Fixed a stat bug with obj id. Added user callback file func.

New API functions:
  SPIFFS_set_file_callback_func

src/spiffs.h

@@ -68,9 +68,10 @@ typedef u16_t spiffs_mode;
 // object type
 typedef u8_t spiffs_obj_type;
 
-#if SPIFFS_HAL_CALLBACK_EXTRA
 struct spiffs_t;
 
+#if SPIFFS_HAL_CALLBACK_EXTRA
+
 /* spi read call function type */
 typedef s32_t (*spiffs_read)(struct spiffs_t *fs, u32_t addr, u32_t size, u8_t *dst);
 /* spi write call function type */
@@ -115,6 +116,19 @@ typedef void (*spiffs_check_callback)(spiffs_check_type type, spiffs_check_repor
     u32_t arg1, u32_t arg2);
 #endif // SPIFFS_HAL_CALLBACK_EXTRA
 
+/* file system listener callback operation */
+typedef enum {
+  /* the file has been created */
+  SPIFFS_CB_CREATED = 0,
+  /* the file has been updated or moved to another page */
+  SPIFFS_CB_UPDATED,
+  /* the file has been deleted */
+  SPIFFS_CB_DELETED,
+} spiffs_fileop_type;
+
+/* file system listener callback function */
+typedef void (*spiffs_file_callback)(struct spiffs_t *fs, spiffs_fileop_type op, spiffs_obj_id obj_id, spiffs_page_ix pix);
+
 #ifndef SPIFFS_DBG
 #define SPIFFS_DBG(...) \
     print(__VA_ARGS__)
@@ -252,7 +266,8 @@ typedef struct spiffs_t {
 
   // check callback function
   spiffs_check_callback check_cb_f;
-
+  // file callback function
+  spiffs_file_callback file_cb_f;
   // mounted flag
   u8_t mounted;
   // user data
@@ -266,6 +281,7 @@ typedef struct {
   spiffs_obj_id obj_id;
   u32_t size;
   spiffs_obj_type type;
+  spiffs_page_ix pix;
   u8_t name[SPIFFS_OBJ_NAME_LEN];
 } spiffs_stat;
 
@@ -616,6 +632,21 @@ s32_t SPIFFS_eof(spiffs *fs, spiffs_file fh);
  */
 s32_t SPIFFS_tell(spiffs *fs, spiffs_file fh);
 
+/**
+ * Registers a callback function that keeps track on operations on file
+ * headers. Do note, that this callback is called from within internal spiffs
+ * mechanisms. Any operations on the actual file system being callbacked from
+ * in this callback will mess things up for sure - do not do this.
+ * This can be used to track where files are and move around during garbage
+ * collection, which in turn can be used to build location tables in ram.
+ * Used in conjuction with SPIFFS_open_by_page this may improve performance
+ * when opening a lot of files.
+ *
+ * @param fs            the file system struct
+ * @param cb_func       the callback on file operations
+ */
+s32_t SPIFFS_set_file_callback_func(spiffs *fs, spiffs_file_callback cb_func);
+
 #if SPIFFS_TEST_VISUALISATION
 /**
  * Prints out a visualization of the filesystem.

src/spiffs_hydrogen.c

@@ -80,11 +80,14 @@ s32_t SPIFFS_mount(spiffs *fs, spiffs_config *config, u8_t *work,
     void *cache, u32_t cache_size,
     spiffs_check_callback check_cb_f) {
   void *user_data;
+  spiffs_file_callback fcb;
   SPIFFS_LOCK(fs);
   user_data = fs->user_data;
+  fcb = fs->file_cb_f;
   memset(fs, 0, sizeof(spiffs));
   memcpy(&fs->cfg, config, sizeof(spiffs_config));
   fs->user_data = user_data;
+  fs->file_cb_f = fcb;
   fs->block_count = SPIFFS_CFG_PHYS_SZ(fs) / SPIFFS_CFG_LOG_BLOCK_SZ(fs);
   fs->work = &work[0];
   fs->lu_work = &work[SPIFFS_CFG_LOG_PAGE_SZ(fs)];
@@ -692,9 +695,10 @@ static s32_t spiffs_stat_pix(spiffs *fs, spiffs_page_ix pix, spiffs_file fh, spi
       obj_id_addr, sizeof(spiffs_obj_id), (u8_t *)&obj_id);
   SPIFFS_API_CHECK_RES(fs, res);
 
