shared: strbuf - add string de-duplication facility

1 files changed, 56 insertions, 0 deletions

diff --git a/src/shared/strbuf.h b/src/shared/strbuf.h
new file mode 100644
index 0000000000..35f232ddb0
--- /dev/null
+++ b/src/shared/strbuf.h
@@ -0,0 +1,56 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2012 Kay Sievers <kay.sievers@vrfy.org>
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+struct strbuf {
+        char *buf;
+        size_t len;
+        struct strbuf_node *root;
+
+        size_t nodes_count;
+        size_t in_count;
+        size_t in_len;
+        size_t dedup_len;
+        size_t dedup_count;
+};
+
+struct strbuf_node {
+        size_t value_off;
+        size_t value_len;
+
+        struct strbuf_child_entry *children;
+        uint8_t children_count;
+};
+
+struct strbuf_child_entry {
+        uint8_t c;
+        struct strbuf_node *child;
+};
+
+struct strbuf *strbuf_new(void);
+ssize_t strbuf_add_string(struct strbuf *str, const char *s, size_t len);
+void strbuf_complete(struct strbuf *str);
+void strbuf_cleanup(struct strbuf *str);