X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Fbuffer-view.cpp;fp=src%2Fcommon%2Fbuffer-view.cpp;h=ebe6869852f90a2bec8e7f1283e24cd130e2f04e;hp=0000000000000000000000000000000000000000;hb=a6bc4ca9d659caf016ef932fcd944029737ac57c;hpb=97535efaa975ca52bf02c2d5e76351bfd2e3defa

diff --git a/src/common/buffer-view.cpp b/src/common/buffer-view.cpp
new file mode 100644
index 000000000..ebe686985
--- /dev/null
+++ b/src/common/buffer-view.cpp
@@ -0,0 +1,115 @@
+/*
+ * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ */
+
+#include <common/buffer-view.h>
+#include <common/dynamic-buffer.h>
+#include <common/error.h>
+
+struct lttng_buffer_view lttng_buffer_view_init(
+		const char *src, size_t offset, ptrdiff_t len)
+{
+	struct lttng_buffer_view view = { .data = src + offset, .size = (size_t) len };
+	return view;
+}
+
+bool lttng_buffer_view_is_valid(const struct lttng_buffer_view *view)
+{
+	return view && view->data && view->size > 0;
+}
+
+struct lttng_buffer_view lttng_buffer_view_from_view(
+		const struct lttng_buffer_view *src, size_t offset,
+		ptrdiff_t len)
+{
+	struct lttng_buffer_view view = { .data = NULL, .size = 0 };
+
+	LTTNG_ASSERT(src);
+
+	if (offset > src->size) {
+		ERR("Attempt to create buffer view from another view with invalid offset (offset > source size): source size = %zu, offset in source = %zu, length = %zd",
+				src->size, offset, len);
+		goto end;
+	}
+
+	if (len != -1 && len > (src->size - offset)) {
+		ERR("Attempt to create buffer view from another view with invalid length (length > space left after offset in source): source size = %zu, offset in source = %zu, length = %zd",
+				src->size, offset, len);
+		goto end;
+	}
+
+	view.data = src->data + offset;
+	view.size = len == -1 ? (src->size - offset) : len;
+end:
+	return view;
+}
+
+struct lttng_buffer_view lttng_buffer_view_from_dynamic_buffer(
+		const struct lttng_dynamic_buffer *src, size_t offset,
+		ptrdiff_t len)
+{
+	struct lttng_buffer_view view = { .data = NULL, .size = 0 };
+
+	LTTNG_ASSERT(src);
+
+	if (offset > src->size) {
+		ERR("Attempt to create buffer view from a dynamic buffer with invalid offset (offset > source size): source size = %zu, offset in source = %zu, length = %zd",
+				src->size, offset, len);
+		goto end;
+	}
+
+	if (len != -1 && len > (src->size - offset)) {
+		ERR("Attempt to create buffer view from a dynamic buffer with invalid length (length > space left after offset in source): source size = %zu, offset in source = %zu, length = %zd",
+				src->size, offset, len);
+		goto end;
+	}
+
+	view.data = src->data + offset;
+	view.size = len == -1 ? (src->size - offset) : len;
+end:
+	return view;
+}
+
+bool lttng_buffer_view_contains_string(const struct lttng_buffer_view *buf,
+		const char *str,
+		size_t len_with_null_terminator)
+{
+	const char *past_buf_end;
+	size_t max_str_len_with_null_terminator;
+	size_t str_len;
+	bool ret;
+
+	past_buf_end = buf->data + buf->size;
+
+	/* Is the start of the string in the buffer view? */
+	if (str < buf->data || str >= past_buf_end) {
+		ret = false;
+		goto end;
+	}
+
+	/*
+	 * Max length the string could have to fit in the buffer, including
+	 * NULL terminator.
+	 */
+	max_str_len_with_null_terminator = past_buf_end - str;
+
+	/* Could the string even fit in the buffer? */
+	if (len_with_null_terminator > max_str_len_with_null_terminator) {
+		ret = false;
+		goto end;
+	}
+
+	str_len = lttng_strnlen(str, max_str_len_with_null_terminator);
+	if (str_len != (len_with_null_terminator - 1)) {
+		ret = false;
+		goto end;
+	}
+
+	ret = true;
+
+end:
+	return ret;
+}