-  s->obj_id = obj_id;
+  s->obj_id = obj_id & ~SPIFFS_OBJ_ID_IX_FLAG;
   s->type = objix_hdr.type;
   s->size = objix_hdr.size == SPIFFS_UNDEFINED_LEN ? 0 : objix_hdr.size;
+  s->pix = pix;
   strncpy((char *)s->name, (char *)objix_hdr.name, SPIFFS_OBJ_NAME_LEN);
 
   return res;
@@ -1081,6 +1085,12 @@ s32_t SPIFFS_tell(spiffs *fs, spiffs_file fh) {
   return res;
 }
 
+s32_t SPIFFS_set_file_callback_func(spiffs *fs, spiffs_file_callback cb_func) {
+  SPIFFS_LOCK(fs);
+  fs->file_cb_f = cb_func;
+  SPIFFS_UNLOCK(fs);
+  return 0;
+}
 
 #if SPIFFS_TEST_VISUALISATION
 s32_t SPIFFS_vis(spiffs *fs) {

src/spiffs_nucleus.c

@@ -871,13 +871,13 @@ void spiffs_cb_object_event(
     spiffs *fs,
     spiffs_fd *fd,
     int ev,
-    spiffs_obj_id obj_id,
+    spiffs_obj_id obj_id_raw,
     spiffs_span_ix spix,
     spiffs_page_ix new_pix,
     u32_t new_size) {
   (void)fd;
   // update index caches in all file descriptors
-  obj_id &= ~SPIFFS_OBJ_ID_IX_FLAG;
+  spiffs_obj_id obj_id = obj_id_raw & ~SPIFFS_OBJ_ID_IX_FLAG;
   u32_t i;
   spiffs_fd *fds = (spiffs_fd *)fs->fd_space;
   for (i = 0; i < fs->fd_count; i++) {
@@ -904,6 +904,22 @@ void spiffs_cb_object_event(
       }
     }
   }
+
+  // callback to user if object index header
+  if (fs->file_cb_f && spix == 0 && (obj_id_raw & SPIFFS_OBJ_ID_IX_FLAG)) {
+    spiffs_fileop_type op;
+    if (ev == SPIFFS_EV_IX_NEW) {
+      op = SPIFFS_CB_CREATED;
+    } else if (ev == SPIFFS_EV_IX_UPD) {
+      op = SPIFFS_CB_UPDATED;
+    } else if (ev == SPIFFS_EV_IX_DEL) {
+      op = SPIFFS_CB_DELETED;
+    } else {
+      SPIFFS_DBG("       callback: WARNING unknown callback event %02x\n", ev);
+      return; // bail out
+    }
+    fs->file_cb_f(fs, op, obj_id, new_pix);
+  }
 }
 
 // Open object by id

src/test/test_hydrogen.c

@@ -546,6 +546,131 @@ TEST(open_by_page) {
 } TEST_END(open_by_page)
 
