static void
ngx_http_lua_timer_handler(ngx_event_t *ev)
{
    int                      n;
    lua_State               *L;
    ngx_int_t                rc;
    ngx_connection_t        *c = NULL;
    ngx_http_request_t      *r = NULL;
    ngx_http_lua_ctx_t      *ctx;
    ngx_http_cleanup_t      *cln;
    ngx_pool_cleanup_t      *pcln;

    ngx_http_lua_timer_ctx_t         tctx;
    ngx_http_lua_main_conf_t        *lmcf;
    ngx_http_core_loc_conf_t        *clcf;
    ngx_http_lua_timer_log_ctx_t    *logctx;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
                   "lua ngx.timer expired");

    ngx_memcpy(&tctx, ev->data, sizeof(ngx_http_lua_timer_ctx_t));
    ngx_free(ev);
    ev = NULL;

    lmcf = tctx.lmcf;

    lmcf->pending_timers--;

    if (lmcf->running_timers >= lmcf->max_running_timers) {
        ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
                      "%i lua_max_running_timers are not enough",
                      lmcf->max_running_timers);
        goto failed;
    }

    c = ngx_http_lua_create_fake_connection(tctx.pool);
    if (c == NULL) {
        goto failed;
    }

    logctx = ngx_palloc(c->pool, sizeof(ngx_http_lua_timer_log_ctx_t));
    if (logctx == NULL) {
        goto failed;
    }

    logctx->connection = c;

    c->log->handler = ngx_http_lua_log_timer_error;
    c->log->data = logctx;

    c->listening = tctx.listening;
    c->addr_text = tctx.client_addr_text;

    r = ngx_http_lua_create_fake_request(c);
    if (r == NULL) {
        goto failed;
    }

    r->main_conf = tctx.main_conf;
    r->srv_conf = tctx.srv_conf;
    r->loc_conf = tctx.loc_conf;

    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

#if defined(nginx_version) && nginx_version >= 1003014

    ngx_http_set_connection_log(r->connection, clcf->error_log);

#else

    c->log->file = clcf->error_log->file;

    if (!(c->log->log_level & NGX_LOG_DEBUG_CONNECTION)) {
        c->log->log_level = clcf->error_log->log_level;
    }

#endif

    dd("lmcf: %p", lmcf);

    ctx = ngx_http_lua_create_ctx(r);
    if (ctx == NULL) {
        goto failed;
    }

    if (tctx.vm_state) {
        ctx->vm_state = tctx.vm_state;

        pcln = ngx_pool_cleanup_add(r->pool, 0);
        if (pcln == NULL) {
            goto failed;
        }

        pcln->handler = ngx_http_lua_cleanup_vm;
        pcln->data = tctx.vm_state;
    }

    ctx->cur_co_ctx = &ctx->entry_co_ctx;

    L = ngx_http_lua_get_lua_vm(r, ctx);
//.........这里部分代码省略.........

static void
ngx_http_lua_socket_resolve_handler(ngx_resolver_ctx_t *ctx)
{
    ngx_http_request_t                  *r;
    ngx_connection_t                    *c;
    ngx_http_upstream_resolved_t        *ur;
    ngx_http_lua_ctx_t                  *lctx;
    lua_State                           *L;
    ngx_http_lua_socket_udp_upstream_t  *u;
    u_char                              *p;
    size_t                               len;
#if defined(nginx_version) && nginx_version >= 1005008
    socklen_t                            socklen;
    struct sockaddr                     *sockaddr;
#else
    struct sockaddr_in                  *sin;
#endif
    ngx_uint_t                           i;
    unsigned                             waiting;

    u = ctx->data;
    r = u->request;
    c = r->connection;
    ur = u->resolved;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "lua udp socket resolve handler");

    lctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
    if (lctx == NULL) {
        return;
    }

    lctx->cur_co_ctx = u->co_ctx;

    u->co_ctx->cleanup = NULL;

    L = lctx->cur_co_ctx->co;

    dd("setting socket_ready to 1");

    waiting = u->waiting;

    if (ctx->state) {
        ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                       "lua udp socket resolver error: %s (waiting: %d)",
                       ngx_resolver_strerror(ctx->state), (int) u->waiting);

        lua_pushnil(L);
        lua_pushlstring(L, (char *) ctx->name.data, ctx->name.len);
        lua_pushfstring(L, " could not be resolved (%d: %s)",
                        (int) ctx->state,
                        ngx_resolver_strerror(ctx->state));
        lua_concat(L, 2);

#if 1
        ngx_resolve_name_done(ctx);
        ur->ctx = NULL;
#endif

        u->prepare_retvals = ngx_http_lua_socket_error_retval_handler;
        ngx_http_lua_socket_udp_handle_error(r, u,
                                             NGX_HTTP_LUA_SOCKET_FT_RESOLVER);

        if (waiting) {
            ngx_http_run_posted_requests(c);
        }

        return;
    }

    ur->naddrs = ctx->naddrs;
    ur->addrs = ctx->addrs;

#if (NGX_DEBUG)
    {
#   if defined(nginx_version) && nginx_version >= 1005008
    u_char      text[NGX_SOCKADDR_STRLEN];
    ngx_str_t   addr;
#   else
    in_addr_t   addr;
#   endif
    ngx_uint_t  i;

