MINOR: hpack: optimize header encoding for short names
For unknown fields, since we know that most of them are less than 127
characters, we don't need to go through the loop and can instead directly
emit the one-byte length encoding. This increases the request rate by
approximately 0.5%.
diff --git a/src/hpack-enc.c b/src/hpack-enc.c
index 73a5fd1..dd0d0ab 100644
--- a/src/hpack-enc.c
+++ b/src/hpack-enc.c
@@ -114,6 +114,12 @@
out->area[len++] = 0x58; // literal with indexing -- name="cache-control" (idx 24)
else if (isteq(n, ist("content-length")))
out->area[len++] = 0x5c; // literal with indexing -- name="content-length" (idx 28)
+ else if (likely(n.len < 127 && len + 1 + n.len <= size)) {
+ out->area[len++] = 0x00; /* literal without indexing -- new name */
+ out->area[len++] = n.len; /* single-byte length encoding */
+ ist2bin(out->area + len, n);
+ len += n.len;
+ }
else if (len_to_bytes(n.len) && len + 1 + len_to_bytes(n.len) + n.len <= size) {
out->area[len++] = 0x00; /* literal without indexing -- new name */
len = hpack_encode_len(out->area, len, n.len);