From 453219cb12d3de60c422fb98fce86d46ea26cbb9 Mon Sep 17 00:00:00 2001
From: Matt Benjamin <mbenjamin@redhat.com>
Date: Tue, 22 Dec 2015 02:15:42 -0500
Subject: [PATCH] librgw: implement small-directory name cache

Augment the existing marker cache with cache of name->type
mappings for up to 128 dirents (appx. 4x the common upper-bound
of 32).

The motivation here is to use the name and type information from
readdir, rather than discarding it.  Boosts perf. at least 60%
on unit test corpus.

Signed-off-by: Matt Benjamin <mbenjamin@redhat.com>
---
 src/rgw/rgw_file.cc | 17 ++++++++++++++++-
 src/rgw/rgw_file.h  | 18 ++++++++++++++----
 2 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/src/rgw/rgw_file.cc b/src/rgw/rgw_file.cc
index d9fd84c7d5f2..4dbb36559360 100644
--- a/src/rgw/rgw_file.cc
+++ b/src/rgw/rgw_file.cc
@@ -62,9 +62,24 @@ namespace rgw {
   {
     /* find either-of <object_name>, <object_name/>, only one of
      * which should exist;  atomicity? */
+    using std::get;
+
     LookupFHResult fhr{nullptr, 0};
+    RGWFileHandle::directory* d = parent->get_directory();
+    if (! d->name_cache.empty()) {
+      RGWFileHandle::dirent_string name{path};
+      const auto& diter = d->name_cache.find(name);
+      if (diter != d->name_cache.end()) {
+	fhr = lookup_fh(parent, path,
+			RGWFileHandle::FLAG_CREATE|
+			((diter->second == RGW_FS_TYPE_DIRECTORY) ?
+			  RGWFileHandle::FLAG_DIRECTORY :
+			  RGWFileHandle::FLAG_NONE));
+	if (get<0>(fhr))
+	  return fhr;
+      }
+    }
     std::string object_name{path};
-
     for (auto ix : { 0, 1 }) {
       switch (ix) {
       case 0:
diff --git a/src/rgw/rgw_file.h b/src/rgw/rgw_file.h
index aaafd384c91e..d4eb03673dda 100644
--- a/src/rgw/rgw_file.h
+++ b/src/rgw/rgw_file.h
@@ -203,8 +203,8 @@ namespace rgw {
 
   private:
     RGWFileHandle(RGWLibFS* _fs, uint32_t fs_inst)
-      : fs(_fs), bucket(nullptr), parent(nullptr), depth(0),
-	flags(FLAG_ROOT)
+      : fs(_fs), bucket(nullptr), parent(nullptr), variant_type{directory()},
+	depth(0), flags(FLAG_ROOT)
       {
 	/* root */
 	fh.fh_type = RGW_FS_TYPE_DIRECTORY;
@@ -231,12 +231,18 @@ namespace rgw {
 
       if (parent->is_root()) {
 	fh.fh_type = RGW_FS_TYPE_DIRECTORY;
+	variant_type = directory();
 	flags |= FLAG_BUCKET;
       } else {
 	bucket = (parent->flags & FLAG_BUCKET) ? parent
 	  : parent->bucket;
-	fh.fh_type = (flags & FLAG_DIRECTORY) ? RGW_FS_TYPE_DIRECTORY
-	  : RGW_FS_TYPE_FILE;
+	if (flags & FLAG_DIRECTORY) {
+	  fh.fh_type = RGW_FS_TYPE_DIRECTORY;
+	  variant_type = directory();
+	} else {
+	  fh.fh_type = RGW_FS_TYPE_FILE;
+	  variant_type = file();
+	}
       }
 
       depth = parent->depth + 1;
@@ -252,6 +258,10 @@ namespace rgw {
       return fhk;
     }
 
+    directory* get_directory() {
+      return get<directory>(&variant_type);
+    }
+
     size_t get_size() const { return state.size; }
 
     uint16_t get_depth() const { return depth; }
-- 
2.47.3