#   if defined(nginx_version) && nginx_version >= 1005008
    addr.data = text;

    for (i = 0; i < ctx->naddrs; i++) {
        addr.len = ngx_sock_ntop(ur->addrs[i].sockaddr, ur->addrs[i].socklen,
                                 text, NGX_SOCKADDR_STRLEN, 0);

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "name was resolved to %V", &addr);
    }
#   else
    for (i = 0; i < ctx->naddrs; i++) {
        dd("addr i: %d %p", (int) i,  &ctx->addrs[i]);

        addr = ntohl(ctx->addrs[i]);

//.........这里部分代码省略.........

static int
ngx_http_lua_socket_udp_receive(lua_State *L)
{
    ngx_http_request_t                  *r;
    ngx_http_lua_socket_udp_upstream_t  *u;
    ngx_int_t                            rc;
    ngx_http_lua_ctx_t                  *ctx;
    ngx_http_lua_co_ctx_t               *coctx;
    size_t                               size;
    int                                  nargs;
    ngx_http_lua_loc_conf_t             *llcf;

    nargs = lua_gettop(L);
    if (nargs != 1 && nargs != 2) {
        return luaL_error(L, "expecting 1 or 2 arguments "
                          "(including the object), but got %d", nargs);
    }

    r = ngx_http_lua_get_req(L);
    if (r == NULL) {
        return luaL_error(L, "no request found");
    }

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua udp socket calling receive() method");

    luaL_checktype(L, 1, LUA_TTABLE);

    lua_rawgeti(L, 1, SOCKET_CTX_INDEX);
    u = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (u == NULL || u->udp_connection.connection == NULL) {
        llcf = ngx_http_get_module_loc_conf(r, ngx_http_lua_module);

        if (llcf->log_socket_errors) {
            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                          "attempt to receive data on a closed socket: u:%p, "
                          "c:%p", u, u ? u->udp_connection.connection : NULL);
        }

        lua_pushnil(L);
        lua_pushliteral(L, "closed");
        return 2;
    }

    if (u->request != r) {
        return luaL_error(L, "bad request");
    }

    if (u->ft_type) {
        u->ft_type = 0;
    }

#if 1
    if (u->waiting) {
        lua_pushnil(L);
        lua_pushliteral(L, "socket busy");
        return 2;
    }
#endif

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua udp socket read timeout: %M", u->read_timeout);

    size = (size_t) luaL_optnumber(L, 2, UDP_MAX_DATAGRAM_SIZE);
    size = ngx_min(size, UDP_MAX_DATAGRAM_SIZE);

    u->recv_buf_size = size;

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua udp socket receive buffer size: %uz", u->recv_buf_size);

    rc = ngx_http_lua_socket_udp_read(r, u);

    if (rc == NGX_ERROR) {
        dd("read failed: %d", (int) u->ft_type);
        rc = ngx_http_lua_socket_udp_receive_retval_handler(r, u, L);
        dd("udp receive retval returned: %d", (int) rc);
        return rc;
    }

    if (rc == NGX_OK) {

        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "lua udp socket receive done in a single run");

        return ngx_http_lua_socket_udp_receive_retval_handler(r, u, L);
    }

    /* n == NGX_AGAIN */

    u->read_event_handler = ngx_http_lua_socket_udp_read_handler;

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
    if (ctx == NULL) {
        return luaL_error(L, "no request ctx found");
    }

    coctx = ctx->cur_co_ctx;
//.........这里部分代码省略.........

static int
ngx_http_lua_ngx_req_set_body_file(lua_State *L)
{
    u_char                      *p;
    ngx_http_request_t          *r;
    int                          n;
    ngx_http_request_body_t     *rb;
    ngx_temp_file_t             *tf;
    ngx_buf_t                   *b;
    ngx_str_t                    name;
    ngx_int_t                    rc;
    int                          clean;
    ngx_open_file_info_t         of;
    ngx_str_t                    key, value;
    ngx_pool_cleanup_t          *cln;
    ngx_pool_cleanup_file_t     *clnf;
    ngx_err_t                    err;
    ngx_chain_t                 *cl;
    ngx_buf_tag_t                tag;

    n = lua_gettop(L);

    if (n != 1 && n != 2) {
        return luaL_error(L, "expecting 1 or 2 arguments but seen %d", n);
    }

    p = (u_char *) luaL_checklstring(L, 1, &name.len);

    lua_pushlightuserdata(L, &ngx_http_lua_request_key);
    lua_rawget(L, LUA_GLOBALSINDEX);
    r = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (r == NULL) {
        return luaL_error(L, "request object not found");
    }

    if (r->discard_body) {
        return luaL_error(L, "request body already discarded asynchronously");
    }

    if (r->request_body == NULL) {
        return luaL_error(L, "request body not read yet");
    }

    name.data = ngx_palloc(r->pool, name.len + 1);
    if (name.data == NULL) {
        return luaL_error(L, "out of memory");
    }

    ngx_memcpy(name.data, p, name.len);
    name.data[name.len] = '\0';

    if (n == 2) {
        luaL_checktype(L, 2, LUA_TBOOLEAN);
        clean = lua_toboolean(L, 2);

