common: compile libcommon as C++

[lttng-tools.git] / src / common / buffer-view.cpp

diff --git a/src/common/buffer-view.cpp b/src/common/buffer-view.cpp
new file mode 100644 (file)
index 0000000..ebe6869
--- /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;
+}