From 244f97a68e9d0f1aab34206caa43254c210ebb1b Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 30 Aug 2021 08:13:50 +0900
Subject: [PATCH 01/26] Cache entries' cover_url

---
 src/library/entry.cr | 12 ++++++++++--
 src/library/title.cr |  5 ++++-
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/library/entry.cr b/src/library/entry.cr
index 92f4def..b5e582f 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -81,9 +81,17 @@ class Entry
 
   def cover_url
     return "#{Config.current.base_url}img/icon.png" if @err_msg
+
+    unless @book.entry_cover_url_cache
+      TitleInfo.new @book.dir do |info|
+        @book.entry_cover_url_cache = info.entry_cover_url
+      end
+    end
+    entry_cover_url = @book.entry_cover_url_cache
+
     url = "#{Config.current.base_url}api/cover/#{@book.id}/#{@id}"
-    TitleInfo.new @book.dir do |info|
-      info_url = info.entry_cover_url[@title]?
+    if entry_cover_url
+      info_url = entry_cover_url[@title]?
       unless info_url.nil? || info_url.empty?
         url = File.join Config.current.base_url, info_url
       end
diff --git a/src/library/title.cr b/src/library/title.cr
index 61c9813..6f2cf8c 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -3,9 +3,12 @@ require "../archive"
 class Title
   getter dir : String, parent_id : String, title_ids : Array(String),
     entries : Array(Entry), title : String, id : String,
-    encoded_title : String, mtime : Time, signature : UInt64
+    encoded_title : String, mtime : Time, signature : UInt64,
+    entry_cover_url_cache : Hash(String, String)?
+  setter entry_cover_url_cache : Hash(String, String)?
 
   @entry_display_name_cache : Hash(String, String)?
+  @entry_cover_url_cache : Hash(String, String)?
 
   def initialize(@dir : String, @parent_id)
     storage = Storage.default

From 51a47b5dddec78840dd496ec03fe956a264ae1c5 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 30 Aug 2021 08:17:52 +0900
Subject: [PATCH 02/26] Cache display_name

---
 src/library/title.cr | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/library/title.cr b/src/library/title.cr
index 6f2cf8c..2983a69 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -9,6 +9,7 @@ class Title
 
   @entry_display_name_cache : Hash(String, String)?
   @entry_cover_url_cache : Hash(String, String)?
+  @cached_display_name : String?
 
   def initialize(@dir : String, @parent_id)
     storage = Storage.default
@@ -180,11 +181,15 @@ class Title
   end
 
   def display_name
+    cached_display_name = @cached_display_name
+    return cached_display_name unless cached_display_name.nil?
+
     dn = @title
     TitleInfo.new @dir do |info|
       info_dn = info.display_name
       dn = info_dn unless info_dn.empty?
     end
+    @cached_display_name = dn
     dn
   end
 
@@ -208,6 +213,7 @@ class Title
   end
 
   def set_display_name(dn)
+    @cached_display_name = nil
     TitleInfo.new @dir do |info|
       info.display_name = dn
       info.save
@@ -217,6 +223,7 @@ class Title
   def set_display_name(entry_name : String, dn)
     TitleInfo.new @dir do |info|
       info.entry_display_name[entry_name] = dn
+      @entry_display_name_cache = info.entry_display_name
       info.save
     end
   end

From 00c9cc1fcdffa1b41dddfbb21bf348252c450706 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 30 Aug 2021 08:19:15 +0900
Subject: [PATCH 03/26] Prevent saving a sort opt unnecessarily

---
 src/library/library.cr |  5 -----
 src/library/title.cr   |  6 +-----
 src/routes/main.cr     |  6 +++---
 src/util/web.cr        | 20 ++++++++++++++++++++
 4 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/src/library/library.cr b/src/library/library.cr
index a5a4a80..30e93b2 100644
--- a/src/library/library.cr
+++ b/src/library/library.cr
@@ -51,11 +51,6 @@ class Library
   def sorted_titles(username, opt : SortOptions? = nil)
     if opt.nil?
       opt = SortOptions.from_info_json @dir, username
-    else
-      TitleInfo.new @dir do |info|
-        info.sort_by[username] = opt.to_tuple
-        info.save
-      end
     end
 
     # Helper function from src/util/util.cr
diff --git a/src/library/title.cr b/src/library/title.cr
index 2983a69..aa4a479 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -1,3 +1,4 @@
+require "digest"
 require "../archive"
 
 class Title
@@ -329,11 +330,6 @@ class Title
   def sorted_entries(username, opt : SortOptions? = nil)
     if opt.nil?
       opt = SortOptions.from_info_json @dir, username
-    else
-      TitleInfo.new @dir do |info|
-        info.sort_by[username] = opt.to_tuple
-        info.save
-      end
     end
 
     case opt.not_nil!.method
diff --git a/src/routes/main.cr b/src/routes/main.cr
index 57917bb..4aa7da6 100644
--- a/src/routes/main.cr
+++ b/src/routes/main.cr
@@ -41,7 +41,7 @@ struct MainRouter
         username = get_username env
 
         sort_opt = SortOptions.from_info_json Library.default.dir, username
-        get_sort_opt
+        get_and_save_sort_opt Library.default.dir
 
         titles = Library.default.sorted_titles username, sort_opt
         percentage = titles.map &.load_percentage username
@@ -59,12 +59,12 @@ struct MainRouter
         username = get_username env
 
         sort_opt = SortOptions.from_info_json title.dir, username
-        get_sort_opt
+        get_and_save_sort_opt title.dir
 
         entries = title.sorted_entries username, sort_opt
-
         percentage = title.load_percentage_for_all_entries username, sort_opt
         title_percentage = title.titles.map &.load_percentage username
+
         layout "title"
       rescue e
         Logger.error e
diff --git a/src/util/web.cr b/src/util/web.cr
index 12459e5..5704ea8 100644
--- a/src/util/web.cr
+++ b/src/util/web.cr
@@ -107,6 +107,26 @@ macro get_sort_opt
   end
 end
 
+macro get_and_save_sort_opt(dir)
+  sort_method = env.params.query["sort"]?
+
+  if sort_method
+    is_ascending = true
+
+    ascend = env.params.query["ascend"]?
+    if ascend && ascend.to_i? == 0
+      is_ascending = false
+    end
+
+    sort_opt = SortOptions.new sort_method, is_ascending
+
+    TitleInfo.new {{dir}} do |info|
+      info.sort_by[username] = sort_opt.to_tuple
+      info.save
+    end
+  end
+end
+
 module HTTP
   class Client
     private def self.exec(uri : URI, tls : TLSContext = nil)

From 4a09aee1771b8aca11b666a83c7ad906355c43e2 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sun, 22 Aug 2021 23:36:28 +0900
Subject: [PATCH 04/26] Implement library caching TitleInfo

* Cache sum of entry progress
* Cache cover_url
* Cache display_name
* Cache sort_opt
---
 src/library/cache.cr   | 159 +++++++++++++++++++++++++++++++++++++++++
 src/library/entry.cr   |  10 +++
 src/library/library.cr |   4 ++
 src/library/title.cr   |  25 ++++++-
 src/library/types.cr   |   3 +
 src/util/web.cr        |   1 +
 6 files changed, 200 insertions(+), 2 deletions(-)
 create mode 100644 src/library/cache.cr

