diff mbox

[v2,7/8] util: add iterators for QemuOpts values

Message ID 20170124095332.23955-8-berrange@redhat.com
State New
Headers show

Commit Message

Daniel P. Berrangé Jan. 24, 2017, 9:53 a.m. UTC 
To iterate over all QemuOpts currently requires using a callback
function which is inconvenient for control flow. Add support for
using iterator functions more directly

  QemuOptsIter iter;
  QemuOpt *opt;

  qemu_opts_iter_init(&iter, opts, "repeated-key");
  while ((opt = qemu_opts_iter_next(&iter)) != NULL) {
      ....do something...
  }

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
---
 include/qemu/option.h |  9 +++++++++
 util/qemu-option.c    | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+)

Comments

Eric Blake Jan. 24, 2017, 6:58 p.m. UTC | #1 
On 01/24/2017 03:53 AM, Daniel P. Berrange wrote:
> To iterate over all QemuOpts currently requires using a callback
> function which is inconvenient for control flow. Add support for
> using iterator functions more directly
> 
>   QemuOptsIter iter;
>   QemuOpt *opt;
> 
>   qemu_opts_iter_init(&iter, opts, "repeated-key");
>   while ((opt = qemu_opts_iter_next(&iter)) != NULL) {
>       ....do something...
>   }
> 
> Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
> ---
>  include/qemu/option.h |  9 +++++++++
>  util/qemu-option.c    | 19 +++++++++++++++++++
>  2 files changed, 28 insertions(+)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>
diff mbox

Patch

diff --git a/include/qemu/option.h b/include/qemu/option.h
index 1f9e3f9..e786df0 100644
--- a/include/qemu/option.h
+++ b/include/qemu/option.h
@@ -100,6 +100,15 @@  typedef int (*qemu_opt_loopfunc)(void *opaque,
 int qemu_opt_foreach(QemuOpts *opts, qemu_opt_loopfunc func, void *opaque,
                      Error **errp);
 
+typedef struct {
+    QemuOpts *opts;
+    QemuOpt *opt;
+    const char *name;
+} QemuOptsIter;
+
+void qemu_opt_iter_init(QemuOptsIter *iter, QemuOpts *opts, const char *name);
+const char *qemu_opt_iter_next(QemuOptsIter *iter);
+
 QemuOpts *qemu_opts_find(QemuOptsList *list, const char *id);
 QemuOpts *qemu_opts_create(QemuOptsList *list, const char *id,
                            int fail_if_exists, Error **errp);
diff --git a/util/qemu-option.c b/util/qemu-option.c
index 3467dc2..d611946 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -332,6 +332,25 @@  const char *qemu_opt_get(QemuOpts *opts, const char *name)
     return opt ? opt->str : NULL;
 }
 
+void qemu_opt_iter_init(QemuOptsIter *iter, QemuOpts *opts, const char *name)
+{
+    iter->opts = opts;
+    iter->opt = QTAILQ_FIRST(&opts->head);
+    iter->name = name;
+}
+
+const char *qemu_opt_iter_next(QemuOptsIter *iter)
+{
+    QemuOpt *ret = iter->opt;
+    if (iter->name) {
+        while (ret && !g_str_equal(iter->name, ret->name)) {
+            ret = QTAILQ_NEXT(ret, next);
+        }
+    }
+    iter->opt = ret ? QTAILQ_NEXT(ret, next) : NULL;
+    return ret ? ret->str : NULL;
+}
+
 /* Get a known option (or its default) and remove it from the list
  * all in one action. Return a malloced string of the option value.
  * Result must be freed by caller with g_free().