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Diffstat (limited to 'lib/vio_fifo.h')
| -rw-r--r-- | lib/vio_fifo.h | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/lib/vio_fifo.h b/lib/vio_fifo.h new file mode 100644 index 00000000..52f3455e --- /dev/null +++ b/lib/vio_fifo.h @@ -0,0 +1,205 @@ +/* VTY I/O FIFO -- header + * Copyright (C) 2010 Chris Hall (GMCH), Highwayman + * + * This file is part of GNU Zebra. + * + * GNU Zebra is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2, or (at your + * option) any later version. + * + * GNU Zebra is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Zebra; see the file COPYING. If not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#ifndef _ZEBRA_VIO_FIFO_H +#define _ZEBRA_VIO_FIFO_H + +#include "zebra.h" +#include <stdint.h> +#include <stdbool.h> + +#include "list_util.h" +#include "zassert.h" + +#ifndef Inline /* in case of compiler issues */ +#define Inline static inline +#endif + +#ifndef Private /* extern, but for "friends" only */ +#define Private extern +#endif + +/* GCC have printf type attribute check. */ +#ifdef __GNUC__ +#define PRINTF_ATTRIBUTE(a,b) __attribute__ ((__format__ (__printf__, a, b))) +#else +#define PRINTF_ATTRIBUTE(a,b) +#endif /* __GNUC__ */ + +/*============================================================================== + * VTY I/O FIFO -- buffering of arbitrary amounts of I/O. + */ + +#ifdef NDEBUG +# define VIO_FIFO_DEBUG 0 /* NDEBUG override */ +#else +# ifndef VIO_FIFO_DEBUG +# define VIO_FIFO_DEBUG 1 /* Set to 1 to turn on debug checks */ +# endif +#endif + +/*============================================================================== + * Data Structures + */ +typedef struct vio_fifo vio_fifo_t ; +typedef struct vio_fifo* vio_fifo ; + +typedef struct vio_fifo_lump vio_fifo_lump_t ; +typedef struct vio_fifo_lump* vio_fifo_lump ; + +struct vio_fifo +{ + struct dl_base_pair(vio_fifo_lump) base ; + + bool one ; + + char* put_ptr ; + char* put_end ; + + char* get_ptr ; + char* get_end ; + + vio_fifo_lump rdr_lump ; + char* rdr_ptr ; + + size_t size ; + + vio_fifo_lump spare ; +} ; + +struct vio_fifo_lump +{ + struct dl_list_pair(vio_fifo_lump) list ; + + char* end ; /* end of this particular lump */ + size_t size ; /* size of lump when allocated */ + char data[] ; +} ; + +/*============================================================================== + * Functions + */ + +extern vio_fifo vio_fifo_init_new(vio_fifo vf, size_t size) ; +extern vio_fifo vio_fifo_reset(vio_fifo vf, int free_structure) ; + +#define vio_fifo_reset_keep(vf) vio_fifo_reset(vf, 0) +#define vio_fifo_reset_free(vf) vio_fifo_reset(vf, 1) + +extern void vio_fifo_clear(vio_fifo vf) ; +Inline bool vio_fifo_empty(vio_fifo vf) ; +extern size_t vio_fifo_room(vio_fifo vf) ; + +extern void vio_fifo_put(vio_fifo vf, const char* src, size_t n) ; +Inline void vio_fifo_put_byte(vio_fifo vf, char b) ; + +extern int vio_fifo_printf(vio_fifo vf, const char* format, ...) + PRINTF_ATTRIBUTE(2, 3) ; +extern int vio_fifo_vprintf(vio_fifo vf, const char *format, va_list args) ; + +extern size_t vio_fifo_get(vio_fifo vf, void* dst, size_t n) ; +Inline int vio_fifo_get_byte(vio_fifo vf) ; +extern void* vio_fifo_get_lump(vio_fifo vf, size_t* have) ; +extern void vio_fifo_got_upto(vio_fifo vf, void* here) ; + +Inline bool vio_fifo_full_lump(vio_fifo vf) ; +extern int vio_fifo_write_nb(vio_fifo vf, int fd, bool all) ; + +extern void* vio_fifo_get_rdr(vio_fifo vf, size_t* have) ; +extern void* vio_fifo_step_rdr(vio_fifo vf, size_t* have, size_t step) ; +extern void vio_fifo_sync_rdr(vio_fifo vf) ; +extern void vio_fifo_drop_rdr(vio_fifo vf) ; + +Private void vio_fifo_lump_new(vio_fifo vf, size_t size) ; +Private int vio_fifo_get_next_byte(vio_fifo vf) ; + +/*============================================================================== + * Debug -- verification function + */ + +Private void vio_fifo_verify(vio_fifo vf) ; + +#if VIO_FIFO_DEBUG +# define VIO_FIFO_DEBUG_VERIFY(vf) vio_fifo_verify(vf) +#else +# define VIO_FIFO_DEBUG_VERIFY(vf) +#endif + +/*============================================================================== + * Inline Functions + */ + +/*------------------------------------------------------------------------------ + * Returns true <=> FIFO is empty + */ +Inline bool +vio_fifo_empty(vio_fifo vf) +{ + return (vf->get_ptr == vf->put_ptr) ; +} + +/*------------------------------------------------------------------------------ + * Put one byte to the FIFO + */ +Inline void +vio_fifo_put_byte(vio_fifo vf, char b) +{ + if (vf->put_ptr >= vf->put_end) + vio_fifo_lump_new(vf, vf->size) ; /* traps put_ptr > put_end */ + + VIO_FIFO_DEBUG_VERIFY(vf) ; + + *vf->put_ptr++ = b ; +} ; + +/*------------------------------------------------------------------------------ + * Get one byte from the FIFO. + * + * Returns: 0x00..0xFF -- byte value (as an int) + * -1 => FIFO is empty. + */ +Inline int +vio_fifo_get_byte(vio_fifo vf) +{ + if (vf->get_end <= (vf->get_ptr + 1)) + return vio_fifo_get_next_byte(vf) ; + + VIO_FIFO_DEBUG_VERIFY(vf) ; + + return (unsigned char)*vf->get_ptr++ ; +} ; + +/*------------------------------------------------------------------------------ + * See if have at least one full lump. + * + * This may be used with vio_fifo_write_nb(..., false) to use FIFO as a sort of + * double buffer. + * + * Returns: true <=> there is at least one full lump in the FIFO + * (excluding the last lump if it happens to be full) + */ +Inline bool +vio_fifo_full_lump(vio_fifo vf) +{ + return (!vf->one && (vf->put_ptr != NULL)) ; +} ; + +#endif /* _ZEBRA_VIO_FIFO_H */ |