diff --git a/src/library/cache.cr b/src/library/cache.cr
new file mode 100644
index 0000000..00c65ba
--- /dev/null
+++ b/src/library/cache.cr
@@ -0,0 +1,159 @@
+require "digest"
+
+class InfoCache
+  alias ProgressCache = Tuple(String, Int32)
+
+  def self.clear
+    clear_cover_url
+    clear_progress_cache
+    clear_sort_opt
+  end
+
+  def self.clean
+    clean_cover_url
+    clean_progress_cache
+    clean_sort_opt
+  end
+
+  # item id => cover_url
+  @@cached_cover_url = {} of String => String
+  @@cached_cover_url_previous = {} of String => String # item id => cover_url
+
+  def self.set_cover_url(id : String, cover_url : String)
+    @@cached_cover_url[id] = cover_url
+  end
+
+  def self.get_cover_url(id : String)
+    @@cached_cover_url[id]?
+  end
+
+  def self.invalidate_cover_url(id : String)
+    @@cached_cover_url.delete id
+  end
+
+  def self.move_cover_url(id : String)
+    if @@cached_cover_url_previous[id]?
+      @@cached_cover_url[id] = @@cached_cover_url_previous[id]
+    end
+  end
+
+  private def self.clear_cover_url
+    @@cached_cover_url_previous = @@cached_cover_url
+    @@cached_cover_url = {} of String => String
+  end
+
+  private def self.clean_cover_url
+    @@cached_cover_url_previous = {} of String => String
+  end
+
+  # book.id:username => {signature, sum}
+  @@progress_cache = {} of String => ProgressCache
+  # book.id => username => {signature, sum}
+  @@progress_cache_previous = {} of String => Hash(String, ProgressCache)
+
+  def self.set_progress_cache(book_id : String, username : String,
+                              entries : Array(Entry), sum : Int32)
+    progress_cache_id = "#{book_id}:#{username}"
+    progress_cache_sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
+    @@progress_cache[progress_cache_id] = {progress_cache_sig, sum}
+    Logger.debug "Progress Cached #{progress_cache_id}"
+  end
+
+  def self.get_progress_cache(book_id : String, username : String,
+                              entries : Array(Entry))
+    progress_cache_id = "#{book_id}:#{username}"
+    progress_cache_sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
+    cached = @@progress_cache[progress_cache_id]?
+    if cached && cached[0] == progress_cache_sig
+      Logger.debug "Progress Cache Hit! #{progress_cache_id}"
+      return cached[1]
+    end
+  end
+
+  def self.invalidate_progress_cache(book_id : String, username : String)
+    progress_cache_id = "#{book_id}:#{username}"
+    if @@progress_cache[progress_cache_id]?
+      @@progress_cache.delete progress_cache_id
+      Logger.debug "Progress Invalidate Cache #{progress_cache_id}"
+    end
+  end
+
+  def self.move_progress_cache(book_id : String)
+    if @@progress_cache_previous[book_id]?
+      @@progress_cache_previous[book_id].each do |username, cached|
+        id = "#{book_id}:#{username}"
+        unless @@progress_cache[id]?
+          # It would be invalidated when entries changed
+          @@progress_cache[id] = cached
+        end
+      end
+    end
+  end
+
+  private def self.clear_progress_cache
+    @@progress_cache_previous = {} of String => Hash(String, ProgressCache)
+    @@progress_cache.each do |id, cached|
+      splitted = id.split(':', 2)
+      book_id = splitted[0]
+      username = splitted[1]
+      unless @@progress_cache_previous[book_id]?
+        @@progress_cache_previous[book_id] = {} of String => ProgressCache
+      end
+
+      @@progress_cache_previous[book_id][username] = cached
+    end
+    @@progress_cache = {} of String => ProgressCache
+  end
+
+  private def self.clean_progress_cache
+    @@progress_cache_previous = {} of String => Hash(String, ProgressCache)
+  end
+
+  # book.dir:username => SortOptions
+  @@cached_sort_opt = {} of String => SortOptions
+  @@cached_sort_opt_previous = {} of String => Hash(String, SortOptions)
+
+  def self.set_sort_opt(dir : String, username : String, sort_opt : SortOptions)
+    id = "#{dir}:#{username}"
+    @@cached_sort_opt[id] = sort_opt
+  end
+
+  def self.get_sort_opt(dir : String, username : String)
+    id = "#{dir}:#{username}"
+    @@cached_sort_opt[id]?
+  end
+
+  def self.invalidate_sort_opt(dir : String, username : String)
+    id = "#{dir}:#{username}"
+    @@cached_sort_opt.delete id
+  end
+
+  def self.move_sort_opt(dir : String)
+    if @@cached_sort_opt_previous[dir]?
+      @@cached_sort_opt_previous[dir].each do |username, cached|
+        id = "#{dir}:#{username}"
+        unless @@cached_sort_opt[id]?
+          @@cached_sort_opt[id] = cached
+        end
+      end
+    end
+  end
+
+  private def self.clear_sort_opt
+    @@cached_sort_opt_previous = {} of String => Hash(String, SortOptions)
+    @@cached_sort_opt.each do |id, cached|
+      splitted = id.split(':', 2)
+      book_dir = splitted[0]
+      username = splitted[1]
+      unless @@cached_sort_opt_previous[book_dir]?
+        @@cached_sort_opt_previous[book_dir] = {} of String => SortOptions
+      end
+      @@cached_sort_opt_previous[book_dir][username] = cached
+    end
+    @@cached_sort_opt = {} of String => SortOptions
+  end
+
+  private def self.clean_sort_opt
+    @@cached_sort_opt_previous = {} of String => Hash(String, SortOptions)
+  end
+end
diff --git a/src/library/entry.cr b/src/library/entry.cr
index b5e582f..cbebf7f 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -44,6 +44,8 @@ class Entry
         MIME.from_filename? e.filename
     end
     file.close
+
+    InfoCache.move_cover_url @id
   end
 
   def to_slim_json : String
@@ -81,6 +83,8 @@ class Entry
 
   def cover_url
     return "#{Config.current.base_url}img/icon.png" if @err_msg
+    cached_cover_url = InfoCache.get_cover_url @id
+    return cached_cover_url if cached_cover_url
 
     unless @book.entry_cover_url_cache
       TitleInfo.new @book.dir do |info|
@@ -96,6 +100,7 @@ class Entry
         url = File.join Config.current.base_url, info_url
       end
     end
+    InfoCache.set_cover_url @id, url
     url
   end
 
@@ -178,6 +183,11 @@ class Entry
   # For backward backward compatibility with v0.1.0, we save entry titles
   #   instead of IDs in info.json
   def save_progress(username, page)
+    InfoCache.invalidate_progress_cache @book.id, username
+    @book.parents.each do |parent|
+      InfoCache.invalidate_progress_cache parent.id, username
+    end
+
     TitleInfo.new @book.dir do |info|
       if info.progress[username]?.nil?
         info.progress[username] = {@title => page}
diff --git a/src/library/library.cr b/src/library/library.cr
index 30e93b2..2638ffd 100644
--- a/src/library/library.cr
+++ b/src/library/library.cr
@@ -102,6 +102,8 @@ class Library
 
     storage = Storage.new auto_close: false
 
+    InfoCache.clear
+
     (Dir.entries @dir)
       .select { |fn| !fn.starts_with? "." }
       .map { |fn| File.join @dir, fn }
@@ -115,6 +117,8 @@ class Library
         @title_ids << title.id
       end
 
+    InfoCache.clean
+
     storage.bulk_insert_ids
     storage.close
 
diff --git a/src/library/title.cr b/src/library/title.cr
index aa4a479..14b5754 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -60,6 +60,10 @@ class Title
     @entries.sort! do |a, b|
       sorter.compare a.title, b.title
     end
+
+    InfoCache.move_cover_url @id
+    InfoCache.move_progress_cache @id
+    InfoCache.move_sort_opt @dir
   end
 
   def to_slim_json : String
@@ -230,6 +234,9 @@ class Title
   end
 
   def cover_url
+    cached_cover_url = InfoCache.get_cover_url @id
+    return cached_cover_url if cached_cover_url
+
     url = "#{Config.current.base_url}img/icon.png"
     readable_entries = @entries.select &.err_msg.nil?
     if readable_entries.size > 0
@@ -241,10 +248,12 @@ class Title
         url = File.join Config.current.base_url, info_url
       end
     end
+    InfoCache.set_cover_url @id, url
     url
   end
 
   def set_cover_url(url : String)
+    InfoCache.invalidate_cover_url @id
     TitleInfo.new @dir do |info|
       info.cover_url = url
       info.save
@@ -252,6 +261,8 @@ class Title
   end
 
   def set_cover_url(entry_name : String, url : String)
+    selected_entry = @entries.find { |entry| entry.display_name == entry_name }
+    InfoCache.invalidate_cover_url selected_entry.id if selected_entry
     TitleInfo.new @dir do |info|
       info.entry_cover_url[entry_name] = url
       info.save
@@ -273,8 +284,13 @@ class Title
   end
 
   def deep_read_page_count(username) : Int32
-    load_progress_for_all_entries(username).sum +
-      titles.flat_map(&.deep_read_page_count username).sum
+    # CACHE HERE
+    cached_sum = InfoCache.get_progress_cache @id, username, @entries
+    return cached_sum unless cached_sum.nil?
+    sum = load_progress_for_all_entries(username).sum +
+          titles.flat_map(&.deep_read_page_count username).sum
+    InfoCache.set_progress_cache @id, username, @entries, sum
+    sum
   end
 
   def deep_total_page_count : Int32
@@ -422,6 +438,11 @@ class Title
   end
 
   def bulk_progress(action, ids : Array(String), username)
+    InfoCache.invalidate_progress_cache @id, username
+    parents.each do |parent|
+      InfoCache.invalidate_progress_cache parent.id, username
+    end
+
     selected_entries = ids
       .map { |id|
         @entries.find &.id.==(id)
diff --git a/src/library/types.cr b/src/library/types.cr
index 4e83135..094cb64 100644
--- a/src/library/types.cr
+++ b/src/library/types.cr
@@ -35,12 +35,15 @@ class SortOptions
   end
 
   def self.from_info_json(dir, username)
+    cached_opt = InfoCache.get_sort_opt dir, username
+    return cached_opt if cached_opt
     opt = SortOptions.new
     TitleInfo.new dir do |info|
       if info.sort_by.has_key? username
         opt = SortOptions.from_tuple info.sort_by[username]
       end
     end
+    InfoCache.set_sort_opt dir, username, opt
     opt
   end
 
diff --git a/src/util/web.cr b/src/util/web.cr
index 5704ea8..5e873ca 100644
--- a/src/util/web.cr
+++ b/src/util/web.cr
@@ -120,6 +120,7 @@ macro get_and_save_sort_opt(dir)
 
     sort_opt = SortOptions.new sort_method, is_ascending
 
+    InfoCache.set_sort_opt {{dir}}, username, sort_opt
     TitleInfo.new {{dir}} do |info|
       info.sort_by[username] = sort_opt.to_tuple
       info.save