    } else {
        clean = 0;
    }

    dd("clean: %d", (int) clean);

    rb = r->request_body;

    /* clean up existing r->request_body->bufs (if any) */

    tag = (ngx_buf_tag_t) &ngx_http_lua_module;

    if (rb->bufs) {
        dd("XXX reusing buf");

        for (cl = rb->bufs; cl; cl = cl->next) {
            if (cl->buf->tag == tag && cl->buf->temporary) {
                dd("free old request body buffer: size:%d",
                   (int) ngx_buf_size(cl->buf));

                ngx_pfree(r->pool, cl->buf->start);
                cl->buf->tag = (ngx_buf_tag_t) NULL;
                cl->buf->temporary = 0;
            }
        }

        rb->bufs->next = NULL;
        b = rb->bufs->buf;

        ngx_memzero(b, sizeof(ngx_buf_t));

        b->tag = tag;

    } else {

        dd("XXX creating new buf");

        rb->bufs = ngx_alloc_chain_link(r->pool);
        if (rb->bufs == NULL) {
            return luaL_error(L, "out of memory");
        }
        rb->bufs->next = NULL;

//.........这里部分代码省略.........

/// Do one iteration.
bool LevenbergMarquardtMDMinimizer::iterate()
{
  const bool debug = getProperty("Debug");
  const double muMax = getProperty("MuMax");
  const double absError = getProperty("AbsError");

  if ( !m_leastSquares )
  {
    throw std::runtime_error("Cost function isn't set up.");
  }
  size_t n = m_leastSquares->nParams();

  if ( n == 0 )
  {
    m_errorString = "No parameters to fit.";
    g_log.warning() << m_errorString << std::endl;
    return false;
  }

  if ( m_mu > muMax )
  {
    //m_errorString = "Failed to converge, maximum mu reached";
    //g_log.warning() << m_errorString << std::endl;
    return false;
  }

  // calculate the first and second derivatives of the cost function.
  if (m_mu == 0.0)
  {// first time calculate everything
    m_F = m_leastSquares->valDerivHessian();
  }
  else if (m_rho > 0)
  {// last iteration was good: calculate new m_der and m_hessian, dont't recalculate m_F
    m_leastSquares->valDerivHessian(false);
  }
  // else if m_rho < 0 last iteration was bad: reuse m_der and m_hessian

  // Calculate damping to hessian
  if (m_mu == 0) // first iteration or accidental zero
  {
    m_mu = m_tau;
    m_nu = 2.0;
  }

  if (debug)
  {
    g_log.warning() << "===========================================================" << std::endl;
    g_log.warning() << "mu=" << m_mu << std::endl << std::endl;
  }

  if (m_D.empty())
  {
    m_D.resize(n);
  }

  // copy the hessian
  GSLMatrix H( m_leastSquares->getHessian() );
  GSLVector dd( m_leastSquares->getDeriv() );

  // scaling factors
  std::vector<double> sf(n);

  for(size_t i = 0; i < n; ++i)
  {
    double d = fabs(dd.get(i));
    if (m_D[i] > d) d = m_D[i];
    m_D[i] = d;
    double tmp = H.get(i,i) + m_mu * d;
    H.set(i,i,tmp);
    sf[i] = sqrt( tmp );
    if ( tmp == 0.0 )
    {
      m_errorString = "Singular matrix.";
      g_log.warning() << m_errorString << std::endl;
      return false;
    }
  }

  // apply scaling
  for(size_t i = 0; i < n; ++i)
  {
    double d = dd.get(i);
    dd.set( i, d / sf[i] );
    for(size_t j = i; j < n; ++j)
    {
      const double f = sf[i] * sf[j];
      double tmp = H.get(i,j);
      H.set(i,j,tmp/f);
      if ( i != j )
      {
        tmp = H.get(j,i);
        H.set(j,i,tmp/f);
      }
    }
  }

  if (debug && m_rho > 0)
  {
    g_log.warning() << "Hessian:\n" << H ;
//.........这里部分代码省略.........

static int
ngx_http_lua_ngx_req_set_body_data(lua_State *L)
{
    ngx_http_request_t          *r;
    int                          n;
    ngx_http_request_body_t     *rb;
    ngx_temp_file_t             *tf;
    ngx_buf_t                   *b;
    ngx_str_t                    body, key, value;
#if 1
    ngx_int_t                    rc;
#endif
    ngx_chain_t                 *cl;
    ngx_buf_tag_t                tag;

    n = lua_gettop(L);

    if (n != 1) {
        return luaL_error(L, "expecting 1 arguments but seen %d", n);
    }

    body.data = (u_char *) luaL_checklstring(L, 1, &body.len);

    lua_pushlightuserdata(L, &ngx_http_lua_request_key);
    lua_rawget(L, LUA_GLOBALSINDEX);
    r = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (r == NULL) {
        return luaL_error(L, "request object not found");
    }

    if (r->discard_body) {
        return luaL_error(L, "request body already discarded asynchronously");
    }

    if (r->request_body == NULL) {
        return luaL_error(L, "request body not read yet");
    }

    rb = r->request_body;

    tag = (ngx_buf_tag_t) &ngx_http_lua_module;

    tf = rb->temp_file;

    if (tf) {
        if (tf->file.fd != NGX_INVALID_FILE) {

            dd("cleaning temp file %.*s", (int) tf->file.name.len,
               tf->file.name.data);

            ngx_http_lua_pool_cleanup_file(r->pool, tf->file.fd);
            tf->file.fd = NGX_INVALID_FILE;

            dd("temp file cleaned: %.*s", (int) tf->file.name.len,
               tf->file.name.data);
        }

        rb->temp_file = NULL;
    }

    if (body.len == 0) {

        if (rb->bufs) {

            for (cl = rb->bufs; cl; cl = cl->next) {
                if (cl->buf->tag == tag && cl->buf->temporary) {

                    dd("free old request body buffer: size:%d",
                       (int) ngx_buf_size(cl->buf));

                    ngx_pfree(r->pool, cl->buf->start);
                    cl->buf->tag = (ngx_buf_tag_t) NULL;
                    cl->buf->temporary = 0;
                }
            }
        }

        rb->bufs = NULL;
        rb->buf = NULL;

        dd("request body is set to empty string");
        goto set_header;
    }

    if (rb->bufs) {

        for (cl = rb->bufs; cl; cl = cl->next) {
            if (cl->buf->tag == tag && cl->buf->temporary) {
                dd("free old request body buffer: size:%d",
                   (int) ngx_buf_size(cl->buf));

                ngx_pfree(r->pool, cl->buf->start);
                cl->buf->tag = (ngx_buf_tag_t) NULL;
                cl->buf->temporary = 0;
            }
        }

        rb->bufs->next = NULL;
//.........这里部分代码省略.........

static int
ngx_http_lua_ngx_req_read_body(lua_State *L)
{
    ngx_http_request_t          *r;
    int                          n;
    ngx_int_t                    rc;
    ngx_http_lua_ctx_t          *ctx;
    ngx_http_lua_co_ctx_t       *coctx;

    n = lua_gettop(L);

    if (n != 0) {
        return luaL_error(L, "expecting 0 arguments but seen %d", n);
    }

    lua_pushlightuserdata(L, &ngx_http_lua_request_key);
    lua_rawget(L, LUA_GLOBALSINDEX);
    r = lua_touserdata(L, -1);
    lua_pop(L, 1);

    if (r == NULL) {
        return luaL_error(L, "request object not found");
    }

    r->request_body_in_single_buf = 1;
    r->request_body_in_persistent_file = 1;
    r->request_body_in_clean_file = 1;

#if 1
    if (r->request_body_in_file_only) {
        r->request_body_file_log_level = 0;
    }
#endif

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
    if (ctx == NULL) {
        return luaL_error(L, "no ctx found");
    }

    ngx_http_lua_check_context(L, ctx, NGX_HTTP_LUA_CONTEXT_REWRITE
                               | NGX_HTTP_LUA_CONTEXT_ACCESS
                               | NGX_HTTP_LUA_CONTEXT_CONTENT);

    coctx = ctx->cur_co_ctx;
    if (coctx == NULL) {
        return luaL_error(L, "no co ctx found");
    }

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
            "lua start to read buffered request body");

    rc = ngx_http_read_client_request_body(r, ngx_http_lua_req_body_post_read);

#if (nginx_version < 1002006) ||                                             \
        (nginx_version >= 1003000 && nginx_version < 1003009)
    r->main->count--;
#endif

    if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
        ctx->exit_code = rc;
        ctx->exited = 1;

        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "http read client request body returned error code %i, "
                       "exitting now", rc);

        return lua_yield(L, 0);
    }

#if (nginx_version >= 1002006 && nginx_version < 1003000) ||                 \
        nginx_version >= 1003009
    r->main->count--;
    dd("decrement r->main->count: %d", (int) r->main->count);
#endif

    if (rc == NGX_AGAIN) {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                       "lua read buffered request body requires I/O "
                       "interruptions");

        ctx->waiting_more_body = 1;
        ctx->req_body_reader_co_ctx = coctx;

        coctx->cleanup = ngx_http_lua_req_body_cleanup;
        coctx->data = r;

        return lua_yield(L, 0);
    }

    /* rc == NGX_OK */

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua has read buffered request body in a single run");

    return 0;
}

uint32 urandweighted(size_t count, double const* chances)
{
    std::discrete_distribution<uint32> dd(chances, chances + count);
    return dd(SFMTEngine::Instance());
}

