SoW-2019-0002: Dynamic Snapshot

[deliverable/lttng-modules.git] / lttng-utils.h

diff --git a/lttng-utils.h b/lttng-utils.h
new file mode 100644 (file)
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--- /dev/null
+++ b/lttng-utils.h
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+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1) */
+#ifndef _LTTNG_UTILS_H
+#define _LTTNG_UTILS_H
+/*
+ * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
+ */
+
+#include <linux/jhash.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+static inline
+struct hlist_head *utils_borrow_hash_table_bucket(
+               struct hlist_head *hash_table,
+               unsigned int hash_table_size,
+               const char *event_name)
+{
+       size_t name_len;
+       uint32_t hash;
+
+       name_len = strlen(event_name);
+
+       hash = jhash(event_name, name_len, 0);
+       return &hash_table[hash & (hash_table_size - 1)];
+}
+#endif /* _LTTNG_UTILS_H */