First Commit

3rdparty/libzip/lib/zip_source_layered.c

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+/*
+  zip_source_layered.c -- create layered source
+  Copyright (C) 2009-2023 Dieter Baron and Thomas Klausner
+
+  This file is part of libzip, a library to manipulate ZIP archives.
+  The authors can be contacted at <info@libzip.org>
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions
+  are met:
+  1. Redistributions of source code must retain the above copyright
+     notice, this list of conditions and the following disclaimer.
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in
+     the documentation and/or other materials provided with the
+     distribution.
+  3. The names of the authors may not be used to endorse or promote
+     products derived from this software without specific prior
+     written permission.
+
+  THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS
+  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+  GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+  IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
+  IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include <stdlib.h>
+
+#include "zipint.h"
+
+
+zip_source_t *
+zip_source_layered(zip_t *za, zip_source_t *src, zip_source_layered_callback cb, void *ud) {
+    if (za == NULL)
+        return NULL;
+
+    return zip_source_layered_create(src, cb, ud, &za->error);
+}
+
+
+zip_source_t *
+zip_source_layered_create(zip_source_t *src, zip_source_layered_callback cb, void *ud, zip_error_t *error) {
+    zip_source_t *zs;
+    zip_int64_t lower_supports, supports;
+
+    lower_supports = zip_source_supports(src);
+    supports = cb(src, ud, &lower_supports, sizeof(lower_supports), ZIP_SOURCE_SUPPORTS);
+    if (supports < 0) {
+        zip_error_set(error,ZIP_ER_INVAL, 0); /* Initialize in case cb doesn't return valid error. */
+        cb(src, ud, error, sizeof(*error), ZIP_SOURCE_ERROR);
+        return NULL;
+    }
+
+    if ((zs = _zip_source_new(error)) == NULL) {
+        return NULL;
+    }
+
+    zs->src = src;
+    zs->cb.l = cb;
+    zs->ud = ud;
+    zs->supports = supports;
+
+    /* Layered sources can't support writing, since we currently have no use case. If we want to revisit this, we have to define how the two sources interact. */
+    zs->supports &= ~(ZIP_SOURCE_SUPPORTS_WRITABLE & ~ZIP_SOURCE_SUPPORTS_SEEKABLE);
+
+    return zs;
+}