MINOR: htx: Add function to drain data from an HTX message

The function htx_drain() can now be used to drain data from an HTX message.

It will be used by other commits to fix bugs, so it must be backported to 1.9.

diff --git a/include/common/htx.h b/include/common/htx.h
index 79a9a13..0eabf24 100644 (file)
--- a/include/common/htx.h
+++ b/include/common/htx.h
@@ -171,6 +171,7 @@ struct htx_blk *htx_defrag(struct htx *htx, struct htx_blk *blk);
 struct htx_blk *htx_add_blk(struct htx *htx, enum htx_blk_type type, uint32_t blksz);
 struct htx_blk *htx_remove_blk(struct htx *htx, struct htx_blk *blk);
 void htx_truncate(struct htx *htx, uint32_t offset);
+struct htx_ret htx_drain(struct htx *htx, uint32_t max);
 
 struct htx_blk *htx_replace_blk_value(struct htx *htx, struct htx_blk *blk,
                                      const struct ist old, const struct ist new);

diff --git a/src/htx.c b/src/htx.c
index 2837451..892bbd6 100644 (file)
--- a/src/htx.c
+++ b/src/htx.c
@@ -307,6 +307,43 @@ void htx_truncate(struct htx *htx, uint32_t offset)
                blk = htx_remove_blk(htx, blk);
 }
 
+/* Drain <count> bytes from the HTX message <htx>. DATA blocks will be cut if
+ * necessary. Others blocks will be removed at once if <count> is large
+ * enough. The function returns an htx_ret with the first block remaing in the
+ * messsage and the amount of data drained. If everything is removed,
+ * htx_ret.blk is set to NULL.
+ */
+struct htx_ret htx_drain(struct htx *htx, uint32_t count)
+{
+       struct htx_blk *blk;
+       struct htx_ret htxret = { .blk = NULL, .ret = 0 };
+
+       blk = htx_get_head_blk(htx);
+       while (count && blk) {
+               uint32_t sz = htx_get_blksz(blk);
+               enum htx_blk_type type = htx_get_blk_type(blk);
+
+               /* Ingore unused block */
+               if (type == HTX_BLK_UNUSED)
+                       goto next;
+
+               if (sz > count) {
+                       if (type == HTX_BLK_DATA) {
+                               htx_cut_data_blk(htx, blk, count);
+                               htxret.ret += count;
+                       }
+                       break;
+               }
+               count -= sz;
+               htxret.ret += sz;
+         next:
+               blk = htx_remove_blk(htx, blk);
+       }
+       htxret.blk = blk;
+
+       return htxret;
+}
+
 /* Tries to append data to the last inserted block, if the type matches and if
  * there is enough non-wrapping space. Only DATA and TRAILERS content can be
  * appended. If the append fails, a new block is inserted. If an error occurred,