Upstream: flush low-level buffers on write retry. If the data to write is bigger than what the socket can send, and the reminder is smaller than NGX_SSL_BUFSIZE, then SSL_write() fails with SSL_ERROR_WANT_WRITE. The reminder of payload however is successfully copied to the low-level buffer and all the output chain buffers are flushed. This means that retry logic doesn't work because ngx_http_upstream_process_non_buffered_request() checks only if there's anything in the output chain buffers and ignores the fact that something may be buffered in low-level parts of the stack. Signed-off-by: Patryk Lesiewicz <patryk@google.com>

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


/* 32-bit crc16 */

static ngx_inline uint32_t
ngx_crc(u_char *data, size_t len)
{
    uint32_t  sum;

    for (sum = 0; len; len--) {

        /*
         * gcc 2.95.2 x86 and icc 7.1.006 compile
         * that operator into the single "rol" opcode,
         * msvc 6.0sp2 compiles it into four opcodes.
         */
        sum = sum >> 1 | sum << 31;

        sum += *data++;
    }

    return sum;
}


#endif /* _NGX_CRC_H_INCLUDED_ */