From bf81a4e48b5eca75a6fc43ba011593f681dfac3a Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sun, 22 Aug 2021 23:51:23 +0900
Subject: [PATCH 05/26] Implement sorted entries cache

sorted_entries cached
---
 src/library/cache.cr   | 87 ++++++++++++++++++++++++++++++++++++++++++
 src/library/entry.cr   |  5 +++
 src/library/library.cr |  4 ++
 src/library/title.cr   | 11 ++++++
 4 files changed, 107 insertions(+)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 00c65ba..1d2dd53 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -157,3 +157,90 @@ class InfoCache
     @@cached_sort_opt_previous = {} of String => Hash(String, SortOptions)
   end
 end
+
+private class SortedEntriesCacheEntry
+  getter key : String, atime : Time
+
+  def initialize(@ctime : Time, @key : String, @value : Array(String))
+    @atime = @ctime
+  end
+
+  def value
+    @atime = Time.utc
+    @value
+  end
+
+  def instance_size
+    @value.size * (instance_sizeof(String) + sizeof(String)) +
+      @value.sum(&.size) + instance_sizeof(SortedEntriesCacheEntry)
+  end
+end
+
+# LRU Cache
+class SortedEntriesCache
+  @@limit : Int128 = Int128.new 1024 * 1024 * 50 # 50MB
+  # key => entry
+  @@cache = {} of String => SortedEntriesCacheEntry
+
+  def self.gen_key(book_id : String, username : String,
+                   entries : Array(Entry), opt : SortOptions?)
+    sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
+    user_context = opt && opt.method == SortMethod::Progress ? username : ""
+    Digest::SHA1.hexdigest (book_id + sig + user_context +
+                            (opt ? opt.to_tuple.to_s : "nil"))
+  end
+
+  def self.get(key : String)
+    entry = @@cache[key]?
+    Logger.debug "SortedEntries Cache Hit! #{key}" unless entry.nil?
+    Logger.debug "SortedEntries Cache Miss #{key}" if entry.nil?
+    return ids2entries entry.value unless entry.nil?
+  end
+
+  def self.set(key : String, value : Array(Entry))
+    @@cache[key] = SortedEntriesCacheEntry.new Time.utc, key, value.map &.id
+    Logger.debug "SortedEntries Cached #{key}"
+    remove_victim_cache
+  end
+
+  def self.invalidate(key : String)
+    @@cache.delete key
+  end
+
+  def self.print
+    sum = @@cache.sum { |_, entry| entry.instance_size }
+    Logger.debug "---- Sorted Entries Cache ----"
+    Logger.debug "Size: #{sum} Bytes"
+    Logger.debug "List:"
+    @@cache.each { |k, v| Logger.debug "#{k} | #{v.atime}" }
+    Logger.debug "------------------------------"
+  end
+
+  private def self.ids2entries(ids : Array(String))
+    e_map = Library.default.deep_entries.to_h { |entry| {entry.id, entry} }
+    entries = [] of Entry
+    begin
+      ids.each do |id|
+        entries << e_map[id]
+      end
+      return entries if ids.size == entries.size
+    rescue
+    end
+  end
+
+  private def self.is_cache_full
+    sum = @@cache.sum { |_, entry| entry.instance_size }
+    sum > @@limit
+  end
+
+  private def self.remove_victim_cache
+    while is_cache_full && @@cache.size > 0
+      Logger.debug "SortedEntries Cache Full! Remove LRU"
+      min = @@cache.min_by? { |_, entry| entry.atime }
+      Logger.debug "Target: #{min[0]}, Last Access Time: #{min[1].atime}" if min
+      invalidate min[0] if min
+
+      print if Logger.get_severity == Log::Severity::Debug
+    end
+  end
+end
diff --git a/src/library/entry.cr b/src/library/entry.cr
index cbebf7f..5b1f3ce 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -187,6 +187,11 @@ class Entry
     @book.parents.each do |parent|
       InfoCache.invalidate_progress_cache parent.id, username
     end
+    [false, true].each do |ascend|
+      sorted_entries_cache_key = SortedEntriesCache.gen_key @book.id, username,
+        @book.entries, SortOptions.new(SortMethod::Progress, ascend)
+      SortedEntriesCache.invalidate sorted_entries_cache_key
+    end
 
     TitleInfo.new @book.dir do |info|
       if info.progress[username]?.nil?
diff --git a/src/library/library.cr b/src/library/library.cr
index 2638ffd..21e5c8b 100644
--- a/src/library/library.cr
+++ b/src/library/library.cr
@@ -61,6 +61,10 @@ class Library
     titles + titles.flat_map &.deep_titles
   end
 
+  def deep_entries
+    titles.flat_map &.deep_entries
+  end
+
   def to_slim_json : String
     JSON.build do |json|
       json.object do
diff --git a/src/library/title.cr b/src/library/title.cr
index 14b5754..6a78ea5 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -344,6 +344,10 @@ class Title
   #   use the default (auto, ascending)
   # When `opt` is not nil, it saves the options to info.json
   def sorted_entries(username, opt : SortOptions? = nil)
+    cache_key = SortedEntriesCache.gen_key @id, username, @entries, opt
+    cached_entries = SortedEntriesCache.get cache_key
+    return cached_entries if cached_entries
+
     if opt.nil?
       opt = SortOptions.from_info_json @dir, username
     end
@@ -377,6 +381,7 @@ class Title
 
     ary.reverse! unless opt.not_nil!.ascend
 
+    SortedEntriesCache.set cache_key, ary
     ary
   end
 
@@ -442,6 +447,12 @@ class Title
     parents.each do |parent|
       InfoCache.invalidate_progress_cache parent.id, username
     end
+    [false, true].each do |ascend|
+      sorted_entries_cache_key =
+        SortedEntriesCache.gen_key @id, username, @entries,
+          SortOptions.new(SortMethod::Progress, ascend)
+      SortedEntriesCache.invalidate sorted_entries_cache_key
+    end
 
     selected_entries = ids
       .map { |id|

From e988a8c121c630bea3d48d4fd749fcfdd7f56043 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 30 Aug 2021 22:53:30 +0900
Subject: [PATCH 06/26] Add config for sorted entries cache

optional
---
 src/config.cr        | 2 ++
 src/library/cache.cr | 8 +++++++-
 src/mango.cr         | 1 +
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/src/config.cr b/src/config.cr
index 332a159..0647aee 100644
--- a/src/config.cr
+++ b/src/config.cr
@@ -20,6 +20,8 @@ class Config
   property plugin_path : String = File.expand_path "~/mango/plugins",
     home: true
   property download_timeout_seconds : Int32 = 30
+  property sorted_entries_cache_enable = false
+  property sorted_entries_cache_capacity_kbs = 51200
   property disable_login = false
   property default_username = ""
   property auth_proxy_header_name = ""
diff --git a/src/library/cache.cr b/src/library/cache.cr
index 1d2dd53..959e0eb 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -178,10 +178,16 @@ end
 
 # LRU Cache
 class SortedEntriesCache
-  @@limit : Int128 = Int128.new 1024 * 1024 * 50 # 50MB
+  @@limit : Int128 = Int128.new 0
   # key => entry
   @@cache = {} of String => SortedEntriesCacheEntry
 
+  def self.init
+    enabled = Config.current.sorted_entries_cache_enable
+    cache_size = Config.current.sorted_entries_cache_capacity_kbs
+    @@limit = Int128.new cache_size * 1024 if enabled
+  end
+
   def self.gen_key(book_id : String, username : String,
                    entries : Array(Entry), opt : SortOptions?)
     sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
diff --git a/src/mango.cr b/src/mango.cr
index e8d32a3..9b58d50 100644
--- a/src/mango.cr
+++ b/src/mango.cr
@@ -55,6 +55,7 @@ class CLI < Clim
       Config.load(opts.config).set_current
 
