#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
+#include <stdint.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>
+#include <assert.h>
-typedef struct _mnemon {
- int dummy;
-} mnemon_t;
+#include <readline/readline.h>
+#include <readline/history.h>
-typedef struct _ic {
- int bin;
+typedef int bool_t;
+
+typedef struct _item {
+ int count;
char *challenge;
char *response;
-} ic_t;
+} item_t;
+
+typedef struct _bin {
+ int count;
+ int items_size;
+ int num_items;
+ item_t **items;
+} bin_t;
+
+typedef struct _category {
+ char *name;
+ int items_size;
+ int num_items;
+ item_t *items;
+} category_t;
+
+typedef struct _mnemon {
+ char *dir_name;
+
+ int categories_size;
+ int num_categories;
+ category_t *categories;
+
+ int bins_size;
+ int num_bins;
+ bin_t *bins;
+} mnemon_t;
+
+static void *
+xmalloc (size_t size)
+{
+ void *ret;
+
+ ret = malloc (size);
+ if (ret == NULL) {
+ fprintf (stderr, "Error: out of memory\n");
+ exit (1);
+ }
+
+ return ret;
+}
+
+static void *
+xrealloc (void *ptr, size_t size)
+{
+ void *ret;
+
+ ret = realloc (ptr, size);
+ if (ret == NULL) {
+ fprintf (stderr, "Error: out of memory\n");
+ exit (1);
+ }
+
+ return ret;
+}
+
+static char *
+xstrdup (const char *s)
+{
+ char *ret;
+
+ ret = strdup (s);
+ if (s == NULL) {
+ fprintf (stderr, "Error: out of memory\n");
+ exit (1);
+ }
+
+ return ret;
+}
static void
xasprintf (char **strp, const char *fmt, ...)
}
}
+static void
+item_init (item_t *item,
+ int count,
+ const char *challenge,
+ const char *response)
+{
+ item->count = count;
+
+ item->challenge = xmalloc (strlen (challenge) + 1 +
+ strlen (response) + 1);
+ item->response = item->challenge + strlen (challenge) + 1;
+
+ strcpy (item->challenge, challenge);
+ strcpy (item->response, response);
+}
+
+static void
+item_fini (item_t *item)
+{
+ /* item->response shares allocation with item->challenge, so
+ * doesn't require a separate call to free */
+ free (item->challenge);
+}
+
+static void
+category_init (category_t *category,
+ const char *name)
+{
+ category->name = xstrdup (name);
+
+ category->items_size = 0;
+ category->num_items = 0;
+ category->items = NULL;
+}
+
+static void
+category_fini (category_t *category)
+{
+ int i;
+
+ for (i = 0; i < category->num_items; i++)
+ item_fini (&category->items[i]);
+
+ free (category->items);
+
+ free (category->name);
+}
+
+static void
+category_grow (category_t *category)
+{
+ if (category->items_size)
+ category->items_size *= 2;
+ else
+ category->items_size = 1;
+
+ category->items = xrealloc (category->items,
+ category->items_size * sizeof (item_t));
+}
+
+static item_t *
+category_add_item (category_t *category,
+ int count,
+ const char *challenge,
+ const char *response)
+{
+ item_t *item;
+
+ if (category->num_items == category->items_size)
+ category_grow (category);
+
+ item = &category->items[category->num_items++];
+
+ item_init (item, count, challenge, response);
+
