MINOR: htx: Store the head position instead of the wrap one
The head of an HTX message is heavily used whereas the wrap position is only
used when a block is added or removed. So it is more logical to store the head
position in the HTX message instead of the wrap one. The wrap position can be
easily deduced. To get it, the new function htx_get_wrap() may be used.
diff --git a/include/common/htx.h b/include/common/htx.h
index 78e62a5..003680a 100644
--- a/include/common/htx.h
+++ b/include/common/htx.h
@@ -152,8 +152,8 @@
uint32_t used; /* number of blocks in use */
uint32_t tail; /* last inserted block */
+ uint32_t head; /* older inserted block */
uint32_t front; /* block's position of the first content before the blocks table */
- uint32_t wrap; /* the position were the blocks table wraps, if any */
uint64_t extra; /* known bytes amount remaining to receive */
uint32_t flags; /* HTX_FL_* */
@@ -345,18 +345,30 @@
}
}
-/* Returns the position of the oldest entry (head).
+/* Returns the wrap position, ie the position where the blocks table wraps.
*
* An signed 32-bits integer is returned to handle -1 case. Blocks position are
* store on unsigned 32-bits integer, but it is impossible to have so much
* blocks to overflow a 32-bits signed integer !
*/
-static inline int32_t htx_get_head(const struct htx *htx)
+static inline int32_t htx_get_wrap(const struct htx *htx)
{
if (!htx->used)
return -1;
+ return ((htx->tail >= htx->head)
+ ? (htx->used + htx->head)
+ : (htx->used - 1) + (htx->head - htx->tail));
+}
- return (((htx->tail + 1U < htx->used) ? htx->wrap : 0) + htx->tail + 1U - htx->used);
+/* Returns the position of the oldest entry (head).
+ *
+ * An signed 32-bits integer is returned to handle -1 case. Blocks position are
+ * store on unsigned 32-bits integer, but it is impossible to have so much
+ * blocks to overflow a 32-bits signed integer !
+ */
+static inline int32_t htx_get_head(const struct htx *htx)
+{
+ return (htx->used ? htx->head : -1);
}
/* Returns the oldest HTX block (head) if the HTX message is not
@@ -424,8 +436,10 @@
head = htx_get_head(htx);
if (head == -1 || pos == head)
return -1;
- if (!pos)
- return (htx->wrap - 1);
+ if (!pos) {
+ /* htx_get_wrap() is always greater than 1 here */
+ return (htx_get_wrap(htx) - 1);
+ }
return (pos - 1);
}
@@ -450,14 +464,11 @@
*/
static inline int32_t htx_get_next(const struct htx *htx, uint32_t pos)
{
- if (!htx->used)
- return -1;
-
- if (pos == htx->tail)
+ if (!htx->used || pos == htx->tail)
return -1;
pos++;
- if (pos >= htx->wrap)
- pos = 0;
+ if (pos == htx_get_wrap(htx))
+ return 0;
return pos;
}
@@ -663,7 +674,7 @@
static inline void htx_reset(struct htx *htx)
{
- htx->data = htx->used = htx->tail = htx->wrap = htx->front = 0;
+ htx->data = htx->used = htx->tail = htx->head = htx->front = 0;
htx->extra = 0;
htx->flags = HTX_FL_NONE;
htx->sl_off = -1;
@@ -779,11 +790,10 @@
int32_t pos;
fprintf(stderr, "htx:%p [ size=%u - data=%u - used=%u - wrap=%s - extra=%llu]\n",
- htx, htx->size, htx->data, htx->used,
- (!htx->used || htx->tail+1 == htx->wrap) ? "NO" : "YES",
+ htx, htx->size, htx->data, htx->used, (htx->tail >= htx->head) ? "NO" : "YES",
(unsigned long long)htx->extra);
- fprintf(stderr, "\thead=%d - tail=%u - front=%u - wrap=%u\n",
- htx_get_head(htx), htx->tail, htx->front, htx->wrap);
+ fprintf(stderr, "\thead=%u, tail=%u - front=%u\n",
+ htx->head, htx->tail, htx->front);
for (pos = htx_get_head(htx); pos != -1; pos = htx_get_next(htx, pos)) {
struct htx_sl *sl;