diff options
Diffstat (limited to 'src/shared/ring.c')
| -rw-r--r-- | src/shared/ring.c | 209 |
1 files changed, 0 insertions, 209 deletions
diff --git a/src/shared/ring.c b/src/shared/ring.c deleted file mode 100644 index 6814918464..0000000000 --- a/src/shared/ring.c +++ /dev/null @@ -1,209 +0,0 @@ -/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ - -/*** - This file is part of systemd. - - Copyright 2014 David Herrmann <dh.herrmann@gmail.com> - - systemd is free software; you can redistribute it and/or modify it - under the terms of the GNU Lesser General Public License as published by - the Free Software Foundation; either version 2.1 of the License, or - (at your option) any later version. - - systemd 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 - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public License - along with systemd; If not, see <http://www.gnu.org/licenses/>. -***/ - -#include <errno.h> -#include <stdlib.h> -#include <string.h> -#include <sys/uio.h> -#include "macro.h" -#include "ring.h" - -#define RING_MASK(_r, _v) ((_v) & ((_r)->size - 1)) - -void ring_flush(Ring *r) { - assert(r); - - r->start = 0; - r->used = 0; -} - -void ring_clear(Ring *r) { - assert(r); - - free(r->buf); - zero(*r); -} - -/* - * Get data pointers for current ring-buffer data. @vec must be an array of 2 - * iovec objects. They are filled according to the data available in the - * ring-buffer. 0, 1 or 2 is returned according to the number of iovec objects - * that were filled (0 meaning buffer is empty). - * - * Hint: "struct iovec" is defined in <sys/uio.h> and looks like this: - * struct iovec { - * void *iov_base; - * size_t iov_len; - * }; - */ -size_t ring_peek(Ring *r, struct iovec *vec) { - assert(r); - - if (r->used == 0) { - return 0; - } else if (r->start + r->used <= r->size) { - if (vec) { - vec[0].iov_base = &r->buf[r->start]; - vec[0].iov_len = r->used; - } - return 1; - } else { - if (vec) { - vec[0].iov_base = &r->buf[r->start]; - vec[0].iov_len = r->size - r->start; - vec[1].iov_base = r->buf; - vec[1].iov_len = r->used - (r->size - r->start); - } - return 2; - } -} - -/* - * Copy data from the ring buffer into the linear external buffer @buf. Copy - * at most @size bytes. If the ring buffer size is smaller, copy less bytes and - * return the number of bytes copied. - */ -size_t ring_copy(Ring *r, void *buf, size_t size) { - size_t l; - - assert(r); - assert(buf); - - if (size > r->used) - size = r->used; - - if (size > 0) { - l = r->size - r->start; - if (size <= l) { - memcpy(buf, &r->buf[r->start], size); - } else { - memcpy(buf, &r->buf[r->start], l); - memcpy((uint8_t*)buf + l, r->buf, size - l); - } - } - - return size; -} - -/* - * Resize ring-buffer to size @nsize. @nsize must be a power-of-2, otherwise - * ring operations will behave incorrectly. - */ -static int ring_resize(Ring *r, size_t nsize) { - uint8_t *buf; - size_t l; - - assert(r); - assert(nsize > 0); - - buf = malloc(nsize); - if (!buf) - return -ENOMEM; - - if (r->used > 0) { - l = r->size - r->start; - if (r->used <= l) { - memcpy(buf, &r->buf[r->start], r->used); - } else { - memcpy(buf, &r->buf[r->start], l); - memcpy(&buf[l], r->buf, r->used - l); - } - } - - free(r->buf); - r->buf = buf; - r->size = nsize; - r->start = 0; - - return 0; -} - -/* - * Resize ring-buffer to provide enough room for @add bytes of new data. This - * resizes the buffer if it is too small. It returns -ENOMEM on OOM and 0 on - * success. - */ -static int ring_grow(Ring *r, size_t add) { - size_t need; - - assert(r); - - if (r->size - r->used >= add) - return 0; - - need = r->used + add; - if (need <= r->used) - return -ENOMEM; - else if (need < 4096) - need = 4096; - - need = ALIGN_POWER2(need); - if (need == 0) - return -ENOMEM; - - return ring_resize(r, need); -} - -/* - * Push @len bytes from @u8 into the ring buffer. The buffer is resized if it - * is too small. -ENOMEM is returned on OOM, 0 on success. - */ -int ring_push(Ring *r, const void *u8, size_t size) { - int err; - size_t pos, l; - - assert(r); - assert(u8); - - if (size == 0) - return 0; - - err = ring_grow(r, size); - if (err < 0) - return err; - - pos = RING_MASK(r, r->start + r->used); - l = r->size - pos; - if (l >= size) { - memcpy(&r->buf[pos], u8, size); - } else { - memcpy(&r->buf[pos], u8, l); - memcpy(r->buf, (const uint8_t*)u8 + l, size - l); - } - - r->used += size; - - return 0; -} - -/* - * Remove @len bytes from the start of the ring-buffer. Note that we protect - * against overflows so removing more bytes than available is safe. - */ -void ring_pull(Ring *r, size_t size) { - assert(r); - - if (size > r->used) - size = r->used; - - r->start = RING_MASK(r, r->start + size); - r->used -= size; -} |