       # Initialize main components
+      SortedEntriesCache.init
       Storage.default
       Queue.default
       Library.default

From 601346b209fbc79c3a72ca6fbf7f51f79d184241 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 30 Aug 2021 23:07:59 +0900
Subject: [PATCH 07/26] Set cache if enabled

---
 src/library/title.cr | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/library/title.cr b/src/library/title.cr
index 6a78ea5..54779c2 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -381,7 +381,9 @@ class Title
 
     ary.reverse! unless opt.not_nil!.ascend
 
-    SortedEntriesCache.set cache_key, ary
+    if Config.current.sorted_entries_cache_enable
+      SortedEntriesCache.set cache_key, ary
+    end
     ary
   end
 

From 365f71cd1d2f2c760f90f2296e80c1cd0278c3b4 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 30 Aug 2021 23:09:36 +0900
Subject: [PATCH 08/26] Change kbs to mbs

---
 src/config.cr        | 2 +-
 src/library/cache.cr | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/config.cr b/src/config.cr
index 0647aee..69feccd 100644
--- a/src/config.cr
+++ b/src/config.cr
@@ -21,7 +21,7 @@ class Config
     home: true
   property download_timeout_seconds : Int32 = 30
   property sorted_entries_cache_enable = false
-  property sorted_entries_cache_capacity_kbs = 51200
+  property sorted_entries_cache_size_mbs = 50
   property disable_login = false
   property default_username = ""
   property auth_proxy_header_name = ""
diff --git a/src/library/cache.cr b/src/library/cache.cr
index 959e0eb..0165496 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -184,8 +184,8 @@ class SortedEntriesCache
 
   def self.init
     enabled = Config.current.sorted_entries_cache_enable
-    cache_size = Config.current.sorted_entries_cache_capacity_kbs
-    @@limit = Int128.new cache_size * 1024 if enabled
+    cache_size = Config.current.sorted_entries_cache_size_mbs
+    @@limit = Int128.new cache_size * 1024 * 1024 if enabled
   end
 
   def self.gen_key(book_id : String, username : String,

From 0a8fd993e524fb36a7249d753992594811e0f3f9 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Fri, 3 Sep 2021 11:11:28 +0900
Subject: [PATCH 09/26] Use bytesize and add comments

---
 src/library/cache.cr | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 0165496..7870df5 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -171,8 +171,10 @@ private class SortedEntriesCacheEntry
   end
 
   def instance_size
-    @value.size * (instance_sizeof(String) + sizeof(String)) +
-      @value.sum(&.size) + instance_sizeof(SortedEntriesCacheEntry)
+    instance_sizeof(SortedEntriesCacheEntry) + # sizeof itself
+      instance_sizeof(String) + @key.bytesize + # allocated memory for @key
+      @value.size * (instance_sizeof(String) + sizeof(String)) +
+      @value.sum(&.bytesize) # elements in Array(String)
   end
 end
 

From 9e90aa17b934baa923ce979af3571bcb4b3650bd Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sat, 4 Sep 2021 14:13:33 +0900
Subject: [PATCH 10/26] Move entry specific method

---
 src/library/cache.cr | 72 +++++++++++++++++++++++---------------------
 src/library/entry.cr |  4 +--
 src/library/title.cr |  4 +--
 3 files changed, 42 insertions(+), 38 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 7870df5..c6e9374 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -159,23 +159,47 @@ class InfoCache
 end
 
 private class SortedEntriesCacheEntry
+  @value : Array(String)
+
   getter key : String, atime : Time
 
-  def initialize(@ctime : Time, @key : String, @value : Array(String))
+  def initialize(@ctime : Time, @key : String, value : Array(Entry))
     @atime = @ctime
+    @value = value.map &.id
   end
 
   def value
     @atime = Time.utc
-    @value
+    SortedEntriesCacheEntry.ids2entries @value
+  end
+
+  # private?
+  def self.ids2entries(ids : Array(String))
+    e_map = Library.default.deep_entries.to_h { |entry| {entry.id, entry} }
+    entries = [] of Entry
+    begin
+      ids.each do |id|
+        entries << e_map[id]
+      end
+      return entries if ids.size == entries.size
+    rescue
+    end
   end
 
   def instance_size
-    instance_sizeof(SortedEntriesCacheEntry) + # sizeof itself
+    instance_sizeof(SortedEntriesCacheEntry) +  # sizeof itself
       instance_sizeof(String) + @key.bytesize + # allocated memory for @key
       @value.size * (instance_sizeof(String) + sizeof(String)) +
       @value.sum(&.bytesize) # elements in Array(String)
   end
+
+  def self.gen_key(book_id : String, username : String,
+                   entries : Array(Entry), opt : SortOptions?)
+    sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
+    user_context = opt && opt.method == SortMethod::Progress ? username : ""
+    Digest::SHA1.hexdigest (book_id + sig + user_context +
+                            (opt ? opt.to_tuple.to_s : "nil"))
+  end
 end
 
 # LRU Cache
@@ -190,24 +214,16 @@ class SortedEntriesCache
     @@limit = Int128.new cache_size * 1024 * 1024 if enabled
   end
 
-  def self.gen_key(book_id : String, username : String,
-                   entries : Array(Entry), opt : SortOptions?)
-    sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
-    user_context = opt && opt.method == SortMethod::Progress ? username : ""
-    Digest::SHA1.hexdigest (book_id + sig + user_context +
-                            (opt ? opt.to_tuple.to_s : "nil"))
-  end
-
   def self.get(key : String)
     entry = @@cache[key]?
-    Logger.debug "SortedEntries Cache Hit! #{key}" unless entry.nil?
-    Logger.debug "SortedEntries Cache Miss #{key}" if entry.nil?
-    return ids2entries entry.value unless entry.nil?
+    Logger.debug "LRUCache Cache Hit! #{key}" unless entry.nil?
+    Logger.debug "LRUCache Cache Miss #{key}" if entry.nil?
+    return entry.value unless entry.nil?
   end
 
   def self.set(key : String, value : Array(Entry))
-    @@cache[key] = SortedEntriesCacheEntry.new Time.utc, key, value.map &.id
-    Logger.debug "SortedEntries Cached #{key}"
+    @@cache[key] = SortedEntriesCacheEntry.new Time.utc, key, value
+    Logger.debug "LRUCache Cached #{key}"
     remove_victim_cache
   end
 
@@ -217,23 +233,11 @@ class SortedEntriesCache
 
   def self.print
     sum = @@cache.sum { |_, entry| entry.instance_size }
-    Logger.debug "---- Sorted Entries Cache ----"
+    Logger.debug "---- LRU Cache ----"
     Logger.debug "Size: #{sum} Bytes"
     Logger.debug "List:"
     @@cache.each { |k, v| Logger.debug "#{k} | #{v.atime}" }
-    Logger.debug "------------------------------"
-  end
-
-  private def self.ids2entries(ids : Array(String))
-    e_map = Library.default.deep_entries.to_h { |entry| {entry.id, entry} }
-    entries = [] of Entry
-    begin
-      ids.each do |id|
-        entries << e_map[id]
-      end
-      return entries if ids.size == entries.size
-    rescue
-    end
+    Logger.debug "-------------------"
   end
 
   private def self.is_cache_full
@@ -243,12 +247,12 @@ class SortedEntriesCache
 
   private def self.remove_victim_cache
     while is_cache_full && @@cache.size > 0
-      Logger.debug "SortedEntries Cache Full! Remove LRU"
+      Logger.debug "LRUCache Cache Full! Remove LRU"
       min = @@cache.min_by? { |_, entry| entry.atime }
-      Logger.debug "Target: #{min[0]}, Last Access Time: #{min[1].atime}" if min
+      Logger.debug "  \
+        Target: #{min[0]}, \
+        Last Access Time: #{min[1].atime}" if min
       invalidate min[0] if min
-
-      print if Logger.get_severity == Log::Severity::Debug
     end
   end
 end
diff --git a/src/library/entry.cr b/src/library/entry.cr
index 5b1f3ce..c7599ff 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -188,8 +188,8 @@ class Entry
       InfoCache.invalidate_progress_cache parent.id, username
     end
     [false, true].each do |ascend|
-      sorted_entries_cache_key = SortedEntriesCache.gen_key @book.id, username,
-        @book.entries, SortOptions.new(SortMethod::Progress, ascend)
+      sorted_entries_cache_key = SortedEntriesCacheEntry.gen_key @book.id,
+        username, @book.entries, SortOptions.new(SortMethod::Progress, ascend)
       SortedEntriesCache.invalidate sorted_entries_cache_key
     end
 
diff --git a/src/library/title.cr b/src/library/title.cr
index 54779c2..ed546ca 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -344,7 +344,7 @@ class Title
   #   use the default (auto, ascending)
   # When `opt` is not nil, it saves the options to info.json
   def sorted_entries(username, opt : SortOptions? = nil)
-    cache_key = SortedEntriesCache.gen_key @id, username, @entries, opt
+    cache_key = SortedEntriesCacheEntry.gen_key @id, username, @entries, opt
     cached_entries = SortedEntriesCache.get cache_key
     return cached_entries if cached_entries
 
