1 files changed, 137 insertions, 0 deletions
diff --git a/src/vppinfra/fifo.c b/src/vppinfra/fifo.c
new file mode 100644
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+++ b/src/vppinfra/fifo.c
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+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/*
+  Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus
+
+  Permission is hereby granted, free of charge, to any person obtaining
+  a copy of this software and associated documentation files (the
+  "Software"), to deal in the Software without restriction, including
+  without limitation the rights to use, copy, modify, merge, publish,
+  distribute, sublicense, and/or sell copies of the Software, and to
+  permit persons to whom the Software is furnished to do so, subject to
+  the following conditions:
+
+  The above copyright notice and this permission notice shall be
+  included in all copies or substantial portions of the Software.
+
+  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+*/
+
+#include <vppinfra/cache.h>
+#include <vppinfra/fifo.h>
+#include <vppinfra/error.h>
+#include <vppinfra/string.h>
+
+/*
+  General first in/first out queues.
+  FIFOs can have arbitrary size and type.
+  Let T be any type (i.e. char, int, struct foo, etc.).
+
+  A null fifo is initialized:
+
+    T * f = 0;
+
+  For example, typedef struct { int a, b; } T;
+
+  Elements can be added in 3 ways.
+
+    #1 1 element is added:
+       T x;
+       x.a = 10; x.b = 20;
+       fifo_add1 (f, x);
+
+    #2 n elements are added
+       T buf[10];
+       initialize buf[0] .. buf[9];
+       fifo_add (f, buf, 10);
+
+    #3 1 element is added, pointer is returned
+       T * x;
+       fifo_add2 (f, x);
+       x->a = 10;
+       x->b = 20;
+
+   Elements are removed 1 at a time:
+       T x;
+       fifo_sub1 (f, x);
+
+   fifo_free (f) frees fifo.
+*/
+
+void *
+_clib_fifo_resize (void *v_old, uword n_new_elts, uword elt_bytes)
+{
+  void *v_new, *end, *head;
+  uword n_old_elts, header_bytes;
+  uword n_copy_bytes, n_zero_bytes;
+  clib_fifo_header_t *f_new, *f_old;
+
+  n_old_elts = clib_fifo_elts (v_old);
+  n_new_elts += n_old_elts;
+  if (n_new_elts < 32)
+    n_new_elts = 32;
+  else
+    n_new_elts = max_pow2 (n_new_elts);
+
+  header_bytes = vec_header_bytes (sizeof (clib_fifo_header_t));
+
+  v_new = clib_mem_alloc_no_fail (n_new_elts * elt_bytes + header_bytes);
+  v_new += header_bytes;
+
+  f_new = clib_fifo_header (v_new);
+  f_new->head_index = 0;
+  f_new->tail_index = n_old_elts;
+  _vec_len (v_new) = n_new_elts;
+
+  /* Copy old -> new. */
+  n_copy_bytes = n_old_elts * elt_bytes;
+  if (n_copy_bytes > 0)
+    {
+      f_old = clib_fifo_header (v_old);
+      end = v_old + _vec_len (v_old) * elt_bytes;
+      head = v_old + f_old->head_index * elt_bytes;
+
+      if (head + n_copy_bytes >= end)
+	{
+	  uword n = end - head;
+	  clib_memcpy (v_new, head, n);
+	  clib_memcpy (v_new + n, v_old, n_copy_bytes - n);
+	}
+      else
+	clib_memcpy (v_new, head, n_copy_bytes);
+    }
+
+  /* Zero empty space. */
+  n_zero_bytes = (n_new_elts - n_old_elts) * elt_bytes;
+  memset (v_new + n_copy_bytes, 0, n_zero_bytes);
+
+  clib_fifo_free (v_old);
+
+  return v_new;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */