Generalize histogram printing to accept a predicate function

[mnemon] / mnemon.c

diff --git a/mnemon.c b/mnemon.c
index 3e49777ff67b258022463267e8d9354610a04a2f..446d449b736d1bb2a1743688aa7bc6d86d19a4dc 100644 (file)
--- a/mnemon.c
+++ b/mnemon.c
@@ -323,6 +323,27 @@ bin_item_index (bin_t      *bin,
     assert (0);
 }
 
+typedef int (item_match_predicate_t) (void *closure, item_t *item);
+
+/* Return the number of items in the bin from the given category (or
+ * from all categories if category == NULL) */
+static int
+bin_num_items_matching (bin_t                  *bin,
+                       item_match_predicate_t  *predicate,
+                       void                    *closure)
+{
+    int i, num_items = 0;
+
+    if (predicate == NULL)
+       return bin->num_items;
+
+    for (i = 0; i < bin->num_items; i++)
+       if ((predicate) (closure, bin->items[i]))
+           num_items++;
+
+    return num_items;
+}
+
 static void
 mnemon_init (mnemon_t *mnemon)
 {
@@ -376,17 +397,31 @@ mnemon_categories_grow (mnemon_t *mnemon)
                                   mnemon->categories_size * sizeof (category_t));
 }
 
+/* Get a category by name if it exists */
 static category_t *
-mnemon_get_category (mnemon_t  *mnemon,
-                    const char *name)
+mnemon_get_category_if_exists (mnemon_t            *mnemon,
+                              const char   *name)
 {
     int i;
-    category_t *category;
 
     for (i = 0; i < mnemon->num_categories; i++)
        if (strcmp (mnemon->categories[i].name, name) == 0)
            return &mnemon->categories[i];
 
+    return NULL;
+}
+
+/* Get a category by name, creating new one if necessary. */
+static category_t *
+mnemon_get_category (mnemon_t  *mnemon,
+                    const char *name)
+{
+    category_t *category;
+
+    category = mnemon_get_category_if_exists (mnemon, name);
+    if (category)
+       return category;
+
     mnemon_categories_grow (mnemon);
 
     category = &mnemon->categories[mnemon->num_categories++];
@@ -746,6 +781,22 @@ mnemon_item_category (mnemon_t     *mnemon,
     assert (0);
 }
 
+typedef struct _item_in_category_closure
+{
+    mnemon_t *mnemon;
+    category_t *category;
+} item_in_category_closure_t;
+
+static int
+mnemon_item_in_category (void *closure, item_t *item)
+{
+    item_in_category_closure_t *iicc = closure;
+    mnemon_t *mnemon = iicc->mnemon;
+    category_t *category = iicc->category;
+
+    return (mnemon_item_category (mnemon, item) == category);
+}
+
 static void
 mnemon_select_item (mnemon_t    *mnemon,
                    bin_t       **bin_ret,
@@ -821,26 +872,46 @@ print_histogram_bar (double       size,
 }
 
 static void
-mnemon_print_histogram (mnemon_t *mnemon)
+mnemon_print_histogram (mnemon_t    *mnemon,
+                       const char  *category_name)
 {
     int i, last_score, max;
+    category_t *category = NULL;
     bin_t *bin;
+    int num_items;
+    item_match_predicate_t *predicate = NULL;
+    void *closure = NULL;
+    item_in_category_closure_t item_in_category;
 
     if (mnemon->num_bins == 0)
        return;
 
-    max = mnemon->bins[0].num_items;
-    for (i = 1; i < mnemon->num_bins; i++)
-       if (mnemon->bins[i].num_items > max)
-           max = mnemon->bins[i].num_items;
+    if (category_name) {
+       category = mnemon_get_category_if_exists (mnemon, category_name);
+       if (category) {
+           predicate = mnemon_item_in_category;
+           item_in_category.mnemon = mnemon;
+           item_in_category.category = category;
+           closure = &item_in_category;
+       }
+    }
+
+    for (i = 0; i < mnemon->num_bins; i++) {
+       num_items = bin_num_items_matching (&mnemon->bins[i],
+                                           predicate, closure);
+       if (i == 0 || num_items > max)
+           max = num_items;
+    }
 
     for (i = 0; i < mnemon->num_bins; i++) {
        bin = &mnemon->bins[i];
        if (i != 0)
            while (bin->score - last_score > 1)
                printf (HISTOGRAM_ROW_FORMAT "\n", ++last_score, 0);
-       printf (HISTOGRAM_ROW_FORMAT " ", bin->score, bin->num_items);
-       print_histogram_bar (bin->num_items, max);
+       num_items = bin_num_items_matching (bin,
+                                           predicate, closure);
+       printf (HISTOGRAM_ROW_FORMAT " ", bin->score, num_items);
+       print_histogram_bar (num_items, max);
        last_score = bin->score;
     }
 }
@@ -849,9 +920,15 @@ static void
 mnemon_handle_command (mnemon_t                *mnemon,
                       const char       *command)
 {
+    const char *arg;
     switch (command[0]) {
        case 'h':
-           mnemon_print_histogram (mnemon);
+           arg = command + 1;
+           while (*arg && isspace (*arg))
+               arg++;
+           if (*arg == '\0')
+               arg = NULL;
+           mnemon_print_histogram (mnemon, arg);
            break;
         default:
            printf ("Unknown command: %s\n", command);