diff options
Diffstat (limited to 'src/shared/strbuf.c')
| -rw-r--r-- | src/shared/strbuf.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/shared/strbuf.c b/src/shared/strbuf.c index 5c858cb68e..9314f097ab 100644 --- a/src/shared/strbuf.c +++ b/src/shared/strbuf.c @@ -25,6 +25,23 @@ #include "util.h" #include "strbuf.h" +/* + * Strbuf stores given strings in a single continous allocated memory + * area. Identical strings are de-duplicated. If the tail of a string + * already exist in the buffer, the tail is returned. + * + * A Particia 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; @@ -58,6 +75,7 @@ static void strbuf_node_cleanup(struct strbuf_node *node) { free(node); } +/* clean up trie data, leave only the string buffer */ void strbuf_complete(struct strbuf *str) { if (!str) return; @@ -66,6 +84,7 @@ void strbuf_complete(struct strbuf *str) { str->root = NULL; } +/* clean up everything */ void strbuf_cleanup(struct strbuf *str) { if (!str) return; @@ -82,6 +101,7 @@ static int strbuf_children_cmp(const void *v1, const void *v2) { 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; |