[libvirt] [PATCH v2 01/15] util: json: add helper to iterate and steal members of json array
Simplifies cases where JSON array members need to be transferred to a
different structure.
---
Notes:
v2:
- iterate from beginning
- add option to keep array member in the array without breaking iteration
- documented callback return codes
src/libvirt_private.syms | 1 +
src/util/virjson.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
src/util/virjson.h | 6 ++++++
3 files changed, 61 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index bf503a5..e21be67 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1762,6 +1762,7 @@ virISCSIScanTargets;
# util/virjson.h
virJSONValueArrayAppend;
+virJSONValueArrayForeachSteal;
virJSONValueArrayGet;
virJSONValueArraySize;
virJSONValueArraySteal;
diff --git a/src/util/virjson.c b/src/util/virjson.c
index 1d8e6d5..d55600a 100644
--- a/src/util/virjson.c
+++ b/src/util/virjson.c
@@ -949,6 +949,60 @@ virJSONValueArraySteal(virJSONValuePtr array,
}
+/**
+ * virJSONValueArrayForeachSteal:
+ * @array: array to iterate
+ * @cb: callback called on every member of the array
+ * @opaque: custom data for the callback
+ *
+ * Iterates members of the array and calls the callback on every single member.
+ * The return codes of the callback are interpreted as follows:
+ * 0: callback claims ownership of the array element and is responsible for
+ * freeing it
+ * 1: callback does not claim the ownership, but the iteration continues
+ * -1: callback doesn't claim ownership and iteration does not continue
+ *
+ * Returns 0 if all members were iterated and/or stolen by the callback; -1
+ * on callback failure or if the JSON value object is not an array.
+ * The rest of the members stay in possession of the array and it's condensed.
+ */
+int
+virJSONValueArrayForeachSteal(virJSONValuePtr array,
+ virJSONArrayIteratorFunc cb,
+ void *opaque)
+{
+ size_t i;
+ size_t j = 0;
+ int ret = 0;
+ int rc;
+
+ if (array->type != VIR_JSON_TYPE_ARRAY)
+ return -1;
+
+ for (i = 0; i < array->data.array.nvalues; i++) {
+ if ((rc = cb(i, array->data.array.values[i], opaque)) < 0) {
+ ret = -1;
+ break;
+ }
+
+ if (rc == 0)
+ array->data.array.values[i] = NULL;
+ }
+
+ /* condense the remaining entries at the beginning */
+ for (i = 0; i < array->data.array.nvalues; i++) {
+ if (!array->data.array.values[i])
+ continue;
+
+ array->data.array.values[j++] = array->data.array.values[i];
+ }
+
+ array->data.array.nvalues = j;
+
+ return ret;
+}
+
+
const char *
virJSONValueGetString(virJSONValuePtr string)
{
diff --git a/src/util/virjson.h b/src/util/virjson.h
index 8b62d65..5b4f172 100644
--- a/src/util/virjson.h
+++ b/src/util/virjson.h
@@ -117,6 +117,12 @@ bool virJSONValueIsArray(virJSONValuePtr array);
ssize_t virJSONValueArraySize(const virJSONValue *array);
virJSONValuePtr virJSONValueArrayGet(virJSONValuePtr object, unsigned int element);
virJSONValuePtr virJSONValueArraySteal(virJSONValuePtr object, unsigned int element);
+typedef int (*virJSONArrayIteratorFunc)(size_t pos,
+ virJSONValuePtr item,
+ void *opaque);
+int virJSONValueArrayForeachSteal(virJSONValuePtr array,
+ virJSONArrayIteratorFunc cb,
+ void *opaque);
int virJSONValueObjectKeysNumber(virJSONValuePtr object);
const char *virJSONValueObjectGetKey(virJSONValuePtr object, unsigned int n);
--
2.10.0