1 files changed, 124 insertions, 0 deletions
diff --git a/src/crimson/os/seastore/extentmap_manager.h b/src/crimson/os/seastore/extentmap_manager.h
new file mode 100644
index 000000000..7d5223b94
--- /dev/null
+++ b/src/crimson/os/seastore/extentmap_manager.h
@@ -0,0 +1,124 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#pragma once
+
+#include <iosfwd>
+#include <list>
+
+#include <boost/intrusive_ptr.hpp>
+#include <boost/smart_ptr/intrusive_ref_counter.hpp>
+
+#include <seastar/core/future.hh>
+
+#include "crimson/osd/exceptions.h"
+#include "crimson/os/seastore/seastore_types.h"
+#include "crimson/os/seastore/transaction_manager.h"
+
+#define PAGE_SIZE 4096
+#define EXTMAP_BLOCK_SIZE 4096
+
+namespace crimson::os::seastore {
+
+struct lext_map_val_t {
+  laddr_t laddr;
+  extent_len_t length = 0;
+
+  lext_map_val_t(
+    laddr_t laddr,
+    extent_len_t length)
+    : laddr(laddr), length(length) {}
+
+};
+
+class extent_mapping_t
+{
+public:
+  objaddr_t logical_offset = 0;  //offset in object
+  laddr_t laddr;     // lextent start address aligned with block size.
+  extent_len_t length = 0;
+  explicit extent_mapping_t(objaddr_t lo) : logical_offset(lo) { }
+
+  extent_mapping_t(
+    objaddr_t lo,
+    laddr_t laddr,
+    extent_len_t length)
+    : logical_offset(lo), laddr(laddr), length(length) {}
+
+  ~extent_mapping_t() {}
+};
+
+enum class extmap_root_state_t : uint8_t {
+  INITIAL = 0,
+  MUTATED = 1,
+  NONE = 0xFF
+};
+
+using extent_map_list_t = std::list<extent_mapping_t>;
+std::ostream &operator<<(std::ostream &out, const extent_mapping_t &rhs);
+std::ostream &operator<<(std::ostream &out, const extent_map_list_t &rhs);
+
+struct extmap_root_t {
+  depth_t depth = 0;
+  extmap_root_state_t state;
+  laddr_t extmap_root_laddr;
+  extmap_root_t(depth_t dep, laddr_t laddr)
+  : depth(dep),
+    extmap_root_laddr(laddr) { state = extmap_root_state_t::INITIAL; }
+};
+
+/**
+ * Abstract interface for managing the object inner offset to logical addr mapping
+ * each onode has an extentmap tree for a particular onode.
+ */
+class ExtentMapManager {
+public:
+  using initialize_extmap_ertr = TransactionManager::alloc_extent_ertr;
+  using initialize_extmap_ret = initialize_extmap_ertr::future<extmap_root_t>;
+  virtual initialize_extmap_ret initialize_extmap(Transaction &t) = 0;
+
+  /* find_lextents
+   *
+   * Return a list of all extent_mapping_t overlapping any portion of lo~len.
+   * or if not find any overlap extent_mapping_t will return the next extent after the range.
+   */
+  using find_lextent_ertr = TransactionManager::read_extent_ertr;
+  using find_lextent_ret = find_lextent_ertr::future<extent_map_list_t>;
+  virtual find_lextent_ret
+    find_lextent(const extmap_root_t &extmap_root, Transaction &t, objaddr_t lo, extent_len_t len) = 0;
+
+  /* add_lextent
+   *
+   * add a new mapping (object offset -> laddr, length) to extent map
+   * return the added extent_mapping_t
+   */
+  using add_lextent_ertr = TransactionManager::read_extent_ertr;
+  using add_lextent_ret = add_lextent_ertr::future<extent_mapping_t>;
+  virtual add_lextent_ret
+    add_lextent(extmap_root_t &extmap_root, Transaction &t, objaddr_t lo, lext_map_val_t val) = 0;
+
+  /* rm_lextent
+   *
+   * remove an existing extent mapping from extent map
+   * return true if the extent mapping is removed, otherwise return false
+   */
+  using rm_lextent_ertr = TransactionManager::read_extent_ertr;
+  using rm_lextent_ret = rm_lextent_ertr::future<bool>;
+  virtual rm_lextent_ret rm_lextent(extmap_root_t &extmap_root, Transaction &t, objaddr_t lo, lext_map_val_t val) = 0;
+
+  virtual ~ExtentMapManager() {}
+};
+using ExtentMapManagerRef = std::unique_ptr<ExtentMapManager>;
+
+namespace extentmap_manager {
+/* creat ExtentMapManager for an extentmap
+ * if it is a new extmap after create_extentmap_manager need call initialize_extmap
+ * to initialize the extent map before use it
+ * if it is an exsiting extmap, needn't initialize_extmap
+ */
+ExtentMapManagerRef create_extentmap_manager(
+  TransactionManager &trans_manager);
+
+}
+
+}