MEDIUM: htx: make htx_add_data() never defragment the buffer
Now instead of trying to fit 100% of the input data into the output
buffer at the risk of defragmenting it, we put what fits into it only
and return the amount of bytes transferred. In a test, compared to the
previous commit, it increases the cached data rate from 44 Gbps to
55 Gbps and saves a lot in case of large buffers : with a 1 MB buffer,
uncached transfers jumped from 700 Mbps to 30 Gbps.
diff --git a/src/htx.c b/src/htx.c
index 32e23d1..9281eba 100644
--- a/src/htx.c
+++ b/src/htx.c
@@ -763,13 +763,69 @@
*/
size_t htx_add_data(struct htx *htx, const struct ist data)
{
- struct htx_blk *blk;
+ struct htx_blk *blk, *tailblk, *headblk, *frtblk;
+ struct ist v;
+ int32_t room;
+ int32_t len = data.len;
- blk = htx_add_data_atonce(htx, data);
- if (blk)
- return data.len;
+ if (!htx->used)
+ goto add_new_block;
+
+ /* Not enough space to store data */
+ if (len > htx_free_data_space(htx))
+ len = htx_free_data_space(htx);
+
+ if (!len)
+ return 0;
+
+ /* get the tail and head block */
+ tailblk = htx_get_tail_blk(htx);
+ headblk = htx_get_head_blk(htx);
+ if (tailblk == NULL || headblk == NULL)
+ goto add_new_block;
+
+ /* Don't try to append data if the last inserted block is not of the
+ * same type */
+ if (htx_get_blk_type(tailblk) != HTX_BLK_DATA)
+ goto add_new_block;
+
+ /*
+ * Same type and enough space: append data
+ */
+ frtblk = htx_get_blk(htx, htx->front);
+ if (tailblk->addr >= headblk->addr) {
+ if (htx->tail != htx->front)
+ goto add_new_block;
+ room = sizeof(htx->blocks[0]) * htx_pos_to_idx(htx, htx->tail) - (frtblk->addr + htx_get_blksz(frtblk));
+ }
else
+ room = headblk->addr - (tailblk->addr + htx_get_blksz(tailblk));
+
+ if (room < len)
+ len = room;
+
+ append_data:
+ /* get the value of the tail block */
+ /* FIXME: check v.len + len < 256MB */
+ v = htx_get_blk_value(htx, tailblk);
+
+ /* Append data and update the block itself */
+ memcpy(v.ptr + v.len, data.ptr, len);
+ htx_set_blk_value_len(tailblk, v.len + len);
+
+ /* Update HTTP message */
+ htx->data += len;
+ return len;
+
+ add_new_block:
+ /* FIXME: check tlr.len (< 256MB) */
+ blk = htx_add_blk(htx, HTX_BLK_DATA, len);
+ if (!blk)
return 0;
+
+ blk->info += len;
+ memcpy(htx_get_blk_ptr(htx, blk), data.ptr, len);
+ return len;
}
/* Adds an HTX block of type TLR in <htx>. It returns the new block on