1 files changed, 217 insertions, 0 deletions
diff --git a/src/plugins/http/http_buffer.c b/src/plugins/http/http_buffer.c
new file mode 100644
index 00000000000..5b4f5fc0300
--- /dev/null
+++ b/src/plugins/http/http_buffer.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (c) 2022 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.
+ */
+
+#include <http/http_buffer.h>
+#include <http/http.h>
+
+static http_buffer_vft_t buf_vfts[HTTP_BUFFER_PTR + 1];
+
+#define HTTP_BUFFER_REGISTER_VFT(type, vft)                                   \
+  static void __attribute__ ((constructor)) http_buf_init_##type (void)       \
+  {                                                                           \
+    buf_vfts[type] = vft;                                                     \
+  }
+
+typedef struct http_buffer_fifo_
+{
+  svm_fifo_t *src;
+  svm_fifo_seg_t *segs;
+  u32 len;
+  u32 offset;
+} http_buffer_fifo_t;
+
+STATIC_ASSERT (sizeof (http_buffer_fifo_t) <= HTTP_BUFFER_DATA_SZ, "buf data");
+
+static void
+buf_fifo_init (http_buffer_t *hb, void *data, u32 len)
+{
+  svm_fifo_t *f = (svm_fifo_t *) data;
+  http_buffer_fifo_t *bf;
+
+  bf = (http_buffer_fifo_t *) &hb->data;
+
+  bf->len = len;
+  bf->offset = 0;
+  bf->src = f;
+  bf->segs = 0;
+}
+
+static void
+buf_fifo_free (http_buffer_t *hb)
+{
+  http_buffer_fifo_t *bf = (http_buffer_fifo_t *) &hb->data;
+
+  bf->src = 0;
+  vec_free (bf->segs);
+}
+
+static svm_fifo_seg_t *
+buf_fifo_get_segs (http_buffer_t *hb, u32 max_len, u32 *n_segs)
+{
+  http_buffer_fifo_t *bf = (http_buffer_fifo_t *) &hb->data;
+
+  u32 _n_segs = 5;
+  int len;
+
+  max_len = clib_max (bf->len - bf->offset, max_len);
+
+  vec_validate (bf->segs, _n_segs);
+
+  len = svm_fifo_segments (bf->src, 0, bf->segs, &_n_segs, max_len);
+  if (len < 0)
+    return 0;
+
+  *n_segs = _n_segs;
+
+  HTTP_DBG (1, "available to send %u n_segs %u", len, *n_segs);
+
+  return bf->segs;
+}
+
+static int
+buf_fifo_drain (http_buffer_t *hb, u32 len)
+{
+  http_buffer_fifo_t *bf = (http_buffer_fifo_t *) &hb->data;
+
+  bf->offset += len;
+  svm_fifo_dequeue_drop (bf->src, len);
+  HTTP_DBG (1, "drained %u len %u offset %u", len, bf->len, bf->offset);
+
+  return len;
+}
+
+static u8
+buf_fifo_is_drained (http_buffer_t *hb)
+{
+  http_buffer_fifo_t *bf = (http_buffer_fifo_t *) &hb->data;
+
+  ASSERT (bf->offset <= bf->len);
+  return (bf->offset == bf->len);
+}
+
+const static http_buffer_vft_t buf_fifo_vft = {
+  .init = buf_fifo_init,
+  .free = buf_fifo_free,
+  .get_segs = buf_fifo_get_segs,
+  .drain = buf_fifo_drain,
+  .is_drained = buf_fifo_is_drained,
+};
+
+HTTP_BUFFER_REGISTER_VFT (HTTP_BUFFER_FIFO, buf_fifo_vft);
+
+typedef struct http_buffer_ptr_
+{
+  svm_fifo_seg_t *segs;
+  svm_fifo_t *f;
+} http_buffer_ptr_t;
+
+STATIC_ASSERT (sizeof (http_buffer_ptr_t) <= HTTP_BUFFER_DATA_SZ, "buf data");
+
+static void
+buf_ptr_init (http_buffer_t *hb, void *data, u32 len)
+{
+  svm_fifo_t *f = (svm_fifo_t *) data;
+  http_buffer_ptr_t *bf;
+  uword ptr;
+  int rv;
+
+  bf = (http_buffer_ptr_t *) &hb->data;
+
+  /* Peek the pointer, do not drain the fifo until done with transfer */
+  rv = svm_fifo_peek (f, 0, sizeof (ptr), (u8 *) &ptr);
+  ASSERT (rv == sizeof (ptr));
+
+  bf->f = f;
+  bf->segs = 0;
+  vec_validate (bf->segs, 1);
+
+  bf->segs[0].data = uword_to_pointer (ptr, u8 *);
+  bf->segs[0].len = len;
+
+  bf->segs[1] = bf->segs[0];
+}
+
+static void
+buf_ptr_free (http_buffer_t *hb)
+{
+  http_buffer_ptr_t *bf = (http_buffer_ptr_t *) &hb->data;
+
+  bf->f = 0;
+  vec_free (bf->segs);
+}
+
+static svm_fifo_seg_t *
+buf_ptr_get_segs (http_buffer_t *hb, u32 max_len, u32 *n_segs)
+{
+  http_buffer_ptr_t *bf = (http_buffer_ptr_t *) &hb->data;
+
+  *n_segs = 1;
+
+  return &bf->segs[1];
+}
+
+static int
+buf_ptr_drain (http_buffer_t *hb, u32 len)
+{
+  http_buffer_ptr_t *bf = (http_buffer_ptr_t *) &hb->data;
+
+  bf->segs[1].data += len;
+  bf->segs[1].len -= len;
+
+  HTTP_DBG (1, "drained %u left %u", len, bf->segs[1].len);
+
+  if (!bf->segs[1].len)
+    {
+      svm_fifo_dequeue_drop (bf->f, sizeof (uword));
+      return sizeof (uword);
+    }
+
+  return 0;
+}
+
+static u8
+buf_ptr_is_drained (http_buffer_t *hb)
+{
+  http_buffer_ptr_t *bf = (http_buffer_ptr_t *) &hb->data;
+
+  ASSERT (bf->segs[1].len <= bf->segs[0].len);
+  return (bf->segs[1].len == 0);
+}
+
+const static http_buffer_vft_t buf_ptr_vft = {
+  .init = buf_ptr_init,
+  .free = buf_ptr_free,
+  .get_segs = buf_ptr_get_segs,
+  .drain = buf_ptr_drain,
+  .is_drained = buf_ptr_is_drained,
+};
+
+HTTP_BUFFER_REGISTER_VFT (HTTP_BUFFER_PTR, buf_ptr_vft);
+
+void
+http_buffer_init (http_buffer_t *hb, http_buffer_type_t type, svm_fifo_t *f,
+		  u32 data_len)
+{
+  hb->vft = &buf_vfts[type];
+  hb->vft->init (hb, f, data_len);
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */