Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 107 insertions, 0 deletions

diff --git a/src/common/split.h b/src/common/split.h
new file mode 100644
index 000000000..1b12963ce
--- /dev/null
+++ b/src/common/split.h
@@ -0,0 +1,107 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab ft=cpp
+
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2019 Red Hat, Inc.
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+#pragma once
+
+#include <string_view>
+
+namespace ceph {
+
+// a forward iterator over the parts of a split string
+class spliterator {
+  std::string_view str; // full string
+  std::string_view delims; // delimiters
+
+  using size_type = std::string_view::size_type;
+  size_type pos = 0; // start position of current part
+  std::string_view part; // view of current part
+
+  // return the next part after the given position
+  std::string_view next(size_type end) {
+    pos = str.find_first_not_of(delims, end);
+    if (pos == str.npos) {
+      return {};
+    }
+    return str.substr(pos, str.find_first_of(delims, pos) - pos);
+  }
+ public:
+  // types required by std::iterator_traits
+  using difference_type = int;
+  using value_type = std::string_view;
+  using pointer = const value_type*;
+  using reference = const value_type&;
+  using iterator_category = std::forward_iterator_tag;
+
+  spliterator() = default;
+
+  spliterator(std::string_view str, std::string_view delims)
+    : str(str), delims(delims), pos(0), part(next(0))
+  {}
+
+  spliterator& operator++() {
+    part = next(pos + part.size());
+    return *this;
+  }
+  spliterator operator++(int) {
+    spliterator tmp = *this;
+    part = next(pos + part.size());
+    return tmp;
+  }
+
+  reference operator*() const { return part; }
+  pointer operator->() const { return &part; }
+
+  friend bool operator==(const spliterator& lhs, const spliterator& rhs) {
+    return lhs.part.data() == rhs.part.data()
+        && lhs.part.size() == rhs.part.size();
+  }
+  friend bool operator!=(const spliterator& lhs, const spliterator& rhs) {
+    return lhs.part.data() != rhs.part.data()
+        || lhs.part.size() != rhs.part.size();
+  }
+};
+
+// represents an immutable range of split string parts
+//
+// ranged-for loop example:
+//
+//   for (std::string_view s : split(input)) {
+//     ...
+//
+// container initialization example:
+//
+//   auto parts = split(input);
+//
+//   std::vector<std::string> strings;
+//   strings.assign(parts.begin(), parts.end());
+//
+class split {
+  std::string_view str; // full string
+  std::string_view delims; // delimiters
+ public:
+  split(std::string_view str, std::string_view delims = ";,= \t\n")
+    : str(str), delims(delims) {}
+
+  using iterator = spliterator;
+  using const_iterator = spliterator;
+
+  iterator begin() const { return {str, delims}; }
+  const_iterator cbegin() const { return {str, delims}; }
+
+  iterator end() const { return {}; }
+  const_iterator cend() const { return {}; }
+};
+
+} // namespace ceph