util: add vector util code.

This is ported from anv, both anv and radv can share this.

Reviewed-by: Nicolai Hähnle <[email protected]>
Acked-by: Jason Ekstrand <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>

1 files changed, 98 insertions, 0 deletions

diff --git a/src/util/u_vector.c b/src/util/u_vector.c
new file mode 100644
index 00000000000..37c4245ebe4
--- /dev/null
+++ b/src/util/u_vector.c
@@ -0,0 +1,98 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * 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 (including the next
+ * paragraph) 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 "util/u_vector.h"
+
+int
+u_vector_init(struct u_vector *vector, uint32_t element_size, uint32_t size)
+{
+   assert(util_is_power_of_two(size));
+   assert(element_size < size && util_is_power_of_two(element_size));
+
+   vector->head = 0;
+   vector->tail = 0;
+   vector->element_size = element_size;
+   vector->size = size;
+   vector->data = malloc(size);
+
+   return vector->data != NULL;
+}
+
+void *
+u_vector_add(struct u_vector *vector)
+{
+   uint32_t offset, size, split, src_tail, dst_tail;
+   void *data;
+
+   if (vector->head - vector->tail == vector->size) {
+      size = vector->size * 2;
+      data = malloc(size);
+      if (data == NULL)
+         return NULL;
+      src_tail = vector->tail & (vector->size - 1);
+      dst_tail = vector->tail & (size - 1);
+      if (src_tail == 0) {
+         /* Since we know that the vector is full, this means that it's
+          * linear from start to end so we can do one copy.
+          */
+         memcpy((char *)data + dst_tail, vector->data, vector->size);
+      } else {
+         /* In this case, the vector is split into two pieces and we have
+          * to do two copies.  We have to be careful to make sure each
+          * piece goes to the right locations.  Thanks to the change in
+          * size, it may or may not still wrap around.
+          */
+         split = u_align_u32(vector->tail, vector->size);
+         assert(vector->tail <= split && split < vector->head);
+         memcpy((char *)data + dst_tail, (char *)vector->data + src_tail,
+                split - vector->tail);
+         memcpy((char *)data + (split & (size - 1)), vector->data,
+                vector->head - split);
+      }
+      free(vector->data);
+      vector->data = data;
+      vector->size = size;
+   }
+
+   assert(vector->head - vector->tail < vector->size);
+
+   offset = vector->head & (vector->size - 1);
+   vector->head += vector->element_size;
+
+   return (char *)vector->data + offset;
+}
+
+void *
+u_vector_remove(struct u_vector *vector)
+{
+   uint32_t offset;
+
+   if (vector->head == vector->tail)
+      return NULL;
+
+   assert(vector->head - vector->tail <= vector->size);
+
+   offset = vector->tail & (vector->size - 1);
+   vector->tail += vector->element_size;
+
+   return (char *)vector->data + offset;
+}