From 7c8b7aecc31439f071cb1f8f3d9baa0afea7d18e Mon Sep 17 00:00:00 2001
From: Kirill A. Korinskiy <catap@catap.ru>
Date: Tue, 21 Apr 2009 21:54:11 +0400
Subject: [PATCH] Implement $upstream_header_time
Cc: catap@catap.ru

---
 src/http/ngx_http_upstream.c |   99 ++++++++++++++++++++++++++++++++++++++++++
 src/http/ngx_http_upstream.h |    2 +
 2 files changed, 101 insertions(+), 0 deletions(-)

diff --git a/src/http/ngx_http_upstream.c b/src/http/ngx_http_upstream.c
index 7ae15cb..4ddc285 100644
--- a/src/http/ngx_http_upstream.c
+++ b/src/http/ngx_http_upstream.c
@@ -118,6 +118,8 @@ static ngx_int_t ngx_http_upstream_status_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_upstream_response_time_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data);
+static ngx_int_t ngx_http_upstream_header_time_variable(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data);
 static ngx_int_t ngx_http_upstream_response_length_variable(
     ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data);
 
@@ -328,6 +330,10 @@ static ngx_http_variable_t  ngx_http_upstream_vars[] = {
       ngx_http_upstream_response_time_variable, 0,
       NGX_HTTP_VAR_NOHASH|NGX_HTTP_VAR_NOCACHEABLE, 0 },
 
+    { ngx_string("upstream_header_time"), NULL,
+      ngx_http_upstream_header_time_variable, 0,
+      NGX_HTTP_VAR_NOHASH|NGX_HTTP_VAR_NOCACHEABLE, 0 },
+
     { ngx_string("upstream_response_length"), NULL,
       ngx_http_upstream_response_length_variable, 0,
       NGX_HTTP_VAR_NOHASH|NGX_HTTP_VAR_NOCACHEABLE, 0 },
@@ -930,6 +936,11 @@ ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u)
         u->state->response_msec = tp->msec - u->state->response_msec;
     }
 
+    if (u->state && u->state->header_sec) {
+        u->state->header_sec = tp->sec - u->state->header_sec;
+        u->state->header_msec = tp->msec - u->state->header_msec;
+    }
+
     u->state = ngx_array_push(r->upstream_states);
     if (u->state == NULL) {
         ngx_http_upstream_finalize_request(r, u,
@@ -942,6 +953,8 @@ ngx_http_upstream_connect(ngx_http_request_t *r, ngx_http_upstream_t *u)
     tp = ngx_timeofday();
     u->state->response_sec = tp->sec;
     u->state->response_msec = tp->msec;
+    u->state->header_sec = tp->sec;
+    u->state->header_msec = tp->msec;
 
     rc = ngx_event_connect_peer(&u->peer);
 
@@ -1843,10 +1856,17 @@ ngx_http_upstream_send_response(ngx_http_request_t *r, ngx_http_upstream_t *u)
     int                        tcp_nodelay;
     ssize_t                    n;
     ngx_int_t                  rc;
+    ngx_time_t                *tp;
     ngx_event_pipe_t          *p;
     ngx_connection_t          *c;
     ngx_http_core_loc_conf_t  *clcf;
 
+    if (u->state && u->state->header_sec) {
+        tp = ngx_timeofday();
+        u->state->header_sec = tp->sec - u->state->header_sec;
+        u->state->header_msec = tp->msec - u->state->header_msec;
+    }
+
     rc = ngx_http_send_header(r);
 
     if (rc == NGX_ERROR || rc > NGX_OK || r->post_action) {
@@ -2754,6 +2774,12 @@ ngx_http_upstream_finalize_request(ngx_http_request_t *r,
         }
     }
 
+    if (u->state && u->state->header_sec && !u->header_sent) {
+        tp = ngx_timeofday();
+        u->state->header_sec = tp->sec - u->state->header_sec;
+        u->state->header_msec = tp->msec - u->state->header_msec;
+    }
+
     u->finalize_request(r, rc);
 
     if (u->peer.free) {
@@ -3602,6 +3628,79 @@ ngx_http_upstream_response_time_variable(ngx_http_request_t *r,
 
 
 static ngx_int_t
+ngx_http_upstream_header_time_variable(ngx_http_request_t *r,
+    ngx_http_variable_value_t *v, uintptr_t data)
+{
+    u_char                     *p;
+    size_t                      len;
+    ngx_time_t                 *tp;
+    ngx_uint_t                  i;
+    ngx_msec_int_t              ms;
+    ngx_http_upstream_state_t  *state;
+
+    tp = ngx_timeofday();
+
+    v->valid = 1;
+    v->no_cacheable = 0;
+    v->not_found = 0;
+
+    if (r->upstream_states == NULL || r->upstream_states->nelts == 0) {
+        v->not_found = 1;
+        return NGX_OK;
+    }
+
+    len = r->upstream_states->nelts * (NGX_TIME_T_LEN + 4 + 2);
+
+    p = ngx_pnalloc(r->pool, len);
+    if (p == NULL) {
+        return NGX_ERROR;
+    }
+
+    v->data = p;
+
+    i = 0;
+    state = r->upstream_states->elts;
+
+    for ( ;; ) {
+        if (state[i].status) {
+
+            ms = (ngx_msec_int_t)
+		(state[i].header_sec * 1000 + state[i].header_msec);
+            ms = (ms >= 0) ? ms : 0;
+            p = ngx_sprintf(p, "%d.%03d", ms / 1000, ms % 1000);
+
+        } else {
+            *p++ = '-';
+        }
+
+        if (++i == r->upstream_states->nelts) {
+            break;
+        }
+
+        if (state[i].peer) {
+            *p++ = ',';
+            *p++ = ' ';
+
+        } else {
+            *p++ = ' ';
+            *p++ = ':';
+            *p++ = ' ';
+
+            if (++i == r->upstream_states->nelts) {
+                break;
+            }
+
+            continue;
+        }
+    }
+
+    v->len = p - v->data;
+
+    return NGX_OK;
+}
+
+
+static ngx_int_t
 ngx_http_upstream_response_length_variable(ngx_http_request_t *r,
     ngx_http_variable_value_t *v, uintptr_t data)
 {
diff --git a/src/http/ngx_http_upstream.h b/src/http/ngx_http_upstream.h
index ad08195..241fe88 100644
--- a/src/http/ngx_http_upstream.h
+++ b/src/http/ngx_http_upstream.h
@@ -43,6 +43,8 @@ typedef struct {
     ngx_uint_t                       bl_state;
 
     ngx_uint_t                       status;
+    time_t                           header_sec;
+    ngx_uint_t                       header_msec;
     time_t                           response_sec;
     ngx_uint_t                       response_msec;
     off_t                           response_length;
-- 
1.6.2