diff --git a/src/ngx_http_lua_args.c b/src/ngx_http_lua_args.c
index b43697c7a1..5d14536d85 100644
--- a/src/ngx_http_lua_args.c
+++ b/src/ngx_http_lua_args.c
@@ -12,6 +12,7 @@
 
 
 #include "ngx_http_lua_args.h"
+#include "ngx_http_lua_string.h"
 #include "ngx_http_lua_util.h"
 
 
@@ -387,23 +388,16 @@ ngx_http_lua_ffi_req_get_querystring_len(ngx_http_request_t *r)
 
 
 int
-ngx_http_lua_ffi_req_get_uri_args_count(ngx_http_request_t *r, int max)
+ngx_http_lua_ffi_get_args_count_helper(u_char *args,
+    size_t len, int max, int *hit)
 {
-    int                      count;
-    u_char                  *p, *last;
-
-    if (r->connection->fd == (ngx_socket_t) -1) {
-        return NGX_HTTP_LUA_FFI_BAD_CONTEXT;
-    }
+    int                         count;
+    u_char                     *p, *last;
 
-    if (max < 0) {
-        max = NGX_HTTP_LUA_MAX_ARGS;
-    }
-
-    last = r->args.data + r->args.len;
+    last = args + len;
     count = 0;
 
-    for (p = r->args.data; p != last; p++) {
+    for (p = args; p != last; p++) {
         if (*p == '&') {
             if (count == 0) {
                 count += 2;
@@ -417,14 +411,13 @@ ngx_http_lua_ffi_req_get_uri_args_count(ngx_http_request_t *r, int max)
     if (count) {
         if (max > 0 && count > max) {
             count = max;
-            ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
-                           "lua hit query args limit %d", max);
+            *hit = 1;
         }
 
         return count;
     }
 
-    if (r->args.len) {
+    if (len) {
         return 1;
     }
 
@@ -433,117 +426,62 @@ ngx_http_lua_ffi_req_get_uri_args_count(ngx_http_request_t *r, int max)
 
 
 int
-ngx_http_lua_ffi_req_get_uri_args(ngx_http_request_t *r, u_char *buf,
-    ngx_http_lua_ffi_table_elt_t *out, int count)
+ngx_http_lua_ffi_req_get_uri_args_count(ngx_http_request_t *r, int max)
 {
-    int                          i, parsing_value = 0;
-    u_char                      *last, *p, *q;
-    u_char                      *src, *dst;
+    int                         rc, hit = 0;
 
-    if (count <= 0) {
-        return NGX_OK;
+    if (r->connection->fd == (ngx_socket_t) -1) {
+        return NGX_HTTP_LUA_FFI_BAD_CONTEXT;
     }
 
-    ngx_memcpy(buf, r->args.data, r->args.len);
-
-    i = 0;
-    last = buf + r->args.len;
-    p = buf;
-    q = p;
-
-    while (p != last) {
-        if (*p == '=' && !parsing_value) {
-            /* key data is between p and q */
-
-            src = q; dst = q;
-
-            ngx_http_lua_unescape_uri(&dst, &src, p - q,
-                                      NGX_UNESCAPE_URI_COMPONENT);
-
-            dd("saving key %.*s", (int) (dst - q), q);
-
-            out[i].key.data = q;
-            out[i].key.len = (int) (dst - q);
-
-            /* skip the current '=' char */
-            p++;
-
-            q = p;
-            parsing_value = 1;
-
-        } else if (*p == '&') {
-            /* reached the end of a key or a value, just save it */
-            src = q; dst = q;
-
-            ngx_http_lua_unescape_uri(&dst, &src, p - q,
-                                      NGX_UNESCAPE_URI_COMPONENT);
+    if (max < 0) {
+        max = NGX_HTTP_LUA_MAX_ARGS;
+    }
 
-            dd("pushing key or value %.*s", (int) (dst - q), q);
+    rc = ngx_http_lua_ffi_get_args_count_helper(r->args.data,
+                                                r->args.len,
+                                                max, &hit);
 
-            if (parsing_value) {
-                /* end of the current pair's value */
-                parsing_value = 0;
+    if (hit) {
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                       "lua hit query args limit %d", max);
+    }
 
-                if (out[i].key.len) {
-                    out[i].value.data = q;
-                    out[i].value.len = (int) (dst - q);
-                    i++;
-                }
+    return rc;
+}
 
-            } else {
-                /* the current parsing pair takes no value,
-                 * just push the value "true" */
-                dd("pushing boolean true");
 
-                if (dst - q) {
-                    out[i].key.data = q;
-                    out[i].key.len = (int) (dst - q);
-                    out[i].value.len = -1;
-                    i++;
-                }
-            }
+int
+ngx_http_lua_ffi_req_get_uri_args(ngx_http_request_t *r, u_char *buf,
+    ngx_http_lua_ffi_table_elt_t *out, int count)
+{
+    ngx_memcpy(buf, r->args.data, r->args.len);
 
-            if (i == count) {
-                return i;
-            }
+    return ngx_http_lua_ffi_decode_args_helper(buf, r->args.len, out, count);
+}
 
-            /* skip the current '&' char */
-            p++;
 
-            q = p;
+int
+ngx_http_lua_ffi_get_args_count(const u_char *args, size_t len, int max)
+{
+    int                         rc, hit = 0;
 
-        } else {
-            p++;
-        }
+    if (max < 0) {
+        max = NGX_HTTP_LUA_MAX_ARGS;
     }
 
