list: rework lookup methods to use C++ templates

common/include/villas/list.h

@@ -29,6 +29,9 @@
 #pragma once
 
 #include <sys/types.h>
+#include <cstring>
+#include <string>
+#include <uuid/uuid.h>
 #include <pthread.h>
 
 #include <villas/common.hpp>
@@ -87,23 +90,8 @@ int vlist_remove(struct vlist *l, size_t idx);
 
 int vlist_insert(struct vlist *l, size_t idx, void *p);
 
-/** Return the first list element which is identified by a string in its first member variable.
- *
- * List elements are pointers to structures of the following form:
- *
- * struct obj {
- *    char *name;
- *    // more members
- * }
- *
- * @see Only possible because of §1424 of http://c0x.coding-guidelines.com/6.7.2.1.html
- */
-void * vlist_lookup(struct vlist *l, const char *name);
-
-ssize_t vlist_lookup_index(struct vlist *l, const void *ptr);
-
 /** Return the first element of the list for which cmp returns zero */
-void * vlist_search(struct vlist *l, cmp_cb_t cmp, void *ctx);
+void * vlist_search(struct vlist *l, cmp_cb_t cmp, const void *ctx);
 
 /** Returns the number of occurences for which cmp returns zero when called on all list elements. */
 int vlist_count(struct vlist *l, cmp_cb_t cmp, void *ctx);
@@ -129,3 +117,38 @@ void vlist_extend(struct vlist *l, size_t len, void *val);
 
 /** Remove all elements for which the callback returns a non-zero return code. */
 void vlist_filter(struct vlist *l, dtor_cb_t cb);
+
+#include <villas/log.h>
+
+/** Lookup an element from the list based on an UUID */
+template<typename T>
+T * vlist_lookup_uuid(struct vlist *l, uuid_t uuid)
+{
+	return (T *) vlist_search(l, [](const void *a, const void *b) -> int {
+		auto *n = reinterpret_cast<const T *>(a);
+		uuid_t u; memcpy(u, b, sizeof(uuid_t));
+
+		return uuid_compare(n->uuid, u);
+	}, uuid);
+}
+
+/** Lookup an element from the list based on a name */
+template<typename T>
+T * vlist_lookup_name(struct vlist *l, const std::string &name)
+{
+	return (T *) vlist_search(l, [](const void *a, const void *b) -> int {
+		auto *e = reinterpret_cast<const T *>(a);
+		auto *s = reinterpret_cast<const std::string *>(b);
+
+		return *s == e->name ? 0 : 1;
+	}, &name);
+}
+
+/** Lookup index of list element based on name */
+template<typename T>
+ssize_t vlist_lookup_index(struct vlist *l, const std::string &name)
+{
+	auto *f = vlist_lookup_name<T>(l, name);
+
+	return f ? vlist_index(l, f) : -1;
+}

common/lib/list.cpp

@@ -28,21 +28,6 @@
 #include <villas/list.h>
 #include <villas/utils.hpp>
 
-/* Compare functions */
-static int cmp_lookup(const void *a, const void *b) {
-	struct name_tag {
-		char *name;
-	};
-
-	const name_tag *obj = (struct name_tag *) a;
-
-	return strcmp(obj->name, (char *) b);
-}
-
-static int cmp_contains(const void *a, const void *b) {
-	return a == b ? 0 : 1;
-}
-
 #ifdef __APPLE__
 static int cmp_sort(void *thunk, const void *a, const void *b) {
 #else
@@ -183,21 +168,11 @@ void vlist_remove_all(struct vlist *l, void *p)
 	pthread_mutex_unlock(&l->lock);
 }
 
-void * vlist_lookup(struct vlist *l, const char *name)
-{
-	return vlist_search(l, cmp_lookup, (void *) name);
-}
-
-ssize_t vlist_lookup_index(struct vlist *l, const void *ptr)
-{
-	void *found = vlist_lookup(l, (char *) ptr);
-
-	return found ? vlist_index(l, found) : -1;
-}
-
 int vlist_contains(struct vlist *l, void *p)
 {
-	return vlist_count(l, cmp_contains, p);
+	return vlist_count(l, [](const void *a, const void *b) {
+		return a == b ? 0 : 1;
+	}, p);
 }
 
 int vlist_count(struct vlist *l, cmp_cb_t cmp, void *ctx)
@@ -220,7 +195,7 @@ int vlist_count(struct vlist *l, cmp_cb_t cmp, void *ctx)
 	return c;
 }
 
-void * vlist_search(struct vlist *l, cmp_cb_t cmp, void *ctx)
+void * vlist_search(struct vlist *l, cmp_cb_t cmp, const void *ctx)
 {
 	void *e;
 

common/lib/log.cpp

@@ -88,8 +88,7 @@ void Log::parse(json_t *cfg)
 	const char *path = nullptr;
 	const char *pattern = nullptr;
 
-	int syslog;
-	int ret;
+	int ret, syslog = 0;
 
 	json_error_t err;
 	json_t *json_expressions = nullptr;

common/tests/unit/list.cpp

@@ -39,7 +39,7 @@ struct data {
 
 TestSuite(list, .description = "List datastructure");
 
-Test(list, vlist_lookup)
+Test(list, vlist_lookup_name)
 {
 	struct vlist l;
 
@@ -56,7 +56,7 @@ Test(list, vlist_lookup)
 		vlist_push(&l, d);
 	}
 
-	struct data *found = (struct data *) vlist_lookup(&l, "woman");
+	struct data *found = vlist_lookup_name<struct data>(&l, "woman");
 
 	cr_assert_eq(found->data, 13);