+ return item;
+}
+
+static void
+category_print (category_t *category,
+ FILE *file)
+{
+ int i;
+ item_t *item;
+
+ for (i = 0; i < category->num_items; i++) {
+ item = &category->items[i];
+ if (i != 0)
+ fprintf (file, "\n");
+ fprintf (file, "%d\n%s\n%s\n",
+ item->count,
+ item->challenge,
+ item->response);
+ }
+}
+
+static void
+bin_init (bin_t *bin,
+ int count)
+{
+ bin->count = count;
+
+ bin->items_size = 0;
+ bin->num_items = 0;
+ bin->items = NULL;
+}
+
+static void
+bin_fini (bin_t *bin)
+{
+ free (bin->items);
+}
+
+static void
+bin_grow (bin_t *bin)
+{
+ if (bin->items_size)
+ bin->items_size *= 2;
+ else
+ bin->items_size = 1;
+
+ bin->items = xrealloc (bin->items,
+ bin->items_size * sizeof (item_t*));
+}
+
+static void
+bin_add_item (bin_t *bin,
+ item_t *item)
+{
+ assert (item->count == bin->count);
+
+ if (bin->num_items == bin->items_size)
+ bin_grow (bin);
+
+ bin->items[bin->num_items++] = item;
+}
+
+static void
+bin_remove_item (bin_t *bin,
+ int item_index)
+{
+ /* Replace the current item with the last item, (no need to shift
+ * any more than that since we don't care about the order of the
+ * items within a bin). */
+ bin->num_items--;
+ if (bin->num_items)
+ bin->items[item_index] = bin->items[bin->num_items];
+}
+
+static void
+mnemon_init (mnemon_t *mnemon)
+{
+ char *home;
+
+ home = getenv ("HOME");
+ if (home == NULL)
+ home = "";
+
+ xasprintf (&mnemon->dir_name, "%s/.mnemon", getenv ("HOME"));
+
+ mnemon->categories_size = 0;
+ mnemon->num_categories = 0;
+ mnemon->categories = NULL;
+
+ mnemon->bins_size = 0;
+ mnemon->num_bins = 0;
+ mnemon->bins = NULL;
+}
+
+static void
+mnemon_fini (mnemon_t *mnemon)
+{
+ int i;
+
+ for (i = 0; i < mnemon->num_bins; i++)
+ bin_fini (&mnemon->bins[i]);
+ free (mnemon->bins);
+
+ for (i = 0; i < mnemon->num_categories; i++)
+ category_fini (&mnemon->categories[i]);
+ free (mnemon->categories);
+
+ free (mnemon->dir_name);
+}
+
+static void
+mnemon_categories_grow (mnemon_t *mnemon)
+{
+ if (mnemon->categories_size)
+ mnemon->categories_size *= 2;
+ else
+ mnemon->categories_size = 1;
+
+ mnemon->categories = xrealloc (mnemon->categories,
+ mnemon->categories_size * sizeof (category_t));
+}
+
+static category_t *
+mnemon_get_category (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];
+
+ mnemon_categories_grow (mnemon);
+
+ category = &mnemon->categories[mnemon->num_categories++];
+
+ category_init (category, name);
+
+ return category;
+}
+
+static void
+mnemon_bins_grow (mnemon_t *mnemon)
+{
+ if (mnemon->bins_size)
+ mnemon->bins_size *= 2;
+ else
+ mnemon->bins_size = 1;
+
+ mnemon->bins = xrealloc (mnemon->bins,
+ mnemon->bins_size * sizeof (bin_t));
+}
+
+static bin_t *
+mnemon_get_bin (mnemon_t *mnemon,
+ int count)
+{
+ int i;
+ bin_t *bin;
+
+ for (i = 0; i < mnemon->num_bins; i++)
+ if (mnemon->bins[i].count == count)
+ return &mnemon->bins[i];
+ else if (mnemon->bins[i].count > count)
+ break;
+