@@ -451,7 +451,7 @@ class Title
     end
     [false, true].each do |ascend|
       sorted_entries_cache_key =
-        SortedEntriesCache.gen_key @id, username, @entries,
+        SortedEntriesCacheEntry.gen_key @id, username, @entries,
           SortOptions.new(SortMethod::Progress, ascend)
       SortedEntriesCache.invalidate sorted_entries_cache_key
     end

From 5e919d3e19c802084ce4076341c41c21e19d8f4d Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sat, 4 Sep 2021 14:37:29 +0900
Subject: [PATCH 11/26] Make entry generic

---
 src/library/cache.cr | 60 +++++++++++++++++++++++++++++++++++---------
 src/library/title.cr |  4 +--
 2 files changed, 50 insertions(+), 14 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index c6e9374..6136dd3 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -1,5 +1,7 @@
 require "digest"
 
+require "./entry"
+
 class InfoCache
   alias ProgressCache = Tuple(String, Int32)
 
@@ -158,23 +160,46 @@ class InfoCache
   end
 end
 
-private class SortedEntriesCacheEntry
-  @value : Array(String)
-
+private class CacheEntry(SaveT, ReturnT)
   getter key : String, atime : Time
 
-  def initialize(@ctime : Time, @key : String, value : Array(Entry))
-    @atime = @ctime
-    @value = value.map &.id
+  @value : SaveT
+
+  def initialize(@key : String, value : ReturnT)
+    @atime = @ctime = Time.utc
+    @value = self.class.to_save_t value
   end
 
   def value
     @atime = Time.utc
-    SortedEntriesCacheEntry.ids2entries @value
+    self.class.to_return_t @value
   end
 
-  # private?
-  def self.ids2entries(ids : Array(String))
+  def self.to_save_t(value : ReturnT)
+    value
+  end
+
+  def self.to_return_t(value : SaveT)
+    value
+  end
+
+  def instance_size
+    instance_sizeof(CacheEntry(SaveT, ReturnT)) + # sizeof itself
+      instance_sizeof(String) + @key.bytesize +   # allocated memory for @key
+      @value.instance_size
+  end
+end
+
+class SortedEntriesCacheEntry < CacheEntry(Array(String), Array(Entry))
+  def self.to_save_t(value : Array(Entry))
+    value.map &.id
+  end
+
+  def self.to_return_t(value : Array(String))
+    ids2entries value
+  end
+
+  private def self.ids2entries(ids : Array(String))
     e_map = Library.default.deep_entries.to_h { |entry| {entry.id, entry} }
     entries = [] of Entry
     begin
@@ -202,11 +227,21 @@ private class SortedEntriesCacheEntry
   end
 end
 
+alias CacheEntryType = SortedEntriesCacheEntry
+
+def generate_cache_entry(key : String, value : Array(Entry) | Int32 | String)
+  if value.is_a? Array(Entry)
+    SortedEntriesCacheEntry.new key, value
+  else
+    CacheEntry(typeof(value), typeof(value)).new key, value
+  end
+end
+
 # LRU Cache
 class SortedEntriesCache
   @@limit : Int128 = Int128.new 0
   # key => entry
-  @@cache = {} of String => SortedEntriesCacheEntry
+  @@cache = {} of String => CacheEntryType
 
   def self.init
     enabled = Config.current.sorted_entries_cache_enable
@@ -221,8 +256,9 @@ class SortedEntriesCache
     return entry.value unless entry.nil?
   end
 
-  def self.set(key : String, value : Array(Entry))
-    @@cache[key] = SortedEntriesCacheEntry.new Time.utc, key, value
+  def self.set(cache_entry : CacheEntryType)
+    key = cache_entry.key
+    @@cache[key] = cache_entry
     Logger.debug "LRUCache Cached #{key}"
     remove_victim_cache
   end
diff --git a/src/library/title.cr b/src/library/title.cr
index ed546ca..c377738 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -346,7 +346,7 @@ class Title
   def sorted_entries(username, opt : SortOptions? = nil)
     cache_key = SortedEntriesCacheEntry.gen_key @id, username, @entries, opt
     cached_entries = SortedEntriesCache.get cache_key
-    return cached_entries if cached_entries
+    return cached_entries if cached_entries.is_a? Array(Entry)
 
     if opt.nil?
       opt = SortOptions.from_info_json @dir, username
@@ -382,7 +382,7 @@ class Title
     ary.reverse! unless opt.not_nil!.ascend
 
     if Config.current.sorted_entries_cache_enable
-      SortedEntriesCache.set cache_key, ary
+      SortedEntriesCache.set generate_cache_entry cache_key, ary
     end
     ary
   end

From 0fd7caef4be10d480b58a3c0c217f0b65e8a1728 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sun, 5 Sep 2021 00:02:05 +0900
Subject: [PATCH 12/26] Rename

---
 src/library/cache.cr | 2 +-
 src/library/entry.cr | 2 +-
 src/library/title.cr | 6 +++---
 src/mango.cr         | 2 +-
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 6136dd3..b399632 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -238,7 +238,7 @@ def generate_cache_entry(key : String, value : Array(Entry) | Int32 | String)
 end
 
 # LRU Cache
-class SortedEntriesCache
+class LRUCache
   @@limit : Int128 = Int128.new 0
   # key => entry
   @@cache = {} of String => CacheEntryType
diff --git a/src/library/entry.cr b/src/library/entry.cr
index c7599ff..176efe1 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -190,7 +190,7 @@ class Entry
     [false, true].each do |ascend|
       sorted_entries_cache_key = SortedEntriesCacheEntry.gen_key @book.id,
         username, @book.entries, SortOptions.new(SortMethod::Progress, ascend)
-      SortedEntriesCache.invalidate sorted_entries_cache_key
+      LRUCache.invalidate sorted_entries_cache_key
     end
 
     TitleInfo.new @book.dir do |info|
diff --git a/src/library/title.cr b/src/library/title.cr
index c377738..a5a6850 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -345,7 +345,7 @@ class Title
   # When `opt` is not nil, it saves the options to info.json
   def sorted_entries(username, opt : SortOptions? = nil)
     cache_key = SortedEntriesCacheEntry.gen_key @id, username, @entries, opt
-    cached_entries = SortedEntriesCache.get cache_key
+    cached_entries = LRUCache.get cache_key
     return cached_entries if cached_entries.is_a? Array(Entry)
 
     if opt.nil?
@@ -382,7 +382,7 @@ class Title
     ary.reverse! unless opt.not_nil!.ascend
 
     if Config.current.sorted_entries_cache_enable
-      SortedEntriesCache.set generate_cache_entry cache_key, ary
+      LRUCache.set generate_cache_entry cache_key, ary
     end
     ary
   end
@@ -453,7 +453,7 @@ class Title
       sorted_entries_cache_key =
         SortedEntriesCacheEntry.gen_key @id, username, @entries,
           SortOptions.new(SortMethod::Progress, ascend)
-      SortedEntriesCache.invalidate sorted_entries_cache_key
+      LRUCache.invalidate sorted_entries_cache_key
     end
 
     selected_entries = ids
diff --git a/src/mango.cr b/src/mango.cr
index 9b58d50..f27165e 100644
--- a/src/mango.cr
+++ b/src/mango.cr
@@ -55,7 +55,7 @@ class CLI < Clim
       Config.load(opts.config).set_current
 
       # Initialize main components
-      SortedEntriesCache.init
+      LRUCache.init
       Storage.default
       Queue.default
       Library.default

From de410f42b8cd67769aa1778d89837cdbde3966a9 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sun, 5 Sep 2021 01:54:19 +0900
Subject: [PATCH 13/26] Replace InfoCache to LRUCache

