[libvirt] [PATCH V5 01/10] Add function to get hash tables key/value pairs
Add a function to the virHashTable for getting an array of the hash table's
key-value pairs and have the keys (optionally) sorted.
Signed-off-by: Stefan Berger <stefanb(a)linux.vnet.ibm.com>
---
v5:
- follwed Eric Blake's suggestions:
- added better description to new function
- return array of key-value pairs rather than only keys
---
src/libvirt_private.syms | 2 ++
src/util/hash.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
src/util/hash.h | 21 +++++++++++++++++++++
3 files changed, 68 insertions(+)
Index: libvirt-acl/src/util/hash.c
===================================================================
--- libvirt-acl.orig/src/util/hash.c
+++ libvirt-acl/src/util/hash.c
@@ -618,3 +618,48 @@ void *virHashSearch(virHashTablePtr tabl
return NULL;
}
+
+struct getKeysIter
+{
+ virHashKeyValuePair *sortArray;
+ unsigned arrayIdx;
+};
+
+static void virHashGetKeysIterator(void *payload,
+ const void *key, void *data)
+{
+ struct getKeysIter *iter = data;
+
+ iter->sortArray[iter->arrayIdx].key = key;
+ iter->sortArray[iter->arrayIdx].value = payload;
+
+ iter->arrayIdx++;
+}
+
+typedef int (*qsort_comp)(const void *, const void *);
+
+virHashKeyValuePairPtr virHashGetItems(virHashTablePtr table,
+ virHashKeyComparator compar)
+{
+ int numElems = virHashSize(table);
+ struct getKeysIter iter = {
+ .arrayIdx = 0,
+ .sortArray = NULL,
+ };
+
+ if (numElems < 0)
+ return NULL;
+
+ if (VIR_ALLOC_N(iter.sortArray, numElems + 1)) {
+ virReportOOMError();
+ return NULL;
+ }
+
+ virHashForEach(table, virHashGetKeysIterator, &iter);
+
+ if (compar)
+ qsort(&iter.sortArray[0], numElems, sizeof(iter.sortArray[0]),
+ (qsort_comp)compar);
+
+ return iter.sortArray;
+}
Index: libvirt-acl/src/util/hash.h
===================================================================
--- libvirt-acl.orig/src/util/hash.h
+++ libvirt-acl/src/util/hash.h
@@ -130,6 +130,27 @@ void *virHashLookup(virHashTablePtr tabl
*/
void *virHashSteal(virHashTablePtr table, const void *name);
+/*
+ * Get the hash table's key/value pairs and have them optionally sorted.
+ * The returned array contains virHashSize() elements. Aditionally,
+ * an empty element has been added to the end of the array whose key == NULL
+ * also indicates the end of the array.
+ * The key/value pairs are only valid as long as the underlying hash
+ * table is not modified, i.e., keys removed or the hash table deleted.
+ * The caller must only free the returned array using VIR_FREE().
+ * The caller must make copies of all returned keys and values if they are
+ * to be used somewhere else.
+ */
+typedef struct _virHashKeyValuePair virHashKeyValuePair;
+typedef virHashKeyValuePair *virHashKeyValuePairPtr;
+struct _virHashKeyValuePair {
+ const void *key;
+ const void *value;
+};
+typedef int (*virHashKeyComparator)(const virHashKeyValuePairPtr ,
+ const virHashKeyValuePairPtr );
+virHashKeyValuePairPtr virHashGetItems(virHashTablePtr table,
+ virHashKeyComparator compar);
/*
* Iterators
Index: libvirt-acl/src/libvirt_private.syms
===================================================================
--- libvirt-acl.orig/src/libvirt_private.syms
+++ libvirt-acl/src/libvirt_private.syms
@@ -559,6 +559,7 @@ virHashAddEntry;
virHashCreate;
virHashForEach;
virHashFree;
+virHashGetItems;
virHashLookup;
virHashRemoveEntry;
virHashRemoveSet;
@@ -566,6 +567,7 @@ virHashSearch;
virHashSize;
virHashSteal;
virHashTableSize;
+virHashUpdateEntry;
# hooks.h