feat(img_cache): allow disabling image cacheing

related to #1954

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### New features
 - feat(chart) add lv_chart_remove_series and lv_chart_hide_series
+- feat(img_cahce) allow disabling image cacheing
 
 ### Bugfixes
 

lv_conf_template.h

@@ -240,7 +240,7 @@ typedef void * lv_fs_drv_user_data_t;
  * (I.e. no new image decoder is added)
  * With complex image decoders (e.g. PNG or JPG) caching can save the continuous open/decode of images.
  * However the opened images might consume additional RAM.
- * LV_IMG_CACHE_DEF_SIZE must be >= 1 */
+ * Set it to 0 to disable caching */
 #define LV_IMG_CACHE_DEF_SIZE       1
 
 /*Declare the type of the user data of image decoder (can be e.g. `void *`, `int`, `struct`)*/

src/lv_core/lv_obj.c

@@ -221,8 +221,9 @@ void lv_init(void)
     _lv_indev_init();
 
     _lv_img_decoder_init();
+#if LV_IMG_CACHE_DEF_SIZE
     lv_img_cache_set_size(LV_IMG_CACHE_DEF_SIZE);
-
+#endif
     /*Test if the IDE has UTF-8 encoding*/
     char * txt = "Á";
 

src/lv_draw/lv_draw_img.c

@@ -40,6 +40,7 @@ LV_ATTRIBUTE_FAST_MEM static void lv_draw_map(const lv_area_t * map_area, const
                                               bool chroma_key, bool alpha_byte);
 
 static void show_error(const lv_area_t * coords, const lv_area_t * clip_area, const char * msg);
+static void draw_cleanup(lv_img_cache_entry_t * cache);
 
 /**********************
  *  STATIC VARIABLES
@@ -267,9 +268,10 @@ LV_ATTRIBUTE_FAST_MEM static lv_res_t lv_img_draw_core(const lv_area_t * coords,
         lv_area_t mask_com; /*Common area of mask and coords*/
         bool union_ok;
         union_ok = _lv_area_intersect(&mask_com, clip_area, &map_area_rot);
+        /*Out of mask. There is nothing to draw so the image is drawn successfully.*/
         if(union_ok == false) {
-            return LV_RES_OK; /*Out of mask. There is nothing to draw so the image is drawn
+            draw_cleanup(cdsc);
-                                 successfully.*/
+            return LV_RES_OK;
         }
 
         lv_draw_map(coords, &mask_com, cdsc->dec_dsc.img_data, draw_dsc, chroma_keyed, alpha_byte);
@@ -279,9 +281,10 @@ LV_ATTRIBUTE_FAST_MEM static lv_res_t lv_img_draw_core(const lv_area_t * coords,
         lv_area_t mask_com; /*Common area of mask and coords*/
         bool union_ok;
         union_ok = _lv_area_intersect(&mask_com, clip_area, coords);
+        /*Out of mask. There is nothing to draw so the image is drawn successfully.*/
         if(union_ok == false) {
-            return LV_RES_OK; /*Out of mask. There is nothing to draw so the image is drawn
+            draw_cleanup(cdsc);
-                                 successfully.*/
+            return LV_RES_OK;
         }
 
         int32_t width = lv_area_get_width(&mask_com);
@@ -306,6 +309,7 @@ LV_ATTRIBUTE_FAST_MEM static lv_res_t lv_img_draw_core(const lv_area_t * coords,
                 lv_img_decoder_close(&cdsc->dec_dsc);
                 LV_LOG_WARN("Image draw can't read the line");
                 _lv_mem_buf_release(buf);
+                draw_cleanup(cdsc);
                 return LV_RES_INV;
             }
 
@@ -318,6 +322,7 @@ LV_ATTRIBUTE_FAST_MEM static lv_res_t lv_img_draw_core(const lv_area_t * coords,
         _lv_mem_buf_release(buf);
     }
 
+    draw_cleanup(cdsc);
     return LV_RES_OK;
 }
 
@@ -649,3 +654,11 @@ static void show_error(const lv_area_t * coords, const lv_area_t * clip_area, co
     lv_draw_label(coords, clip_area, &label_dsc, msg, NULL);
 }
 
