make grep faster (close bug 758), reduce small memory leak in CONFIG_FEATURE_CLEANUP mode

git-svn-id: svn://busybox.net/trunk/busybox@14361 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 62 insertions, 16 deletions

diff --git a/findutils/grep.c b/findutils/grep.c
index 3c5167e28..e1ce8e5fa 100644
--- a/findutils/grep.c
+++ b/findutils/grep.c
@@ -11,8 +11,9 @@
 /* BB_AUDIT GNU defects - always acts as -a.  */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/grep.html */
 /*
- * Apr 2004 by Vladimir Oleynik <dzo@simtreas.ru> -
+ * 2004,2006 (C) Vladimir Oleynik <dzo@simtreas.ru> -
  * correction "-e pattern1 -e pattern2" logic and more optimizations.
+ * precompiled regex
 */
 
 #include <stdio.h>
@@ -82,6 +83,13 @@ static int last_line_printed;
 static llist_t *pattern_head;   /* growable list of patterns to match */
 static char *cur_file;          /* the current file we are reading */
 
+typedef struct GREP_LIST_DATA {
+        char *pattern;
+        regex_t preg;
+#define PATTERN_MEM_A 1
+#define COMPILED 2
+        int flg_mem_alocated_compiled;
+} grep_list_data_t;
 
 static void print_line(const char *line, int linenum, char decoration)
 {
@@ -115,12 +123,14 @@ static int grep_file(FILE *file)
 
         while ((line = bb_get_chomped_line_from_file(file)) != NULL) {
                 llist_t *pattern_ptr = pattern_head;
+                grep_list_data_t * gl;
 
                 linenum++;
                 ret = 0;
                 while (pattern_ptr) {
+                        gl = (grep_list_data_t *)pattern_ptr->data;
                         if (FGREP_FLAG) {
-                                ret = strstr(line, pattern_ptr->data) != NULL;
+                                ret = strstr(line, gl->pattern) != NULL;
                         } else {
                                 /*
                                  * test for a postitive-assertion match (regexec returns success (0)
@@ -128,10 +138,11 @@ static int grep_file(FILE *file)
                                  * match (regexec returns failure (REG_NOMATCH) and the user specified
                                  * invert search)
                                  */
-                                regex_t regex;
-                                xregcomp(&regex, pattern_ptr->data, reflags);
-                                ret |= regexec(&regex, line, 0, NULL, 0) == 0;
-                                regfree(&regex);
+                                if(!(gl->flg_mem_alocated_compiled & COMPILED)) {
+                                        gl->flg_mem_alocated_compiled |= COMPILED;
+                                        xregcomp(&(gl->preg), gl->pattern, reflags);
+                                }
+                                ret |= regexec(&(gl->preg), line, 0, NULL, 0) == 0;
                         }
                         pattern_ptr = pattern_ptr->link;
                 } /* while (pattern_ptr) */
@@ -230,6 +241,25 @@ static int grep_file(FILE *file)
         return nmatches;
 }
 
+#if ENABLE_FEATURE_CLEAN_UP
+#define new_grep_list_data(p, m) add_grep_list_data(p, m)
+static char * add_grep_list_data(char *pattern, int flg_used_mem)
+#else
+#define new_grep_list_data(p, m) add_grep_list_data(p)
+static char * add_grep_list_data(char *pattern)
+#endif
+{
+        grep_list_data_t *gl = xmalloc(sizeof(grep_list_data_t));
+        gl->pattern = pattern;
+#if ENABLE_FEATURE_CLEAN_UP
+        gl->flg_mem_alocated_compiled = flg_used_mem;
+#else
+        gl->flg_mem_alocated_compiled = 0;
+#endif
+        return (char *)gl;
+}
+
+
 static void load_regexes_from_file(llist_t *fopt)
 {
         char *line;
@@ -243,7 +273,8 @@ static void load_regexes_from_file(llist_t *fopt)
                 free(cur);
                 f = bb_xfopen(ffile, "r");
                 while ((line = bb_get_chomped_line_from_file(f)) != NULL) {
-                        pattern_head = llist_add_to(pattern_head, line);
+                        pattern_head = llist_add_to(pattern_head,
+                                new_grep_list_data(line, PATTERN_MEM_A));
                 }
         }
 }
@@ -296,7 +327,7 @@ extern int grep_main(int argc, char **argv)
                 lines_after = 0;
         } else if(lines_before > 0)
                 before_buf = (char **)xcalloc(lines_before, sizeof(char *));
-        }
+  }
 #else
         /* with auto sanity checks */
         bb_opt_complementally = "H-h:e::f::c-n:q-n:l-n";
@@ -309,6 +340,13 @@ extern int grep_main(int argc, char **argv)
                 print_filename++;
         if(opt & GREP_OPT_h)
                 print_filename--;
+        if (pattern_head != NULL) {
+                /* convert char *argv[] to grep_list_data_t */
+                llist_t *cur;
+
+                for(cur = pattern_head; cur; cur = cur->link)
+                        cur->data = new_grep_list_data(cur->data, 0);
+        }
         if(opt & GREP_OPT_f)
                 load_regexes_from_file(fopt);
 
@@ -333,7 +371,9 @@ extern int grep_main(int argc, char **argv)
                 if (*argv == NULL)
                         bb_show_usage();
                 else {
-                        pattern_head = llist_add_to(pattern_head, *argv++);
+                        char *pattern = new_grep_list_data(*argv++, 0);
+
+                        pattern_head = llist_add_to(pattern_head, pattern);
                         argc--;
                 }
         }
@@ -373,14 +413,20 @@ extern int grep_main(int argc, char **argv)
         }
 
         /* destroy all the elments in the pattern list */
-        if (ENABLE_FEATURE_CLEAN_UP)
-        while (pattern_head) {
-                llist_t *pattern_head_ptr = pattern_head;
-
-                pattern_head = pattern_head->link;
-                free(pattern_head_ptr);
+        if (ENABLE_FEATURE_CLEAN_UP) {
+                while (pattern_head) {
+                        llist_t *pattern_head_ptr = pattern_head;
+                        grep_list_data_t *gl =
+                                (grep_list_data_t *)pattern_head_ptr->data;
+
+                        pattern_head = pattern_head->link;
+                        if((gl->flg_mem_alocated_compiled & PATTERN_MEM_A))
+                                free(gl->pattern);
+                        if((gl->flg_mem_alocated_compiled & COMPILED))
+                                regfree(&(gl->preg));
+                        free(pattern_head_ptr);
+                }
         }
-
         /* 0 = success, 1 = failed, 2 = error */
         /* If the -q option is specified, the exit status shall be zero
          * if an input line is selected, even if an error was detected.  */