 
+static struct {
+  u32_t calls;
+  spiffs_fileop_type op;
+  spiffs_obj_id obj_id;
+  spiffs_page_ix pix;
+} ucb;
+
+void test_cb(spiffs *fs, spiffs_fileop_type op, spiffs_obj_id obj_id, spiffs_page_ix pix) {
+  ucb.calls++;
+  ucb.op = op;
+  ucb.obj_id = obj_id;
+  ucb.pix = pix;
+  //printf("%4i  op:%i objid:%04x pix:%04x\n", ucb.calls, ucb.op, ucb.obj_id, ucb.pix);
+}
+
+TEST(user_callback_basic) {
+  SPIFFS_set_file_callback_func(FS, test_cb);
+  int res;
+  memset(&ucb, 0, sizeof(ucb));
+  spiffs_file fd = SPIFFS_open(FS, "foo", SPIFFS_CREAT | SPIFFS_APPEND | SPIFFS_RDWR, 0);
+  TEST_CHECK_GE(fd, 0);
+  TEST_CHECK_EQ(ucb.calls, 1);
+  TEST_CHECK_EQ(ucb.op, SPIFFS_CB_CREATED);
+  spiffs_stat s;
+  res = SPIFFS_fstat(FS, fd, &s);
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.obj_id, s.obj_id);
+  TEST_CHECK_EQ(ucb.pix, s.pix);
+
+  res = SPIFFS_write(FS, fd, "howdy partner", 14);
+  TEST_CHECK_GE(res, 0);
+  res = SPIFFS_fflush(FS, fd);
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.calls, 2);
+  TEST_CHECK_EQ(ucb.op, SPIFFS_CB_UPDATED);
+  TEST_CHECK_EQ(ucb.obj_id, s.obj_id);
+  TEST_CHECK_EQ(ucb.pix, s.pix);
+
+  res = SPIFFS_fremove(FS, fd);
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.calls, 3);
+  TEST_CHECK_EQ(ucb.op, SPIFFS_CB_DELETED);
+  TEST_CHECK_EQ(ucb.obj_id, s.obj_id);
+  TEST_CHECK_EQ(ucb.pix, s.pix);
+
+  return TEST_RES_OK;
+} TEST_END(user_callback_basic)
+
+
+TEST(user_callback_gc) {
+  SPIFFS_set_file_callback_func(FS, test_cb);
+
+  char name[32];
+  int f;
+  int size = SPIFFS_DATA_PAGE_SIZE(FS);
+  int pages_per_block = SPIFFS_PAGES_PER_BLOCK(FS) - SPIFFS_OBJ_LOOKUP_PAGES(FS);
+  int files = (pages_per_block-1)/2;
+  int res;
+
+  // fill block with files
+  for (f = 0; f < files; f++) {
+    sprintf(name, "file%i", f);
+    res = test_create_and_write_file(name, size, 1);
+    TEST_CHECK(res >= 0);
+  }
+  for (f = 0; f < files; f++) {
+    sprintf(name, "file%i", f);
+    res = read_and_verify(name);
+    TEST_CHECK(res >= 0);
+  }
+  // remove all files in block
+  for (f = 0; f < files; f++) {
+    sprintf(name, "file%i", f);
+    res = SPIFFS_remove(FS, name);
+    TEST_CHECK(res >= 0);
+  }
+
+  memset(&ucb, 0, sizeof(ucb));
+  spiffs_file fd = SPIFFS_open(FS, "foo", SPIFFS_CREAT | SPIFFS_APPEND | SPIFFS_RDWR, 0);
+  TEST_CHECK_GE(fd, 0);
+  TEST_CHECK_EQ(ucb.calls, 1);
+  TEST_CHECK_EQ(ucb.op, SPIFFS_CB_CREATED);
+  spiffs_stat s;
+  res = SPIFFS_fstat(FS, fd, &s);
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.obj_id, s.obj_id);
+  TEST_CHECK_EQ(ucb.pix, s.pix);
+
+  res = SPIFFS_write(FS, fd, "howdy partner", 14);
+  TEST_CHECK_GE(res, 0);
+  res = SPIFFS_fflush(FS, fd);
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.calls, 2);
+  TEST_CHECK_EQ(ucb.op, SPIFFS_CB_UPDATED);
+  TEST_CHECK_EQ(ucb.obj_id, s.obj_id);
+  TEST_CHECK_EQ(ucb.pix, s.pix);
+
+  u32_t tot, us;
+  SPIFFS_info(FS, &tot, &us);
+
+  // do a hard gc, should move our file
+  res = SPIFFS_gc(FS, tot-us*2);
+  TEST_CHECK_GE(res, 0);
+
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.calls, 3);
+  TEST_CHECK_EQ(ucb.op, SPIFFS_CB_UPDATED);
+  TEST_CHECK_EQ(ucb.obj_id, s.obj_id);
+  TEST_CHECK_NEQ(ucb.pix, s.pix);
+
+  res = SPIFFS_fstat(FS, fd, &s);
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.pix, s.pix);
+
+  res = SPIFFS_fremove(FS, fd);
+  TEST_CHECK_GE(res, 0);
+  TEST_CHECK_EQ(ucb.calls, 4);
+  TEST_CHECK_EQ(ucb.op, SPIFFS_CB_DELETED);
+  TEST_CHECK_EQ(ucb.obj_id, s.obj_id);
+  TEST_CHECK_EQ(ucb.pix, s.pix);
+
+  return TEST_RES_OK;
+} TEST_END(user_callback_gc)
+
+
 TEST(rename) {
   int res;