[Tarantool-patches] [PATCH 1/4] xrow: rework coio_read_xrow to keep parsed input
Serge Petrenko
sergepetrenko at tarantool.org
Mon Dec 6 06:05:59 MSK 2021
Here's the corresponding change in libsmall:
Subject: [PATCH] ibuf: introduce xpos field
ibuf->xpos is the pointer to the not-yet-parsed input, so that
rpos <= xpos <= wpos. This is useful when the user processes input in
multiple stages, and needs the input data for a longer period of time than
just "until the data is read".
---
https://github.com/tarantool/small/tree/sp/ibuf-xpos
include/small/ibuf.h | 10 +++++++++-
small/ibuf.c | 4 +++-
2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/include/small/ibuf.h b/include/small/ibuf.h
index 00d7781..a6646b5 100644
--- a/include/small/ibuf.h
+++ b/include/small/ibuf.h
@@ -61,6 +61,8 @@ struct ibuf
char *buf;
/** Start of input. */
char *rpos;
+ /** End of parsed input. */
+ char *xpos;
/** End of useful input */
char *wpos;
/** End of buffer. */
@@ -100,6 +102,12 @@ ibuf_capacity(struct ibuf *ibuf)
return ibuf->end - ibuf->buf;
}
+static inline size_t
+ibuf_unparsed(struct ibuf *ibuf)
+{
+ return ibuf->wpos - ibuf->xpos;
+}
+
/**
* Integer value of the position in the buffer - stable
* in case of realloc.
@@ -115,7 +123,7 @@ ibuf_pos(struct ibuf *ibuf)
static inline void
ibuf_reset(struct ibuf *ibuf)
{
- ibuf->rpos = ibuf->wpos = ibuf->buf;
+ ibuf->rpos = ibuf->xpos = ibuf->wpos = ibuf->buf;
}
void *
diff --git a/small/ibuf.c b/small/ibuf.c
index fe3f441..85345f4 100644
--- a/small/ibuf.c
+++ b/small/ibuf.c
@@ -37,7 +37,7 @@ void
ibuf_create(struct ibuf *ibuf, struct slab_cache *slabc, size_t
start_capacity)
{
ibuf->slabc = slabc;
- ibuf->buf = ibuf->rpos = ibuf->wpos = ibuf->end = NULL;
+ ibuf->buf = ibuf->rpos = ibuf->xpos = ibuf->wpos = ibuf->end = NULL;
ibuf->start_capacity = start_capacity;
/* Don't allocate the buffer yet. */
}
@@ -99,7 +99,9 @@ ibuf_reserve_slow(struct ibuf *ibuf, size_t size)
ibuf->buf = ptr;
ibuf->end = ibuf->buf + slab_capacity(slab);
}
+ size_t xsize = ibuf->xpos - ibuf->rpos;
ibuf->rpos = ibuf->buf;
+ ibuf->xpos = ibuf->rpos + xsize;
ibuf->wpos = ibuf->rpos + used;
return ibuf->wpos;
}
--
2.30.1 (Apple Git-130)
--
Serge Petrenko
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