exposed SPIFFS_open_by_page function

src/spiffs.h

@@ -49,6 +49,8 @@ extern "C" {
 
 #define SPIFFS_ERR_FILE_EXISTS          -10030
 
+#define SPIFFS_ERR_NOT_A_FILE           -10031
+
 #define SPIFFS_ERR_INTERNAL             -10050
 
 #define SPIFFS_ERR_TEST                 -10100
@@ -326,14 +328,13 @@ s32_t SPIFFS_creat(spiffs *fs, const char *path, spiffs_mode mode);
  */
 spiffs_file SPIFFS_open(spiffs *fs, const char *path, spiffs_flags flags, spiffs_mode mode);
 
-
 /**
  * Opens a file by given dir entry.
  * Optimization purposes, when traversing a file system with SPIFFS_readdir
  * a normal SPIFFS_open would need to traverse the filesystem again to find
  * the file, whilst SPIFFS_open_by_dirent already knows where the file resides.
  * @param fs            the file system struct
- * @param path          the dir entry to the file
+ * @param e             the dir entry to the file
  * @param flags         the flags for the open command, can be combinations of
  *                      SPIFFS_APPEND, SPIFFS_TRUNC, SPIFFS_CREAT, SPIFFS_RD_ONLY,
  *                      SPIFFS_WR_ONLY, SPIFFS_RDWR, SPIFFS_DIRECT.
@@ -342,6 +343,22 @@ spiffs_file SPIFFS_open(spiffs *fs, const char *path, spiffs_flags flags, spiffs
  */
 spiffs_file SPIFFS_open_by_dirent(spiffs *fs, struct spiffs_dirent *e, spiffs_flags flags, spiffs_mode mode);
 
+/**
+ * Opens a file by given page index.
+ * Optimization purposes, opens a file by directly pointing to the page
+ * index in the spi flash.
+ * If the page index does not point to a file header SPIFFS_ERR_NOT_A_FILE
+ * is returned.
+ * @param fs            the file system struct
+ * @param page_ix       the page index
+ * @param flags         the flags for the open command, can be combinations of
+ *                      SPIFFS_APPEND, SPIFFS_TRUNC, SPIFFS_CREAT, SPIFFS_RD_ONLY,
+ *                      SPIFFS_WR_ONLY, SPIFFS_RDWR, SPIFFS_DIRECT.
+ *                      SPIFFS_CREAT will have no effect in this case.
+ * @param mode          ignored, for posix compliance
+ */
+spiffs_file SPIFFS_open_by_page(spiffs *fs, spiffs_page_ix page_ix, spiffs_flags flags, spiffs_mode mode);
+
 /**
  * Reads from given filehandle.
  * @param fs            the file system struct

src/spiffs_hydrogen.c

@@ -280,6 +280,49 @@ spiffs_file SPIFFS_open_by_dirent(spiffs *fs, struct spiffs_dirent *e, spiffs_fl
   return SPIFFS_FH_OFFS(fs, fd->file_nbr);
 }
 
