[libvirt] [PATCH RFC 03/40] util: hash: Introduce virHashHasEntry

[Peter Krempa]

Add a helper that checks whether an entry with given name exists but
does not touch the userdata.

Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
 src/libvirt_private.syms |  1 +
 src/util/virhash.c       | 49 ++++++++++++++++++++++++++++++++--------
 src/util/virhash.h       |  1 +
 3 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index c155f51174..588f0a4356 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -2065,6 +2065,7 @@ virHashEqual;
 virHashForEach;
 virHashFree;
 virHashGetItems;
+virHashHasEntry;
 virHashLookup;
 virHashNew;
 virHashRemoveAll;
diff --git a/src/util/virhash.c b/src/util/virhash.c
index de03032bf1..df07e37e42 100644
--- a/src/util/virhash.c
+++ b/src/util/virhash.c
@@ -445,6 +445,26 @@ virHashAtomicUpdate(virHashAtomicPtr table,
 }


+static virHashEntryPtr
+virHashGetEntry(const virHashTable *table,
+                const void *name)
+{
+    size_t key;
+    virHashEntryPtr entry;
+
+    if (!table || !name)
+        return NULL;
+
+    key = virHashComputeKey(table, name);
+    for (entry = table->table[key]; entry; entry = entry->next) {
+        if (table->keyEqual(entry->name, name))
+            return entry;
+    }
+
+    return NULL;
+}
+
+
 /**
  * virHashLookup:
  * @table: the hash table
@@ -457,18 +477,29 @@ virHashAtomicUpdate(virHashAtomicPtr table,
 void *
 virHashLookup(const virHashTable *table, const void *name)
 {
-    size_t key;
-    virHashEntryPtr entry;
+    virHashEntryPtr entry = virHashGetEntry(table, name);

-    if (!table || !name)
+    if (!entry)
         return NULL;

-    key = virHashComputeKey(table, name);
-    for (entry = table->table[key]; entry; entry = entry->next) {
-        if (table->keyEqual(entry->name, name))
-            return entry->payload;
-    }
-    return NULL;
+    return entry->payload;
+}
+
+
+/**
+ * virHashHasEntry:
+ * @table: the hash table
+ * @name: the name of the userdata
+ *
+ * Find whether entry specified by @name exists.
+ *
+ * Returns true if the entry exists and false otherwise
+ */
+bool
+virHashHasEntry(const virHashTable *table,
+                const void *name)
+{
+    return !!virHashGetEntry(table, name);
 }


diff --git a/src/util/virhash.h b/src/util/virhash.h
index d7de0618cb..8087965ee9 100644
--- a/src/util/virhash.h
+++ b/src/util/virhash.h
@@ -150,6 +150,7 @@ ssize_t virHashRemoveAll(virHashTablePtr table);
  * Retrieve the userdata.
  */
 void *virHashLookup(const virHashTable *table, const void *name);
+bool virHashHasEntry(const virHashTable *table, const void *name);

 /*
  * Retrieve & remove the userdata.
-- 
2.21.0