+ mnemon_bins_grow (mnemon);
+
+ bin = &mnemon->bins[i];
+
+ /* Make room to insert new bin at its sorted location. */
+ memmove (bin + 1, bin, (mnemon->num_bins - i) * sizeof (bin_t));
+ mnemon->num_bins++;
+
+ bin_init (bin, count);
+
+ return bin;
+}
+
+static void
+mnemon_remove_bin (mnemon_t *mnemon,
+ bin_t *bin)
+{
+ int i = bin - mnemon->bins;
+
+ memmove (bin, bin + 1, (mnemon->num_bins - i) * sizeof (bin_t));
+ mnemon->num_bins--;
+}
+
static void
chomp (char *s)
{
}
static void
-mnemon_load_from_file (mnemon_t *mnemon,
- char *path)
+mnemon_load_category (mnemon_t *mnemon,
+ const char *name)
{
FILE *file;
char *line = NULL, *end;
size_t line_size = 0;
ssize_t bytes_read;
int line_count = 0;
+ char *path;
+ category_t *category;
+ int i;
+
+ path = xmalloc (strlen (mnemon->dir_name) + 1 + strlen (name) + 1);
+ sprintf (path, "%s/%s", mnemon->dir_name, name);
file = fopen (path, "r");
if (file == NULL) {
exit (1);
}
+ category = mnemon_get_category (mnemon, name);
+
while (1) {
- ic_t ic;
+ int count;
+ char *challenge, *response;
/* Read bin number (ignoring blank separator lines) */
do {
chomp (line);
} while (*line == '\0');
- ic.bin = strtol (line, &end, 10);
+ count = strtol (line, &end, 10);
if (*end != '\0') {
fprintf (stderr, "Failed to parse bin number from \"%s\" at %s:%d\n",
line, path, line_count);
break;
line_count++;
chomp (line);
- ic.challenge = strdup (line);
+ challenge = strdup (line);
/* Read response */
bytes_read = getline (&line, &line_size, file);
break;
line_count++;
chomp (line);
- ic.response = strdup (line);
+ response = line;
- /* XXX: Add ic to mnemon here */
- printf ("%d: %s => %s\n", ic.bin, ic.challenge, ic.response);
- free (ic.challenge);
- free (ic.response);
+ category_add_item (category, count, challenge, response);
+
+ free (challenge);
}
END_OF_FILE:
free (line);
fclose (file);
+ free (path);
+
+ /* Resize category items to fit exactly. */
+ category->items_size = category->num_items;
+ category->items = xrealloc (category->items, category->items_size * sizeof (item_t));
+
+ /* Now that the category is completely loaded, with stable
+ * pointers to every item, we can add each item to its appropriate
+ * bin. */
+ for (i = 0; i < category->num_items; i++) {
+ item_t *item = &category->items[i];
+ bin_t *bin = mnemon_get_bin (mnemon, item->count);
+
+ bin_add_item (bin, item);
+ }
}
static void
-mnemon_load_from_directory_recursive (mnemon_t *mnemon,
- char *path)
+mnemon_load (mnemon_t *mnemon)
{
DIR *dir;
struct dirent *dirent;
- char *child_path;
- dir = opendir (path);
+ dir = opendir (mnemon->dir_name);
if (dir == NULL) {
fprintf (stderr, "Error: Failed to open directory %s: %s\n",
- path, strerror (errno));
+ mnemon->dir_name, strerror (errno));
exit (1);
}
if (dirent == NULL)
break;
- xasprintf (&child_path, "%s/%s", path, dirent->d_name);
- if (dirent->d_type == DT_DIR) {
- if (strcmp (dirent->d_name, ".") &&
- strcmp (dirent->d_name, ".."))
