Add a helper module for simple regular files

* procfs_file.h: New file, declares procfs_file_make_node.
* procfs_file.c: New file, implements procfs_file_make_node.
* main.c: Use them.
* Makefile: Add the procfs_file module.

1 files changed, 59 insertions, 0 deletions

diff --git a/procfs_file.c b/procfs_file.c
new file mode 100644
index 0000000..62419ee
--- /dev/null
+++ b/procfs_file.c
@@ -0,0 +1,59 @@
+#include <hurd/hurd_types.h>
+#include <stdlib.h>
+#include <string.h>
+#include "procfs.h"
+#include "procfs_file.h"
+
+struct procfs_file
+{
+  void *contents;
+  size_t len;
+  void (*cleanup)(void *contents);
+};
+
+error_t
+procfs_file_getcontents (void *hook, void **contents, size_t *contents_len)
+{
+  struct procfs_file *f = hook;
+
+  *contents = f->contents;
+  *contents_len = f->len;
+  return 0;
+}
+
+void
+procfs_file_cleanup (void *hook)
+{
+  struct procfs_file *f = hook;
+
+  if (f->cleanup)
+    f->cleanup (f->contents);
+
+  free (f);
+}
+
+struct node *
+procfs_file_make_node (void *contents, ssize_t len, void (*cleanup)(void *))
+{
+  static const struct procfs_node_ops ops = {
+    .get_contents = procfs_file_getcontents,
+    .cleanup = procfs_file_cleanup,
+  };
+  struct procfs_file *f;
+  struct node *np;
+
+  f = malloc (sizeof *f);
+  if (! f)
+    return NULL;
+
+  f->contents = contents;
+  f->len = (len >= 0) ? len : strlen (f->contents);
+  f->cleanup = cleanup;
+
+  np = procfs_make_node (&ops, f);
+  if (! np)
+    free (f);
+
+  return np;
+}
+