+static void draw_cleanup(lv_img_cache_entry_t * cache)
+{
+/*Automatically close images with no caching*/
+#if LV_IMG_CACHE_DEF_SIZE == 0
+    lv_img_decoder_close(&cache->dec_dsc);
+#endif
+}
+

src/lv_draw/lv_img_cache.c

@@ -19,7 +19,7 @@
 /*********************
  *      DEFINES
  *********************/
-/*Decrement life with this value in every open*/
+/*Decrement life with this value on every open*/
 #define LV_IMG_CACHE_AGING 1
 
 /*Boost life by this factor (multiply time_to_open with this value)*/
@@ -29,10 +29,6 @@
  * "die" from very high values */
 #define LV_IMG_CACHE_LIFE_LIMIT 1000
 
-#if LV_IMG_CACHE_DEF_SIZE < 1
-    #error "LV_IMG_CACHE_DEF_SIZE must be >= 1. See lv_conf.h"
-#endif
-
 /**********************
  *      TYPEDEFS
  **********************/
@@ -40,11 +36,16 @@
 /**********************
  *  STATIC PROTOTYPES
  **********************/
+#if LV_IMG_CACHE_DEF_SIZE == 0
+static lv_img_cache_entry_t cache_temp;
+#endif
 
 /**********************
  *  STATIC VARIABLES
  **********************/
+#if LV_IMG_CACHE_DEF_SIZE
 static uint16_t entry_cnt;
+#endif
 
 /**********************
  *      MACROS
@@ -64,6 +65,10 @@ static uint16_t entry_cnt;
  */
 lv_img_cache_entry_t * _lv_img_cache_open(const void * src, lv_color_t color)
 {
+    /*Is the image cached?*/
+    lv_img_cache_entry_t * cached_src = NULL;
+
+#if LV_IMG_CACHE_DEF_SIZE
     if(entry_cnt == 0) {
         LV_LOG_WARN("lv_img_cache_open: the cache size is 0");
         return NULL;
@@ -79,8 +84,6 @@ lv_img_cache_entry_t * _lv_img_cache_open(const void * src, lv_color_t color)
         }
     }
 
-    /*Is the image cached?*/
-    lv_img_cache_entry_t * cached_src = NULL;
     for(i = 0; i < entry_cnt; i++) {
         bool match = false;
         lv_img_src_t src_type = lv_img_src_get_type(cache[i].dec_dsc.src);
@@ -104,48 +107,51 @@ lv_img_cache_entry_t * _lv_img_cache_open(const void * src, lv_color_t color)
     }
 
     /*The image is not cached then cache it now*/
-    if(cached_src == NULL) {
+    if(cached_src) return cached_src;
-        /*Find an entry to reuse. Select the entry with the least life*/
-        cached_src = &cache[0];
-        for(i = 1; i < entry_cnt; i++) {
-            if(cache[i].life < cached_src->life) {
-                cached_src = &cache[i];
-            }
-        }
 
-        /*Close the decoder to reuse if it was opened (has a valid source)*/
+    /*Find an entry to reuse. Select the entry with the least life*/
-        if(cached_src->dec_dsc.src) {
+    cached_src = &cache[0];
-            lv_img_decoder_close(&cached_src->dec_dsc);
+    for(i = 1; i < entry_cnt; i++) {
-            LV_LOG_INFO("image draw: cache miss, close and reuse an entry");
+        if(cache[i].life < cached_src->life) {
+            cached_src = &cache[i];
         }
-        else {
-            LV_LOG_INFO("image draw: cache miss, cached to an empty entry");
-        }
-
-        /*Open the image and measure the time to open*/
-        uint32_t t_start;
-        t_start                          = lv_tick_get();
-        cached_src->dec_dsc.time_to_open = 0;
-        lv_res_t open_res                = lv_img_decoder_open(&cached_src->dec_dsc, src, color);
-        if(open_res == LV_RES_INV) {
-            LV_LOG_WARN("Image draw cannot open the image resource");
-            lv_img_decoder_close(&cached_src->dec_dsc);
-            _lv_memset_00(&cached_src->dec_dsc, sizeof(lv_img_decoder_dsc_t));
-            _lv_memset_00(cached_src, sizeof(lv_img_cache_entry_t));
-            cached_src->life = INT32_MIN; /*Make the empty entry very "weak" to force its use  */
-            return NULL;
-        }
-
-        cached_src->life = 0;
-
-        /*If `time_to_open` was not set in the open function set it here*/
-        if(cached_src->dec_dsc.time_to_open == 0) {
-            cached_src->dec_dsc.time_to_open = lv_tick_elaps(t_start);
-        }
-
-        if(cached_src->dec_dsc.time_to_open == 0) cached_src->dec_dsc.time_to_open = 1;
     }
 