//.........这里部分代码省略.........
    sr_headers_len  = nsubreqs * sizeof(ngx_http_headers_out_t *);
    sr_bodies_len   = nsubreqs * sizeof(ngx_str_t);

    p = ngx_pcalloc(r->pool, sr_statuses_len + sr_headers_len +
            sr_bodies_len);

    if (p == NULL) {
        return luaL_error(L, "out of memory");
    }

    coctx->sr_statuses = (void *) p;
    p += sr_statuses_len;

    coctx->sr_headers = (void *) p;
    p += sr_headers_len;

    coctx->sr_bodies = (void *) p;

    coctx->nsubreqs = nsubreqs;

    coctx->done = 0;
    coctx->waiting = 0;

    extra_vars = NULL;

    for (index = 0; index < nsubreqs; index++) {
        coctx->waiting++;

        lua_rawgeti(L, 1, index + 1);
        if (lua_isnil(L, -1)) {
            return luaL_error(L, "only array-like tables are allowed");
        }

        dd("queries query: top %d", lua_gettop(L));

        if (lua_type(L, -1) != LUA_TTABLE) {
            return luaL_error(L, "the query argument %d is not a table, "
                    "but a %s",
                    index, lua_typename(L, lua_type(L, -1)));
        }

        nargs = lua_objlen(L, -1);

        if (nargs != 1 && nargs != 2) {
            return luaL_error(L, "query argument %d expecting one or "
                    "two arguments", index);
        }

        lua_rawgeti(L, 2, 1); /* queries query uri */

        dd("queries query uri: %d", lua_gettop(L));

        dd("first arg in first query: %s", lua_typename(L, lua_type(L, -1)));

        body = NULL;

        extra_args.data = NULL;
        extra_args.len = 0;

        if (extra_vars != NULL) {
            /* flush out existing elements in the array */
            extra_vars->nelts = 0;
        }

        vars_action = 0;

ngx_int_t
ngx_http_lua_rewrite_handler(ngx_http_request_t *r)
{
    ngx_http_lua_loc_conf_t     *llcf;
    ngx_http_lua_ctx_t          *ctx;
    ngx_int_t                    rc;
    ngx_http_lua_main_conf_t    *lmcf;

    /* XXX we need to take into account ngx_rewrite's location dump */
    if (r->uri_changed) {
        return NGX_DECLINED;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua rewrite handler, uri:\"%V\" c:%ud", &r->uri,
                   r->main->count);

    lmcf = ngx_http_get_module_main_conf(r, ngx_http_lua_module);

    if (!lmcf->postponed_to_rewrite_phase_end) {
        ngx_http_core_main_conf_t       *cmcf;
        ngx_http_phase_handler_t        tmp;
        ngx_http_phase_handler_t        *ph;
        ngx_http_phase_handler_t        *cur_ph;
        ngx_http_phase_handler_t        *last_ph;

        lmcf->postponed_to_rewrite_phase_end = 1;

        cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

        ph = cmcf->phase_engine.handlers;
        cur_ph = &ph[r->phase_handler];
        last_ph = &ph[cur_ph->next - 1];

#if 0
        if (cur_ph == last_ph) {
            dd("XXX our handler is already the last rewrite phase handler");
        }
#endif

        if (cur_ph < last_ph) {
            dd("swaping the contents of cur_ph and last_ph...");

            tmp      = *cur_ph;

            memmove(cur_ph, cur_ph + 1,
                (last_ph - cur_ph) * sizeof (ngx_http_phase_handler_t));

            *last_ph = tmp;

            r->phase_handler--; /* redo the current ph */

            return NGX_DECLINED;
        }
    }

    llcf = ngx_http_get_module_loc_conf(r, ngx_http_lua_module);

    if (llcf->rewrite_handler == NULL) {
        dd("no rewrite handler found");
        return NGX_DECLINED;
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);

    dd("ctx = %p", ctx);

    if (ctx == NULL) {
        ctx = ngx_http_lua_create_ctx(r);
        if (ctx == NULL) {
            return NGX_HTTP_INTERNAL_SERVER_ERROR;
        }
    }

    dd("entered? %d", (int) ctx->entered_rewrite_phase);

    if (ctx->entered_rewrite_phase) {
        dd("rewriteby: calling wev handler");
        rc = ctx->resume_handler(r);
        dd("rewriteby: wev handler returns %d", (int) rc);

        if (rc == NGX_OK) {
            rc = NGX_DECLINED;
        }

        if (rc == NGX_DECLINED) {
            if (r->header_sent) {
                dd("header already sent");

                /* response header was already generated in access_by_lua*,
                 * so it is no longer safe to proceed to later phases
                 * which may generate responses again */

                if (!ctx->eof) {
                    dd("eof not yet sent");

                    rc = ngx_http_lua_send_chain_link(r, ctx, NULL
                                                     /* indicate last_buf */);
                    if (rc == NGX_ERROR || rc > NGX_OK) {
                        return rc;
//.........这里部分代码省略.........

ngx_int_t
ngx_http_modsecurity_body_filter(ngx_http_request_t *r, ngx_chain_t *in)
{
    int buffer_fully_loadead = 0;
    ngx_chain_t *chain = in;
    ngx_http_modsecurity_ctx_t *ctx = NULL;
#ifdef MODSECURITY_SANITY_CHECKS
    ngx_list_part_t *part = &r->headers_out.headers.part;
    ngx_table_elt_t *data = part->elts;
    ngx_uint_t i = 0;
#endif

    if (in == NULL) {
        return ngx_http_next_body_filter(r, in);
    }

    ctx = ngx_http_get_module_ctx(r, ngx_http_modsecurity);

    dd("body filter, recovering ctx: %p", ctx);

