Debugger: Add cache statistics command

Add `info cache` command that reports cache usage and cumulative hit
rates for glyph, CG, and archive data.

src/ald_manager.c

@@ -148,3 +148,7 @@ int ald_get_maxno(DRIFILETYPE type) {
 		return 0;
 	return dri[type]->maxno;
 }
+
+CacheStats ald_get_cache_stats(void) {
+	return cache_get_stats(dri_cache);
+}

src/ald_manager.h

@@ -25,6 +25,7 @@
 #define __ALD_MANAGER__
 
 #include "portab.h"
+#include "cache.h"
 #include "dri.h"
 
 #define DRIFILETYPEMAX 7
@@ -44,6 +45,6 @@ bool ald_exists(DRIFILETYPE type, int no);
 dridata *ald_getdata(DRIFILETYPE type, int no);
 void ald_freedata(dridata *data);
 int ald_get_maxno(DRIFILETYPE type);
+CacheStats ald_get_cache_stats(void);
 
 #endif /* !__ALD_MANAGER__ */
-

src/cache.c

@@ -41,6 +41,8 @@ struct Cache {
 	size_t capacity;
 	size_t size;
 	size_t count;
+	size_t hits;
+	size_t misses;
 };
 
 static bool is_pinned(const Cache *cache, const CacheEntry *entry) {
@@ -112,8 +114,11 @@ void *cache_get(Cache *cache, const void *key) {
 	if (!cache || !key)
 		return NULL;
 	CacheEntry *entry = find_entry(cache, key, cache->ops.hash(key));
-	if (!entry)
+	if (!entry) {
+		cache->misses++;
 		return NULL;
+	}
+	cache->hits++;
 	lru_remove(cache, entry);
 	lru_prepend(cache, entry);
 	return entry->data;
@@ -176,3 +181,15 @@ size_t cache_clear(Cache *cache) {
 	}
 	return cache->count;
 }
+
+CacheStats cache_get_stats(const Cache *cache) {
+	if (!cache)
+		return (CacheStats){0};
+	return (CacheStats){
+		.count = cache->count,
+		.size = cache->size,
+		.capacity = cache->capacity,
+		.hits = cache->hits,
+		.misses = cache->misses,
+	};
+}

src/cache.h

@@ -40,6 +40,14 @@ typedef enum {
 	CACHE_INSERT_NOMEM,
 } CacheInsertResult;
 
+typedef struct {
+	size_t count;
+	size_t size;
+	size_t capacity;
+	size_t hits;
+	size_t misses;
+} CacheStats;
+
 Cache *cache_new(size_t capacity, const CacheOps *ops);
 void cache_destroy(Cache *cache);
 
@@ -55,4 +63,7 @@ bool cache_remove(Cache *cache, const void *key);
 /* Removes all unpinned entries and returns the number of entries left. */
 size_t cache_clear(Cache *cache);
 
+/* Returns zero-filled statistics when cache is NULL. */
+CacheStats cache_get_stats(const Cache *cache);
+
 #endif /* XSYSTEM35_CACHE_H */

src/cache_test.c

@@ -64,14 +64,27 @@ void cache_test(void) {
 	Cache *cache = cache_new(2, &ops);
 	ASSERT_TRUE(cache);
 	destroyed = 0;
+	CacheStats stats = cache_get_stats(cache);
+	ASSERT_EQUAL(stats.count, 0);
+	ASSERT_EQUAL(stats.size, 0);
+	ASSERT_EQUAL(stats.capacity, 2);
+	ASSERT_EQUAL(stats.hits, 0);
+	ASSERT_EQUAL(stats.misses, 0);
 
 	// A lookup makes k1 most-recently used, so inserting k3 evicts k2.
 	int k1 = 1, k2 = 2, k3 = 3, k4 = 4, k5 = 5;
 	ASSERT_EQUAL(cache_insert(cache, &k1, new_value(1), 1), CACHE_INSERT_OK);
 	ASSERT_EQUAL(cache_insert(cache, &k2, new_value(2), 1), CACHE_INSERT_OK);
+	stats = cache_get_stats(cache);
+	ASSERT_EQUAL(stats.count, 2);
+	ASSERT_EQUAL(stats.size, 2);
+	ASSERT_EQUAL(stats.capacity, 2);
 	ASSERT_EQUAL(((TestValue *)cache_get(cache, &k1))->value, 1);
 	ASSERT_EQUAL(cache_insert(cache, &k3, new_value(3), 1), CACHE_INSERT_OK);
 	ASSERT_NULL(cache_get(cache, &k2));
+	stats = cache_get_stats(cache);
+	ASSERT_EQUAL(stats.hits, 1);
+	ASSERT_EQUAL(stats.misses, 1);
 