-    if (p != q || parsing_value) {
-        src = q; dst = q;
-
-        ngx_http_lua_unescape_uri(&dst, &src, p - q,
-                                  NGX_UNESCAPE_URI_COMPONENT);
-
-        dd("pushing key or value %.*s", (int) (dst - q), q);
-
-        if (parsing_value) {
-            if (out[i].key.len) {
-                out[i].value.data = q;
-                out[i].value.len = (int) (dst - q);
-                i++;
-            }
+    rc = ngx_http_lua_ffi_get_args_count_helper((u_char *) args,
+                                                len, max, &hit);
 
-        } else {
-            if (dst - q) {
-                out[i].key.data = q;
-                out[i].key.len = (int) (dst - q);
-                out[i].value.len = (int) -1;
-                i++;
-            }
-        }
+    if (hit) {
+        ngx_log_debug1(NGX_LOG_DEBUG_HTTP, ngx_cycle->log, 0,
+                       "lua hit query args limit %d", max);
     }
 
-    return i;
+    return rc;
 }
+
+
 #endif /* NGX_LUA_NO_FFI_API */
 
 
diff --git a/src/ngx_http_lua_string.c b/src/ngx_http_lua_string.c
index 239b2322ab..eb4a2b6dce 100644
--- a/src/ngx_http_lua_string.c
+++ b/src/ngx_http_lua_string.c
@@ -762,6 +762,130 @@ ngx_http_lua_ffi_escape_uri(const u_char *src, size_t len, u_char *dst)
     ngx_http_lua_escape_uri(dst, (u_char *) src, len, NGX_ESCAPE_URI_COMPONENT);
 }
 
-#endif
+
+int
+ngx_http_lua_ffi_decode_args_helper(u_char *args, size_t len,
+    ngx_http_lua_ffi_table_elt_t *out, int count)
+{
+    int                          i, parsing_value = 0;
+    u_char                      *last, *p, *q;
+    u_char                      *src, *dst;
+
+    if (count <= 0) {
+        return NGX_OK;
+    }
+
+    i = 0;
+    p = args;
+    q = p;
+    last = args + len;
+
+    while (p != last) {
+        if (*p == '=' && !parsing_value) {
+            /* key data is between p and q */
+
+            src = q; dst = q;
+
+            ngx_http_lua_unescape_uri(&dst, &src, p - q,
+                                      NGX_UNESCAPE_URI_COMPONENT);
+
+            dd("saving key %.*s", (int) (dst - q), q);
+
+            out[i].key.data = q;
+            out[i].key.len = (int) (dst - q);
+
+            /* skip the current '=' char */
+            p++;
+
+            q = p;
+            parsing_value = 1;
+
+        } else if (*p == '&') {
+            /* reached the end of a key or a value, just save it */
+            src = q; dst = q;
+
+            ngx_http_lua_unescape_uri(&dst, &src, p - q,
+                                      NGX_UNESCAPE_URI_COMPONENT);
+
+            dd("pushing key or value %.*s", (int) (dst - q), q);
+
+            if (parsing_value) {
+                /* end of the current pair's value */
+                parsing_value = 0;
+
+                if (out[i].key.len) {
+                    out[i].value.data = q;
+                    out[i].value.len = (int) (dst - q);
+                    i++;
+                }
+
+            } else {
+                /* the current parsing pair takes no value,
+                 * just push the value "true" */
+                dd("pushing boolean true");
+
+                if (dst - q) {
+                    out[i].key.data = q;
+                    out[i].key.len = (int) (dst - q);
+                    out[i].value.len = -1;
+                    i++;
+                }
+            }
+
+            if (i == count) {
+                return i;
+            }
+
+            /* skip the current '&' char */
+            p++;
+
+            q = p;
+
+        } else {
+            p++;
+        }
+    }
+
+    if (p != q || parsing_value) {
+        src = q; dst = q;
+
+        ngx_http_lua_unescape_uri(&dst, &src, p - q,
+                                  NGX_UNESCAPE_URI_COMPONENT);
+
+        dd("pushing key or value %.*s", (int) (dst - q), q);
+
+        if (parsing_value) {
+            if (out[i].key.len) {
+                out[i].value.data = q;
+                out[i].value.len = (int) (dst - q);
+                i++;
+            }
+
+        } else {
+            if (dst - q) {
+                out[i].key.data = q;
+                out[i].key.len = (int) (dst - q);
+                out[i].value.len = (int) -1;
+                i++;
+            }
+        }
+    }
+
+    return i;
+}
+
+
+int
+ngx_http_lua_ffi_decode_args(u_char *buf, const u_char *args, size_t len,
+    ngx_http_lua_ffi_table_elt_t *out, int count)
+{
+    ngx_memcpy(buf, args, len);
+
+    return ngx_http_lua_ffi_decode_args_helper(buf, len, out, count);
+}
+
+
+#endif /* NGX_LUA_NO_FFI_API */
+
 
 /* vi:set ft=c ts=4 sw=4 et fdm=marker: */
diff --git a/src/ngx_http_lua_string.h b/src/ngx_http_lua_string.h
index b54cbdfce8..07bfd89c0f 100644
--- a/src/ngx_http_lua_string.h
+++ b/src/ngx_http_lua_string.h
@@ -15,6 +15,15 @@
 void ngx_http_lua_inject_string_api(lua_State *L);
 
 
+#ifndef NGX_LUA_NO_FFI_API
+#include "ngx_http_lua_util.h"
+
+int ngx_http_lua_ffi_decode_args_helper(u_char *args, size_t len,
+    ngx_http_lua_ffi_table_elt_t *out, int count);
+#endif
+
+
 #endif /* _NGX_HTTP_LUA_STRING_H_INCLUDED_ */
 
+
 /* vi:set ft=c ts=4 sw=4 et fdm=marker: */