qpb: Add support for protobuf.

[mirror_frr.git] / qpb / qpb_allocator.h

diff --git a/qpb/qpb_allocator.h b/qpb/qpb_allocator.h
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+/*
+ * qpb_allocator.h
+ *
+ * @copyright Copyright (C) 2016 Sproute Networks, Inc.
+ *
+ * @author Avneesh Sachdev <avneesh@sproute.com>
+ *
+ * This file is part of Quagga.
+ *
+ * Quagga is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * Quagga is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Quagga; see the file COPYING.  If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+/*
+ * Header file for quagga protobuf memory management code.
+ */
+
+#ifndef _QPB_ALLOCATOR_H_
+#define _QPB_ALLOCATOR_H_
+
+#include <google/protobuf-c/protobuf-c.h>
+
+struct linear_allocator_t_;
+
+/*
+ * Alias for ProtobufCAllocator that is easier on the fingers.
+ */
+typedef ProtobufCAllocator qpb_allocator_t;
+
+/*
+ * qpb_alloc
+ */
+static inline void *
+qpb_alloc (qpb_allocator_t *allocator, size_t size)
+{
+  return allocator->alloc (allocator->allocator_data, size);
+}
+
+/*
+ * qpb_alloc_ptr_array
+ *
+ * Allocate space for the specified number of pointers.
+ */
+static inline void *
+qpb_alloc_ptr_array (qpb_allocator_t *allocator, size_t num_ptrs)
+{
+  return qpb_alloc (allocator, num_ptrs * sizeof (void *));
+}
+
+/*
+ * qpb_free
+ */
+static inline void
+qpb_free (qpb_allocator_t *allocator, void *ptr)
+{
+  allocator->free (allocator->allocator_data, ptr);
+}
+
+/*
+ * QPB_ALLOC
+ *
+ * Convenience macro to reduce the probability of allocating memory of
+ * incorrect size. It returns enough memory to store the given type,
+ * and evaluates to an appropriately typed pointer.
+ */
+#define QPB_ALLOC(allocator, type)             \
+  (type *) qpb_alloc(allocator, sizeof(type))
+
+
+/*
+ * Externs.
+ */
+extern void qpb_allocator_init_linear (qpb_allocator_t *,
+                                      struct linear_allocator_t_ *);
+
+/*
+ * The following macros are for the common case where a qpb allocator
+ * is being used alongside a linear allocator that allocates memory
+ * off of the stack.
+ */
+#define QPB_DECLARE_STACK_ALLOCATOR(allocator, size)   \
+    qpb_allocator_t allocator;                         \
+    linear_allocator_t lin_ ## allocator;              \
+    char lin_ ## allocator ## _buf[size]
+
+#define QPB_INIT_STACK_ALLOCATOR(allocator)                            \
+  do                                                                   \
+    {                                                                  \
+      linear_allocator_init(&(lin_ ## allocator),                      \
+                           lin_ ## allocator ## _buf,                  \
+                           sizeof(lin_ ## allocator ## _buf));         \
+      qpb_allocator_init_linear(&allocator, &(lin_ ## allocator));     \
+    } while (0)
+
+#define QPB_RESET_STACK_ALLOCATOR(allocator)           \
+  do                                                   \
+    {                                                  \
+      linear_allocator_reset (&(lin_ ## allocator));   \
+    } while (0)
+
+#endif /* _QPB_ALLOCATOR_H_ */