+    /*Close the decoder to reuse if it was opened (has a valid source)*/
+    if(cached_src->dec_dsc.src) {
+        lv_img_decoder_close(&cached_src->dec_dsc);
+        LV_LOG_INFO("image draw: cache miss, close and reuse an entry");
+    }
+    else {
+        LV_LOG_INFO("image draw: cache miss, cached to an empty entry");
+    }
+
+#else
+    cached_src = &cache_temp;
+#endif
+    /*Open the image and measure the time to open*/
+    uint32_t t_start;
+    t_start                          = lv_tick_get();
+    cached_src->dec_dsc.time_to_open = 0;
+    lv_res_t open_res                = lv_img_decoder_open(&cached_src->dec_dsc, src, color);
+    if(open_res == LV_RES_INV) {
+        LV_LOG_WARN("Image draw cannot open the image resource");
+        lv_img_decoder_close(&cached_src->dec_dsc);
+        _lv_memset_00(&cached_src->dec_dsc, sizeof(lv_img_decoder_dsc_t));
+        _lv_memset_00(cached_src, sizeof(lv_img_cache_entry_t));
+        cached_src->life = INT32_MIN; /*Make the empty entry very "weak" to force its use  */
+        return NULL;
+    }
+
+    cached_src->life = 0;
+
+    /*If `time_to_open` was not set in the open function set it here*/
+    if(cached_src->dec_dsc.time_to_open == 0) {
+        cached_src->dec_dsc.time_to_open = lv_tick_elaps(t_start);
+    }
+
+    if(cached_src->dec_dsc.time_to_open == 0) cached_src->dec_dsc.time_to_open = 1;
+
     return cached_src;
 }
 
@@ -157,6 +163,10 @@ lv_img_cache_entry_t * _lv_img_cache_open(const void * src, lv_color_t color)
  */
 void lv_img_cache_set_size(uint16_t new_entry_cnt)
 {
+#if LV_IMG_CACHE_DEF_SIZE == 0
+    LV_UNUSED(new_entry_cnt);
+    LV_LOG_WARN("Can't change cache size because it's disabled by LV_IMG_CACHE_DEF_SIZE = 0");
+#else
     if(LV_GC_ROOT(_lv_img_cache_array) != NULL) {
         /*Clean the cache before free it*/
         lv_img_cache_invalidate_src(NULL);
@@ -178,6 +188,7 @@ void lv_img_cache_set_size(uint16_t new_entry_cnt)
         _lv_memset_00(&LV_GC_ROOT(_lv_img_cache_array)[i].dec_dsc, sizeof(lv_img_decoder_dsc_t));
         _lv_memset_00(&LV_GC_ROOT(_lv_img_cache_array)[i], sizeof(lv_img_cache_entry_t));
     }
+#endif
 }
 
 /**
@@ -187,7 +198,7 @@ void lv_img_cache_set_size(uint16_t new_entry_cnt)
  */
 void lv_img_cache_invalidate_src(const void * src)
 {
-
+#if LV_IMG_CACHE_DEF_SIZE
     lv_img_cache_entry_t * cache = LV_GC_ROOT(_lv_img_cache_array);
 
     uint16_t i;
@@ -201,6 +212,7 @@ void lv_img_cache_invalidate_src(const void * src)
             _lv_memset_00(&cache[i], sizeof(lv_img_cache_entry_t));
         }
     }
+#endif
 }
 
 /**********************