--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/libmlk-core/core/vfs-zip.c	Wed Oct 13 15:58:02 2021 +0200
@@ -0,0 +1,123 @@
+/*
+ * vfs-zip.c -- VFS subsystem for zip archives
+ *
+ * Copyright (c) 2020-2021 David Demelier <markand@malikania.fr>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <assert.h>
+#include <string.h>
+
+#include <zip.h>
+
+#include "error.h"
+#include "vfs-zip.h"
+#include "vfs.h"
+
+static inline int
+mkflags(const char *mode)
+{
+	/* TODO: this should check for mutual exclusions. */
+	int flags = 0;
+
+	for (; *mode; ++mode) {
+		switch (*mode) {
+		case 'w':
+			flags |= ZIP_CREATE;
+			break;
+		case 'x':
+			flags |= ZIP_EXCL;
+			break;
+		case '+':
+			flags |= ZIP_TRUNCATE;
+			break;
+		case 'r':
+			flags |= ZIP_RDONLY;
+			break;
+		default:
+			break;
+		}
+	}
+
+	return flags;
+}
+
+static size_t
+file_read(struct vfs_file *file, void *buf, size_t bufsz)
+{
+	return zip_fread(file->data, buf, bufsz);
+}
+
+static size_t
+file_write(struct vfs_file *file, const void *buf, size_t bufsz)
+{
+	(void)file;
+	(void)buf;
+	(void)bufsz;
+
+	return errorf("operation not supported");
+}
+
+static int
+file_flush(struct vfs_file *file)
+{
+	(void)file;
+
+	return 0;
+}
+
+static void
+file_finish(struct vfs_file *file)
+{
+	zip_fclose(file->data);
+}
+
+static int
+impl_open(struct vfs *vfs, struct vfs_file *file, const char *entry, const char *mode)
+{
+	(void)mode;
+
+	if (!(file->data = zip_fopen(vfs->data, entry, 0)))
+		return errorf("unable to open file in archive");
+
+	file->read = file_read;
+	file->write = file_write;
+	file->flush = file_flush;
+	file->finish = file_finish;
+
+	return 0;
+}
+
+static void
+impl_finish(struct vfs *vfs)
+{
+	zip_close(vfs->data);
+}
+
+int
+vfs_zip(struct vfs *vfs, const char *file, const char *mode)
+{
+	assert(vfs);
+	assert(file);
+
+	memset(vfs, 0, sizeof (*vfs));
+
+	if (!(vfs->data = zip_open(file, mkflags(mode), NULL)))
+		return errorf("%s: unable to open zip file", file);
+
+	vfs->open = impl_open;
+	vfs->finish = impl_finish;
+
+	return 0;
+}