[Qemu-devel] [PATCH V15 2/6] avoid duplication of default value in QemuOpts

2013-05-30 Thread Dongxu Wang
From: Dong Xu Wang wdon...@linux.vnet.ibm.com

This patch will move the default value entirely to QemuOptDesc.

When getting the value of an option that hasn't been set, and
QemuOptDesc has a default value, return that.  Else, behave as
before.

Example: qemu_opt_get_number(opts, foo, 42)

   If foo has been set in opts, return its value.

   Else, if opt's QemuOptDesc has a default value for foo, return
   that.

   Else, return 42.

   Note that the last argument is useless when QemuOptDesc has a
   default value.  Ugly.  If it bothers us, we could assert.

Example: qemu_opt_get(opts, bar)

   If bar has been set in opts, return its value.

   Else, if opt's QemuOptDesc has a default value for bar, return
   that.

   Else, return NULL.

Signed-off-by: Dong Xu Wang wdon...@linux.vnet.ibm.com

v13-v14:
1) change code style.
2) assert errors.
Signed-off-by: Dongxu Wang wdon...@linux.vnet.ibm.com
---
 util/qemu-option.c | 66 --
 1 file changed, 49 insertions(+), 17 deletions(-)

diff --git a/util/qemu-option.c b/util/qemu-option.c
index 84d8c8b..bd2acdc 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -525,9 +525,31 @@ static QemuOpt *qemu_opt_find(QemuOpts *opts, const char 
*name)
 return NULL;
 }
 
+static const QemuOptDesc *find_desc_by_name(const QemuOptDesc *desc,
+const char *name)
+{
+int i;
+
+for (i = 0; desc[i].name != NULL; i++) {
+if (strcmp(desc[i].name, name) == 0) {
+return desc[i];
+}
+}
+
+return NULL;
+}
+
 const char *qemu_opt_get(QemuOpts *opts, const char *name)
 {
 QemuOpt *opt = qemu_opt_find(opts, name);
+const QemuOptDesc *desc;
+
+if (!opt) {
+desc = find_desc_by_name(opts-list-desc, name);
+if (desc  desc-def_value_str) {
+return desc-def_value_str;
+}
+}
 return opt ? opt-str : NULL;
 }
 
@@ -546,9 +568,17 @@ bool qemu_opt_has_help_opt(QemuOpts *opts)
 bool qemu_opt_get_bool(QemuOpts *opts, const char *name, bool defval)
 {
 QemuOpt *opt = qemu_opt_find(opts, name);
+const QemuOptDesc *desc;
+Error *local_err = NULL;
 
-if (opt == NULL)
+if (opt == NULL) {
+desc = find_desc_by_name(opts-list-desc, name);
+if (desc  desc-def_value_str) {
+parse_option_bool(name, desc-def_value_str, defval, local_err);
+assert(!local_err);
+}
 return defval;
+}
 assert(opt-desc  opt-desc-type == QEMU_OPT_BOOL);
 return opt-value.boolean;
 }
@@ -556,9 +586,17 @@ bool qemu_opt_get_bool(QemuOpts *opts, const char *name, 
bool defval)
 uint64_t qemu_opt_get_number(QemuOpts *opts, const char *name, uint64_t defval)
 {
 QemuOpt *opt = qemu_opt_find(opts, name);
+const QemuOptDesc *desc;
+Error *local_err = NULL;
 
-if (opt == NULL)
+if (opt == NULL) {
+desc = find_desc_by_name(opts-list-desc, name);
+if (desc  desc-def_value_str) {
+parse_option_number(name, desc-def_value_str, defval, 
local_err);
+assert(!local_err);
+}
 return defval;
+}
 assert(opt-desc  opt-desc-type == QEMU_OPT_NUMBER);
 return opt-value.uint;
 }
@@ -566,9 +604,17 @@ uint64_t qemu_opt_get_number(QemuOpts *opts, const char 
*name, uint64_t defval)
 uint64_t qemu_opt_get_size(QemuOpts *opts, const char *name, uint64_t defval)
 {
 QemuOpt *opt = qemu_opt_find(opts, name);
+const QemuOptDesc *desc;
+Error *local_err = NULL;
 
-if (opt == NULL)
+if (opt == NULL) {
+desc = find_desc_by_name(opts-list-desc, name);
+if (desc  desc-def_value_str) {
+parse_option_size(name, desc-def_value_str, defval, local_err);
+assert(!local_err);
+}
 return defval;
+}
 assert(opt-desc  opt-desc-type == QEMU_OPT_SIZE);
 return opt-value.uint;
 }
@@ -609,20 +655,6 @@ static bool opts_accepts_any(const QemuOpts *opts)
 return opts-list-desc[0].name == NULL;
 }
 
-static const QemuOptDesc *find_desc_by_name(const QemuOptDesc *desc,
-const char *name)
-{
-int i;
-
-for (i = 0; desc[i].name != NULL; i++) {
-if (strcmp(desc[i].name, name) == 0) {
-return desc[i];
-}
-}
-
-return NULL;
-}
-
 static void opt_set(QemuOpts *opts, const char *name, const char *value,
 bool prepend, Error **errp)
 {
-- 
1.7.11.7




Re: [Qemu-devel] [PATCH V15 2/6] avoid duplication of default value in QemuOpts

2013-05-30 Thread Eric Blake
On 05/30/2013 03:55 AM, Dongxu Wang wrote:
 From: Dong Xu Wang wdon...@linux.vnet.ibm.com
 
 This patch will move the default value entirely to QemuOptDesc.
 
 When getting the value of an option that hasn't been set, and
 QemuOptDesc has a default value, return that.  Else, behave as
 before.
 
 Example: qemu_opt_get_number(opts, foo, 42)
 
If foo has been set in opts, return its value.
 
Else, if opt's QemuOptDesc has a default value for foo, return
that.
 
Else, return 42.
 
Note that the last argument is useless when QemuOptDesc has a
default value.  Ugly.  If it bothers us, we could assert.
 
 Example: qemu_opt_get(opts, bar)
 
If bar has been set in opts, return its value.
 
Else, if opt's QemuOptDesc has a default value for bar, return
that.
 
Else, return NULL.
 
 Signed-off-by: Dong Xu Wang wdon...@linux.vnet.ibm.com
 
 v13-v14:
 1) change code style.
 2) assert errors.
 Signed-off-by: Dongxu Wang wdon...@linux.vnet.ibm.com

Again, a bit of a mess at the tail of the commit message.

 ---
  util/qemu-option.c | 66 
 --
  1 file changed, 49 insertions(+), 17 deletions(-)
 

Reviewed-by: Eric Blake ebl...@redhat.com

-- 
Eric Blake   eblake redhat com+1-919-301-3266
Libvirt virtualization library http://libvirt.org



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