Mercurial > hg > nginx
view src/http/ngx_http_huff_encode.c @ 7993:96ae8e57b3dd
Avoid sending "Connection: keep-alive" when shutting down.
When a worker process is shutting down, keepalive is not used: this is checked
before the ngx_http_set_keepalive() call in ngx_http_finalize_connection().
Yet the "Connection: keep-alive" header was still sent, even if we know that
the worker process is shutting down, potentially resulting in additional
requests being sent to the connection which is going to be closed anyway.
While clients are expected to be able to handle asynchronous close events
(see ticket #1022), it is certainly possible to send the "Connection: close"
header instead, informing the client that the connection is going to be closed
and potentially saving some unneeded work.
With this change, we additionally check for worker process shutdown just
before sending response headers, and disable keepalive accordingly.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 11 Jan 2022 02:23:49 +0300 |
parents | 336084ff943b |
children |
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/* * Copyright (C) Nginx, Inc. * Copyright (C) Valentin V. Bartenev * Copyright (C) 2015 Vlad Krasnov */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { uint32_t code; uint32_t len; } ngx_http_huff_encode_code_t; static ngx_http_huff_encode_code_t ngx_http_huff_encode_table[256] = { {0x00001ff8, 13}, {0x007fffd8, 23}, {0x0fffffe2, 28}, {0x0fffffe3, 28}, {0x0fffffe4, 28}, {0x0fffffe5, 28}, {0x0fffffe6, 28}, {0x0fffffe7, 28}, {0x0fffffe8, 28}, {0x00ffffea, 24}, {0x3ffffffc, 30}, {0x0fffffe9, 28}, {0x0fffffea, 28}, {0x3ffffffd, 30}, {0x0fffffeb, 28}, {0x0fffffec, 28}, {0x0fffffed, 28}, {0x0fffffee, 28}, {0x0fffffef, 28}, {0x0ffffff0, 28}, {0x0ffffff1, 28}, {0x0ffffff2, 28}, {0x3ffffffe, 30}, {0x0ffffff3, 28}, {0x0ffffff4, 28}, {0x0ffffff5, 28}, {0x0ffffff6, 28}, {0x0ffffff7, 28}, {0x0ffffff8, 28}, {0x0ffffff9, 28}, {0x0ffffffa, 28}, {0x0ffffffb, 28}, {0x00000014, 6}, {0x000003f8, 10}, {0x000003f9, 10}, {0x00000ffa, 12}, {0x00001ff9, 13}, {0x00000015, 6}, {0x000000f8, 8}, {0x000007fa, 11}, {0x000003fa, 10}, {0x000003fb, 10}, {0x000000f9, 8}, {0x000007fb, 11}, {0x000000fa, 8}, {0x00000016, 6}, {0x00000017, 6}, {0x00000018, 6}, {0x00000000, 5}, {0x00000001, 5}, {0x00000002, 5}, {0x00000019, 6}, {0x0000001a, 6}, {0x0000001b, 6}, {0x0000001c, 6}, {0x0000001d, 6}, {0x0000001e, 6}, {0x0000001f, 6}, {0x0000005c, 7}, {0x000000fb, 8}, {0x00007ffc, 15}, {0x00000020, 6}, {0x00000ffb, 12}, {0x000003fc, 10}, {0x00001ffa, 13}, {0x00000021, 6}, {0x0000005d, 7}, {0x0000005e, 7}, {0x0000005f, 7}, {0x00000060, 7}, {0x00000061, 7}, {0x00000062, 7}, {0x00000063, 7}, {0x00000064, 7}, {0x00000065, 7}, {0x00000066, 7}, {0x00000067, 7}, {0x00000068, 7}, {0x00000069, 7}, {0x0000006a, 7}, {0x0000006b, 7}, {0x0000006c, 7}, {0x0000006d, 7}, {0x0000006e, 7}, {0x0000006f, 7}, {0x00000070, 