1 files changed, 136 insertions, 0 deletions
diff --git a/lib/io/test/istream_read.c b/lib/io/test/istream_read.c
new file mode 100644
index 0000000..3e4c22f
--- /dev/null
+++ b/lib/io/test/istream_read.c
@@ -0,0 +1,136 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * istream_read.c
+ *
+ * Copyright (C) 2023 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "io/istream.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 buffer[103];		/* sliding window into the file */
+static sqfs_u64 offset = 0;		/* byte offset into the "file" */
+
+static int dummy_precache(istream_t *strm);
+static const char *dummy_get_filename(istream_t *strm);
+
+static istream_t dummy = {
+	{
+		1,
+		NULL,
+		NULL,
+	},
+	0,
+	0,
+	false,
+	buffer,
+	dummy_precache,
+	dummy_get_filename,
+};
+
+static int dummy_precache(istream_t *strm)
+{
+	sqfs_u8 x;
+
+	TEST_ASSERT(strm == &dummy);
+
+	while (strm->buffer_used < sizeof(buffer)) {
+		if (offset < end0) {
+			x = 'A';
+		} else if (offset < end1) {
+			x = 'B';
+		} else if (offset < end2) {
+			x = 'C';
+		} else {
+			strm->eof = true;
+			break;
+		}
+
+		strm->buffer[strm->buffer_used++] = x;
+		++offset;
+	}
+
+	return 0;
+}
+
+static const char *dummy_get_filename(istream_t *strm)
+{
+	TEST_ASSERT(strm == &dummy);
+	return "dummy file";
+}
+
+int main(int argc, char **argv)
+{
+	sqfs_u8 read_buffer[61];
+	sqfs_u64 read_off = 0;
+	const char *name;
+	(void)argc; (void)argv;
+
+	name = istream_get_filename(&dummy);
+	TEST_NOT_NULL(name);
+	TEST_STR_EQUAL(name, "dummy file");
+
+	/* region 1 */
+	while (read_off < end0) {
+		size_t read_diff = end0 - read_off;
+
+		if (read_diff > sizeof(read_buffer))
+			read_diff = sizeof(read_buffer);
+
+		int ret = istream_read(&dummy, read_buffer, read_diff);
+		TEST_ASSERT(ret > 0);
+		TEST_ASSERT((size_t)ret <= read_diff);
+
+		for (int i = 0; i < ret; ++i) {
+			TEST_EQUAL_UI(read_buffer[i], 'A');
+		}
+
+		read_off += ret;
+	}
+
+	/* region 2 */
+	while (read_off < end1) {
+		size_t read_diff = end1 - read_off;
+
+		if (read_diff > sizeof(read_buffer))
+			read_diff = sizeof(read_buffer);
+
+		int ret = istream_read(&dummy, read_buffer, read_diff);
+		TEST_ASSERT(ret > 0);
+		TEST_ASSERT((size_t)ret <= read_diff);
+
+		for (int i = 0; i < ret; ++i) {
+			TEST_EQUAL_UI(read_buffer[i], 'B');
+		}
+
+		read_off += ret;
+	}
+
+	/* region 3 */
+	for (;;) {
+		size_t read_diff = sizeof(read_buffer);
+
+		int ret = istream_read(&dummy, read_buffer, read_diff);
+		TEST_ASSERT(ret >= 0);
+		TEST_ASSERT((size_t)ret <= read_diff);
+
+		if (ret == 0) {
+			TEST_EQUAL_UI(read_off, end2);
+			break;
+		}
+
+		for (int i = 0; i < ret; ++i) {
+			TEST_EQUAL_UI(read_buffer[i], 'C');
+		}
+
+		read_off += ret;
+		TEST_ASSERT(read_off <= end2);
+	}
+
+	return EXIT_SUCCESS;
+}