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pbuf: Simplify pbuf_get_contiguous implementation

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Use pbuf_skip_const() to simplify the implementation.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
This commit is contained in:
Axel Lin 2017-10-27 11:37:29 +08:00 committed by Dirk Ziegelmeier
parent c1efb9e296
commit 41cf4012af
1 changed files with 15 additions and 15 deletions
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30
src/core/pbuf.c
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@ -110,6 +110,9 @@
volatile u8_t pbuf_free_ooseq_pending;
#define PBUF_POOL_IS_EMPTY() pbuf_pool_is_empty()
static const struct pbuf *
pbuf_skip_const(const struct pbuf *in, u16_t in_offset, u16_t *out_offset);
/**
* Attempt to reclaim some memory from queued out-of-sequence TCP segments
* if we run out of pool pbufs. It's better to give priority to new packets
@ -1071,27 +1074,24 @@ void *
pbuf_get_contiguous(const struct pbuf *p, void *buffer, size_t bufsize, u16_t len, u16_t offset)
{
const struct pbuf *q;
uint16_t out_offset;
LWIP_ERROR("pbuf_get_contiguous: invalid buf", (p != NULL), return NULL;);
LWIP_ERROR("pbuf_get_contiguous: invalid dataptr", (buffer != NULL), return NULL;);
LWIP_ERROR("pbuf_get_contiguous: invalid dataptr", (bufsize >= len), return NULL;);
for (q = p; q != NULL; q = q->next) {
if ((offset != 0) && (offset >= q->len)) {
/* don't copy from this buffer -> on to the next */
offset = (u16_t)(offset - q->len);
} else {
if (q->len >= (offset + len)) {
/* all data in this pbuf, return zero-copy */
return (u8_t *)q->payload + offset;
}
/* need to copy */
if (pbuf_copy_partial(q, buffer, len, offset) != len) {
/* copying failed: pbuf is too short */
return NULL;
}
return buffer;
q = pbuf_skip_const(p, offset, &out_offset);
if (q != NULL) {
if (q->len >= (out_offset + len)) {
/* all data in this pbuf, return zero-copy */
return (u8_t *)q->payload + out_offset;
}
/* need to copy */
if (pbuf_copy_partial(q, buffer, len, out_offset) != len) {
/* copying failed: pbuf is too short */
return NULL;
}
return buffer;
}
/* pbuf is too short (offset does not fit in) */
return NULL;