7}, {0x00000071, 7}, {0x00000072, 7}, {0x000000fc, 8}, {0x00000073, 7}, {0x000000fd, 8}, {0x00001ffb, 13}, {0x0007fff0, 19}, {0x00001ffc, 13}, {0x00003ffc, 14}, {0x00000022, 6}, {0x00007ffd, 15}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00007ffe, 15}, {0x000007fc, 11}, {0x00003ffd, 14}, {0x00001ffd, 13}, {0x0ffffffc, 28}, {0x000fffe6, 20}, {0x003fffd2, 22}, {0x000fffe7, 20}, {0x000fffe8, 20}, {0x003fffd3, 22}, {0x003fffd4, 22}, {0x003fffd5, 22}, {0x007fffd9, 23}, {0x003fffd6, 22}, {0x007fffda, 23}, {0x007fffdb, 23}, {0x007fffdc, 23}, {0x007fffdd, 23}, {0x007fffde, 23}, {0x00ffffeb, 24}, {0x007fffdf, 23}, {0x00ffffec, 24}, {0x00ffffed, 24}, {0x003fffd7, 22}, {0x007fffe0, 23}, {0x00ffffee, 24}, {0x007fffe1, 23}, {0x007fffe2, 23}, {0x007fffe3, 23}, {0x007fffe4, 23}, {0x001fffdc, 21}, {0x003fffd8, 22}, {0x007fffe5, 23}, {0x003fffd9, 22}, {0x007fffe6, 23}, {0x007fffe7, 23}, {0x00ffffef, 24}, {0x003fffda, 22}, {0x001fffdd, 21}, {0x000fffe9, 20}, {0x003fffdb, 22}, {0x003fffdc, 22}, {0x007fffe8, 23}, {0x007fffe9, 23}, {0x001fffde, 21}, {0x007fffea, 23}, {0x003fffdd, 22}, {0x003fffde, 22}, {0x00fffff0, 24}, {0x001fffdf, 21}, {0x003fffdf, 22}, {0x007fffeb, 23}, {0x007fffec, 23}, {0x001fffe0, 21}, {0x001fffe1, 21}, {0x003fffe0, 22}, {0x001fffe2, 21}, {0x007fffed, 23}, {0x003fffe1, 22}, {0x007fffee, 23}, {0x007fffef, 23}, {0x000fffea, 20}, {0x003fffe2, 22}, {0x003fffe3, 22}, {0x003fffe4, 22}, {0x007ffff0, 23}, {0x003fffe5, 22}, {0x003fffe6, 22}, {0x007ffff1, 23}, {0x03ffffe0, 26}, {0x03ffffe1, 26}, {0x000fffeb, 20}, {0x0007fff1, 19}, {0x003fffe7, 22}, {0x007ffff2, 23}, {0x003fffe8, 22}, {0x01ffffec, 25}, {0x03ffffe2, 26}, {0x03ffffe3, 26}, {0x03ffffe4, 26}, {0x07ffffde, 27}, {0x07ffffdf, 27}, {0x03ffffe5, 26}, {0x00fffff1, 24}, {0x01ffffed, 25}, {0x0007fff2, 19}, {0x001fffe3, 21}, {0x03ffffe6, 26}, {0x07ffffe0, 27}, {0x07ffffe1, 27}, {0x03ffffe7, 26}, {0x07ffffe2, 27}, {0x00fffff2, 24}, {0x001fffe4, 21}, {0x001fffe5, 21}, {0x03ffffe8, 26}, {0x03ffffe9, 26}, {0x0ffffffd, 28}, {0x07ffffe3, 27}, {0x07ffffe4, 27}, {0x07ffffe5, 27}, {0x000fffec, 20}, {0x00fffff3, 24}, {0x000fffed, 20}, {0x001fffe6, 21}, {0x003fffe9, 22}, {0x001fffe7, 21}, {0x001fffe8, 21}, {0x007ffff3, 23}, {0x003fffea, 22}, {0x003fffeb, 22}, {0x01ffffee, 25}, {0x01ffffef, 25}, {0x00fffff4, 24}, {0x00fffff5, 24}, {0x03ffffea, 26}, {0x007ffff4, 23}, {0x03ffffeb, 26}, {0x07ffffe6, 27}, {0x03ffffec, 26}, {0x03ffffed, 26}, {0x07ffffe7, 27}, {0x07ffffe8, 27}, {0x07ffffe9, 27}, {0x07ffffea, 27}, {0x07ffffeb, 27}, {0x0ffffffe, 28}, {0x07ffffec, 27}, {0x07ffffed, 27}, {0x07ffffee, 27}, {0x07ffffef, 27}, {0x07fffff0, 27}, {0x03ffffee, 26} }; /* same as above, but embeds lowercase transformation */ static ngx_http_huff_encode_code_t ngx_http_huff_encode_table_lc[256] = { {0x00001ff8, 13}, {0x007fffd8, 23}, {0x0fffffe2, 28}, {0x0fffffe3, 28}, {0x0fffffe4, 28}, {0x0fffffe5, 28}, {0x0fffffe6, 