copy from src/core/ngx_hunk.h
copy to src/core/ngx_buf.h
--- a/src/core/ngx_hunk.h
+++ b/src/core/ngx_buf.h
@@ -1,61 +1,87 @@
-#ifndef _NGX_HUNK_H_INCLUDED_
-#define _NGX_HUNK_H_INCLUDED_
+#ifndef _NGX_BUF_H_INCLUDED_
+#define _NGX_BUF_H_INCLUDED_
 
 
 #include <ngx_config.h>
 #include <ngx_core.h>
 
 
-/* hunk type */
+#if 0
+/* the buf type */
 
-/* the hunk is in memory */
+/* the buf's content is in memory */
 #define NGX_HUNK_IN_MEMORY    0x0001
-/* the hunk's content can be changed */
+/* the buf's content can be changed */
 #define NGX_HUNK_TEMP         0x0002
-/* the hunk's content is in cache and can not be changed */
+/* the buf's content is in cache and can not be changed */
 #define NGX_HUNK_MEMORY       0x0004
-/* the hunk's content is mmap()ed and can not be changed */
 #define NGX_HUNK_MMAP         0x0008
 
+/* the buf's content is recycled */
 #define NGX_HUNK_RECYCLED     0x0010
 
-/* the hunk is in file */
+/* the buf's content is in a file */
 #define NGX_HUNK_FILE         0x0020
 
 #define NGX_HUNK_STORAGE      (NGX_HUNK_IN_MEMORY                            \
                                |NGX_HUNK_TEMP|NGX_HUNK_MEMORY|NGX_HUNK_MMAP  \
                                |NGX_HUNK_RECYCLED|NGX_HUNK_FILE)
 
-/* hunk flags */
+/* the buf flags */
 
-/* in thread state flush means to write the hunk completely before return */
-/* in event state flush means to start to write the hunk */
+/* in thread state flush means to write the buf completely before return */
+/* in event state flush means to start to write the buf */
 #define NGX_HUNK_FLUSH        0x0100
-/* last hunk */
+
+/* the last buf */
 #define NGX_HUNK_LAST         0x0200
 
 
 #define NGX_HUNK_PREREAD      0x2000
 #define NGX_HUNK_LAST_SHADOW  0x4000
 #define NGX_HUNK_TEMP_FILE    0x8000
+#endif
 
 
-typedef void *                   ngx_hunk_tag_t;
+typedef void *                   ngx_buf_tag_t;
 
-typedef struct ngx_hunk_s        ngx_hunk_t;
+typedef struct ngx_buf_s         ngx_buf_t;
 
-struct ngx_hunk_s {
+struct ngx_buf_s {
     u_char          *pos;
     u_char          *last;
     off_t            file_pos;
     off_t            file_last;
 
     int              type;
-    u_char          *start;         /* start of hunk */
-    u_char          *end;           /* end of hunk */
-    ngx_hunk_tag_t   tag;
+    u_char          *start;         /* start of buffer */
+    u_char          *end;           /* end of buffer */
+    ngx_buf_tag_t    tag;
     ngx_file_t      *file;
-    ngx_hunk_t      *shadow;
+    ngx_buf_t       *shadow;
+
+
+    /* the buf's content can be changed */
+    unsigned         temporary:1;
+
+    /*
+     * the buf's content is in a memory cache or in a read only memory
+     * and can not be changed
+     */
+    unsigned         memory:1;
+
+    /* the buf's content is mmap()ed and can not be changed */
+    unsigned         mmap:1;
+    unsigned         recycled:1;
+    unsigned         in_file:1;
+    unsigned         flush:1;
+    unsigned         last_buf:1;
+
+    unsigned         last_shadow:1;
+    unsigned         temp_file:1;
+
+    unsigned         zerocopy_busy:1;
+
     /* STUB */ int   num;
 };
 
@@ -63,8 +89,8 @@ struct ngx_hunk_s {
 typedef struct ngx_chain_s       ngx_chain_t;
 
 struct ngx_chain_s {
-    ngx_hunk_t  *hunk;
-    ngx_chain_t *next;
+    ngx_buf_t    *buf;
+    ngx_chain_t  *next;
 };
 
