firmware: speed up directory scanning

src/ff.c

@@ -2822,6 +2822,46 @@ FRESULT f_readdir (
 }
 
 
+FRESULT l_opendirbycluster (
+  FATFS *fs,
+  DIR *dj,
+  const TCHAR *path,
+  DWORD clust
+)
+{
+  FRESULT res;
+  res = chk_mounted(&path, &fs, 0);
+  DEF_NAMEBUF;
+  INIT_BUF(*dj);
+  dj->sclust = clust;
+  dj->fs = fs;
+  dj->id = fs->id;
+  dj->dir = 0;
+  res = dir_sdi(dj, 0);
+  FREE_BUF();
+  return res;
+}
+
+FRESULT l_openfilebycluster (
+  FATFS *fs,           /* Pointer to file system object */
+  FIL *fp,             /* Pointer to the blank file object */
+  const TCHAR *path,
+  DWORD clust,         /* Cluster number to be opened */
+  DWORD fsize          /* File size to be assumed */
+)
+{
+  chk_mounted(&path, &fs, 0);
+  fp->flag = FA_READ;
+  fp->org_clust = clust;
+  fp->fsize = fsize;
+  fp->fptr = 0;
+  fp->dsect = 0;
+  fp->fs = fs;
+
+  return FR_OK;
+}
+
+
 
 #if _FS_MINIMIZE == 0
 /*-----------------------------------------------------------------------*/
@@ -2854,27 +2894,6 @@ FRESULT f_stat (
 	LEAVE_FF(dj.fs, res);
 }
 
-
-FRESULT l_openfilebycluster (
-  FATFS *fs,           /* Pointer to file system object */
-  FIL *fp,             /* Pointer to the blank file object */
-  const TCHAR *path,
-  DWORD clust,         /* Cluster number to be opened */
-  DWORD fsize          /* File size to be assumed */
-)
-{
-  chk_mounted(&path, &fs, 0);
-  fp->flag = FA_READ;
-  fp->org_clust = clust;
-  fp->fsize = fsize;
-  fp->fptr = 0;
-  fp->dsect = 0;
-  fp->fs = fs;
-
-  return FR_OK;
-}
-
-
 #if !_FS_READONLY
 /*-----------------------------------------------------------------------*/
 /* Get Number of Free Clusters                                           */

src/ff.h

@@ -398,6 +398,7 @@ typedef enum {
 
 /* Low Level functions */
 FRESULT l_openfilebycluster(FATFS *fs, FIL *fp, const TCHAR *path, DWORD clust, DWORD fsize);   /* Open a file by its start cluster using supplied file size */
+FRESULT l_opendirbycluster (FATFS *fs, DIR *dj, const TCHAR *path, DWORD clust);
 
 /* application level functions */
 FRESULT f_mount (BYTE, FATFS*);						/* Mount/Unmount a logical drive */

src/fileops.c

@@ -47,6 +47,10 @@ void file_reinit(void) {
   file_init();
 }
 
+FRESULT dir_open_by_filinfo(DIR* dir, FILINFO* fno) {
+  return l_opendirbycluster(&fatfs, dir, (TCHAR*)"", fno->clust);
+}
+
 void file_open_by_filinfo(FILINFO* fno) {
   file_res = l_openfilebycluster(&fatfs, &file_handle, (TCHAR*)"", fno->clust, fno->fsize);
 }

src/fileops.h

@@ -41,6 +41,7 @@ enum filestates file_status;
 
 void file_init(void);
 void file_open(uint8_t* filename, BYTE flags);
+FRESULT dir_open_by_filinfo(DIR* dir, FILINFO* fno_param);
 void file_open_by_filinfo(FILINFO* fno);
 void file_close(void);
 void file_seek(uint32_t offset);

src/filetypes.c

@@ -53,7 +53,7 @@ uint16_t scan_flat(const char* path) {
   return numentries;
 }
 
-uint32_t scan_dir(char* path, char mkdb, uint32_t this_dir_tgt) {
+uint32_t scan_dir(char* path, FILINFO* fno_param, char mkdb, uint32_t this_dir_tgt) {
   DIR dir;
   FILINFO fno;
   FRESULT res;
@@ -103,7 +103,11 @@ uint32_t scan_dir(char* path, char mkdb, uint32_t this_dir_tgt) {
         sram_writelong(0L, next_subdir_tgt - 4);
       }
     }
-    res = f_opendir(&dir, (TCHAR*)path);
+    if(fno_param) {
+      res = dir_open_by_filinfo(&dir, fno_param);
+    } else {
+      res = f_opendir(&dir, path);
+    }
     if (res == FR_OK) {
       if(pass && parent_tgt && mkdb) {
         /* write backlink to parent dir
@@ -162,7 +166,7 @@ uint32_t scan_dir(char* path, char mkdb, uint32_t this_dir_tgt) {
                 db_tgt += sizeof(next_subdir_tgt) + sizeof(len) + pathlen + 2;
               }
               parent_tgt = this_dir_tgt;
-              scan_dir(path, mkdb, next_subdir_tgt);
+              scan_dir(path, &fno, mkdb, next_subdir_tgt);
               dir_tgt += 4;
               was_empty = 0;
             }

src/filetypes.h

@@ -50,7 +50,7 @@ char fs_path[256];
 SNES_FTYPE determine_filetype(char* filename);
 //uint32_t scan_fs();
 uint16_t scan_flat(const char* path);
-uint32_t scan_dir(char* path, char mkdb, uint32_t this_subdir_tgt);
+uint32_t scan_dir(char* path, FILINFO* fno_param, char mkdb, uint32_t this_subdir_tgt);
 FRESULT get_db_id(uint32_t*);
 int get_num_dirent(uint32_t addr);
 void sort_all_dir(uint32_t endaddr);

src/main.c

@@ -145,7 +145,7 @@ printf("PCONP=%lx\n", LPC_SC->PCONP);
     if((mem_magic != 0x12345678) || (mem_dir_id != saved_dir_id) || (newcard)) {
       newcard = 0;
       /* generate fs footprint (interesting files only) */
-      uint32_t curr_dir_id = scan_dir(fs_path, 0, 0);
+      uint32_t curr_dir_id = scan_dir(fs_path, NULL, 0, 0);
       printf("curr dir id = %lx\n", curr_dir_id);
       /* files changed or no database found? */
       if((get_db_id(&saved_dir_id) != FR_OK)
@@ -154,7 +154,7 @@ printf("PCONP=%lx\n", LPC_SC->PCONP);
 	printf("saved dir id = %lx\n", saved_dir_id);
 	printf("rebuilding database...");
 	snes_bootprint("     rebuilding database ...    \0");
-	curr_dir_id = scan_dir(fs_path, 1, 0);
+	curr_dir_id = scan_dir(fs_path, NULL, 1, 0);
 	sram_writeblock(&curr_dir_id, SRAM_DB_ADDR, 4);
 	uint32_t endaddr, direndaddr;
 	sram_readblock(&endaddr, SRAM_DB_ADDR+4, 4);