28}, {0x0fffffe7, 28}, {0x0fffffe8, 28}, {0x00ffffea, 24}, {0x3ffffffc, 30}, {0x0fffffe9, 28}, {0x0fffffea, 28}, {0x3ffffffd, 30}, {0x0fffffeb, 28}, {0x0fffffec, 28}, {0x0fffffed, 28}, {0x0fffffee, 28}, {0x0fffffef, 28}, {0x0ffffff0, 28}, {0x0ffffff1, 28}, {0x0ffffff2, 28}, {0x3ffffffe, 30}, {0x0ffffff3, 28}, {0x0ffffff4, 28}, {0x0ffffff5, 28}, {0x0ffffff6, 28}, {0x0ffffff7, 28}, {0x0ffffff8, 28}, {0x0ffffff9, 28}, {0x0ffffffa, 28}, {0x0ffffffb, 28}, {0x00000014, 6}, {0x000003f8, 10}, {0x000003f9, 10}, {0x00000ffa, 12}, {0x00001ff9, 13}, {0x00000015, 6}, {0x000000f8, 8}, {0x000007fa, 11}, {0x000003fa, 10}, {0x000003fb, 10}, {0x000000f9, 8}, {0x000007fb, 11}, {0x000000fa, 8}, {0x00000016, 6}, {0x00000017, 6}, {0x00000018, 6}, {0x00000000, 5}, {0x00000001, 5}, {0x00000002, 5}, {0x00000019, 6}, {0x0000001a, 6}, {0x0000001b, 6}, {0x0000001c, 6}, {0x0000001d, 6}, {0x0000001e, 6}, {0x0000001f, 6}, {0x0000005c, 7}, {0x000000fb, 8}, {0x00007ffc, 15}, {0x00000020, 6}, {0x00000ffb, 12}, {0x000003fc, 10}, {0x00001ffa, 13}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00001ffb, 13}, {0x0007fff0, 19}, {0x00001ffc, 13}, {0x00003ffc, 14}, {0x00000022, 6}, {0x00007ffd, 15}, {0x00000003, 5}, {0x00000023, 6}, {0x00000004, 5}, {0x00000024, 6}, {0x00000005, 5}, {0x00000025, 6}, {0x00000026, 6}, {0x00000027, 6}, {0x00000006, 5}, {0x00000074, 7}, {0x00000075, 7}, {0x00000028, 6}, {0x00000029, 6}, {0x0000002a, 6}, {0x00000007, 5}, {0x0000002b, 6}, {0x00000076, 7}, {0x0000002c, 6}, {0x00000008, 5}, {0x00000009, 5}, {0x0000002d, 6}, {0x00000077, 7}, {0x00000078, 7}, {0x00000079, 7}, {0x0000007a, 7}, {0x0000007b, 7}, {0x00007ffe, 15}, {0x000007fc, 11}, {0x00003ffd, 14}, {0x00001ffd, 13}, {0x0ffffffc, 28}, {0x000fffe6, 20}, {0x003fffd2, 22}, {0x000fffe7, 20}, {0x000fffe8, 20}, {0x003fffd3, 22}, {0x003fffd4, 22}, {0x003fffd5, 22}, {0x007fffd9, 23}, {0x003fffd6, 22}, {0x007fffda, 23}, {0x007fffdb, 23}, {0x007fffdc, 23}, {0x007fffdd, 23}, {0x007fffde, 23}, {0x00ffffeb, 24}, {0x007fffdf, 23}, {0x00ffffec, 24}, {0x00ffffed, 24}, {0x003fffd7, 22}, {0x007fffe0, 23}, {0x00ffffee, 24}, {0x007fffe1, 23}, {0x007fffe2, 23}, {0x007fffe3, 23}, {0x007fffe4, 23}, {0x001fffdc, 21}, {0x003fffd8, 22}, {0x007fffe5, 23}, {0x003fffd9, 22}, {0x007fffe6, 23}, {0x007fffe7, 23}, {0x00ffffef, 24}, {0x003fffda, 22}, {0x001fffdd, 21}, {0x000fffe9, 20}, {0x003fffdb, 22}, {0x003fffdc, 22}, {0x007fffe8, 23}, {0x007fffe9, 23}, {0x001fffde, 21}, {0x007fffea, 23}, {0x003fffdd, 22}, {0x003fffde, 22}, {0x00fffff0, 24}, {0x001fffdf, 21}, {0x003fffdf, 22}, {0x007fffeb, 23}, {0x007fffec, 23}, {0x001fffe0, 21}, {0x001fffe1, 21}, {0x003fffe0, 22}, {0x001fffe2, 21}, {0x007fffed, 23}, {0x003fffe1, 22}, {0x007fffee, 23}, {0x007fffef, 23}, {0x000fffea, 20}, {0x003fffe2, 22}, {0x003fffe3, 22}, {0x003fffe4, 22}, {0x007ffff0, 23}, {0x003fffe5, 22}, {0x003fffe6, 22}, {0x007ffff1, 23}, {0x03ffffe0, 