From: Christopher Faulet <cfaulet@haproxy.com>
Date: Wed, 12 Jun 2019 09:28:11 +0000 (+0200)
Subject: MINOR: htx: Use an array of char to store HTX blocks
X-Git-Tag: v2.1-dev2~379
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2bf43f074669367515d438d0e399a5c826588bbf;p=thirdparty%2Fhaproxy.git

MINOR: htx: Use an array of char to store HTX blocks

Instead of using a array of (struct block), it is more natural and intuitive to
use an array of char. Indeed, not only (struct block) are stored in this array,
but also their payload.
---

diff --git a/include/common/htx.h b/include/common/htx.h
index 3c9aa68ad2..1b67c21396 100644
--- a/include/common/htx.h
+++ b/include/common/htx.h
@@ -216,7 +216,7 @@ struct htx {
 	/* XXX 4 bytes unused */
 
 	/* Blocks representing the HTTP message itself */
-	struct htx_blk blocks[0] __attribute__((aligned(8)));
+	char blocks[0] __attribute__((aligned(8)));
 };
 
 
@@ -329,23 +329,23 @@ static inline struct ist htx_sl_res_reason(const struct htx_sl *sl)
 }
 
 /* Converts a position to the corresponding relative address */
-static inline uint32_t htx_pos_to_idx(const struct htx *htx, uint32_t pos)
+static inline uint32_t htx_pos_to_addr(const struct htx *htx, uint32_t pos)
 {
-	return ((htx->size / sizeof(htx->blocks[0])) - pos - 1);
+	return htx->size - (pos + 1) * sizeof(struct htx_blk);
 }
 
 /* Returns the position of the block <blk>. It is the caller responsibility to
  * be sure <blk> is part of <htx>. */
 static inline uint32_t htx_get_blk_pos(const struct htx *htx, const struct htx_blk *blk)
 {
-	return (htx->blocks + (htx->size / sizeof(htx->blocks[0])) - blk - 1);
+	return ((htx->blocks + htx->size - (char *)blk) / sizeof(struct htx_blk) - 1);
 }
 
 /* Returns the block at the position <pos>. It is the caller responsibility to
  * be sure the block at the position <pos> exists. */
 static inline struct htx_blk *htx_get_blk(const struct htx *htx, uint32_t pos)
 {
-	return ((struct htx_blk *)(htx->blocks) + htx_pos_to_idx(htx, pos));
+	return (struct htx_blk *)(htx->blocks + htx_pos_to_addr(htx, pos));
 }
 
 /* Returns the type of the block <blk> */
@@ -635,7 +635,7 @@ static inline uint32_t htx_meta_space(const struct htx *htx)
 	if (htx->tail == -1)
 		return 0;
 
-	return ((htx->tail + 1 - htx->head) * sizeof(htx->blocks[0]));
+	return ((htx->tail + 1 - htx->head) * sizeof(struct htx_blk));
 }
 
 /* Returns the space used (payload + metadata) in <htx> */
@@ -657,9 +657,9 @@ static inline uint32_t htx_free_data_space(const struct htx *htx)
 {
 	uint32_t free = htx_free_space(htx);
 
-	if (free < sizeof(htx->blocks[0]))
+	if (free < sizeof(struct htx_blk))
 		return 0;
-	return (free - sizeof(htx->blocks[0]));
+	return (free - sizeof(struct htx_blk));
 }
 
 /* Returns the maximum size for a block, not exceeding <max> bytes. <max> may be
@@ -671,9 +671,9 @@ static inline uint32_t htx_get_max_blksz(const struct htx *htx, int32_t max)
 
 	if (max != -1 && free > max)
 		free = max;
-	if (free < sizeof(htx->blocks[0]))
+	if (free < sizeof(struct htx_blk))
 		return 0;
-	return (free - sizeof(htx->blocks[0]));
+	return (free - sizeof(struct htx_blk));
 }
 
 /* Returns 1 if the message has less than 1/4 of its capacity free, otherwise 0 */
diff --git a/src/htx.c b/src/htx.c
index bbf1f8fc1d..93acbaaae5 100644
--- a/src/htx.c
+++ b/src/htx.c
@@ -137,12 +137,12 @@ static struct htx_blk *htx_reserve_nxblk(struct htx *htx, uint32_t blksz)
 	 * message.
 	 */
 	tail = htx->tail + 1;
-	if (sizeof(htx->blocks[0]) * htx_pos_to_idx(htx, tail) >= htx->tail_addr)
+	if (htx_pos_to_addr(htx, tail) >= htx->tail_addr)
 		;
 	else if (htx->head > 0) {
 		htx_defrag_blks(htx);
 		tail = htx->tail + 1;
-		BUG_ON(sizeof(htx->blocks[0]) * htx_pos_to_idx(htx, tail) < htx->tail_addr);
+		BUG_ON(htx_pos_to_addr(htx, tail) < htx->tail_addr);
 	}
 	else
 		goto defrag;
@@ -157,9 +157,7 @@ static struct htx_blk *htx_reserve_nxblk(struct htx *htx, uint32_t blksz)
          *     used, the other one is never used again, until the next defrag.
 	 */
 	headroom = (htx->end_addr - htx->head_addr);
-	tailroom = (!htx->head_addr
-		    ? sizeof(htx->blocks[0]) * htx_pos_to_idx(htx, tail) - htx->tail_addr
-		    : 0);
+	tailroom = (!htx->head_addr ? htx_pos_to_addr(htx, tail) - htx->tail_addr : 0);
 	BUG_ON((int32_t)headroom < 0);
 	BUG_ON((int32_t)tailroom < 0);
 
@@ -223,7 +221,7 @@ static int htx_prepare_blk_expansion(struct htx *htx, struct htx_blk *blk, int32
 	BUG_ON(htx->head == -1);
 
 	headroom = (htx->end_addr - htx->head_addr);
-	tailroom = sizeof(htx->blocks[0]) * htx_pos_to_idx(htx, htx->tail) - htx->tail_addr;
+	tailroom = (htx_pos_to_addr(htx, htx->tail) - htx->tail_addr);
 	BUG_ON((int32_t)headroom < 0);
 	BUG_ON((int32_t)tailroom < 0);
 
@@ -492,7 +490,7 @@ struct htx_blk *htx_add_data_atonce(struct htx *htx, struct ist data)
 	 * Same type and enough space: append data
 	 */
 	headroom = (htx->end_addr - htx->head_addr);
-	tailroom = sizeof(htx->blocks[0]) * htx_pos_to_idx(htx, htx->tail) - htx->tail_addr;
+	tailroom = (htx_pos_to_addr(htx, htx->tail) - htx->tail_addr);
 	BUG_ON((int32_t)headroom < 0);
 	BUG_ON((int32_t)tailroom < 0);
 
@@ -952,7 +950,7 @@ size_t htx_add_data(struct htx *htx, const struct ist data)
 	if (!htx->head_addr) {
 		if (tailblk->addr+sz != htx->tail_addr)
 			goto add_new_block;
-		room = sizeof(htx->blocks[0]) * htx_pos_to_idx(htx, htx->tail) - htx->tail_addr;
+		room = (htx_pos_to_addr(htx, htx->tail) - htx->tail_addr);
 	}
 	else {
 		if (tailblk->addr+sz != htx->head_addr)