TARFS File API: tarf_open(), tarf_close(), tarf_read(), tarf_pread(), tarf_lseek(), tarf_mmap(), tarf_munmap(), tarf_dupfd(), tarf_stat(), tarf_fstat(), tarf_fcntl(), tarf_ioctl(). More...

#include <file.h>

Data Fields
uintptr_t	fp_vaddr
uint32_t	fp_pos
size_t	fp_size
int	fp_idx

Detailed Description

TARFS File API: tarf_open(), tarf_close(), tarf_read(), tarf_pread(), tarf_lseek(), tarf_mmap(), tarf_munmap(), tarf_dupfd(), tarf_stat(), tarf_fstat(), tarf_fcntl(), tarf_ioctl().

tarf_dupfd() is similar to POSIX dup(), except that the duplicated file descriptor does not share its file position with the original. Instead, a completely independent copy of the file descriptor is created.

How it works: open() uses inode_lookup() to find the requested inode, allocates a file descriptor structure, initializes it from the inode, and increments the filesystem reference count.

close() decrements the filesystem reference count.

read() and pread() are implemented as simple memcpy() operations.

Functions that operate on a file descriptor rely on the open()/close() reference-counting protocol. The filesystem reference is acquired by open() and released by close(), guaranteeing that the filesystem remains valid for the lifetime of every open file descriptor. This internal file descriptor maps to a local fd number as descriptor_ptr = s_tarfs[slot]->fs_fds[local_fd];

TARFS file descriptor, 16 bytes

Definition at line 63 of file file.h.

Field Documentation

◆ fp_idx

int tarfs_fp::fp_idx

associated inode index

Definition at line 68 of file file.h.

Referenced by tard_fdopendir(), tarf_fstat(), and tarf_open().

◆ fp_pos

uint32_t tarfs_fp::fp_pos

current file pointer position. can be set 1 byte past the file end, i.e. fp_pos = fp_size

Definition at line 66 of file file.h.

Referenced by tarf_ioctl(), tarf_lseek(), tarf_open(), tarf_read(), and tarf_sendfile().

◆ fp_size

size_t tarfs_fp::fp_size

file size in bytes. NOTE: If fp_size is 0, then fp_vaddr could be invalid and must not be read

Definition at line 67 of file file.h.

Referenced by tarf_fstat(), tarf_ioctl(), tarf_lseek(), tarf_mmap(), tarf_open(), tarf_pread(), and tarf_sendfile().

◆ fp_vaddr

uintptr_t tarfs_fp::fp_vaddr

file virtual address, absolute. zero indicates unused fd.

Definition at line 65 of file file.h.

Referenced by tarf_mmap(), tarf_open(), tarf_pread(), and tarf_sendfile().

The documentation for this struct was generated from the following file:

/cygdrive/d/Arduino/libraries/tarfs/src/file.h