot);
if (start)
virDomainSnapshotFree(start);
xmlXPathFreeContext(ctxt);
xmlFreeDoc(xml);
VIR_FREE(doc);
- for (i = 0; i < count; i++) {
- VIR_FREE(names[i]);
- if (parents)
- VIR_FREE(parents[i]);
- }
- VIR_FREE(names);
- VIR_FREE(parents);
if (dom)
virDomainFree(dom);
--
1.7.10.2
8:18 a.m.
New subject: [libvirt] [PATCH 6/6] snapshot: use new virsh function for snapshot-list
On 06/09/12 06:34, Eric Blake wrote:
Operating on a list of snapshot objects looks so much simpler.
In particular, since the helper function already trimmed out
irrelevant entries, we no longer have quite so many special cases
on finding the first snapshot to operate on.
* tools/virsh.c (cmdSnapshotList): Use previous patches.
---
tools/virsh.c | 207 +++++++++------------------------------------------------
1 file changed, 31 insertions(+), 176 deletions(-)
ACK.
Peter
8:03 p.m.
New subject: [libvirt] [PATCH 6/6] snapshot: use new virsh function for snapshot-list
On 06/12/2012 07:18 AM, Peter Krempa wrote:
On 06/09/12 06:34, Eric Blake wrote:
> Operating on a list of snapshot objects looks so much simpler.
> In particular, since the helper function already trimmed out
> irrelevant entries, we no longer have quite so many special cases
> on finding the first snapshot to operate on.
>
> * tools/virsh.c (cmdSnapshotList): Use previous patches.
> ---
> tools/virsh.c | 207
> +++++++++------------------------------------------------
> 1 file changed, 31 insertions(+), 176 deletions(-)
>
ACK.
As mentioned in 2/6, I'll squash this in for my v2, now that the
callback struct is only used by one client instead of generic to
vshTreePrint:
diff --git i/tools/virsh.c w/tools/virsh.c
index 84db8d3..c7877b3 100644
--- i/tools/virsh.c
+++ w/tools/virsh.c
@@ -13473,15 +13473,15 @@ vshTreePrint(vshControl *ctl, vshTreeLookup
lookup, void *opaque,
return ret;
}
-struct vshTreeArray {
+struct vshNodeList {
char **names;
char **parents;
};
static const char *
-vshTreeArrayLookup(int devid, bool parent, void *opaque)
+vshNodeListLookup(int devid, bool parent, void *opaque)
{
- struct vshTreeArray *arrays = opaque;
+ struct vshNodeList *arrays = opaque;
if (parent)
return arrays->parents[devid];
return arrays->names[devid];
@@ -13536,7 +13536,7 @@ cmdNodeListDevices(vshControl *ctl, const vshCmd
*cmd ATTRIBUTE_UNUSED)
qsort(&devices[0], num_devices, sizeof(char*), namesorter);
if (tree) {
char **parents = vshMalloc(ctl, sizeof(char *) * num_devices);
- struct vshTreeArray arrays = { devices, parents };
+ struct vshNodeList arrays = { devices, parents };
for (i = 0; i < num_devices; i++) {
virNodeDevicePtr dev = virNodeDeviceLookupByName(ctl->conn,
devices[i]);
@@ -13550,7 +13550,7 @@ cmdNodeListDevices(vshControl *ctl, const vshCmd
*cmd ATTRIBUTE_UNUSED)
}
for (i = 0 ; i < num_devices ; i++) {
if (parents[i] == NULL &&
- vshTreePrint(ctl, vshTreeArrayLookup, &arrays, num_devices,
+ vshTreePrint(ctl, vshNodeListLookup, &arrays, num_devices,
i) < 0)
ret = false;
}
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
4546
days inactive
4550
days old
22 comments
2 participants
participants (2)
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Eric Blake -
Peter Krempa