+spiffs_file SPIFFS_open_by_page(spiffs *fs, spiffs_page_ix page_ix, spiffs_flags flags, spiffs_mode mode) {
+  SPIFFS_API_CHECK_CFG(fs);
+  SPIFFS_API_CHECK_MOUNT(fs);
+  SPIFFS_LOCK(fs);
+
+  spiffs_fd *fd;
+
+  s32_t res = spiffs_fd_find_new(fs, &fd);
+  SPIFFS_API_CHECK_RES_UNLOCK(fs, res);
+
+  if (SPIFFS_IS_LOOKUP_PAGE(fs, page_ix)) {
+    res = SPIFFS_ERR_NOT_A_FILE;
+    spiffs_fd_return(fs, fd->file_nbr);
+    SPIFFS_API_CHECK_RES_UNLOCK(fs, res);
+  }
+
+  res = spiffs_object_open_by_page(fs, page_ix, fd, flags, mode);
+  if (res == SPIFFS_ERR_IS_FREE ||
+      res == SPIFFS_ERR_DELETED ||
+      res == SPIFFS_ERR_NOT_FINALIZED ||
+      res == SPIFFS_ERR_NOT_INDEX ||
+      res == SPIFFS_ERR_INDEX_SPAN_MISMATCH) {
+    res = SPIFFS_ERR_NOT_A_FILE;
+  }
+  if (res < SPIFFS_OK) {
+    spiffs_fd_return(fs, fd->file_nbr);
+  }
+  SPIFFS_API_CHECK_RES_UNLOCK(fs, res);
+  if (flags & SPIFFS_TRUNC) {
+    res = spiffs_object_truncate(fd, 0, 0);
+    if (res < SPIFFS_OK) {
+      spiffs_fd_return(fs, fd->file_nbr);
+    }
+    SPIFFS_API_CHECK_RES_UNLOCK(fs, res);
+  }
+
+  fd->fdoffset = 0;
+
+  SPIFFS_UNLOCK(fs);
+
+  return SPIFFS_FH_OFFS(fs, fd->file_nbr);
+}
+
 s32_t SPIFFS_read(spiffs *fs, spiffs_file fh, void *buf, s32_t len) {
   SPIFFS_API_CHECK_CFG(fs);
   SPIFFS_API_CHECK_MOUNT(fs);

src/test/test_hydrogen.c

@@ -359,6 +359,70 @@ TEST(open_by_dirent) {
 } TEST_END(open_by_dirent)
 
 
+TEST(open_by_page) {
+  int res;
+
+  char *files[4] = {
+      "file1",
+      "file2",
+      "file3",
+      "file4"
+  };
+  int file_cnt = sizeof(files)/sizeof(char *);
+
+  int i;
+  int size = SPIFFS_DATA_PAGE_SIZE(FS);
+
+  for (i = 0; i < file_cnt; i++) {
+    res = test_create_and_write_file(files[i], size, size);
+    TEST_CHECK(res >= 0);
+  }
+
+  spiffs_DIR d;
+  struct spiffs_dirent e;
+  struct spiffs_dirent *pe = &e;
+
+  int found = 0;
+  SPIFFS_opendir(FS, "/", &d);
+  while ((pe = SPIFFS_readdir(&d, pe))) {
+    spiffs_file fd = SPIFFS_open_by_dirent(FS, pe, SPIFFS_RDWR, 0);
+    TEST_CHECK(fd >= 0);
+    res = read_and_verify_fd(fd, pe->name);
+    TEST_CHECK(res == SPIFFS_OK);
+    fd = SPIFFS_open_by_page(FS, pe->pix, SPIFFS_RDWR, 0);
+    TEST_CHECK(fd >= 0);
+    res = SPIFFS_fremove(FS, fd);
+    TEST_CHECK(res == SPIFFS_OK);
+    SPIFFS_close(FS, fd);
+    found++;
+  }
+  SPIFFS_closedir(&d);
+
+  TEST_CHECK(found == file_cnt);
+
+  found = 0;
+  SPIFFS_opendir(FS, "/", &d);
+  while ((pe = SPIFFS_readdir(&d, pe))) {
+    found++;
+  }
+  SPIFFS_closedir(&d);
+
+  TEST_CHECK(found == 0);
+
+  spiffs_file fd;
+  // test opening a lookup page
+  fd = SPIFFS_open_by_page(FS, 0, SPIFFS_RDWR, 0);
+  TEST_CHECK_LT(fd, 0);
+  TEST_CHECK_EQ(SPIFFS_errno(FS), SPIFFS_ERR_NOT_A_FILE);
+  // test opening a proper page but not being object index
+  fd = SPIFFS_open_by_page(FS, SPIFFS_OBJ_LOOKUP_PAGES(FS)+1, SPIFFS_RDWR, 0);
+  TEST_CHECK_LT(fd, 0);
+  TEST_CHECK_EQ(SPIFFS_errno(FS), SPIFFS_ERR_NOT_A_FILE);
+
+  return TEST_RES_OK;
+} TEST_END(open_by_page)
+
+
 TEST(rename) {
   int res;