new file mode 100644
--- /dev/null
+++ b/src/http/ngx_http_write_filter.c
@@ -0,0 +1,82 @@
+
+#include <ngx_config.h>
+
+#include <ngx_hunk.h>
+#include <ngx_http.h>
+#include <ngx_http_filter.h>
+#include <ngx_event_write.h>
+
+#include <ngx_http_write_filter.h>
+
+
+ngx_http_module_t  ngx_http_write_filter_module;
+
+
+/* STUB */
+static ngx_http_write_filter_ctx_t module_ctx;
+
+void ngx_http_write_filter_init()
+{
+     module_ctx.buffer_output = 10240;
+     module_ctx.out = NULL;
+
+     ngx_http_write_filter_module.ctx = &module_ctx;
+}
+/* */
+
+
+int ngx_http_write_filter(ngx_http_request_t *r, ngx_chain_t *in)
+{
+    int    last;
+    off_t  size, flush;
+    ngx_chain_t  *ch, **prev, *chain;
+    ngx_http_write_filter_ctx_t  *ctx;
+
+    ctx = (ngx_http_write_filter_ctx_t *)
+                              ngx_get_module_ctx(r->main ? r->main : r,
+                                                &ngx_http_write_filter_module);
+    size = flush = 0;
+    last = 0;
+    prev = &ctx->out;
+
+    /* find size, flush point and last link of saved chain */
+    for (ch = ctx->out; ch; ch = ch->next) {
+        prev = &ch->next;
+        size += ch->hunk->last.file - ch->hunk->pos.file;
+
+        if (ch->hunk->type & NGX_HUNK_FLUSH)
+            flush = size;
+
+        if (ch->hunk->type & NGX_HUNK_LAST)
+            last = 1;
+    }
+
+    /* add new chain to existent one */
+    for (/* void */; in; in = in->next) {
+        ngx_test_null(ch, ngx_palloc(r->pool, sizeof(ngx_chain_t)),
+                      NGX_HTTP_FILTER_ERROR);
+
+        ch->hunk = in->hunk;
+        ch->next = NULL;
+        *prev = ch;
+        prev = &ch->next;
+        size += ch->hunk->last.file - ch->hunk->pos.file;
+
+        if (ch->hunk->type & NGX_HUNK_FLUSH)
+            flush = size;
+
+        if (ch->hunk->type & NGX_HUNK_LAST)
+            last = 1;
+    }
+
+    if (flush == 0 && size < ctx->buffer_output)
+        return NGX_HTTP_FILTER_DONE;
+
+    chain = ngx_event_write(r->connection, ctx->out, flush);
+    if (chain == (ngx_chain_t *) -1)
+        return NGX_HTTP_FILTER_ERROR;
+
+    ctx->out = chain;
+
+    return (chain ? NGX_HTTP_FILTER_AGAIN : NGX_HTTP_FILTER_DONE);
+}