 
@@ -77,7 +103,7 @@ typedef struct {
 typedef int  (*ngx_output_chain_filter_pt)(void *ctx, ngx_chain_t *out);
 
 typedef struct {
-    ngx_hunk_t                  *hunk;
+    ngx_buf_t                   *buf;
     ngx_chain_t                 *in;
     ngx_chain_t                 *free;
     ngx_chain_t                 *busy;
@@ -87,9 +113,9 @@ typedef struct {
     unsigned                     need_in_temp;
 
     ngx_pool_t                  *pool;
-    ngx_int_t                    hunks;
+    ngx_int_t                    allocated;
     ngx_bufs_t                   bufs;
-    ngx_hunk_tag_t               tag;
+    ngx_buf_tag_t                tag;
 
     ngx_output_chain_filter_pt   output_filter;
     void                        *filter_ctx;
@@ -107,6 +133,17 @@ typedef struct {
 #define NGX_CHAIN_ERROR     (ngx_chain_t *) NGX_ERROR
 
 
+#define ngx_buf_in_memory(b)        (b->temporary || b->memory || b->mmap)
+#define ngx_buf_in_memory_only(b)   (ngx_buf_in_memory(b) && !b->in_file)
+#define ngx_buf_special(b)                                                   \
+        ((b->flush || b->last) && !ngx_buf_in_memory(b) && !b->in_file)
+
+#define ngx_buf_size(b)                                                      \
+        (ngx_buf_in_memory(b) ? (size_t) (b->last - b->pos):                 \
+                                (size_t) (b->file_last - b->file_pos))
+
+#if 0
+
 #define ngx_hunk_in_memory_only(h)                                           \
          ((h->type & (NGX_HUNK_IN_MEMORY|NGX_HUNK_FILE)) == NGX_HUNK_IN_MEMORY)
 /*
@@ -115,28 +152,34 @@ typedef struct {
 
 */
 
-#define ngx_hunk_special(h)                                                  \
-        (h->type == (h->type & (NGX_HUNK_FLUSH|NGX_HUNK_LAST)))
+
+
+#define ngx_hunk_special(b)                                                  \
+        (b->type == (b->type & (NGX_HUNK_FLUSH|NGX_HUNK_LAST)))
 
 
-#define ngx_hunk_size(h)                                                     \
-        ((h->type & NGX_HUNK_IN_MEMORY) ? (size_t) (h->last - h->pos):       \
-                                          (size_t) (h->file_last - h->file_pos))
+#define ngx_hunk_size(b)                                                     \
+        ((b->type & NGX_HUNK_IN_MEMORY) ? (size_t) (b->last - b->pos):       \
+                                          (size_t) (b->file_last - b->file_pos))
+
+#endif
 
 
-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_chain_t *ngx_create_chain_of_bufs(ngx_pool_t *pool, ngx_bufs_t *bufs);
 
-#define ngx_alloc_hunk(pool) ngx_palloc(pool, sizeof(ngx_hunk_t))
-#define ngx_calloc_hunk(pool) ngx_pcalloc(pool, sizeof(ngx_hunk_t))
+
+#define ngx_alloc_buf(pool)  ngx_palloc(pool, sizeof(ngx_buf_t))
+#define ngx_calloc_buf(pool) ngx_pcalloc(pool, sizeof(ngx_buf_t))
 
 
 #define ngx_alloc_chain_link(pool) ngx_palloc(pool, sizeof(ngx_chain_t))
 
 
-#define ngx_alloc_link_and_set_hunk(chain, h, pool, error)                   \
+#define ngx_alloc_link_and_set_buf(chain, b, pool, error)                    \
             do {                                                             \
                 ngx_test_null(chain, ngx_alloc_chain_link(pool), error);     \
-                chain->hunk = h;                                             \
+                chain->buf = b;                                              \
                 chain->next = NULL;                                          \
             } while (0);
 
@@ -155,7 +198,7 @@ int ngx_chain_writer(void *data, ngx_cha
 
 int ngx_chain_add_copy(ngx_pool_t *pool, ngx_chain_t **chain, ngx_chain_t *in);
 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);
 
 
-#endif /* _NGX_HUNK_H_INCLUDED_ */
+#endif /* _NGX_BUF_H_INCLUDED_ */