c: move c files into nostrdb in prep for switchover

2024-01-25 14:30:16 -08:00
parent cc75a8450a
commit 954f48b23d
60 changed files with 24 additions and 414 deletions
--- a/nostrdb/container_of.h
+++ b/nostrdb/container_of.h
@@ -0,0 +1,145 @@
+/* CC0 (Public domain) - see LICENSE file for details */
+#ifndef CCAN_CONTAINER_OF_H
+#define CCAN_CONTAINER_OF_H
+#include <stddef.h>
+
+#include "config.h"
+#include "check_type.h"
+
+/**
+ * container_of - get pointer to enclosing structure
+ * @member_ptr: pointer to the structure member
+ * @containing_type: the type this member is within
+ * @member: the name of this member within the structure.
+ *
+ * Given a pointer to a member of a structure, this macro does pointer
+ * subtraction to return the pointer to the enclosing type.
+ *
+ * Example:
+ *    struct foo {
+ *        int fielda, fieldb;
+ *        // ...
+ *    };
+ *    struct info {
+ *        int some_other_field;
+ *        struct foo my_foo;
+ *    };
+ *
+ *    static struct info *foo_to_info(struct foo *foo)
+ *    {
+ *        return container_of(foo, struct info, my_foo);
+ *    }
+ */
+#define container_of(member_ptr, containing_type, member)        \
+     ((containing_type *)                        \
+      ((char *)(member_ptr)                        \
+       - container_off(containing_type, member))            \
+      + check_types_match(*(member_ptr), ((containing_type *)0)->member))
+
+
+/**
+ * container_of_or_null - get pointer to enclosing structure, or NULL
+ * @member_ptr: pointer to the structure member
+ * @containing_type: the type this member is within
+ * @member: the name of this member within the structure.
+ *
+ * Given a pointer to a member of a structure, this macro does pointer
+ * subtraction to return the pointer to the enclosing type, unless it
+ * is given NULL, in which case it also returns NULL.
+ *
+ * Example:
+ *    struct foo {
+ *        int fielda, fieldb;
+ *        // ...
+ *    };
+ *    struct info {
+ *        int some_other_field;
+ *        struct foo my_foo;
+ *    };
+ *
+ *    static struct info *foo_to_info_allowing_null(struct foo *foo)
+ *    {
+ *        return container_of_or_null(foo, struct info, my_foo);
+ *    }
+ */
+static inline char *container_of_or_null_(void *member_ptr, size_t offset)
+{
+    return member_ptr ? (char *)member_ptr - offset : NULL;
+}
+#define container_of_or_null(member_ptr, containing_type, member)    \
+    ((containing_type *)                        \
+     container_of_or_null_(member_ptr,                \
+                   container_off(containing_type, member))    \
+     + check_types_match(*(member_ptr), ((containing_type *)0)->member))
+
+/**
+ * container_off - get offset to enclosing structure
+ * @containing_type: the type this member is within
+ * @member: the name of this member within the structure.
+ *
+ * Given a pointer to a member of a structure, this macro does
+ * typechecking and figures out the offset to the enclosing type.
+ *
+ * Example:
+ *    struct foo {
+ *        int fielda, fieldb;
+ *        // ...
+ *    };
+ *    struct info {
+ *        int some_other_field;
+ *        struct foo my_foo;
+ *    };
+ *
+ *    static struct info *foo_to_info(struct foo *foo)
+ *    {
+ *        size_t off = container_off(struct info, my_foo);
+ *        return (void *)((char *)foo - off);
+ *    }
+ */
+#define container_off(containing_type, member)    \
+    offsetof(containing_type, member)
+
+/**
+ * container_of_var - get pointer to enclosing structure using a variable
+ * @member_ptr: pointer to the structure member
+ * @container_var: a pointer of same type as this member's container
+ * @member: the name of this member within the structure.
+ *
+ * Given a pointer to a member of a structure, this macro does pointer
+ * subtraction to return the pointer to the enclosing type.
+ *
+ * Example:
+ *    static struct info *foo_to_i(struct foo *foo)
+ *    {
+ *        struct info *i = container_of_var(foo, i, my_foo);
+ *        return i;
+ *    }
+ */
+#if HAVE_TYPEOF
+#define container_of_var(member_ptr, container_var, member) \
+    container_of(member_ptr, typeof(*container_var), member)
+#else
+#define container_of_var(member_ptr, container_var, member)    \
+    ((void *)((char *)(member_ptr)    -            \
+          container_off_var(container_var, member)))
+#endif
+
+/**
+ * container_off_var - get offset of a field in enclosing structure
+ * @container_var: a pointer to a container structure
+ * @member: the name of a member within the structure.
+ *
+ * Given (any) pointer to a structure and a its member name, this
+ * macro does pointer subtraction to return offset of member in a
+ * structure memory layout.
+ *
+ */
+#if HAVE_TYPEOF
+#define container_off_var(var, member)        \
+    container_off(typeof(*var), member)
+#else
+#define container_off_var(var, member)            \
+    ((const char *)&(var)->member - (const char *)(var))
+#endif
+
+#endif /* CCAN_CONTAINER_OF_H */