1 files changed, 128 insertions, 0 deletions
diff --git a/src/crimson/os/seastore/segment_manager.h b/src/crimson/os/seastore/segment_manager.h
new file mode 100644
index 000000000..61c6509d1
--- /dev/null
+++ b/src/crimson/os/seastore/segment_manager.h
@@ -0,0 +1,128 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#pragma once
+
+#include <iosfwd>
+
+#include <boost/intrusive_ptr.hpp>
+#include <boost/smart_ptr/intrusive_ref_counter.hpp>
+#include <seastar/core/future.hh>
+
+#include "include/ceph_assert.h"
+#include "crimson/os/seastore/seastore_types.h"
+#include "include/buffer_fwd.h"
+#include "crimson/osd/exceptions.h"
+
+namespace crimson::os::seastore {
+
+class Segment : public boost::intrusive_ref_counter<
+  Segment,
+  boost::thread_unsafe_counter>{
+public:
+
+  enum class segment_state_t : uint8_t {
+    EMPTY = 0,
+    OPEN = 1,
+    CLOSED = 2
+  };
+
+  /**
+   * get_segment_id
+   */
+  virtual segment_id_t get_segment_id() const = 0;
+
+  /**
+   * min next write location
+   */
+  virtual segment_off_t get_write_ptr() const = 0;
+
+  /**
+   * max capacity
+   */
+  virtual segment_off_t get_write_capacity() const = 0;
+
+  /**
+   * close
+   *
+   * Closes segment for writes.  Won't complete until
+   * outstanding writes to this segment are complete.
+   */
+  using close_ertr = crimson::errorator<
+    crimson::ct_error::input_output_error,
+    crimson::ct_error::invarg,
+    crimson::ct_error::enoent>;
+  virtual close_ertr::future<> close() = 0;
+
+
+  /**
+   * write
+   *
+   * @param offset offset of write, must be aligned to <> and >= write pointer, advances
+   *               write pointer
+   * @param bl     buffer to write, will be padded if not aligned
+  */
+  using write_ertr = crimson::errorator<
+    crimson::ct_error::input_output_error, // media error or corruption
+    crimson::ct_error::invarg,             // if offset is < write pointer or misaligned
+    crimson::ct_error::ebadf,              // segment closed
+    crimson::ct_error::enospc              // write exceeds segment size
+    >;
+  virtual write_ertr::future<> write(
+    segment_off_t offset, ceph::bufferlist bl) = 0;
+
+  virtual ~Segment() {}
+};
+using SegmentRef = boost::intrusive_ptr<Segment>;
+
+constexpr size_t PADDR_SIZE = sizeof(paddr_t);
+
+class SegmentManager {
+public:
+  using open_ertr = crimson::errorator<
+    crimson::ct_error::input_output_error,
+    crimson::ct_error::invarg,
+    crimson::ct_error::enoent>;
+  virtual open_ertr::future<SegmentRef> open(segment_id_t id) = 0;
+
+  using release_ertr = crimson::errorator<
+    crimson::ct_error::input_output_error,
+    crimson::ct_error::invarg,
+    crimson::ct_error::enoent>;
+  virtual release_ertr::future<> release(segment_id_t id) = 0;
+
+  using read_ertr = crimson::errorator<
+    crimson::ct_error::input_output_error,
+    crimson::ct_error::invarg,
+    crimson::ct_error::enoent,
+    crimson::ct_error::erange>;
+  virtual read_ertr::future<> read(
+    paddr_t addr,
+    size_t len,
+    ceph::bufferptr &out) = 0;
+  read_ertr::future<ceph::bufferptr> read(
+    paddr_t addr,
+    size_t len) {
+    auto ptrref = std::make_unique<ceph::bufferptr>(
+      buffer::create_page_aligned(len));
+    return read(addr, len, *ptrref).safe_then(
+      [ptrref=std::move(ptrref)]() mutable {
+	return read_ertr::make_ready_future<bufferptr>(std::move(*ptrref));
+      });
+  }
+
+  /* Methods for discovering device geometry, segmentid set, etc */
+  virtual size_t get_size() const = 0;
+  virtual segment_off_t get_block_size() const = 0;
+  virtual segment_off_t get_segment_size() const = 0;
+  virtual segment_id_t get_num_segments() const {
+    ceph_assert(get_size() % get_segment_size() == 0);
+    return ((segment_id_t)(get_size() / get_segment_size()));
+  }
+  virtual const seastore_meta_t &get_meta() const = 0;
+
+  virtual ~SegmentManager() {}
+};
+using SegmentManagerRef = std::unique_ptr<SegmentManager>;
+
+}