From 13a54167ae37b75df8b929f533aa44096d59b17e Mon Sep 17 00:00:00 2001 From: Carl Worth Date: Tue, 15 May 2007 16:25:34 -0700 Subject: [PATCH] Add support for sequential introduction of a category This allows a particular category to be configured so that new items will be introduced in the order they exist in the file, rather than randomly, (though once an item leaves bin 0 it gets the same random treatment as all other items). The behavior is controlled by a new option at the beginning of the file that looks like this: order = sequential If there is no option it will be treated as random, (and when written out the order option will be set to either sequential or random). --- mnemon.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 148 insertions(+), 2 deletions(-) diff --git a/mnemon.c b/mnemon.c index 63ea457..321ab14 100644 --- a/mnemon.c +++ b/mnemon.c @@ -48,11 +48,20 @@ typedef struct _bin { item_t **items; } bin_t; +typedef enum { + CATEGORY_ORDER_RANDOM, + CATEGORY_ORDER_SEQUENTIAL +} category_order_t; + typedef struct _category { char *name; int items_size; int num_items; item_t *items; + + /* Support sequential introduction of items from bin 0 */ + category_order_t order; + int bin_zero_head; } category_t; typedef struct _mnemon { @@ -163,6 +172,8 @@ category_init (category_t *category, category->items_size = 0; category->num_items = 0; category->items = NULL; + category->order = CATEGORY_ORDER_RANDOM; + category->bin_zero_head = 0; } static void @@ -208,6 +219,18 @@ category_add_item (category_t *category, return item; } +static item_t * +category_next_bin_zero_item (category_t *category) +{ + int *i = &category->bin_zero_head; + + for ( ; *i < category->num_items; *i = *i + 1) + if (category->items[*i].score == 0) + return &category->items[*i]; + + return NULL; +} + static void category_print (category_t *category, FILE *file) @@ -215,6 +238,9 @@ category_print (category_t *category, int i; item_t *item; + fprintf (file, "order = %s\n\n", + category->order == CATEGORY_ORDER_RANDOM ? "random" : "sequential"); + for (i = 0; i < category->num_items; i++) { item = &category->items[i]; if (i != 0) @@ -279,6 +305,24 @@ bin_remove_item (bin_t *bin, bin->items[item_index] = bin->items[bin->num_items]; } +/* Find the index for an item within a bin. + * + * XXX: This is currently a linear search, so is a potential + * performance problem. + */ +static int +bin_item_index (bin_t *bin, + item_t *item) +{ + int i; + + for (i = 0; i < bin->num_items; i++) + if (bin->items[i] == item) + return i; + + assert (0); +} + static void mnemon_init (mnemon_t *mnemon) { @@ -414,6 +458,26 @@ chomp (char *s) s[len - 1] = '\0'; } +static char * +trim_space (char *string) +{ + char *s; + + s = string; + while (*s && isspace (*s)) + s++; + + string = s; + + s = string + strlen (string) - 1; + while (s > string && isspace (*s)) { + *s = '\0'; + s--; + } + + return string; +} + static void mnemon_load_category (mnemon_t *mnemon, const char *name) @@ -447,6 +511,52 @@ mnemon_load_category (mnemon_t *mnemon, chomp (line); \ } while (0) + /* Parse options */ + while (1) { + char *name, *equal, *value; + + /* Ignore blank lines */ + READ_LINE; + if (*line == '\0') + continue; + + /* An initial digit means we hit an item. Trigger the + * spaghetti machine. */ + if (*line >= '0' && *line <= '9') + goto PARSE_BIN; + + equal = strchr (line, '='); + if (equal == NULL) { + fprintf (stderr, "Malformed option, (expected name=value): \"%s\" at %s:%d\n", + line, path, line_count); + exit (1); + } + + value = equal + 1; + name = line; + *equal = '\0'; + + name = trim_space (name); + value = trim_space (value); + + if (strcmp (name, "order") == 0) { + if (strcmp (value, "sequential") == 0) { + category->order = CATEGORY_ORDER_SEQUENTIAL; + } else if (strcmp (value, "random") == 0) { + category->order = CATEGORY_ORDER_RANDOM; + } else { + fprintf (stderr, "Unknown value for \"order\" option \"%s\" at %s:%d\n", + value, path, line_count); + exit (1); + } + } else { + fprintf (stderr, "Unknown option %s at %s:%d\n", + name, path, line_count); + exit (1); + } + } + + /* Parse items */ while (1) { int score; char *challenge, *response; @@ -457,6 +567,7 @@ mnemon_load_category (mnemon_t *mnemon, continue; /* Read bin number */ + PARSE_BIN: score = strtol (line, &end, 10); if (*end != '\0') { fprintf (stderr, "Failed to parse bin number from \"%s\" at %s:%d\n", @@ -617,20 +728,55 @@ rand_within_exponential (int num_values) return ones; } +/* Find the category to which an item belongs. */ +static category_t * +mnemon_item_category (mnemon_t *mnemon, + item_t *item) +{ + category_t *category; + int i, item_index; + + for (i = 0; i < mnemon->num_categories; i++) { + category = &mnemon->categories[i]; + item_index = item - category->items; + if (item_index >= 0 && item_index < category->num_items) + return category; + } + + assert (0); +} + static void mnemon_select_item (mnemon_t *mnemon, bin_t **bin_ret, int *item_index_ret) { - int bin_index; + int bin_index, item_index; bin_t *bin; bin_index = rand_within_exponential (mnemon->num_bins); bin = &mnemon->bins[bin_index]; + item_index = rand_within (bin->num_items); + + if (bin->score == 0) { + category_t *category; + item_t *item; + + item = bin->items[item_index]; + + category = mnemon_item_category (mnemon, item); + + if (category->order == CATEGORY_ORDER_SEQUENTIAL) { + item = category_next_bin_zero_item (category); + if (item) + item_index = bin_item_index (bin, item); + } + } + *bin_ret = bin; - *item_index_ret = rand_within (bin->num_items); + *item_index_ret = item_index; } -- 2.43.0