Patchwork [V16,3/7] Create four QemuOptsList related functions

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Submitter Robert Wang
Date June 18, 2013, 9:31 a.m.
Message ID <1371547919-15654-4-git-send-email-wdongxu@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/252196/
State New
Headers show

Comments

Robert Wang - June 18, 2013, 9:31 a.m.
This patch creates 4 functions, count_opts_list, qemu_opts_append,
qemu_opts_free and qemu_opts_print_help, they are used in following
commits.



Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
---
v16->v17:
1) discard double-initialization.
2) use pointer directly, not g_strdup.

v12->v13:
1) simply assert that neither argument has merge_lists set.
2) drop superfluous paranthesesis around p == first.

v11->v12:
1) renmae functions.
2) fix loop styles and code styles.
3) qemu_opts_apend will not return NULL now.
4) merge_lists value is from arguments in qemu_opts_append.

v6->v7:
1) Fix typo.

v5->v6:
1) allocate enough space in append_opts_list function.
 include/qemu/option.h |  3 +++
 util/qemu-option.c    | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 76 insertions(+)
Eric Blake - July 10, 2013, 4:07 p.m.
On 06/18/2013 03:31 AM, Dong Xu Wang wrote:
> This patch creates 4 functions, count_opts_list, qemu_opts_append,
> qemu_opts_free and qemu_opts_print_help, they are used in following
> commits.
> 
> 
> 
> Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
> ---

> +
> +/* Create a new QemuOptsList and make its desc to the merge of first
> + * and second. It will allocate space for one new QemuOptsList plus

s/make its desc to the merge of/with a desc of the merge of the/

> + * enough space for QemuOptDesc in first and second QemuOptsList.
> + * First argument's QemuOptDesc members take precedence over second's.
> + * The result's name and implied_opt_name are not copied from them.
> + * Both merge_lists should not be set. Both list can be NULL.

s/list/lists/


> +    dest->name = "append_opts_list";
> +    dest->implied_opt_name = NULL;
> +    assert((!first || !first->merge_lists)
> +        && (!second || !second->merge_lists));

Indentation - usually, an operator is intended to the column after the
containing ( on the line above.

> +
> +/* free a QemuOptsList, can accept NULL as arguments */
> +void qemu_opts_free(QemuOptsList *list)
> +{
> +    g_free(list);
> +}

Do we really need a function for this, or can callers just call g_free
directly?  But it doesn't hurt to have the layer of indirection,
especially if we might be freeing more than one thing in the future.

> +
> +void qemu_opts_print_help(QemuOptsList *list)
> +{
> +    int i;
> +    printf("Supported options:\n");
> +    for (i = 0; list && list->desc[i].name; i++) {
> +        printf("%-16s %s\n", list->desc[i].name,
> +            list->desc[i].help ?

Indentation - 'list' should start on the column after the containing (
on the line above.

> +                list->desc[i].help : "No description available");
> +    }
> +}
> 

None of my findings are fatal to the algorithm, so I leave it up to the
maintainer whether to touch this up as part of preparing for a pull
request, or whether to request a v17 respin.

Patch

diff --git a/include/qemu/option.h b/include/qemu/option.h
index b928ab0..c7a5c14 100644
--- a/include/qemu/option.h
+++ b/include/qemu/option.h
@@ -157,4 +157,7 @@  int qemu_opts_print(QemuOpts *opts);
 int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
                       int abort_on_failure);
 
+QemuOptsList *qemu_opts_append(QemuOptsList *first, QemuOptsList *second);
+void qemu_opts_free(QemuOptsList *list);
+void qemu_opts_print_help(QemuOptsList *list);
 #endif
diff --git a/util/qemu-option.c b/util/qemu-option.c
index bd2acdc..5dd62e8 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -1218,3 +1218,76 @@  int qemu_opts_foreach(QemuOptsList *list, qemu_opts_loopfunc func, void *opaque,
     loc_pop(&loc);
     return rc;
 }
+
+static size_t count_opts_list(QemuOptsList *list)
+{
+    size_t i;
+
+    for (i = 0; list && list->desc[i].name; i++) {
+        ;
+    }
+
+    return i;
+}
+
+/* Create a new QemuOptsList and make its desc to the merge of first
+ * and second. It will allocate space for one new QemuOptsList plus
+ * enough space for QemuOptDesc in first and second QemuOptsList.
+ * First argument's QemuOptDesc members take precedence over second's.
+ * The result's name and implied_opt_name are not copied from them.
+ * Both merge_lists should not be set. Both list can be NULL.
+ */
+QemuOptsList *qemu_opts_append(QemuOptsList *first,
+                               QemuOptsList *second)
+{
+    size_t num_first_opts, num_second_opts;
+    QemuOptsList *dest = NULL;
+    int i;
+    int index = 0;
+    QemuOptsList *p = first;
+
+    num_first_opts = count_opts_list(first);
+    num_second_opts = count_opts_list(second);
+
+    dest = g_malloc0(sizeof(QemuOptsList)
+        + (num_first_opts + num_second_opts + 1) * sizeof(QemuOptDesc));
+
+    dest->name = "append_opts_list";
+    dest->implied_opt_name = NULL;
+    assert((!first || !first->merge_lists)
+        && (!second || !second->merge_lists));
+    QTAILQ_INIT(&dest->head);
+
+    for (i = 0; p && p->desc[i].name; i++) {
+        if (!find_desc_by_name(dest->desc, p->desc[i].name)) {
+            dest->desc[index].name = p->desc[i].name;
+            dest->desc[index].help = p->desc[i].help;
+            dest->desc[index].type = p->desc[i].type;
+            dest->desc[index].def_value_str =  p->desc[i].def_value_str;
+            index++;
+        }
+        if (p == first && p && !p->desc[i].name) {
+            p = second;
+            i = 0;
+        }
+    }
+    dest->desc[index].name = NULL;
+    return dest;
+}
+
+/* free a QemuOptsList, can accept NULL as arguments */
+void qemu_opts_free(QemuOptsList *list)
+{
+    g_free(list);
+}
+
+void qemu_opts_print_help(QemuOptsList *list)
+{
+    int i;
+    printf("Supported options:\n");
+    for (i = 0; list && list->desc[i].name; i++) {
+        printf("%-16s %s\n", list->desc[i].name,
+            list->desc[i].help ?
+                list->desc[i].help : "No description available");
+    }
+}