26}, {0x03ffffe1, 26}, {0x000fffeb, 20}, {0x0007fff1, 19}, {0x003fffe7, 22}, {0x007ffff2, 23}, {0x003fffe8, 22}, {0x01ffffec, 25}, {0x03ffffe2, 26}, {0x03ffffe3, 26}, {0x03ffffe4, 26}, {0x07ffffde, 27}, {0x07ffffdf, 27}, {0x03ffffe5, 26}, {0x00fffff1, 24}, {0x01ffffed, 25}, {0x0007fff2, 19}, {0x001fffe3, 21}, {0x03ffffe6, 26}, {0x07ffffe0, 27}, {0x07ffffe1, 27}, {0x03ffffe7, 26}, {0x07ffffe2, 27}, {0x00fffff2, 24}, {0x001fffe4, 21}, {0x001fffe5, 21}, {0x03ffffe8, 26}, {0x03ffffe9, 26}, {0x0ffffffd, 28}, {0x07ffffe3, 27}, {0x07ffffe4, 27}, {0x07ffffe5, 27}, {0x000fffec, 20}, {0x00fffff3, 24}, {0x000fffed, 20}, {0x001fffe6, 21}, {0x003fffe9, 22}, {0x001fffe7, 21}, {0x001fffe8, 21}, {0x007ffff3, 23}, {0x003fffea, 22}, {0x003fffeb, 22}, {0x01ffffee, 25}, {0x01ffffef, 25}, {0x00fffff4, 24}, {0x00fffff5, 24}, {0x03ffffea, 26}, {0x007ffff4, 23}, {0x03ffffeb, 26}, {0x07ffffe6, 27}, {0x03ffffec, 26}, {0x03ffffed, 26}, {0x07ffffe7, 27}, {0x07ffffe8, 27}, {0x07ffffe9, 27}, {0x07ffffea, 27}, {0x07ffffeb, 27}, {0x0ffffffe, 28}, {0x07ffffec, 27}, {0x07ffffed, 27}, {0x07ffffee, 27}, {0x07ffffef, 27}, {0x07fffff0, 27}, {0x03ffffee, 26} }; #if (NGX_PTR_SIZE == 8) #if (NGX_HAVE_LITTLE_ENDIAN) #if (NGX_HAVE_GCC_BSWAP64) #define ngx_http_huff_encode_buf(dst, buf) \ (*(uint64_t *) (dst) = __builtin_bswap64(buf)) #else #define ngx_http_huff_encode_buf(dst, buf) \ ((dst)[0] = (u_char) ((buf) >> 56), \ (dst)[1] = (u_char) ((buf) >> 48), \ (dst)[2] = (u_char) ((buf) >> 40), \ (dst)[3] = (u_char) ((buf) >> 32), \ (dst)[4] = (u_char) ((buf) >> 24), \ (dst)[5] = (u_char) ((buf) >> 16), \ (dst)[6] = (u_char) ((buf) >> 8), \ (dst)[7] = (u_char) (buf)) #endif #else /* !NGX_HAVE_LITTLE_ENDIAN */ #define ngx_http_huff_encode_buf(dst, buf) \ (*(uint64_t *) (dst) = (buf)) #endif #else /* NGX_PTR_SIZE == 4 */ #define ngx_http_huff_encode_buf(dst, buf) \ (*(uint32_t *) (dst) = htonl(buf)) #endif size_t ngx_http_huff_encode(u_char *src, size_t len, u_char *dst, ngx_uint_t lower) { u_char *end; size_t hlen; ngx_uint_t buf, pending, code; ngx_http_huff_encode_code_t *table, *next; table = lower ? ngx_http_huff_encode_table_lc : ngx_http_huff_encode_table; hlen = 0; buf = 0; pending = 0; end = src + len; while (src != end) { next = &table[*src++]; code = next->code; pending += next->len; /* accumulate bits */ if (pending < sizeof(buf) * 8) { buf |= code << (sizeof(buf) * 8 - pending); continue; } if (hlen + sizeof(buf) >= len) { return 0; } pending -= sizeof(buf) * 8; buf |= code >> pending; ngx_http_huff_encode_buf(&dst[hlen], buf); hlen += sizeof(buf); buf = pending ? code << (sizeof(buf) * 8 - pending) : 0; } if (pending == 0) { return hlen; } buf |= (ngx_uint_t) -1 >> pending; pending = ngx_align(pending, 8); if (hlen + pending / 8 >= len) { return 0; } buf >>= sizeof(buf) * 8 - pending; do { pending -= 8; dst[hlen++] = (u_char) (buf >> pending); } while (pending); return hlen; }