/***
This file is part of systemd.
- Copyright 2012 Kay Sievers <kay.sievers@vrfy.org>
+ Copyright 2012 Kay Sievers <kay@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
#include "util.h"
#include "strbuf.h"
+/*
+ * Strbuf stores given strings in a single continous allocated memory
+ * area. Identical strings are de-duplicated and return the same offset
+ * as the first string stored. If the tail of a string already exists
+ * in the buffer, the tail is returned.
+ *
+ * A trie (http://en.wikipedia.org/wiki/Trie) is used to maintain the
+ * information about the stored strings.
+ *
+ * Example of udev rules:
+ * $ ./udevadm test .
+ * ...
+ * read rules file: /usr/lib/udev/rules.d/99-systemd.rules
+ * rules contain 196608 bytes tokens (16384 * 12 bytes), 39742 bytes strings
+ * 23939 strings (207859 bytes), 20404 de-duplicated (171653 bytes), 3536 trie nodes used
+ * ...
+ */
+
struct strbuf *strbuf_new(void) {
struct strbuf *str;
free(node);
}
+/* clean up trie data, leave only the string buffer */
void strbuf_complete(struct strbuf *str) {
if (!str)
return;
str->root = NULL;
}
+/* clean up everything */
void strbuf_cleanup(struct strbuf *str) {
if (!str)
return;
return n1->c - n2->c;
}
+/* add string, return the index/offset into the buffer */
ssize_t strbuf_add_string(struct strbuf *str, const char *s, size_t len) {
uint8_t c;
struct strbuf_node *node;