- {
- mnemon_load_from_directory_recursive (mnemon, child_path);
- }
- } else if (dirent->d_type == DT_REG) {
+ if (dirent->d_type == DT_REG) {
/* Ignore files matching *~, (yes, this shouldn't be
* hard-coded in such an ad-hoc way, but there you go. */
- if (child_path[strlen(child_path)-1] != '~')
- mnemon_load_from_file (mnemon, child_path);
- } else {
- fprintf (stderr, "Warning: Ignoring file %s\n", child_path);
+ if (dirent->d_name[strlen(dirent->d_name)-1] != '~')
+ mnemon_load_category (mnemon, dirent->d_name);
}
-
- free (child_path);
}
closedir (dir);
}
static void
-mnemon_init (mnemon_t *mnemon)
+mnemon_save (mnemon_t *mnemon)
{
- char *dot_mnemon;
- char *home;
+ int i, err;
+ char *filename, *lock_filename;
+ FILE *file;
+ category_t *category;
- home = getenv ("HOME");
- if (home == NULL)
- home = "";
+ for (i = 0; i < mnemon->num_categories; i++) {
+ category = &mnemon->categories[i];
+
+ xasprintf (&filename, "%s/%s",
+ mnemon->dir_name, category->name);
+ xasprintf (&lock_filename, "%s/.#%s",
+ mnemon->dir_name, category->name);
+
+ file = fopen (lock_filename, "w");
+ if (file == NULL) {
+ fprintf (stderr, "Error: Failed to open %s for writing: %s\n",
+ lock_filename, strerror (errno));
+ continue;
+ }
+
+ category_print (category, file);
+
+ fclose (file);
+
+ err = rename (lock_filename, filename);
+ if (err < 0) {
+ fprintf (stderr, "Error: Failes to rename %s to %s: %s\n",
+ lock_filename, filename, strerror (errno));
+ continue;
+ }
+
+ free (filename);
+ free (lock_filename);
+ }
+}
+
+/* Return a uniformly-distributed pseudo-random integer within the
+ * range:
+ *
+ * 0 <= result < num_values
+ */
+static int
+rand_within (int num_values)
+{
+ return (int) (num_values * (rand() / (RAND_MAX + 1.0)));
+}
+
+/* Return an exponentially-distributed pseudo-random integer within
+ * the range:
+ *
+ * 0 <= result < num_values
+ *
+ * The distribution is such that each successively larger value will
+ * occur with a probability of half of the previous value.
+ */
+static int
+rand_within_exponential (int num_values)
+{
+ static int r;
+ static uint32_t mask = 0;
+ int ones;
+ int bit;
- xasprintf (&dot_mnemon, "%s/.mnemon", getenv ("HOME"));
+ /* Optimize the constant case. */
+ if (num_values == 1)
+ return 0;
- mnemon_load_from_directory_recursive (mnemon, dot_mnemon);
+ ones = 0;
- free (dot_mnemon);
+ do {
+ if (mask == 0) {
+ r = rand ();
+ mask = 1 << 31;
+ while (mask > RAND_MAX)
+ mask >>= 1;
+ }
+ bit = r & mask;
+ mask >>= 1;
+ if (bit) {
+ ones++;
+ if (ones == num_values)
+ ones = 0;
+ }
+ } while (bit);
+
+ return ones;
+}
+
+static void
+mnemon_select_item (mnemon_t *mnemon,
+ bin_t **bin_ret,
+ int *item_index_ret)
+{
+ int bin_index;
+ bin_t *bin;
+
+ bin_index = rand_within_exponential (mnemon->num_bins);
+
+ bin = &mnemon->bins[bin_index];
+
+ *bin_ret = bin;
+ *item_index_ret = rand_within (bin->num_items);
+}
+
+static void
+mnemon_do_challenges (mnemon_t *mnemon)
+{
+ bin_t *bin;
+ int item_index;
+ item_t *item;
+ char *response;
+ bool_t correct;
+
+ while (1) {
+ mnemon_select_item (mnemon, &bin, &item_index);
+ item = bin->items[item_index];
+
+ printf ("%s\n", item->challenge);
+
+ response = readline ("> ");
+ if (response == NULL) {
+ printf ("\n");
+ break;
+ }
+
+ correct = (strcmp (response, item->response) == 0);
+
+ bin_remove_item (bin, item_index);
+ if (bin->num_items == 0)
+ mnemon_remove_bin (mnemon, bin);
+
+ if (correct) {
+ printf ("Correct!\n\n");
+ item->count++;
+ } else {
+ printf (" %s is the correct answer.\n\n",
+ item->response);
+ item->count--;
+ if (item->count > 0)
+ item->count = -1;
+ }
+
+ bin = mnemon_get_bin (mnemon, item->count);
+
+ bin_add_item (bin, item);
+ }
}
int
{
mnemon_t mnemon;
+ srand (1);
+
mnemon_init (&mnemon);
+ mnemon_load (&mnemon);
+
+ mnemon_do_challenges (&mnemon);
+
+ mnemon_save (&mnemon);
+
+ mnemon_fini (&mnemon);
+
return 0;
}