Linked list for history buffer

diff --git a/avr/cli_readline.c b/avr/cli_readline.c
index 32c15c8a59b4fd5b49eab2278ad78db930d34c06..e34f0c8c747750b9b26c42cb8a9b592041365639 100644 (file)
--- a/avr/cli_readline.c
+++ b/avr/cli_readline.c
@@ -213,79 +213,146 @@ static void putnstr(char *str, int n)
 #define getcmd_getch()         vt_parse()
 #define getcmd_cbeep()         getcmd_putch('\a')
 
-#define HIST_MAX                       20
 
-static int_fast8_t hist_max;
-static int_fast8_t hist_add_idx;
-static int_fast8_t hist_cur = -1;
+struct hist_node_s {
+       struct hist_node_s *next;
+       char line[];
+};
+typedef struct hist_node_s hist_node;
+
 
-static char *hist_list[HIST_MAX];
+static hist_node *hist_head;
+static hist_node *hist_cur;
 
-static void cread_add_to_hist(char *line)
+static hist_node *hist_search_node(char *line)
 {
-       if (hist_max) {
-               int_fast8_t last = hist_add_idx;
-               if (--last < 0)
-                       last = hist_max;
+       hist_node *p = hist_head;
 
-               if (!strcmp(line, hist_list[last]))
-                       return;
+       while (p && strcmp(p->line, line))
+               p = p->next;
+       return p;
+}
+
+#if 0
+static hist_node *hist_insert(char *line)
+{
+       hist_node *p = (hist_node *) malloc(sizeof (hist_node) + strlen(line) + 1);
+
+       if (p) {
+               strcpy(p->line, line);
+               p->next = hist_head;
+               hist_head = p;
        }
+       return p;
+}
+#endif
+
+static hist_node *hist_new(char *line)
+{
+       hist_node *p = (hist_node *) malloc(sizeof (hist_node) + strlen(line) + 1);
 
-       char *p = strdup(line);
        if (p) {
-               free(hist_list[hist_add_idx]);
-               hist_list[hist_add_idx] = p;
+               strcpy(p->line, line);
+               p->next = NULL;
+       }
+       return p;
+}
 
-               if (++hist_add_idx >= HIST_MAX)
-                       hist_add_idx = 0;
+static hist_node *hist_delete(void)
+{
+       hist_node *p = NULL;
+       hist_node *q = hist_head;
 
-               if (hist_add_idx > hist_max)
-                       hist_max = hist_add_idx;
+       if (q) {
+               while(q->next) {
+                       p = q;
+                       q = q->next;
+               }
+               free(q);
+               if (p)
+                       p->next = NULL;
        }
+       return p;
 }
 
-static char *hist_prev(void)
+static hist_node *hist_unlink(hist_node *pos)
 {
-       char *ret;
-       int_fast8_t old_cur;
+       hist_node *p = NULL;
+       hist_node *q = hist_head;
 
-       if (hist_cur < 0)
-               return NULL;
+       while(q && q != pos) {
+               p = q;
+               q = q->next;
+       }
+       if (q) {
+               if (p)
+                       p->next = q->next;
+               else
+                       hist_head = q->next;
+               q->next = NULL;
+       }
+       return q;
+}
 
-       old_cur = hist_cur;
-       if (--hist_cur < 0)
-               hist_cur = hist_max;
+static uint_fast8_t hist_count(void)
+{
+       hist_node *p = hist_head;
+       uint_fast8_t n = 0;
 
-       if (hist_cur == hist_add_idx) {
-               hist_cur = old_cur;
-               ret = NULL;
-       } else {
-               ret = hist_list[hist_cur];
+       while (p) {
+               ++n;
+               p = p->next;
        }
+       return n;
+}
 
-       return ret;
+static hist_node *cread_add_to_hist(char *line)
+{
+       hist_node * p;
+
+       p = hist_search_node(line);
+       if (p)
+               hist_unlink(p);
+       else
+               p = hist_new(line);
+
+       if (p) {
+               p->next = hist_head;
+               hist_head = p;
+       }
+
+       if (hist_count() > CONFIG_SYS_HIST_MAX)
+               hist_delete();
+       return p;
 }
 
-static char *hist_next(void)
+static char *hist_prev(void)
 {
-       char *ret;
+       hist_node *p = hist_cur;
 
-       if (hist_cur < 0)
+       if (p == NULL)
                return NULL;
 
-       if (hist_cur == hist_add_idx)
-               return NULL;
+       hist_cur = hist_cur->next;
 
-       if (++hist_cur > hist_max)
-               hist_cur = 0;
+       return  p->line;
+}
 
-       if (hist_cur == hist_add_idx)
-               ret = "";
-       else
-               ret = hist_list[hist_cur];
+static char *hist_next(void)
+{
+       hist_node *p = NULL;
+       hist_node *q = hist_head;
+
+       if(q == hist_cur)
+               return NULL;
+
+       while(q->next != hist_cur) {
+               p = q;
+               q = q->next;
+       }
+       hist_cur = q;
 
-       return ret;
+       return p ? p->line : "";
 }
 
 
@@ -516,8 +583,7 @@ static int cread_line(const FLASH char *const prompt, char *buf,
 
        if (enable_history) {
                if (buf[0])
-                       cread_add_to_hist(buf);
-               hist_cur = hist_add_idx;
+               hist_cur = cread_add_to_hist(buf);
        }
        return 0;
 }

diff --git a/include/config.h b/include/config.h
index b7454e2e2e4de430080b91ba5bab70da4871bc09..e75b596271927d6b785a511f540834cd0861de9b 100644 (file)
--- a/include/config.h
+++ b/include/config.h
@@ -61,6 +61,7 @@
 #define CONFIG_SYS_I2C_CLOCK   100000L /* SCL clock frequency in Hz */
 
 #define CONFIG_SYS_CBSIZE      250
+#define CONFIG_SYS_HIST_MAX    20
 #define CONFIG_SYS_MAXARGS     20
 #define CONFIG_SYS_ENV_NAMELEN 16