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-rw-r--r--libnetdata/simple_pattern/simple_pattern.c262
1 files changed, 262 insertions, 0 deletions
diff --git a/libnetdata/simple_pattern/simple_pattern.c b/libnetdata/simple_pattern/simple_pattern.c
new file mode 100644
index 0000000..57b0aec
--- /dev/null
+++ b/libnetdata/simple_pattern/simple_pattern.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+struct simple_pattern {
+ const char *match;
+ size_t len;
+
+ SIMPLE_PREFIX_MODE mode;
+ char negative;
+
+ struct simple_pattern *child;
+
+ struct simple_pattern *next;
+};
+
+static inline struct simple_pattern *parse_pattern(char *str, SIMPLE_PREFIX_MODE default_mode) {
+ // fprintf(stderr, "PARSING PATTERN: '%s'\n", str);
+
+ SIMPLE_PREFIX_MODE mode;
+ struct simple_pattern *child = NULL;
+
+ char *s = str, *c = str;
+
+ // skip asterisks in front
+ while(*c == '*') c++;
+
+ // find the next asterisk
+ while(*c && *c != '*') c++;
+
+ // do we have an asterisk in the middle?
+ if(*c == '*' && c[1] != '\0') {
+ // yes, we have
+ child = parse_pattern(c, default_mode);
+ c[1] = '\0';
+ }
+
+ // check what this one matches
+
+ size_t len = strlen(s);
+ if(len >= 2 && *s == '*' && s[len - 1] == '*') {
+ s[len - 1] = '\0';
+ s++;
+ mode = SIMPLE_PATTERN_SUBSTRING;
+ }
+ else if(len >= 1 && *s == '*') {
+ s++;
+ mode = SIMPLE_PATTERN_SUFFIX;
+ }
+ else if(len >= 1 && s[len - 1] == '*') {
+ s[len - 1] = '\0';
+ mode = SIMPLE_PATTERN_PREFIX;
+ }
+ else
+ mode = default_mode;
+
+ // allocate the structure
+ struct simple_pattern *m = callocz(1, sizeof(struct simple_pattern));
+ if(*s) {
+ m->match = strdupz(s);
+ m->len = strlen(m->match);
+ m->mode = mode;
+ }
+ else {
+ m->mode = SIMPLE_PATTERN_SUBSTRING;
+ }
+
+ m->child = child;
+
+ return m;
+}
+
+SIMPLE_PATTERN *simple_pattern_create(const char *list, const char *separators, SIMPLE_PREFIX_MODE default_mode) {
+ struct simple_pattern *root = NULL, *last = NULL;
+
+ if(unlikely(!list || !*list)) return root;
+
+ int isseparator[256] = {
+ [' '] = 1 // space
+ , ['\t'] = 1 // tab
+ , ['\r'] = 1 // carriage return
+ , ['\n'] = 1 // new line
+ , ['\f'] = 1 // form feed
+ , ['\v'] = 1 // vertical tab
+ };
+
+ if (unlikely(separators && *separators)) {
+ memset(&isseparator[0], 0, sizeof(isseparator));
+ while(*separators) isseparator[(unsigned char)*separators++] = 1;
+ }
+
+ char *buf = mallocz(strlen(list) + 1);
+ const char *s = list;
+
+ while(s && *s) {
+ buf[0] = '\0';
+ char *c = buf;
+
+ char negative = 0;
+
+ // skip all spaces
+ while(isseparator[(unsigned char)*s])
+ s++;
+
+ if(*s == '!') {
+ negative = 1;
+ s++;
+ }
+
+ // empty string
+ if(unlikely(!*s))
+ break;
+
+ // find the next space
+ char escape = 0;
+ while(*s) {
+ if(*s == '\\' && !escape) {
+ escape = 1;
+ s++;
+ }
+ else {
+ if (isseparator[(unsigned char)*s] && !escape) {
+ s++;
+ break;
+ }
+
+ *c++ = *s++;
+ escape = 0;
+ }
+ }
+
+ // terminate our string
+ *c = '\0';
+
+ // if we matched the empty string, skip it
+ if(unlikely(!*buf))
+ continue;
+
+ // fprintf(stderr, "FOUND PATTERN: '%s'\n", buf);
