[libvirt] [PATCH 1/8] Add qemuMonitorGetObjectListPaths() method for QMP qom-list command

[Daniel P. Berrange]

On Tue, Jul 02, 2013 at 09:39:19AM -0400, John Ferlan wrote:
> Add a new qemuMonitorGetObjectListPaths() method to support invocation
> of the 'qom-list' JSON monitor command with a provided path.
> 
> The returned list of paired data fields of "name" and "type" that can
> be used to peruse QOM configuration data and eventually utilize for the
> balloon statistics.
> 
> The test does a "{"execute":"qom-list", "arguments": { "path": "/"}}" which
> returns "{"return": [{"name": "machine", "type": "child<container>"},
> {"name": "type", "type": "string"}]}" resulting in a return of an array
> of 2 elements with [0].name="machine", [0].type="child<container>".  The [1]
> entry appears to be a header that could be used some day via a command such
> as "virsh qemuobject --list" to format output.

Top marks for adding a test !

> ---
>  src/qemu/qemu_monitor.c      | 33 ++++++++++++++++
>  src/qemu/qemu_monitor.h      | 15 +++++++
>  src/qemu/qemu_monitor_json.c | 93 ++++++++++++++++++++++++++++++++++++++++++++
>  src/qemu/qemu_monitor_json.h |  6 +++
>  tests/qemumonitorjsontest.c  | 77 ++++++++++++++++++++++++++++++++++++
>  5 files changed, 224 insertions(+)


> diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
> index 86ef635..2e92f8c 100644
> --- a/src/qemu/qemu_monitor.h
> +++ b/src/qemu/qemu_monitor.h
> @@ -679,6 +679,21 @@ int qemuMonitorGetKVMState(qemuMonitorPtr mon,
>  
>  int qemuMonitorGetObjectTypes(qemuMonitorPtr mon,
>                                char ***types);
> +
> +typedef struct _qemuMonitorListPath qemuMonitorListPath;
> +typedef qemuMonitorListPath *qemuMonitorListPathPtr;
> +
> +struct _qemuMonitorListPath {
> +    char *name;
> +    char *type;
> +};
> +
> +int qemuMonitorGetObjectListPaths(qemuMonitorPtr mon,
> +                                  const char *path,
> +                                  qemuMonitorListPathPtr **paths);
> +
> +void qemuMonitorListPathFree(qemuMonitorListPathPtr paths);

The qom related monitor calls are super generic, which also means
they are a super PITA to deal with in code. To mitigate this, I
think we should try to keep code that uses the qom commands
isolated in the qemu_monitor* files, and then expose higher level
APIs to the rest of the QEMU driver code.

So I think it is ok to expose these APIs in qemu_monitor_json.h,
but we should not expose it in qemu_monitor.h

Daniel
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