Add block queue rotational parsing

Author: dtrugman

include/pfs/block.hpp

@@ -18,6 +18,7 @@
 #define PFS_BLOCK_HPP
 
 #include "types.hpp"
+#include "block_queue.hpp"
 
 namespace pfs {
 
@@ -40,6 +41,7 @@ class block final
     dev_t get_dev() const;
 
     block_stat get_stat() const;
+    block_queue get_queue() const;
 
 public: // Getters
 

include/pfs/block_queue.hpp

@@ -0,0 +1,56 @@
+/*
+ *  Copyright 2020-present Daniel Trugman
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef PFS_BLOCK_QUEUE_HPP
+#define PFS_BLOCK_QUEUE_HPP
+
+#include "types.hpp"
+
+namespace pfs {
+
+// Hint: See 'https://www.kernel.org/doc/Documentation/block/queue-sysfs.txt'
+class block_queue final
+{
+public:
+    block_queue(const block_queue&) = default;
+    block_queue(block_queue&&)      = default;
+
+    block_queue& operator=(const block_queue&) = delete;
+    block_queue& operator=(block_queue&&) = delete;
+
+public: // Properties
+    const std::string& dir() const;
+
+public: // Getters
+    bool get_rotational() const;
+
+private:
+    friend class block;
+    block_queue(const std::string& block_root);
+
+private:
+    static std::string build_block_queue_root(const std::string& block_root);
+
+private:
+    static const std::string QUEUE_DIR;
+
+private:
+    const std::string _block_queue_root;
+};
+
+} // namespace pfs
+
+#endif // PFS_BLOCK_HPP

sample/enum_block.cpp

@@ -36,6 +36,9 @@ static void enum_block(const pfs::block& block)
 
         auto stat = block.get_stat();
         print(stat);
+
+        auto queue = block.get_queue();
+        print(queue);
     }
     catch (const std::runtime_error& ex)
     {

sample/format.hpp

@@ -19,6 +19,7 @@
 #include <sstream>
 
 #include "pfs/procfs.hpp"
+#include "pfs/sysfs.hpp"
 
 template <typename T>
 inline std::string join(const T& container)
@@ -748,3 +749,12 @@ inline std::ostream& operator<<(std::ostream& out,
 
     return out;
 }
+
+inline std::ostream& operator<<(std::ostream& out,
+                                const pfs::block_queue& queue)
+{
+    out << std::boolalpha;
+    out << "rotational[" << queue.get_rotational() << "] ";
+
+    return out;
+}

src/block.cpp

@@ -83,4 +83,9 @@ block_stat block::get_stat() const
     return parsers::parse_block_stat_line(line);
 }
 
+block_queue block::get_queue() const
+{
+    return block_queue(_block_root);
+}
+
 } // namespace pfs

src/block_queue.cpp

@@ -0,0 +1,56 @@
+/*
+ *  Copyright 2020-present Daniel Trugman
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#include <string>
+
+#include "pfs/defer.hpp"
+#include "pfs/parsers/common.hpp"
+#include "pfs/parsers/generic.hpp"
+#include "pfs/block_queue.hpp"
+
+namespace pfs {
+
+using namespace impl;
+
+const std::string block_queue::QUEUE_DIR("queue/");
+
+block_queue::block_queue(const std::string& block_root)
+    : _block_queue_root(build_block_queue_root(block_root))
+{}
+
+std::string block_queue::build_block_queue_root(const std::string& block_root)
+{
+    return block_root + QUEUE_DIR;
+}
+
+const std::string& block_queue::dir() const
+{
+    return _block_queue_root;
+}
+
+bool block_queue::get_rotational() const
+{
+    static const std::string SIZE_FILE("rotational");
+    auto path = _block_queue_root + SIZE_FILE;
+
+    auto value = utils::readline(path);
+
+    int number;
+    parsers::to_number(value, number, utils::base::decimal);
+    return number != 0;
+}
+
+} // namespace pfs