test code v1

src/decompressor_zstd.c

@@ -0,0 +1,127 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/* Minimal zstd decompressor for EROFS FreeBSD */
+#include <sys/param.h>
+#include <sys/malloc.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+
+#include "internal.h"
+
+#ifdef ZSTDIO
+#define ZSTD_STATIC_LINKING_ONLY
+#include <contrib/zstd/lib/zstd.h>
+#endif
+
+bool
+erofs_zstd_available(void)
+{
+#ifdef ZSTDIO
+	return (true);
+#else
+	return (false);
+#endif
+}
+
+int
+z_erofs_load_zstd_config(struct erofs_mount *em, const void *data,
+    size_t size)
+{
+	const struct z_erofs_zstd_cfgs *zstd;
+
+	if (!erofs_zstd_available()) {
+		vfs_mount_error(em->mnt,
+		    "erofs: ZSTD compression requires ZSTDIO support");
+		return (EOPNOTSUPP);
+	}
+	if (size < sizeof(*zstd))
+		return (EINVAL);
+	zstd = data;
+	if (zstd->format != 0 || zstd->windowlog > 10)
+		return (EOPNOTSUPP);
+	em->zstd_windowlog = zstd->windowlog;
+	return (0);
+}
+
+#ifdef ZSTDIO
+static void *
+zstd_alloc(void *opaque, size_t size)
+{
+	return (malloc(size, opaque, M_WAITOK));
+}
+
+static void
+zstd_free(void *opaque, void *address)
+{
+	free(address, opaque);
+}
+
+static const ZSTD_customMem zstd_erofs_alloc = {
+	.customAlloc = zstd_alloc,
+	.customFree = zstd_free,
+	.opaque = M_EROFS,
+};
+
+int
+zstd_decompress(void *src, size_t srclen, void *dst, size_t dstlen, int n,
+    bool partial)
+{
+	ZSTD_DCtx *dctx;
+	ZSTD_inBuffer input;
+	ZSTD_outBuffer output;
+	size_t in_before, out_before, ret;
+	int error;
+
+	if (n < 10 || n > 20 || dstlen == 0)
+		return (-1);
+	dctx = ZSTD_createDCtx_advanced(zstd_erofs_alloc);
+	if (dctx == NULL)
+		return (-1);
+	ret = ZSTD_DCtx_setParameter(dctx, ZSTD_d_windowLogMax, n);
+	if (ZSTD_isError(ret)) {
+		ZSTD_freeDCtx(dctx);
+		return (-1);
+	}
+
+	input = (ZSTD_inBuffer) {
+		.src = src,
+		.size = srclen,
+	};
+	output = (ZSTD_outBuffer) {
+		.dst = dst,
+		.size = dstlen,
+	};
+	ret = 1;
+	while (output.pos != output.size) {
+		in_before = input.pos;
+		out_before = output.pos;
+		ret = ZSTD_decompressStream(dctx, &output, &input);
+		if (ZSTD_isError(ret) ||
+		    (input.pos == in_before && output.pos == out_before))
+			break;
+		if (ret == 0)
+			break;
+	}
+	error = 0;
+	if (ZSTD_isError(ret) || output.pos != output.size)
+		error = -1;
+	else if (!partial && (ret != 0 || input.pos != input.size))
+		error = -1;
+	ret = ZSTD_freeDCtx(dctx);
+	if (ZSTD_isError(ret))
+		error = -1;
+	return (error);
+}
+#else
+int
+zstd_decompress(void *src, size_t srclen, void *dst, size_t dstlen, int n,
+    bool partial)
+{
+	(void)src;
+	(void)srclen;
+	(void)dst;
+	(void)dstlen;
+	(void)n;
+	(void)partial;
+	return (-1);
+}
+#endif