copy from src/core/ngx_hunk.c
copy to src/core/ngx_buf.c
--- a/src/core/ngx_hunk.c
+++ b/src/core/ngx_buf.c
@@ -3,63 +3,77 @@
 #include <ngx_core.h>
 
 
-ngx_hunk_t *ngx_create_temp_hunk(ngx_pool_t *pool, size_t size)
+ngx_buf_t *ngx_create_temp_buf(ngx_pool_t *pool, size_t size)
 {
-    ngx_hunk_t *h;
+    ngx_buf_t *b;
 
-    ngx_test_null(h, ngx_alloc_hunk(pool), NULL);
+    if (!(b = ngx_calloc_buf(pool))) {
+        return NULL;
+    }
 
-    ngx_test_null(h->start, ngx_palloc(pool, size), NULL);
-
-    h->pos = h->start;
-    h->last = h->start;
+    if (!(b->start = ngx_palloc(pool, size))) {
+        return NULL;
+    }
 
-    h->file_pos = 0;
-    h->file_last = 0;
-
-    h->end = h->last + size;
+    b->pos = b->start;
+    b->last = b->start;
+    b->end = b->last + size;
+    b->temporary = 1;
 
-    h->type = NGX_HUNK_TEMP|NGX_HUNK_IN_MEMORY;
-    h->file = NULL;
-    h->shadow = NULL;
+    /*
+    b->file_pos = 0;
+    b->file_last = 0;
 
-    h->tag = 0;
+    b->file = NULL;
+    b->shadow = NULL;
 
-    return h;
+    b->tag = 0;
+    */
+
+    return b;
 }
 
 
-ngx_chain_t *ngx_create_chain_of_hunks(ngx_pool_t *pool, ngx_bufs_t *bufs)
+ngx_chain_t *ngx_create_chain_of_bufs(ngx_pool_t *pool, ngx_bufs_t *bufs)
 {
+    u_char       *p;
     ngx_int_t     i;
-    u_char       *p;
-    ngx_hunk_t   *h;
+    ngx_buf_t    *b;
     ngx_chain_t  *chain, *cl, **ll;
 
-    ngx_test_null(p, ngx_palloc(pool, bufs->num * bufs->size), NULL);
+    if (!(p = ngx_palloc(pool, bufs->num * bufs->size))) {
+        return NULL;
+    }
 
     ll = &chain;
 
     for (i = 0; i < bufs->num; i++) {
-        ngx_test_null(h, ngx_alloc_hunk(pool), NULL);
+        if (!(b = ngx_calloc_buf(pool))) {
+            return NULL;
+        }
 
-        h->pos = p;
-        h->last = p;
-        h->file_pos = 0;
-        h->file_last = 0;
+        b->pos = p;
+        b->last = p;
+        b->temporary = 1;
 
-        h->type = NGX_HUNK_IN_MEMORY|NGX_HUNK_TEMP;
+        b->start = p;
+        p += bufs->size;
+        b->end = p;
 
-        h->start = p;
-        p += bufs->size;
-        h->end = p;
+        /*
+        b->file_pos = 0;
+        b->file_last = 0;
 
-        h->file = NULL;
-        h->shadow = NULL;
-        h->tag = 0;
+        b->file = NULL;
+        b->shadow = NULL;
+        b->tag = 0;
+        */
 
-        ngx_test_null(cl, ngx_alloc_chain_link(pool), NULL);
-        cl->hunk = h;
+        if (!(cl = ngx_alloc_chain_link(pool))) {
+            return NULL;
+        }
+
+        cl->buf = b;
         *ll = cl;
         ll = &cl->next;
     }
@@ -83,7 +97,7 @@ int ngx_chain_add_copy(ngx_pool_t *pool,
     while (in) {
         ngx_test_null(cl, ngx_alloc_chain_link(pool), NGX_ERROR);
 
-        cl->hunk = in->hunk;
+        cl->buf = in->buf;
         *ll = cl;
         ll = &cl->next;
         in = in->next;
@@ -96,7 +110,7 @@ int ngx_chain_add_copy(ngx_pool_t *pool,
 
 
 void ngx_chain_update_chains(ngx_chain_t **free, ngx_chain_t **busy,
-                             ngx_chain_t **out, ngx_hunk_tag_t tag)
+                             ngx_chain_t **out, ngx_buf_tag_t tag)
 {
     ngx_chain_t  *tl;
 
@@ -115,22 +129,22 @@ void ngx_chain_update_chains(ngx_chain_t
     *out = NULL;
 
     while (*busy) {
-        if (ngx_hunk_size((*busy)->hunk) != 0) {
+        if (ngx_buf_size((*busy)->buf) != 0) {
             break;
         }
 
 #if (HAVE_WRITE_ZEROCOPY)
-        if ((*busy)->hunk->type & NGX_HUNK_ZEROCOPY_BUSY) {
+        if ((*busy)->buf->zerocopy_busy) {
             break;
         }
 #endif
 
-        if ((*busy)->hunk->tag != tag) {
+        if ((*busy)->buf->tag != tag) {
             *busy = (*busy)->next;
             continue;
         }
 
-        (*busy)->hunk->pos = (*busy)->hunk->last = (*busy)->hunk->start;
+        (*busy)->buf->pos = (*busy)->buf->last = (*busy)->buf->start;
 
         tl = *busy;
         *busy = (*busy)->next;