Fijxu
/
nginx-quic
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

QUIC: unroll and inline ngx_quic_varint_len()/ngx_quic_build_int(). 

According to profiling, those two are among most frequently called,
so inlining is generally useful, and unrolling should help with it.
Further, this fixes undefined behaviour seen with invalid values.

Inspired by Yu Liu.
This commit is contained in:
Sergey Kandaurov 2021-05-22 18:40:45 +03:00
parent 69441d941a
commit ee4e5edf35
1 changed files with 39 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
src/event/quic/ngx_event_quic_transport.c
View File

@ -66,6 +66,9 @@
#define ngx_quic_write_uint32_aligned(p, s) \
(*(uint32_t *) (p) = htonl((uint32_t) (s)), (p) + sizeof(uint32_t))
#define ngx_quic_build_int_set(p, value, len, bits) \
(*(p)++ = ((value >> ((len) * 8)) & 0xff) | ((bits) << 6))
#define NGX_QUIC_VERSION(c) (0xff000000 + (c))
@ -244,40 +247,56 @@ ngx_quic_copy_bytes(u_char *pos, u_char *end, size_t len, u_char *dst)
}
static ngx_uint_t
static ngx_inline ngx_uint_t
ngx_quic_varint_len(uint64_t value)
{
ngx_uint_t bits;
bits = 0;
while (value >> ((8 << bits) - 2)) {
bits++;
if (value < (1 << 6)) {
return 1;
}
return 1 << bits;
if (value < (1 << 14)) {
return 2;
}
if (value < (1 << 30)) {
return 4;
}
return 8;
}
static void
static ngx_inline void
ngx_quic_build_int(u_char **pos, uint64_t value)
{
u_char *p;
ngx_uint_t bits, len;
u_char *p;
p = *pos;
bits = 0;
while (value >> ((8 << bits) - 2)) {
bits++;
if (value < (1 << 6)) {
ngx_quic_build_int_set(p, value, 0, 0);
} else if (value < (1 << 14)) {
ngx_quic_build_int_set(p, value, 1, 1);
ngx_quic_build_int_set(p, value, 0, 0);
} else if (value < (1 << 30)) {
ngx_quic_build_int_set(p, value, 3, 2);
ngx_quic_build_int_set(p, value, 2, 0);
ngx_quic_build_int_set(p, value, 1, 0);
ngx_quic_build_int_set(p, value, 0, 0);
} else {
ngx_quic_build_int_set(p, value, 7, 3);
ngx_quic_build_int_set(p, value, 6, 0);
ngx_quic_build_int_set(p, value, 5, 0);
ngx_quic_build_int_set(p, value, 4, 0);
ngx_quic_build_int_set(p, value, 3, 0);
ngx_quic_build_int_set(p, value, 2, 0);
ngx_quic_build_int_set(p, value, 1, 0);
ngx_quic_build_int_set(p, value, 0, 0);
}
len = (1 << bits);
while (len--) {
*p++ = value >> (len * 8);
}
**pos |= bits << 6;
*pos = p;
}