From 673941f81dfc724f9d98d1d1c0e50c8e08e3e327 Mon Sep 17 00:00:00 2001
From: Ruslan Ermilov <ru@nginx.com>
Date: Tue, 21 Apr 2015 19:09:04 +0300
Subject: [PATCH] Upstream: simplified ip_hash and hash peer selection code.

Now that peers are stored as a list, the weighted and unweighted
cases became nearly identical.
---
 .../modules/ngx_http_upstream_hash_module.c   | 30 +++++--------------
 .../ngx_http_upstream_ip_hash_module.c        | 28 +++++------------
 src/stream/ngx_stream_upstream_hash_module.c  | 30 +++++--------------
 3 files changed, 23 insertions(+), 65 deletions(-)

diff --git a/src/http/modules/ngx_http_upstream_hash_module.c b/src/http/modules/ngx_http_upstream_hash_module.c
index 56ec38ae0..e3dd0b6a5 100644
--- a/src/http/modules/ngx_http_upstream_hash_module.c
+++ b/src/http/modules/ngx_http_upstream_hash_module.c
@@ -170,7 +170,7 @@ ngx_http_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data)
     uint32_t                      hash;
     ngx_int_t                     w;
     uintptr_t                     m;
-    ngx_uint_t                    i, n, p;
+    ngx_uint_t                    n, p;
     ngx_http_upstream_rr_peer_t  *peer;
 
     ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0,
@@ -211,28 +211,14 @@ ngx_http_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data)
         hp->hash += hash;
         hp->rehash++;
 
-        if (!hp->rrp.peers->weighted) {
-            p = hp->hash % hp->rrp.peers->number;
+        w = hp->hash % hp->rrp.peers->total_weight;
+        peer = hp->rrp.peers->peer;
+        p = 0;
 
-            peer = hp->rrp.peers->peer;
-            for (i = 0; i < p; i++) {
-                peer = peer->next;
-            }
-
-        } else {
-            w = hp->hash % hp->rrp.peers->total_weight;
-
-            for (peer = hp->rrp.peers->peer, i = 0;
-                 peer;
-                 peer = peer->next, i++)
-            {
-                w -= peer->weight;
-                if (w < 0) {
-                    break;
-                }
-            }
-
-            p = i;
+        while (w >= peer->weight) {
+            w -= peer->weight;
+            peer = peer->next;
+            p++;
         }
 
         n = p / (8 * sizeof(uintptr_t));
diff --git a/src/http/modules/ngx_http_upstream_ip_hash_module.c b/src/http/modules/ngx_http_upstream_ip_hash_module.c
index d1d71e478..401b58e5c 100644
--- a/src/http/modules/ngx_http_upstream_ip_hash_module.c
+++ b/src/http/modules/ngx_http_upstream_ip_hash_module.c
@@ -181,28 +181,14 @@ ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data)
             hash = (hash * 113 + iphp->addr[i]) % 6271;
         }
 
-        if (!iphp->rrp.peers->weighted) {
-            p = hash % iphp->rrp.peers->number;
+        w = hash % iphp->rrp.peers->total_weight;
+        peer = iphp->rrp.peers->peer;
+        p = 0;
 
-            peer = iphp->rrp.peers->peer;
-            for (i = 0; i < p; i++) {
-                peer = peer->next;
-            }
-
-        } else {
-            w = hash % iphp->rrp.peers->total_weight;
-
-            for (peer = iphp->rrp.peers->peer, i = 0;
-                 peer;
-                 peer = peer->next, i++)
-            {
-                w -= peer->weight;
-                if (w < 0) {
-                    break;
-                }
-            }
-
-            p = i;
+        while (w >= peer->weight) {
+            w -= peer->weight;
+            peer = peer->next;
+            p++;
         }
 
         n = p / (8 * sizeof(uintptr_t));
diff --git a/src/stream/ngx_stream_upstream_hash_module.c b/src/stream/ngx_stream_upstream_hash_module.c
index aa68cad97..14f50222d 100644
--- a/src/stream/ngx_stream_upstream_hash_module.c
+++ b/src/stream/ngx_stream_upstream_hash_module.c
@@ -164,7 +164,7 @@ ngx_stream_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data)
     uint32_t                        hash;
     ngx_int_t                       w;
     uintptr_t                       m;
-    ngx_uint_t                      i, n, p;
+    ngx_uint_t                      n, p;
     ngx_stream_upstream_rr_peer_t  *peer;
 
     ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0,
@@ -204,28 +204,14 @@ ngx_stream_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data)
         hp->hash += hash;
         hp->rehash++;
 
-        if (!hp->rrp.peers->weighted) {
-            p = hp->hash % hp->rrp.peers->number;
+        w = hp->hash % hp->rrp.peers->total_weight;
+        peer = hp->rrp.peers->peer;
+        p = 0;
 
-            peer = hp->rrp.peers->peer;
-            for (i = 0; i < p; i++) {
-                peer = peer->next;
-            }
-
-        } else {
-            w = hp->hash % hp->rrp.peers->total_weight;
-
-            for (peer = hp->rrp.peers->peer, i = 0;
-                 peer;
-                 peer = peer->next, i++)
-            {
-                w -= peer->weight;
-                if (w < 0) {
-                    break;
-                }
-            }
-
-            p = i;
+        while (w >= peer->weight) {
+            w -= peer->weight;
+            peer = peer->next;
+            p++;
         }
 
         n = p / (8 * sizeof(uintptr_t));