 	// Pinned entries survive both capacity eviction and cache_clear().
 	((TestValue *)cache_get(cache, &k1))->pinned = true;
@@ -94,4 +107,11 @@ void cache_test(void) {
 	ASSERT_EQUAL(cache_clear(cache), 0);
 	ASSERT_EQUAL(destroyed, 4);
 	cache_destroy(cache);
+
+	stats = cache_get_stats(NULL);
+	ASSERT_EQUAL(stats.count, 0);
+	ASSERT_EQUAL(stats.size, 0);
+	ASSERT_EQUAL(stats.capacity, 0);
+	ASSERT_EQUAL(stats.hits, 0);
+	ASSERT_EQUAL(stats.misses, 0);
 }

src/cg.c

@@ -354,6 +354,10 @@ void cg_reset(void) {
 	memset(&loc_where0, 0, sizeof(loc_where0));
 }
 
+CacheStats cg_get_cache_stats(void) {
+	return cache_get_stats(cg_cache);
+}
+
 /*
  * Set cg display location
  *  x     : display location x

src/cg.h

@@ -25,6 +25,7 @@
 #define __CG__
 
 #include <SDL_rect.h>
+#include "cache.h"
 #include "portab.h"
 
 struct SDL_Surface;
@@ -88,6 +89,7 @@ extern void cgdata_free(cgdata *cg);
 extern struct SDL_Surface *cg_load_as_sdlsurface(int no);
 struct SDL_Surface *cg_load_as_sdlsurface_from_data(uint8_t *data, size_t size, bool mosaic, bool as_alpha);
 extern void load_censor_list(const char *path);
+extern CacheStats cg_get_cache_stats(void);
 
 extern int cg_vspPB;
 extern int cg_fflg;

src/debugger_cui.c

@@ -23,6 +23,9 @@
 #include "debugger.h"
 #include "debugger_private.h"
 #include "debug_symbol.h"
+#include "ald_manager.h"
+#include "cg.h"
+#include "font.h"
 #include "nact.h"
 #include "variable.h"
 #ifdef HAVE_SIGACTION
@@ -207,6 +210,34 @@ static const char * const help_help = NULL;
 
 static CommandResult cmd_help(void);
 
+static const char desc_info[] = "Print information about the program.";
+static const char help_info[] =
+	"Syntax: info cache\n"
+	"\n"
+	"Displays usage and lookup statistics for each cache.";
+
+static void print_cache_stats(const char *name, CacheStats stats) {
+	size_t lookups = stats.hits + stats.misses;
+	double hit_rate = lookups ? 100.0 * stats.hits / lookups : 0.0;
+	printf("%-8s %8zu %12zu %12zu %8zu %8zu %8.1f%%\n",
+	       name, stats.count, stats.size, stats.capacity,
+	       stats.hits, stats.misses, hit_rate);
+}
+
+static CommandResult cmd_info(void) {
+	char *arg = strtok(NULL, whitespaces);
+	if (!arg || strcmp(arg, "cache") || strtok(NULL, whitespaces)) {
+		puts(help_info);
+		return CONTINUE_REPL;
+	}
+
+	puts("Cache     Entries         Size     Capacity     Hits   Misses  Hit rate");
+	print_cache_stats("Glyph", font_get_cache_stats());
+	print_cache_stats("CG", cg_get_cache_stats());
+	print_cache_stats("Archive", ald_get_cache_stats());
+	return CONTINUE_REPL;
+}
+
 static const char desc_list[] = "List specified function or line.";
 static const char help_list[] =
 	"Syntax: list\n"
@@ -361,6 +392,7 @@ const Command dbg_cui_commands[] = {
 	{"continue",  "c",   desc_continue,  help_continue,  cmd_continue},
 	{"delete",    "d",   desc_delete,    help_delete,    cmd_delete},
 	{"help",      "h",   desc_help,      help_help,      cmd_help},
+	{"info",      "i",   desc_info,      help_info,      cmd_info},
 	{"list",      "l",   desc_list,      help_list,      cmd_list},
 	{"step",      "s",   desc_step,      help_step,      cmd_step},
 	{"finish",    NULL,  desc_finish,    help_finish,    cmd_finish},

src/font.c

@@ -416,6 +416,10 @@ bool font_get_antialias(void) {
 	return this.antialiase_on;
 }
 
+CacheStats font_get_cache_stats(void) {
+	return cache_get_stats(glyph_cache);
+}
+
 #ifdef __EMSCRIPTEN__
 EM_ASYNC_JS(bool, load_mincho_font, (void), {
 	return await xsystem35.load_mincho_font();

src/font.h

@@ -25,6 +25,7 @@
 #define __FONT_H__
 
 #include <SDL_surface.h>
+#include "cache.h"
 #include "config.h"
 #include "portab.h"
 
@@ -55,6 +56,7 @@ extern void font_measure_text(FontSpec spec, const char *str_utf8, int len, bool
 // Rows by which a rendered surface extends above the character cell. Subtract
 // it from a Y coordinate that denotes the cell top before blitting.
 extern int font_cell_overhang(FontSpec spec);
+extern CacheStats font_get_cache_stats(void);
 
 #ifdef __EMSCRIPTEN__
 extern bool load_mincho_font(void);