背景

 1
 2 // FIXME: 不太理解为什么需要很多个clean up function
 3  // Cleanup functions are stored in a single-linked list.
 4  // The list's head node is inlined in the iterator.
 5  struct CleanupNode {
 6    // True if the node is not used. Only …

 1
 2class Arena {
 3 public:
 4  Arena();
 5
 6  Arena(const Arena&) = delete;
 7  Arena& operator=(const Arena&) = delete;
 8
 9  ~Arena();
10
11  // Return a pointer to a newly allocated memory block of "bytes" bytes.
12  char* Allocate(size_t bytes); …

 1
 2class LEVELDB_EXPORT FilterPolicy {
 3 public:
 4  virtual ~FilterPolicy();
 5
 6  // Return the name of this policy.  Note that if the filter encoding
 7  // changes in an incompatible way, the name returned by this method
 8  // must be changed.  Otherwise, old incompatible filters may be
 9  // …

 1
 2
 3namespace leveldb {
 4
 5class LEVELDB_EXPORT Cache;
 6
 7// Create a new cache with a fixed size capacity.  This implementation
 8// of Cache uses a least-recently-used eviction policy.
 9LEVELDB_EXPORT Cache* NewLRUCache(size_t …

 1
 2// A Comparator object provides a total order across slices that are
 3// used as keys in an sstable or a database.  A Comparator implementation
 4// must be thread-safe since leveldb may invoke its methods …