    if (ctx == NULL) {
        return ngx_http_next_body_filter(r, in);
    }

#ifdef MODSECURITY_SANITY_CHECKS
#if 0
    dd("dumping stored ctx headers");
    for (i = 0; i < ctx->sanity_headers_out->nelts; i++)
    {
	ngx_http_modsecurity_header_t *vals = ctx->sanity_headers_out->elts;
	ngx_str_t *s2 = &vals[i].name, *s3 = &vals[i].value;
	dd(" dump[%d]: name = '%.*s', value = '%.*s'", (int)i,
		(int)s2->len, (char*)s2->data,
		(int)s3->len, (char*)s3->data);
    }
#endif
    /*
     * Identify if there is a header that was not inspected by ModSecurity.
     */
    int worth_to_fail = 0;

    for (i = 0; ; i++)
    {
        int found = 0;
        ngx_uint_t j = 0;
        ngx_table_elt_t *s1;
        ngx_http_modsecurity_header_t *vals;

        if (i >= part->nelts)
        {
            if (part->next == NULL) {
                break;
            }

            part = part->next;
            data = part->elts;
            i = 0;
        }

        vals = ctx->sanity_headers_out->elts;
        s1 = &data[i];

        /*
         * Headers that were inspected by ModSecurity.
         */
        while (j < ctx->sanity_headers_out->nelts)
        {
            ngx_str_t *s2 = &vals[j].name;
            ngx_str_t *s3 = &vals[j].value;

            if (s1->key.len == s2->len && ngx_strncmp(s1->key.data, s2->data, s1->key.len) == 0)
            {
                if (s1->value.len == s3->len && ngx_strncmp(s1->value.data, s3->data, s1->value.len) == 0)
                {
                    found = 1;
                    break;
                }
            }
            j++;
        }
        if (!found) {
            dd("header: `%.*s' with value: `%.*s' was not inspected by ModSecurity",
                (int) s1->key.len,
                (const char *) s1->key.data,
                (int) s1->value.len,
                (const char *) s1->value.data);
	    worth_to_fail++;
        }
    }

    if (worth_to_fail)
    {
        dd("%d header(s) were not inspected by ModSecurity, so exiting", worth_to_fail);
        return ngx_http_filter_finalize_request(r,
            &ngx_http_modsecurity, NGX_HTTP_INTERNAL_SERVER_ERROR);
    }
#endif

    for (; chain != NULL; chain = chain->next)
    {
//.........这里部分代码省略.........

static ngx_int_t
ngx_http_lua_rewrite_by_chunk(lua_State *L, ngx_http_request_t *r)
{
    int                      co_ref;
    lua_State               *co;
    ngx_int_t                rc;
    ngx_connection_t        *c;
    ngx_http_lua_ctx_t      *ctx;
    ngx_http_cleanup_t      *cln;

    ngx_http_lua_loc_conf_t     *llcf;

    /*  {{{ new coroutine to handle request */
    co = ngx_http_lua_new_thread(r, L, &co_ref);

    if (co == NULL) {
        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
                      "lua: failed to create new coroutine to handle request");

        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    /*  move code closure to new coroutine */
    lua_xmove(L, co, 1);

    /*  set closure's env table to new coroutine's globals table */
    ngx_http_lua_get_globals_table(co);
    lua_setfenv(co, -2);

    /*  save nginx request in coroutine globals table */
    ngx_http_lua_set_req(co, r);

    /*  {{{ initialize request context */
    ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);

    dd("ctx = %p", ctx);

    if (ctx == NULL) {
        return NGX_ERROR;
    }

    ngx_http_lua_reset_ctx(r, L, ctx);

    ctx->entered_rewrite_phase = 1;

    ctx->cur_co_ctx = &ctx->entry_co_ctx;
    ctx->cur_co_ctx->co = co;
    ctx->cur_co_ctx->co_ref = co_ref;
#ifdef NGX_LUA_USE_ASSERT
    ctx->cur_co_ctx->co_top = 1;
#endif

    /*  }}} */

    /*  {{{ register request cleanup hooks */
    if (ctx->cleanup == NULL) {
        cln = ngx_http_cleanup_add(r, 0);
        if (cln == NULL) {
            return NGX_HTTP_INTERNAL_SERVER_ERROR;
        }

        cln->handler = ngx_http_lua_request_cleanup_handler;
        cln->data = ctx;
        ctx->cleanup = &cln->handler;
    }
    /*  }}} */

    ctx->context = NGX_HTTP_LUA_CONTEXT_REWRITE;

    llcf = ngx_http_get_module_loc_conf(r, ngx_http_lua_module);

    if (llcf->check_client_abort) {
        r->read_event_handler = ngx_http_lua_rd_check_broken_connection;

    } else {
        r->read_event_handler = ngx_http_block_reading;
    }

    rc = ngx_http_lua_run_thread(L, r, ctx, 0);

    if (rc == NGX_ERROR || rc > NGX_OK) {
        return rc;
    }

    c = r->connection;

    if (rc == NGX_AGAIN) {
        rc = ngx_http_lua_run_posted_threads(c, L, r, ctx);

    } else if (rc == NGX_DONE) {
        ngx_http_lua_finalize_request(r, NGX_DONE);
        rc = ngx_http_lua_run_posted_threads(c, L, r, ctx);
    }

    if (rc == NGX_OK || rc == NGX_DECLINED) {
        if (r->header_sent) {
            dd("header already sent");

            /* response header was already generated in access_by_lua*,
             * so it is no longer safe to proceed to later phases
//.........这里部分代码省略.........

