Add scratchbuf implementation

This should fill the requirements for "we need to loop over a lot of
strings that usually are small enough to remain on stack, but we want to
protect ourselves against huge strings not fitting in the static
buffer we estimated as sufficient"

2 files changed, 92 insertions, 0 deletions

diff --git a/testsuite/.gitignore b/testsuite/.gitignore
index 2b71a47..9d26b88 100644
--- a/testsuite/.gitignore
+++ b/testsuite/.gitignore
@@ -2,6 +2,7 @@
 *.la
 *.so
 /.dirstamp
+/test-scratchbuf
 /test-strbuf
 /test-array
 /test-util
@@ -20,6 +21,8 @@
 /test-tools
 /rootfs
 /stamp-rootfs
+/test-scratchbuf.log
+/test-scratchbuf.trs
 /test-strbuf.log
 /test-strbuf.trs
 /test-array.log
diff --git a/testsuite/test-scratchbuf.c b/testsuite/test-scratchbuf.c
new file mode 100644
index 0000000..6d86957
--- /dev/null
+++ b/testsuite/test-scratchbuf.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C)  2016 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <shared/scratchbuf.h>
+
+#include "testsuite.h"
+
+static int test_scratchbuf_onlystack(const struct test *t)
+{
+	struct scratchbuf sbuf;
+	const char *smallstr = "xyz";
+	char buf[3 + 2];
+	char buf2[3 + 1];
+
+	scratchbuf_init(&sbuf, buf, sizeof(buf));
+	assert_return(scratchbuf_alloc(&sbuf, strlen(smallstr) + 1) == 0, EXIT_FAILURE);
+	assert_return(sbuf.need_free == false, EXIT_FAILURE);
+	scratchbuf_release(&sbuf);
+
+	scratchbuf_init(&sbuf, buf2, sizeof(buf2));
+	assert_return(scratchbuf_alloc(&sbuf, strlen(smallstr) + 1) == 0, EXIT_FAILURE);
+	assert_return(sbuf.need_free == false, EXIT_FAILURE);
+	scratchbuf_release(&sbuf);
+
+	memcpy(scratchbuf_str(&sbuf), smallstr, strlen(smallstr) + 1);
+	assert_return(strcmp(scratchbuf_str(&sbuf), smallstr) == 0, EXIT_FAILURE);
+
+	return 0;
+}
+DEFINE_TEST(test_scratchbuf_onlystack,
+		.description = "test scratchbuf for buffer on stack only");
+
+
+static int test_scratchbuf_heap(const struct test *t)
+{
+	struct scratchbuf sbuf;
+	const char *smallstr = "xyz";
+	const char *largestr = "xyzxyzxyz";
+	const char *largestr2 = "xyzxyzxyzxyzxyz";
+	char buf[3 + 1];
+
+	scratchbuf_init(&sbuf, buf, sizeof(buf));
+
+	/* Initially only on stack */
+	assert_return(scratchbuf_alloc(&sbuf, strlen(smallstr) + 1) == 0, EXIT_FAILURE);
+	assert_return(sbuf.need_free == false, EXIT_FAILURE);
+	memcpy(scratchbuf_str(&sbuf), smallstr, strlen(smallstr) + 1);
+
+	/* Grow once to heap */
+	assert_return(scratchbuf_alloc(&sbuf, strlen(largestr) + 1) == 0, EXIT_FAILURE);
+	assert_return(sbuf.need_free == true, EXIT_FAILURE);
+	assert_return(sbuf.size == strlen(largestr) + 1, EXIT_FAILURE);
+	assert_return(strcmp(scratchbuf_str(&sbuf), smallstr) == 0, EXIT_FAILURE);
+	memcpy(scratchbuf_str(&sbuf), largestr, strlen(largestr) + 1);
+	assert_return(strcmp(scratchbuf_str(&sbuf), largestr) == 0, EXIT_FAILURE);
+
+	/* Grow again - realloc should take place */
+	assert_return(scratchbuf_alloc(&sbuf, strlen(largestr2) + 1) == 0, EXIT_FAILURE);
+	assert_return(sbuf.need_free == true, EXIT_FAILURE);
+	assert_return(sbuf.size == strlen(largestr2) + 1, EXIT_FAILURE);
+	memcpy(scratchbuf_str(&sbuf), largestr2, strlen(largestr2) + 1);
+	assert_return(strcmp(scratchbuf_str(&sbuf), largestr2) == 0, EXIT_FAILURE);
+
+	scratchbuf_release(&sbuf);
+
+	return 0;
+}
+DEFINE_TEST(test_scratchbuf_heap,
+		.description = "test scratchbuf for buffer on that grows to heap");
+
+TESTSUITE_MAIN();