+ struct simple_pattern *m = parse_pattern(buf, default_mode);
+ m->negative = negative;
+
+ // link it at the end
+ if(unlikely(!root))
+ root = last = m;
+ else {
+ last->next = m;
+ last = m;
+ }
+ }
+
+ freez(buf);
+ return (SIMPLE_PATTERN *)root;
+}
+
+static inline char *add_wildcarded(const char *matched, size_t matched_size, char *wildcarded, size_t *wildcarded_size) {
+ //if(matched_size) {
+ // char buf[matched_size + 1];
+ // strncpyz(buf, matched, matched_size);
+ // fprintf(stderr, "ADD WILDCARDED '%s' of length %zu\n", buf, matched_size);
+ //}
+
+ if(unlikely(wildcarded && *wildcarded_size && matched && *matched && matched_size)) {
+ size_t wss = *wildcarded_size - 1;
+ size_t len = (matched_size < wss)?matched_size:wss;
+ if(likely(len)) {
+ strncpyz(wildcarded, matched, len);
+
+ *wildcarded_size -= len;
+ return &wildcarded[len];
+ }
+ }
+
+ return wildcarded;
+}
+
+static inline int match_pattern(struct simple_pattern *m, const char *str, size_t len, char *wildcarded, size_t *wildcarded_size) {
+ char *s;
+
+ if(m->len <= len) {
+ switch(m->mode) {
+ case SIMPLE_PATTERN_SUBSTRING:
+ if(!m->len) return 1;
+ if((s = strstr(str, m->match))) {
+ wildcarded = add_wildcarded(str, s - str, wildcarded, wildcarded_size);
+ if(!m->child) {
+ wildcarded = add_wildcarded(&s[m->len], len - (&s[m->len] - str), wildcarded, wildcarded_size);
+ return 1;
+ }
+ return match_pattern(m->child, &s[m->len], len - (s - str) - m->len, wildcarded, wildcarded_size);
+ }
+ break;
+
+ case SIMPLE_PATTERN_PREFIX:
+ if(unlikely(strncmp(str, m->match, m->len) == 0)) {
+ if(!m->child) {
+ wildcarded = add_wildcarded(&str[m->len], len - m->len, wildcarded, wildcarded_size);
+ return 1;
+ }
+ return match_pattern(m->child, &str[m->len], len - m->len, wildcarded, wildcarded_size);
+ }
+ break;
+
+ case SIMPLE_PATTERN_SUFFIX:
+ if(unlikely(strcmp(&str[len - m->len], m->match) == 0)) {
+ wildcarded = add_wildcarded(str, len - m->len, wildcarded, wildcarded_size);
+ if(!m->child) return 1;
+ return 0;
+ }
+ break;
+
+ case SIMPLE_PATTERN_EXACT:
+ default:
+ if(unlikely(strcmp(str, m->match) == 0)) {
+ if(!m->child) return 1;
+ return 0;
+ }
+ break;
+ }
+ }
+
+ return 0;
+}
+
+int simple_pattern_matches_extract(SIMPLE_PATTERN *list, const char *str, char *wildcarded, size_t wildcarded_size) {
+ struct simple_pattern *m, *root = (struct simple_pattern *)list;
+
+ if(unlikely(!root || !str || !*str)) return 0;
+
+ size_t len = strlen(str);
+ for(m = root; m ; m = m->next) {
+ char *ws = wildcarded;
+ size_t wss = wildcarded_size;
+ if(unlikely(ws)) *ws = '\0';
+
+ if (match_pattern(m, str, len, ws, &wss)) {
+
+ //if(ws && wss)
+ // fprintf(stderr, "FINAL WILDCARDED '%s' of length %zu\n", ws, strlen(ws));
+
+ if (m->negative) return 0;
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+static inline void free_pattern(struct simple_pattern *m) {
+ if(!m) return;
+
+ free_pattern(m->child);
+ free_pattern(m->next);
+ freez((void *)m->match);
+ freez(m);
+}
+
+void simple_pattern_free(SIMPLE_PATTERN *list) {
+ if(!list) return;
+
+ free_pattern(((struct simple_pattern *)list));
+}