//.........这里部分代码省略.........
        }

        /* to work around the -1 check in ngx_worker_process_cycle: */
        lmcf->watcher->fd = (ngx_socket_t) -2;

        lmcf->watcher->idle = 1;
        lmcf->watcher->read->handler = ngx_http_lua_abort_pending_timers;
        lmcf->watcher->data = lmcf;
    }

    vm = ngx_http_lua_get_lua_vm(r, ctx);

    co = lua_newthread(vm);

    /* L stack: time func [args] thread */

    ngx_http_lua_probe_user_coroutine_create(r, L, co);

    lua_createtable(co, 0, 0);  /* the new globals table */

    /* co stack: global_tb */

    lua_createtable(co, 0, 1);  /* the metatable */
    ngx_http_lua_get_globals_table(co);
    lua_setfield(co, -2, "__index");
    lua_setmetatable(co, -2);

    /* co stack: global_tb */

    ngx_http_lua_set_globals_table(co);

    /* co stack: <empty> */

    dd("stack top: %d", lua_gettop(L));

    lua_xmove(vm, L, 1);    /* move coroutine from main thread to L */

    /* L stack: time func [args] thread */
    /* vm stack: empty */

    lua_pushvalue(L, 2);    /* copy entry function to top of L*/

    /* L stack: time func [args] thread func */

    lua_xmove(L, co, 1);    /* move entry function from L to co */

    /* L stack: time func [args] thread */
    /* co stack: func */

    ngx_http_lua_get_globals_table(co);
    lua_setfenv(co, -2);

    /* co stack: func */

    lua_pushlightuserdata(L, &ngx_http_lua_coroutines_key);
    lua_rawget(L, LUA_REGISTRYINDEX);

    /* L stack: time func [args] thread corountines */

    lua_pushvalue(L, -2);

    /* L stack: time func [args] thread coroutines thread */

    co_ref = luaL_ref(L, -2);
    lua_pop(L, 1);

static void
ngx_http_lua_abort_pending_timers(ngx_event_t *ev)
{
    ngx_int_t                    i, n;
    ngx_event_t                **events;
    ngx_connection_t            *c, *saved_c = NULL;
    ngx_rbtree_node_t           *cur, *prev, *next, *sentinel, *temp;
    ngx_http_lua_timer_ctx_t    *tctx;
    ngx_http_lua_main_conf_t    *lmcf;

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
                   "lua abort pending timers");

    c = ev->data;
    lmcf = c->data;

    dd("lua connection fd: %d", (int) c->fd);

    if (!c->close) {
        return;
    }

    c->read->closed = 1;
    c->write->closed = 1;

    /* we temporarily use a valid fd (0) to make ngx_free_connection happy */

    c->fd = 0;

    if (ngx_cycle->files) {
        saved_c = ngx_cycle->files[0];
    }

    ngx_free_connection(c);

    c->fd = (ngx_socket_t) -1;

    if (ngx_cycle->files) {
        ngx_cycle->files[0] = saved_c;
    }

    if (lmcf->pending_timers == 0) {
        return;
    }

    /* expire pending timers immediately */

    sentinel = ngx_event_timer_rbtree.sentinel;

    cur = ngx_event_timer_rbtree.root;

    /* XXX nginx does not guarentee the parent of root is meaningful,
     * so we temporarily override it to simplify tree traversal. */
    temp = cur->parent;
    cur->parent = NULL;

    prev = NULL;

    events = ngx_pcalloc(ngx_cycle->pool,
                         lmcf->pending_timers * sizeof(ngx_event_t));
    if (events == NULL) {
        return;
    }

    n = 0;

    dd("root: %p, root parent: %p, sentinel: %p", cur, cur->parent, sentinel);

    while (n < lmcf->pending_timers) {
        if  (cur == sentinel || cur == NULL) {
            ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0,
                          "lua pending timer counter got out of sync: %i",
                          lmcf->pending_timers);
            break;
        }

        dd("prev: %p, cur: %p, cur parent: %p, cur left: %p, cur right: %p",
           prev, cur, cur->parent, cur->left, cur->right);

        if (prev == cur->parent) {
            /* neither of the children has been accessed yet */

            next = cur->left;
            if (next == sentinel) {
                ev = (ngx_event_t *)
                    ((char *) cur - offsetof(ngx_event_t, timer));

                if (ev->handler == ngx_http_lua_timer_handler) {
                    dd("found node: %p", cur);
                    events[n++] = ev;
                }

                next = (cur->right != sentinel) ? cur->right : cur->parent;
            }

        } else if (prev == cur->left) {
            /* just accessed the left child */

            ev = (ngx_event_t *)
                ((char *) cur - offsetof(ngx_event_t, timer));
//.........这里部分代码省略.........