---
 src/library/cache.cr   | 197 ++++++++---------------------------------
 src/library/entry.cr   |  12 ++-
 src/library/library.cr |   4 -
 src/library/title.cr   |  28 +++---
 src/library/types.cr   |   7 +-
 src/util/web.cr        |   3 +-
 6 files changed, 61 insertions(+), 190 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index b399632..f772c66 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -1,164 +1,7 @@
 require "digest"
 
 require "./entry"
-
-class InfoCache
-  alias ProgressCache = Tuple(String, Int32)
-
-  def self.clear
-    clear_cover_url
-    clear_progress_cache
-    clear_sort_opt
-  end
-
-  def self.clean
-    clean_cover_url
-    clean_progress_cache
-    clean_sort_opt
-  end
-
-  # item id => cover_url
-  @@cached_cover_url = {} of String => String
-  @@cached_cover_url_previous = {} of String => String # item id => cover_url
-
-  def self.set_cover_url(id : String, cover_url : String)
-    @@cached_cover_url[id] = cover_url
-  end
-
-  def self.get_cover_url(id : String)
-    @@cached_cover_url[id]?
-  end
-
-  def self.invalidate_cover_url(id : String)
-    @@cached_cover_url.delete id
-  end
-
-  def self.move_cover_url(id : String)
-    if @@cached_cover_url_previous[id]?
-      @@cached_cover_url[id] = @@cached_cover_url_previous[id]
-    end
-  end
-
-  private def self.clear_cover_url
-    @@cached_cover_url_previous = @@cached_cover_url
-    @@cached_cover_url = {} of String => String
-  end
-
-  private def self.clean_cover_url
-    @@cached_cover_url_previous = {} of String => String
-  end
-
-  # book.id:username => {signature, sum}
-  @@progress_cache = {} of String => ProgressCache
-  # book.id => username => {signature, sum}
-  @@progress_cache_previous = {} of String => Hash(String, ProgressCache)
-
-  def self.set_progress_cache(book_id : String, username : String,
-                              entries : Array(Entry), sum : Int32)
-    progress_cache_id = "#{book_id}:#{username}"
-    progress_cache_sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
-    @@progress_cache[progress_cache_id] = {progress_cache_sig, sum}
-    Logger.debug "Progress Cached #{progress_cache_id}"
-  end
-
-  def self.get_progress_cache(book_id : String, username : String,
-                              entries : Array(Entry))
-    progress_cache_id = "#{book_id}:#{username}"
-    progress_cache_sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
-    cached = @@progress_cache[progress_cache_id]?
-    if cached && cached[0] == progress_cache_sig
-      Logger.debug "Progress Cache Hit! #{progress_cache_id}"
-      return cached[1]
-    end
-  end
-
-  def self.invalidate_progress_cache(book_id : String, username : String)
-    progress_cache_id = "#{book_id}:#{username}"
-    if @@progress_cache[progress_cache_id]?
-      @@progress_cache.delete progress_cache_id
-      Logger.debug "Progress Invalidate Cache #{progress_cache_id}"
-    end
-  end
-
-  def self.move_progress_cache(book_id : String)
-    if @@progress_cache_previous[book_id]?
-      @@progress_cache_previous[book_id].each do |username, cached|
-        id = "#{book_id}:#{username}"
-        unless @@progress_cache[id]?
-          # It would be invalidated when entries changed
-          @@progress_cache[id] = cached
-        end
-      end
-    end
-  end
-
-  private def self.clear_progress_cache
-    @@progress_cache_previous = {} of String => Hash(String, ProgressCache)
-    @@progress_cache.each do |id, cached|
-      splitted = id.split(':', 2)
-      book_id = splitted[0]
-      username = splitted[1]
-      unless @@progress_cache_previous[book_id]?
-        @@progress_cache_previous[book_id] = {} of String => ProgressCache
-      end
-
-      @@progress_cache_previous[book_id][username] = cached
-    end
-    @@progress_cache = {} of String => ProgressCache
-  end
-
-  private def self.clean_progress_cache
-    @@progress_cache_previous = {} of String => Hash(String, ProgressCache)
-  end
-
-  # book.dir:username => SortOptions
-  @@cached_sort_opt = {} of String => SortOptions
-  @@cached_sort_opt_previous = {} of String => Hash(String, SortOptions)
-
-  def self.set_sort_opt(dir : String, username : String, sort_opt : SortOptions)
-    id = "#{dir}:#{username}"
-    @@cached_sort_opt[id] = sort_opt
-  end
-
-  def self.get_sort_opt(dir : String, username : String)
-    id = "#{dir}:#{username}"
-    @@cached_sort_opt[id]?
-  end
-
-  def self.invalidate_sort_opt(dir : String, username : String)
-    id = "#{dir}:#{username}"
-    @@cached_sort_opt.delete id
-  end
-
-  def self.move_sort_opt(dir : String)
-    if @@cached_sort_opt_previous[dir]?
-      @@cached_sort_opt_previous[dir].each do |username, cached|
-        id = "#{dir}:#{username}"
-        unless @@cached_sort_opt[id]?
-          @@cached_sort_opt[id] = cached
-        end
-      end
-    end
-  end
-
-  private def self.clear_sort_opt
-    @@cached_sort_opt_previous = {} of String => Hash(String, SortOptions)
-    @@cached_sort_opt.each do |id, cached|
-      splitted = id.split(':', 2)
-      book_dir = splitted[0]
-      username = splitted[1]
-      unless @@cached_sort_opt_previous[book_dir]?
-        @@cached_sort_opt_previous[book_dir] = {} of String => SortOptions
-      end
-      @@cached_sort_opt_previous[book_dir][username] = cached
-    end
-    @@cached_sort_opt = {} of String => SortOptions
-  end
-
-  private def self.clean_sort_opt
-    @@cached_sort_opt_previous = {} of String => Hash(String, SortOptions)
-  end
-end
+require "./types"
 
 private class CacheEntry(SaveT, ReturnT)
   getter key : String, atime : Time
@@ -227,11 +70,45 @@ class SortedEntriesCacheEntry < CacheEntry(Array(String), Array(Entry))
   end
 end
 
-alias CacheEntryType = SortedEntriesCacheEntry
+class SortOptionsCacheEntry < CacheEntry(Tuple(String, Bool), SortOptions)
+  def self.to_save_t(value : SortOptions)
+    value.to_tuple
+  end
 
-def generate_cache_entry(key : String, value : Array(Entry) | Int32 | String)
+  def self.to_return_t(value : Tuple(String, Bool))
+    SortOptions.from_tuple value
+  end
+
+  def instance_size
+    instance_sizeof(SortOptionsCacheEntry) +
+      @value[0].instance_size
+  end
+end
+
+class String
+  def instance_size
+    instance_sizeof(String) + bytesize
+  end
+end
+
+struct Tuple(*T)
+  def instance_size
+    sizeof(T) # iterate T and add instance_size of that
+  end
+end
+
+alias CacheableType = Array(Entry) | String | Tuple(String, Int32) |
+                      SortOptions
+alias CacheEntryType = SortedEntriesCacheEntry |
+                       SortOptionsCacheEntry |
+                       CacheEntry(String, String) |
+                       CacheEntry(Tuple(String, Int32), Tuple(String, Int32))
+
+def generate_cache_entry(key : String, value : CacheableType)
   if value.is_a? Array(Entry)
     SortedEntriesCacheEntry.new key, value
+  elsif value.is_a? SortOptions
+    SortOptionsCacheEntry.new key, value
   else
     CacheEntry(typeof(value), typeof(value)).new key, value
   end
diff --git a/src/library/entry.cr b/src/library/entry.cr
index 176efe1..2c1ae34 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -44,8 +44,6 @@ class Entry
         MIME.from_filename? e.filename
     end
     file.close
-
-    InfoCache.move_cover_url @id
   end
 
   def to_slim_json : String
@@ -83,8 +81,8 @@ class Entry
 
   def cover_url
     return "#{Config.current.base_url}img/icon.png" if @err_msg
-    cached_cover_url = InfoCache.get_cover_url @id
-    return cached_cover_url if cached_cover_url
+    cached_cover_url = LRUCache.get "#{@id}:cover_url"
+    return cached_cover_url if cached_cover_url.is_a? String
 
     unless @book.entry_cover_url_cache
       TitleInfo.new @book.dir do |info|
@@ -100,7 +98,7 @@ class Entry
         url = File.join Config.current.base_url, info_url
       end
     end
-    InfoCache.set_cover_url @id, url
+    LRUCache.set generate_cache_entry "#{@id}:cover_url", url
     url
   end
 
