ralloc: add a linear allocator as a child node of ralloc

v2: remove goto, cosmetic changes

Tested-by: Edmondo Tommasina <[email protected]> (v1)
Reviewed-by: Nicolai Hähnle <[email protected]>

1 files changed, 80 insertions, 4 deletions

diff --git a/src/util/ralloc.h b/src/util/ralloc.h
index d74a39875c1..3e2d342b45e 100644
--- a/src/util/ralloc.h
+++ b/src/util/ralloc.h
@@ -407,10 +407,6 @@ bool ralloc_asprintf_append (char **str, const char *fmt, ...)
 bool ralloc_vasprintf_append(char **str, const char *fmt, va_list args);
 /// @}
 
-#ifdef __cplusplus
-} /* end of extern "C" */
-#endif
-
 /**
  * Declare C++ new and delete operators which use ralloc.
  *
@@ -454,4 +450,84 @@ public:                                                                  \
 #define DECLARE_RZALLOC_CXX_OPERATORS(type) \
    DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, rzalloc_size)
 
+#define DECLARE_LINEAR_ALLOC_CXX_OPERATORS(type) \
+   DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_alloc_child)
+
+#define DECLARE_LINEAR_ZALLOC_CXX_OPERATORS(type) \
+   DECLARE_ALLOC_CXX_OPERATORS_TEMPLATE(type, linear_zalloc_child)
+
+
+/**
+ * Do a fast allocation from the linear buffer, also known as the child node
+ * from the allocator's point of view. It can't be freed directly. You have
+ * to free the parent or the ralloc parent.
+ *
+ * \param parent   parent node of the linear allocator
+ * \param size     size to allocate (max 32 bits)
+ */
+void *linear_alloc_child(void *parent, unsigned size);
+
+/**
+ * Allocate a parent node that will hold linear buffers. The returned
+ * allocation is actually the first child node, but it's also the handle
+ * of the parent node. Use it for all child node allocations.
+ *
+ * \param ralloc_ctx  ralloc context, must not be NULL
+ * \param size        size to allocate (max 32 bits)
+ */
+void *linear_alloc_parent(void *ralloc_ctx, unsigned size);
+
+/**
+ * Same as linear_alloc_child, but also clears memory.
+ */
+void *linear_zalloc_child(void *parent, unsigned size);
+
+/**
+ * Same as linear_alloc_parent, but also clears memory.
+ */
+void *linear_zalloc_parent(void *ralloc_ctx, unsigned size);
+
+/**
+ * Free the linear parent node. This will free all child nodes too.
+ * Freeing the ralloc parent will also free this.
+ */
+void linear_free_parent(void *ptr);
+
+/**
+ * Same as ralloc_steal, but steals the linear parent node.
+ */
+void ralloc_steal_linear_parent(void *new_ralloc_ctx, void *ptr);
+
+/**
+ * Return the ralloc parent of the linear parent node.
+ */
+void *ralloc_parent_of_linear_parent(void *ptr);
+
+/**
+ * Same as realloc except that the linear allocator doesn't free child nodes,
+ * so it's reduced to memory duplication. It's used in places where
+ * reallocation is required. Don't use it often. It's much slower than
+ * realloc.
+ */
+void *linear_realloc(void *parent, void *old, unsigned new_size);
+
+/* The functions below have the same semantics as their ralloc counterparts,
+ * except that they always allocate a linear child node.
+ */
+char *linear_strdup(void *parent, const char *str);
+char *linear_asprintf(void *parent, const char *fmt, ...);
+char *linear_vasprintf(void *parent, const char *fmt, va_list args);
+bool linear_asprintf_append(void *parent, char **str, const char *fmt, ...);
+bool linear_vasprintf_append(void *parent, char **str, const char *fmt,
+                             va_list args);
+bool linear_asprintf_rewrite_tail(void *parent, char **str, size_t *start,
+                                  const char *fmt, ...);
+bool linear_vasprintf_rewrite_tail(void *parent, char **str, size_t *start,
+                                   const char *fmt, va_list args);
+bool linear_strcat(void *parent, char **dest, const char *str);
+
+#ifdef __cplusplus
+} /* end of extern "C" */
+#endif
+
 #endif