Changeset 43788b2 in mainline for uspace/app/bithenge/transform.h

Timestamp:

2012-07-26T22:26:19Z (13 years ago)

Author:

Sean Bartell <wingedtachikoma@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

5a7c0e6

Parents:

842ed146

Message:

Bithenge: add transform context in preparation for parameters

File:

• uspace/app/bithenge/transform.h (modified) (5 diffs)

uspace/app/bithenge/transform.h

@@ -48 +48 @@
 } bithenge_transform_t;
 
+/** Context and parameters used when applying transforms. */
+typedef struct {
+        /** @privatesection */
+} bithenge_transform_context_t;
+
 /** Operations that may be provided by a transform. */
 typedef struct bithenge_transform_ops {
         /** @copydoc bithenge_transform_t::bithenge_transform_apply */
-        int (*apply)(bithenge_transform_t *self, bithenge_node_t *in, bithenge_node_t **out);
+        int (*apply)(bithenge_transform_t *self,
+            bithenge_transform_context_t *context, bithenge_node_t *in,
+            bithenge_node_t **out);
         /** @copydoc bithenge_transform_t::bithenge_transform_prefix_length */
-        int (*prefix_length)(bithenge_transform_t *self, bithenge_blob_t *blob, aoff64_t *out);
+        int (*prefix_length)(bithenge_transform_t *self,
+            bithenge_transform_context_t *context, bithenge_blob_t *blob,
+            aoff64_t *out);
         /** Destroy the transform.
          * @param self The transform. */
@@ -59 +68 @@
 } bithenge_transform_ops_t;
 
-/** Apply a transform.
+/** Initialize a transform context. It must be destroyed with @a
+ * bithenge_transform_context_destroy after it is used.
+ * @param[out] context The context to initialize. */
+static inline void bithenge_transform_context_init(
+    bithenge_transform_context_t *context)
+{
+}
+
+/** Destroy a transform context.
+ * @param context The context to destroy.
+ * @return EOK on success or an error code from errno.h. */
+static inline void bithenge_transform_context_destroy(
+    bithenge_transform_context_t *context)
+{
+}
+
+/** Apply a transform. Takes ownership of nothing.
  * @memberof bithenge_transform_t
  * @param self The transform.
+ * @param context The context.
  * @param in The input tree.
  * @param[out] out Where the output tree will be stored.
  * @return EOK on success or an error code from errno.h. */
 static inline int bithenge_transform_apply(bithenge_transform_t *self,
-    bithenge_node_t *in, bithenge_node_t **out)
+    bithenge_transform_context_t *context, bithenge_node_t *in,
+    bithenge_node_t **out)
 {
         assert(self);
         assert(self->ops);
-        return self->ops->apply(self, in, out);
+        return self->ops->apply(self, context, in, out);
 }
 
@@ -76 +103 @@
  * other words, figure out how many bytes this transform will use up.  This
  * method is optional and can return an error, but it must succeed for struct
- * subtransforms.
+ * subtransforms. Takes ownership of nothing.
  * @memberof bithenge_transform_t
  * @param self The transform.
+ * @param context The context.
  * @param blob The blob.
  * @param[out] out Where the prefix length will be stored.
@@ -84 +112 @@
  * errno.h. */
 static inline int bithenge_transform_prefix_length(bithenge_transform_t *self,
-    bithenge_blob_t *blob, aoff64_t *out)
+    bithenge_transform_context_t *context, bithenge_blob_t *blob,
+    aoff64_t *out)
 {
         assert(self);
@@ -90 +119 @@
         if (!self->ops->prefix_length)
                 return ENOTSUP;
-        return self->ops->prefix_length(self, blob, out);
+        return self->ops->prefix_length(self, context, blob, out);
 }