@@ -183,9 +181,9 @@ class Entry
   # For backward backward compatibility with v0.1.0, we save entry titles
   #   instead of IDs in info.json
   def save_progress(username, page)
-    InfoCache.invalidate_progress_cache @book.id, username
+    LRUCache.invalidate "#{@book.id}:#{username}:progress_sum"
     @book.parents.each do |parent|
-      InfoCache.invalidate_progress_cache parent.id, username
+      LRUCache.invalidate "#{parent.id}:#{username}:progress_sum"
     end
     [false, true].each do |ascend|
       sorted_entries_cache_key = SortedEntriesCacheEntry.gen_key @book.id,
diff --git a/src/library/library.cr b/src/library/library.cr
index 21e5c8b..9351e60 100644
--- a/src/library/library.cr
+++ b/src/library/library.cr
@@ -106,8 +106,6 @@ class Library
 
     storage = Storage.new auto_close: false
 
-    InfoCache.clear
-
     (Dir.entries @dir)
       .select { |fn| !fn.starts_with? "." }
       .map { |fn| File.join @dir, fn }
@@ -121,8 +119,6 @@ class Library
         @title_ids << title.id
       end
 
-    InfoCache.clean
-
     storage.bulk_insert_ids
     storage.close
 
diff --git a/src/library/title.cr b/src/library/title.cr
index a5a6850..cdf78fd 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -60,10 +60,6 @@ class Title
     @entries.sort! do |a, b|
       sorter.compare a.title, b.title
     end
-
-    InfoCache.move_cover_url @id
-    InfoCache.move_progress_cache @id
-    InfoCache.move_sort_opt @dir
   end
 
   def to_slim_json : String
@@ -234,8 +230,8 @@ class Title
   end
 
   def cover_url
-    cached_cover_url = InfoCache.get_cover_url @id
-    return cached_cover_url if cached_cover_url
+    cached_cover_url = LRUCache.get "#{@id}:cover_url"
+    return cached_cover_url if cached_cover_url.is_a? String
 
     url = "#{Config.current.base_url}img/icon.png"
     readable_entries = @entries.select &.err_msg.nil?
@@ -248,12 +244,12 @@ class Title
         url = File.join Config.current.base_url, info_url
       end
     end
-    InfoCache.set_cover_url @id, url
+    LRUCache.set generate_cache_entry "#{@id}:cover_url", url
     url
   end
 
   def set_cover_url(url : String)
-    InfoCache.invalidate_cover_url @id
+    LRUCache.invalidate "#{@id}:cover_url"
     TitleInfo.new @dir do |info|
       info.cover_url = url
       info.save
@@ -262,7 +258,7 @@ class Title
 
   def set_cover_url(entry_name : String, url : String)
     selected_entry = @entries.find { |entry| entry.display_name == entry_name }
-    InfoCache.invalidate_cover_url selected_entry.id if selected_entry
+    LRUCache.invalidate "#{selected_entry.id}:cover_url" if selected_entry
     TitleInfo.new @dir do |info|
       info.entry_cover_url[entry_name] = url
       info.save
@@ -284,12 +280,14 @@ class Title
   end
 
   def deep_read_page_count(username) : Int32
-    # CACHE HERE
-    cached_sum = InfoCache.get_progress_cache @id, username, @entries
-    return cached_sum unless cached_sum.nil?
+    key = "#{@id}:#{username}:progress_sum"
+    sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
+    cached_sum = LRUCache.get key
+    return cached_sum[1] if cached_sum.is_a? Tuple(String, Int32) &&
+                            cached_sum[0] == sig
     sum = load_progress_for_all_entries(username).sum +
           titles.flat_map(&.deep_read_page_count username).sum
-    InfoCache.set_progress_cache @id, username, @entries, sum
+    LRUCache.set generate_cache_entry key, {sig, sum}
     sum
   end
 
@@ -445,9 +443,9 @@ class Title
   end
 
   def bulk_progress(action, ids : Array(String), username)
-    InfoCache.invalidate_progress_cache @id, username
+    LRUCache.invalidate "#{@id}:#{username}:progress_sum"
     parents.each do |parent|
-      InfoCache.invalidate_progress_cache parent.id, username
+      LRUCache.invalidate "#{parent.id}:#{username}:progress_sum"
     end
     [false, true].each do |ascend|
       sorted_entries_cache_key =
diff --git a/src/library/types.cr b/src/library/types.cr
index 094cb64..891ee08 100644
--- a/src/library/types.cr
+++ b/src/library/types.cr
@@ -35,15 +35,16 @@ class SortOptions
   end
 
   def self.from_info_json(dir, username)
-    cached_opt = InfoCache.get_sort_opt dir, username
-    return cached_opt if cached_opt
+    key = "#{dir}:#{username}:sort_opt"
+    cached_opt = LRUCache.get key
+    return cached_opt if cached_opt.is_a? SortOptions
     opt = SortOptions.new
     TitleInfo.new dir do |info|
       if info.sort_by.has_key? username
         opt = SortOptions.from_tuple info.sort_by[username]
       end
     end
-    InfoCache.set_sort_opt dir, username, opt
+    LRUCache.set generate_cache_entry key, opt
     opt
   end
 
diff --git a/src/util/web.cr b/src/util/web.cr
index 5e873ca..9b967da 100644
--- a/src/util/web.cr
+++ b/src/util/web.cr
@@ -120,7 +120,8 @@ macro get_and_save_sort_opt(dir)
 
     sort_opt = SortOptions.new sort_method, is_ascending
 
-    InfoCache.set_sort_opt {{dir}}, username, sort_opt
+    key = "#{{{dir}}}:#{username}:sort_opt"
+    LRUCache.set generate_cache_entry key, sort_opt
     TitleInfo.new {{dir}} do |info|
       info.sort_by[username] = sort_opt.to_tuple
       info.save

From 847f516a65c9dac283b11e4f31de8d9ee449df54 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sun, 5 Sep 2021 02:35:44 +0900
Subject: [PATCH 14/26] Cache TitleInfo using LRUCache

---
 src/library/types.cr | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/src/library/types.cr b/src/library/types.cr
index 891ee08..46d2a7c 100644
--- a/src/library/types.cr
+++ b/src/library/types.cr
@@ -92,6 +92,18 @@ class TitleInfo
   @@mutex_hash = {} of String => Mutex
 
   def self.new(dir, &)
+    key = "#{dir}:info.json"
+    info = LRUCache.get key
+    if info.is_a? String
+      begin
+        instance = TitleInfo.from_json info
+        instance.dir = dir
+        yield instance
+        return
+      rescue
+      end
+    end
+
     if @@mutex_hash[dir]?
       mutex = @@mutex_hash[dir]
     else
@@ -105,6 +117,7 @@ class TitleInfo
         instance = TitleInfo.from_json File.read json_path
       end
       instance.dir = dir
+      LRUCache.set generate_cache_entry key, instance.to_json
       yield instance
     end
   end
@@ -112,5 +125,7 @@ class TitleInfo
   def save
     json_path = File.join @dir, "info.json"
     File.write json_path, self.to_pretty_json
+    key = "#{@dir}:info.json"
+    LRUCache.set generate_cache_entry key, self.to_json
   end
 end

From 11976b15f9f66b92df78bf00fbecdf45a8850905 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sun, 5 Sep 2021 03:02:20 +0900
Subject: [PATCH 15/26] Make LRUCache togglable

---
 src/library/cache.cr | 10 ++++++++--
 src/library/title.cr |  4 +---
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index f772c66..5b3d2bd 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -120,13 +120,17 @@ class LRUCache
   # key => entry
   @@cache = {} of String => CacheEntryType
 
+  def self.enabled
+    Config.current.sorted_entries_cache_enable
+  end
+
   def self.init
-    enabled = Config.current.sorted_entries_cache_enable
     cache_size = Config.current.sorted_entries_cache_size_mbs
     @@limit = Int128.new cache_size * 1024 * 1024 if enabled
   end
 
   def self.get(key : String)
+    return unless enabled
     entry = @@cache[key]?
     Logger.debug "LRUCache Cache Hit! #{key}" unless entry.nil?
     Logger.debug "LRUCache Cache Miss #{key}" if entry.nil?
@@ -134,6 +138,7 @@ class LRUCache
   end
 
   def self.set(cache_entry : CacheEntryType)
+    return unless enabled
     key = cache_entry.key
     @@cache[key] = cache_entry
     Logger.debug "LRUCache Cached #{key}"
@@ -141,6 +146,7 @@ class LRUCache
   end
 
   def self.invalidate(key : String)
+    return unless enabled
     @@cache.delete key
   end
 
@@ -149,7 +155,7 @@ class LRUCache
     Logger.debug "---- LRU Cache ----"
     Logger.debug "Size: #{sum} Bytes"
     Logger.debug "List:"
-    @@cache.each { |k, v| Logger.debug "#{k} | #{v.atime}" }
+    @@cache.each { |k, v| Logger.debug "#{k} | #{v.atime} | #{v.instance_size}" }
     Logger.debug "-------------------"
   end
 
diff --git a/src/library/title.cr b/src/library/title.cr
index cdf78fd..8333642 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -379,9 +379,7 @@ class Title
 
     ary.reverse! unless opt.not_nil!.ascend
 
-    if Config.current.sorted_entries_cache_enable
-      LRUCache.set generate_cache_entry cache_key, ary
-    end
+    LRUCache.set generate_cache_entry cache_key, ary
     ary
   end
 

