libio: Add a test case for istream-to-ostream splice

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

2 files changed, 123 insertions, 2 deletions

diff --git a/lib/io/Makemodule.am b/lib/io/Makemodule.am
index b8c03f6..b795788 100644
--- a/lib/io/Makemodule.am
+++ b/lib/io/Makemodule.am
@@ -29,9 +29,12 @@ test_istream_read_LDADD = libio.a libutil.a libcompat.a
 test_istream_skip_SOURCES = lib/io/test/istream_skip.c
 test_istream_skip_LDADD = libio.a libutil.a libcompat.a
 
+test_stream_splice_SOURCES = lib/io/test/stream_splice.c
+test_stream_splice_LDADD = libio.a libutil.a libcompat.a
+
 check_PROGRAMS += test_get_line test_sparse_fb test_istream_read
-check_PROGRAMS += test_istream_skip
+check_PROGRAMS += test_istream_skip test_stream_splice
 TESTS += test_get_line test_sparse_fb test_istream_read
-TESTS += test_istream_skip
+TESTS += test_istream_skip test_stream_splice
 
 EXTRA_DIST += $(top_srcdir)/lib/io/test/get_line.txt
diff --git a/lib/io/test/stream_splice.c b/lib/io/test/stream_splice.c
new file mode 100644
index 0000000..c5ca38e
--- /dev/null
+++ b/lib/io/test/stream_splice.c
@@ -0,0 +1,118 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * stream_splice.c
+ *
+ * Copyright (C) 2023 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "io/istream.h"
+#include "io/ostream.h"
+#include "util/test.h"
+
+static const sqfs_u64 end0 = 449;	/* region 1: filled with 'A' */
+static const sqfs_u64 end1 = 521;	/* region 2: filled with 'B' */
+static const sqfs_u64 end2 = 941;	/* region 3: filled with 'C' */
+
+static sqfs_u8 byte_at_offset(sqfs_u64 off)
+{
+	if (off < end0)
+		return 'A';
+	if (off < end1)
+		return 'B';
+	return 'C';
+}
+
+/*****************************************************************************/
+
+static int out_append(ostream_t *strm, const void *data, size_t size);
+
+static sqfs_u64 out_offset = 0;
+
+static ostream_t out = {
+	{ 1, NULL, NULL },
+	out_append,
+	NULL,
+	NULL,
+	NULL,
+};
+
+static int out_append(ostream_t *strm, const void *data, size_t size)
+{
+	const sqfs_u8 *ptr = data;
+
+	TEST_ASSERT(strm == &out);
+	TEST_ASSERT(size > 0);
+
+	while (size--) {
+		sqfs_u8 x = *(ptr++);
+		sqfs_u8 y = byte_at_offset(out_offset++);
+
+		TEST_EQUAL_UI(x, y);
+		TEST_ASSERT(out_offset <= end2);
+	}
+
+	return 0;
+}
+
+/*****************************************************************************/
+
+static int in_precache(istream_t *strm);
+
+static sqfs_u8 in_buffer[109];
+static sqfs_u64 in_offset = 0;
+
+static istream_t in = {
+	{ 1, NULL, NULL },
+	0,
+	0,
+	false,
+	in_buffer,
+	in_precache,
+	NULL,
+};
+
+static int in_precache(istream_t *strm)
+{
+	TEST_ASSERT(strm == &in);
+
+	while (strm->buffer_used < sizeof(in_buffer)) {
+		if (in_offset == end2) {
+			strm->eof = true;
+			break;
+		}
+
+		in_buffer[strm->buffer_used++] = byte_at_offset(in_offset++);
+	}
+
+	return 0;
+}
+
+/*****************************************************************************/
+
+int main(int argc, char **argv)
+{
+	sqfs_u64 total = 0;
+	sqfs_s32 ret;
+	(void)argc; (void)argv;
+
+	for (;;) {
+		ret = ostream_append_from_istream(&out, &in, 211);
+		TEST_ASSERT(ret >= 0);
+
+		if (ret == 0)
+			break;
+
+		total += ret;
+		TEST_ASSERT(total <= end2);
+		TEST_ASSERT(out_offset <= end2);
+		TEST_ASSERT(in_offset <= end2);
+		TEST_ASSERT(in_offset >= out_offset);
+		TEST_EQUAL_UI(total, out_offset);
+	}
+
+	TEST_EQUAL_UI(total, end2);
+	TEST_EQUAL_UI(out_offset, end2);
+	TEST_EQUAL_UI(in_offset, end2);
+	return EXIT_SUCCESS;
+}