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Subject[PATCH -perf/perf/core v2 1/3] perf: Add strfilter for general purpose string filter
Date
Add strfilter for general purpose string filter.
Every filter rules are descrived by glob matching pattern
and '!' prefix which means Logical NOT.
A strfilter consists of those filter rules connected
with '&' and '|'. A set of rules can be folded by using
'(' and ')'. It also accepts spaces around rules and those
operators.
Format:
<rule> ::= <glob-exp> | "!" <rule> | <rule> <op> <rule> | "(" <rule> ")"
<op> ::= "&" | "|"
e.g.
"(add* | del*) & *timer" filter rules pass strings which
start with add or del and end with timer.
This will be used by perf probe --filter.

Changes in V2:
- Fix to check result of strdup() and strfilter__alloc().
- Encapsulate and simplify interfaces as like as regex(3).

Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: linux-kernel@vger.kernel.org
---
tools/perf/Makefile | 2
tools/perf/util/strfilter.c | 200 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/strfilter.h | 49 +++++++++++
3 files changed, 251 insertions(+), 0 deletions(-)
create mode 100644 tools/perf/util/strfilter.c
create mode 100644 tools/perf/util/strfilter.h
diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index cc714af..b41c6d5 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -412,6 +412,7 @@ LIB_H += util/help.h
LIB_H += util/session.h
LIB_H += util/strbuf.h
LIB_H += util/strlist.h
+LIB_H += util/strfilter.h
LIB_H += util/svghelper.h
LIB_H += util/run-command.h
LIB_H += util/sigchain.h
@@ -452,6 +453,7 @@ LIB_OBJS += $(OUTPUT)util/quote.o
LIB_OBJS += $(OUTPUT)util/strbuf.o
LIB_OBJS += $(OUTPUT)util/string.o
LIB_OBJS += $(OUTPUT)util/strlist.o
+LIB_OBJS += $(OUTPUT)util/strfilter.o
LIB_OBJS += $(OUTPUT)util/usage.o
LIB_OBJS += $(OUTPUT)util/wrapper.o
LIB_OBJS += $(OUTPUT)util/sigchain.o
diff --git a/tools/perf/util/strfilter.c b/tools/perf/util/strfilter.c
new file mode 100644
index 0000000..4064b7d
--- /dev/null
+++ b/tools/perf/util/strfilter.c
@@ -0,0 +1,200 @@
+#include <ctype.h>
+#include "util.h"
+#include "string.h"
+#include "strfilter.h"
+
+/* Operators */
+static const char *OP_and = "&"; /* Logical AND */
+static const char *OP_or = "|"; /* Logical OR */
+static const char *OP_not = "!"; /* Logical NOT */
+
+#define is_operator(c) ((c) == '|' || (c) == '&' || (c) == '!')
+#define is_separator(c) (is_operator(c) || (c) == '(' || (c) == ')')
+
+static void strfilter_node__delete(struct strfilter_node *self)
+{
+ if (self) {
+ if (self->p && !is_operator(*self->p))
+ free((char *)self->p);
+ strfilter_node__delete(self->l);
+ strfilter_node__delete(self->r);
+ free(self);
+ }
+}
+
+void strfilter__delete(struct strfilter *self)
+{
+ if (self) {
+ strfilter_node__delete(self->root);
+ free(self);
+ }
+}
+
+static const char *get_token(const char *s, const char **e)
+{
+ const char *p;
+
+ while (isspace(*s)) /* Skip spaces */
+ s++;
+
+ if (*s == '\0') {
+ p = s;
+ goto end;
+ }
+
+ p = s + 1;
+ if (!is_separator(*s)) {
+ /* End search */
+retry:
+ while (*p && !is_separator(*p) && !isspace(*p))
+ p++;
+ /* Escape and special case: '!' is also used in glob pattern */
+ if (*(p - 1) == '\\' || (*p == '!' && *(p - 1) == '[')) {
+ p++;
+ goto retry;
+ }
+ }
+end:
+ *e = p;
+ return s;
+}
+
+static struct strfilter_node *strfilter_node__alloc(const char *op,
+ struct strfilter_node *l,
+ struct strfilter_node *r)
+{
+ struct strfilter_node *ret = zalloc(sizeof(struct strfilter_node));
+
+ if (ret) {
+ ret->p = op;
+ ret->l = l;
+ ret->r = r;
+ }
+
+ return ret;
+}
+
+static struct strfilter_node *strfilter_node__new(const char *s,
+ const char **ep)
+{
+ struct strfilter_node root, *cur, *last_op;
+ const char *e;
+
+ if (!s)
+ return NULL;
+
+ memset(&root, 0, sizeof(root));
+ last_op = cur = &root;
+
+ s = get_token(s, &e);
+ while (*s != '\0' && *s != ')') {
+ switch (*s) {