static ngx_int_t
ngx_http_srcache_fetch_subrequest(ngx_http_request_t *r,
        ngx_http_srcache_loc_conf_t *conf, ngx_http_srcache_ctx_t *ctx)
{
    ngx_http_srcache_ctx_t         *sr_ctx;
    ngx_http_post_subrequest_t     *psr;
    ngx_str_t                       args;
    ngx_uint_t                      flags = 0;
    ngx_http_request_t             *sr;
    ngx_int_t                       rc;

    ngx_http_srcache_parsed_request_t  *parsed_sr;

    dd_enter();

    parsed_sr = ngx_palloc(r->pool, sizeof(ngx_http_srcache_parsed_request_t));
    if (parsed_sr == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    parsed_sr->method      = conf->fetch->method;
    parsed_sr->method_name = conf->fetch->method_name;

    parsed_sr->request_body = NULL;
    parsed_sr->content_length_n = -1;

    if (ngx_http_complex_value(r, &conf->fetch->location,
                &parsed_sr->location) != NGX_OK)
    {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    if (parsed_sr->location.len == 0) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    if (ngx_http_complex_value(r, &conf->fetch->args, &parsed_sr->args)
            != NGX_OK)
    {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    args.data = NULL;
    args.len = 0;

    if (ngx_http_parse_unsafe_uri(r, &parsed_sr->location, &args, &flags)
            != NGX_OK) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    if (args.len > 0 && parsed_sr->args.len == 0) {
        parsed_sr->args = args;
    }

    sr_ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_srcache_ctx_t));
    if (sr_ctx == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    sr_ctx->in_fetch_subrequest = 1;

    psr = ngx_palloc(r->pool, sizeof(ngx_http_post_subrequest_t));
    if (psr == NULL) {
        return NGX_HTTP_INTERNAL_SERVER_ERROR;
    }

    psr->handler = ngx_http_srcache_fetch_post_subrequest;
    psr->data = sr_ctx;

    dd("firing the fetch subrequest");

    dd("fetch location: %.*s", (int) parsed_sr->location.len,
            parsed_sr->location.data);

    dd("fetch args: %.*s", (int) parsed_sr->args.len,
            parsed_sr->args.data);

    rc = ngx_http_subrequest(r, &parsed_sr->location, &parsed_sr->args,
            &sr, psr, flags);

    if (rc != NGX_OK) {
        return NGX_ERROR;
    }

    rc = ngx_http_srcache_adjust_subrequest(sr, parsed_sr);

    if (rc != NGX_OK) {
        return NGX_ERROR;
    }

    ngx_http_set_ctx(sr, sr_ctx, ngx_http_srcache_filter_module);

    ctx->fetch_sr = sr;

    return NGX_OK;
}

ngx_int_t
ngx_http_lua_post_subrequest(ngx_http_request_t *r, void *data, ngx_int_t rc)
{
    ngx_http_request_t            *pr;
    ngx_http_lua_ctx_t            *pr_ctx;
    ngx_http_lua_ctx_t            *ctx; /* subrequest ctx */
    ngx_http_lua_co_ctx_t         *pr_coctx;
    size_t                         len;
    ngx_str_t                     *body_str;
    u_char                        *p;
    ngx_chain_t                   *cl;

    ngx_http_lua_post_subrequest_data_t         *psr_data = data;

    ctx = psr_data->ctx;

    if (ctx->run_post_subrequest) {
        return NGX_OK;
    }

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "lua run post subrequest handler: rc:%d", rc);

    ctx->run_post_subrequest = 1;

    pr = r->parent;

    pr_ctx = ngx_http_get_module_ctx(pr, ngx_http_lua_module);
    if (pr_ctx == NULL) {
        return NGX_ERROR;
    }

    pr_coctx = psr_data->pr_co_ctx;

    pr_coctx->waiting--;

    if (pr_coctx->waiting == 0) {
        pr_coctx->done = 1;
    }

    if (pr_ctx->entered_content_phase) {
        ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                "lua restoring write event handler");

        pr->write_event_handler = ngx_http_lua_content_wev_handler;
    }

    dd("status rc = %d", (int) rc);
    dd("status headers_out.status = %d", (int) r->headers_out.status);
    dd("uri: %.*s", (int) r->uri.len, r->uri.data);

    /*  capture subrequest response status */
    if (rc == NGX_ERROR) {
        pr_coctx->sr_statuses[ctx->index] = NGX_HTTP_INTERNAL_SERVER_ERROR;

    } else if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
        pr_coctx->sr_statuses[ctx->index] = rc;

    } else {
        pr_coctx->sr_statuses[ctx->index] = r->headers_out.status;
    }

    if (pr_coctx->sr_statuses[ctx->index] == 0) {
        pr_coctx->sr_statuses[ctx->index] = NGX_HTTP_OK;
    }

    dd("pr_coctx status: %d", (int) pr_coctx->sr_statuses[ctx->index]);

    /* copy subrequest response headers */

    pr_coctx->sr_headers[ctx->index] = &r->headers_out;

    /* copy subrequest response body */

    body_str = &pr_coctx->sr_bodies[ctx->index];

    len = 0;
    for (cl = ctx->body; cl; cl = cl->next) {
        /*  ignore all non-memory buffers */
        len += cl->buf->last - cl->buf->pos;
    }

    body_str->len = len;

    if (len == 0) {
        body_str->data = NULL;

    } else {
        p = ngx_palloc(r->pool, len);
        if (p == NULL) {