+ case '&': /* Exchg last OP->r with AND */
+ if (!cur->r || !last_op->r)
+ goto error;
+ cur = strfilter_node__alloc(OP_and, last_op->r, NULL);
+ if (!cur)
+ goto nomem;
+ last_op->r = cur;
+ last_op = cur;
+ break;
+ case '|': /* Exchg the root with OR */
+ if (!cur->r || !root.r)
+ goto error;
+ cur = strfilter_node__alloc(OP_or, root.r, NULL);
+ if (!cur)
+ goto nomem;
+ root.r = cur;
+ last_op = cur;
+ break;
+ case '!': /* Add NOT as a leaf node */
+ if (cur->r)
+ goto error;
+ cur->r = strfilter_node__alloc(OP_not, NULL, NULL);
+ if (!cur->r)
+ goto nomem;
+ cur = cur->r;
+ break;
+ case '(': /* Recursively parses inside the parenthesis */
+ if (cur->r)
+ goto error;
+ cur->r = strfilter_node__new(s + 1, &s);
+ if (!s)
+ goto nomem;
+ if (!cur->r || *s != ')')
+ goto error;
+ e = s + 1;
+ break;
+ default:
+ if (cur->r)
+ goto error;
+ cur->r = strfilter_node__alloc(NULL, NULL, NULL);
+ if (!cur->r)
+ goto nomem;
+ cur->r->p = strndup(s, e - s);
+ if (!cur->r->p)
+ goto nomem;
+ }
+ s = get_token(e, &e);
+ }
+ if (!cur->r)
+ goto error;
+ *ep = s;
+ return root.r;
+nomem:
+ s = NULL;
+error:
+ *ep = s;
+ strfilter_node__delete(root.r);
+ return NULL;
+}
+
+/*
+ * Parse filter rule and return new strfilter.
+ * Return NULL if fail, and *ep == NULL if memory allocation failed.
+ */
+struct strfilter *strfilter__new(const char *rules, const char **err)
+{
+ struct strfilter *ret = zalloc(sizeof(struct strfilter));
+ const char *ep = NULL;
+
+ if (ret)
+ ret->root = strfilter_node__new(rules, &ep);
+
+ if (!ret || !ret->root || *ep != '\0') {
+ if (err)
+ *err = ep;
+ strfilter__delete(ret);
+ ret = NULL;
+ }
+
+ return ret;
+}
+
+static bool strfilter_node__compare(struct strfilter_node *self,
+ const char *str)
+{
+ if (!self || !self->p)
+ return false;
+
+ switch (*self->p) {
+ case '|': /* OR */
+ return strfilter_node__compare(self->l, str) ||
+ strfilter_node__compare(self->r, str);
+ case '&': /* AND */
+ return strfilter_node__compare(self->l, str) &&
+ strfilter_node__compare(self->r, str);
+ case '!': /* NOT */
+ return !strfilter_node__compare(self->r, str);
+ default:
+ return strglobmatch(str, self->p);
+ }
+}
+
+/* Return true if STR matches the filter rules */
+bool strfilter__compare(struct strfilter *self, const char *str)
+{
+ if (!self)
+ return false;
+ return strfilter_node__compare(self->root, str);
+}
diff --git a/tools/perf/util/strfilter.h b/tools/perf/util/strfilter.h
new file mode 100644
index 0000000..7647337
--- /dev/null
+++ b/tools/perf/util/strfilter.h
@@ -0,0 +1,49 @@
+#ifndef __PERF_STRFILTER_H
+#define __PERF_STRFILTER_H
+/* General purpose glob matching filter */
+
+#include <linux/list.h>
+#include <stdbool.h>
+
+/* A node of string filter */
+struct strfilter_node {
+ struct strfilter_node *l; /* Tree left branche (for &,|) */
+ struct strfilter_node *r; /* Tree right branche (for !,&,|) */
+ const char *p; /* Operator or rule */
+};
+
+/* String filter */
+struct strfilter {
+ struct strfilter_node *root;
+};
+
+/**
+ * strfilter__new - Create a new string filter
+ * @rules: Filter rule, which is a combination of glob expressions.
+ * @err: Pointer which points an error detected on @rules
+ *
+ * Parse @rules and return new strfilter. Return NULL if an error detected.
+ * In that case, *@err will indicate where it is detected, and *@err is NULL
+ * if a memory allocation is failed.
+ */
+struct strfilter *strfilter__new(const char *rules, const char **err);
+
+/**
+ * strfilter__compare - compare given string and a string filter
+ * @self: String filter
+ * @str: target string
+ *
+ * Compare @str and @self. Return true if the str match the rule
+ */
+bool strfilter__compare(struct strfilter *self, const char *str);
+
+/**
+ * strfilter__delete - delete a string filter
+ * @self: String filter to delete
+ *
+ * Delete @self.
+ */
+void strfilter__delete(struct strfilter *self);
+
+#endif
+


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