From c75c71709ff64bfb97a10a4f0d577f0f2f6ff764 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Sun, 5 Sep 2021 11:21:53 +0900
Subject: [PATCH 16/26] make check

---
 src/library/cache.cr | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 5b3d2bd..ca6af53 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -155,7 +155,9 @@ class LRUCache
     Logger.debug "---- LRU Cache ----"
     Logger.debug "Size: #{sum} Bytes"
     Logger.debug "List:"
-    @@cache.each { |k, v| Logger.debug "#{k} | #{v.atime} | #{v.instance_size}" }
+    @@cache.each do |k, v|
+      Logger.debug "#{k} | #{v.atime} | #{v.instance_size}"
+    end
     Logger.debug "-------------------"
   end
 

From c5b6a8b5b950d685f2490633c8914e53a6640c05 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Sun, 5 Sep 2021 13:57:20 +0000
Subject: [PATCH 17/26] Improve instance_size for Tuple

---
 src/library/cache.cr | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index ca6af53..612345c 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -93,7 +93,15 @@ end
 
 struct Tuple(*T)
   def instance_size
-    sizeof(T) # iterate T and add instance_size of that
+    sizeof(T) + # total size of non-reference types
+      self.sum do |e|
+        next 0 unless e.is_a? Reference
+        if e.responds_to? :instance_size
+          e.instance_size
+        else
+          instance_sizeof(typeof(e))
+        end
+      end
   end
 end
 

From 565a535d22f16d230d2048aa7e6d9ed1cd2b8fe4 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 6 Sep 2021 02:23:02 +0900
Subject: [PATCH 18/26] Remove caching verbosely, add cached_cover_url

---
 src/library/cache.cr | 21 +--------------------
 src/library/entry.cr |  3 ---
 src/library/title.cr | 10 ++++------
 src/library/types.cr |  4 ----
 src/util/web.cr      |  1 -
 5 files changed, 5 insertions(+), 34 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 612345c..5d3797e 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -70,21 +70,6 @@ class SortedEntriesCacheEntry < CacheEntry(Array(String), Array(Entry))
   end
 end
 
-class SortOptionsCacheEntry < CacheEntry(Tuple(String, Bool), SortOptions)
-  def self.to_save_t(value : SortOptions)
-    value.to_tuple
-  end
-
-  def self.to_return_t(value : Tuple(String, Bool))
-    SortOptions.from_tuple value
-  end
-
-  def instance_size
-    instance_sizeof(SortOptionsCacheEntry) +
-      @value[0].instance_size
-  end
-end
-
 class String
   def instance_size
     instance_sizeof(String) + bytesize
@@ -105,18 +90,14 @@ struct Tuple(*T)
   end
 end
 
-alias CacheableType = Array(Entry) | String | Tuple(String, Int32) |
-                      SortOptions
+alias CacheableType = Array(Entry) | String | Tuple(String, Int32)
 alias CacheEntryType = SortedEntriesCacheEntry |
-                       SortOptionsCacheEntry |
                        CacheEntry(String, String) |
                        CacheEntry(Tuple(String, Int32), Tuple(String, Int32))
 
 def generate_cache_entry(key : String, value : CacheableType)
   if value.is_a? Array(Entry)
     SortedEntriesCacheEntry.new key, value
-  elsif value.is_a? SortOptions
-    SortOptionsCacheEntry.new key, value
   else
     CacheEntry(typeof(value), typeof(value)).new key, value
   end
diff --git a/src/library/entry.cr b/src/library/entry.cr
index 2c1ae34..28b7122 100644
--- a/src/library/entry.cr
+++ b/src/library/entry.cr
@@ -81,8 +81,6 @@ class Entry
 
   def cover_url
     return "#{Config.current.base_url}img/icon.png" if @err_msg
-    cached_cover_url = LRUCache.get "#{@id}:cover_url"
-    return cached_cover_url if cached_cover_url.is_a? String
 
     unless @book.entry_cover_url_cache
       TitleInfo.new @book.dir do |info|
@@ -98,7 +96,6 @@ class Entry
         url = File.join Config.current.base_url, info_url
       end
     end
-    LRUCache.set generate_cache_entry "#{@id}:cover_url", url
     url
   end
 
diff --git a/src/library/title.cr b/src/library/title.cr
index 8333642..8d97387 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -11,6 +11,7 @@ class Title
   @entry_display_name_cache : Hash(String, String)?
   @entry_cover_url_cache : Hash(String, String)?
   @cached_display_name : String?
+  @cached_cover_url : String?
 
   def initialize(@dir : String, @parent_id)
     storage = Storage.default
@@ -230,8 +231,8 @@ class Title
   end
 
   def cover_url
-    cached_cover_url = LRUCache.get "#{@id}:cover_url"
-    return cached_cover_url if cached_cover_url.is_a? String
+    cached_cover_url = @cached_cover_url
+    return cached_cover_url unless cached_cover_url.nil?
 
     url = "#{Config.current.base_url}img/icon.png"
     readable_entries = @entries.select &.err_msg.nil?
@@ -244,12 +245,11 @@ class Title
         url = File.join Config.current.base_url, info_url
       end
     end
-    LRUCache.set generate_cache_entry "#{@id}:cover_url", url
+    @cached_cover_url = url
     url
   end
 
   def set_cover_url(url : String)
-    LRUCache.invalidate "#{@id}:cover_url"
     TitleInfo.new @dir do |info|
       info.cover_url = url
       info.save
@@ -257,8 +257,6 @@ class Title
   end
 
   def set_cover_url(entry_name : String, url : String)
-    selected_entry = @entries.find { |entry| entry.display_name == entry_name }
-    LRUCache.invalidate "#{selected_entry.id}:cover_url" if selected_entry
     TitleInfo.new @dir do |info|
       info.entry_cover_url[entry_name] = url
       info.save
diff --git a/src/library/types.cr b/src/library/types.cr
index 46d2a7c..a4de007 100644
--- a/src/library/types.cr
+++ b/src/library/types.cr
@@ -35,16 +35,12 @@ class SortOptions
   end
 
   def self.from_info_json(dir, username)
-    key = "#{dir}:#{username}:sort_opt"
-    cached_opt = LRUCache.get key
-    return cached_opt if cached_opt.is_a? SortOptions
     opt = SortOptions.new
     TitleInfo.new dir do |info|
       if info.sort_by.has_key? username
         opt = SortOptions.from_tuple info.sort_by[username]
       end
     end
-    LRUCache.set generate_cache_entry key, opt
     opt
   end
 
diff --git a/src/util/web.cr b/src/util/web.cr
index 9b967da..1b3a42c 100644
--- a/src/util/web.cr
+++ b/src/util/web.cr
@@ -121,7 +121,6 @@ macro get_and_save_sort_opt(dir)
     sort_opt = SortOptions.new sort_method, is_ascending
 
     key = "#{{{dir}}}:#{username}:sort_opt"
-    LRUCache.set generate_cache_entry key, sort_opt
     TitleInfo.new {{dir}} do |info|
       info.sort_by[username] = sort_opt.to_tuple
       info.save

From 9807db6ac02682d20dd9ce1021725c5257b749d2 Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 6 Sep 2021 02:29:31 +0900
Subject: [PATCH 19/26] Fix bug on entry_cover_url_cache

---
 src/library/title.cr | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/library/title.cr b/src/library/title.cr
index 8d97387..f93bf3c 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -259,6 +259,7 @@ class Title
   def set_cover_url(entry_name : String, url : String)
     TitleInfo.new @dir do |info|
       info.entry_cover_url[entry_name] = url
+      @entry_cover_url_cache = info.entry_cover_url
       info.save
     end
   end

From 5cb85ea8577c606e6aeceeab49294a8c10e3e9bb Mon Sep 17 00:00:00 2001
From: Leeingnyo <dyd1928@naver.com>
Date: Mon, 6 Sep 2021 09:40:53 +0900
Subject: [PATCH 20/26] Set cached data when changed

---
 src/library/title.cr | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/library/title.cr b/src/library/title.cr
index f93bf3c..f1915d4 100644
--- a/src/library/title.cr
+++ b/src/library/title.cr
@@ -215,7 +215,7 @@ class Title
   end
 
   def set_display_name(dn)
-    @cached_display_name = nil
+    @cached_display_name = dn
     TitleInfo.new @dir do |info|
       info.display_name = dn
       info.save
@@ -250,6 +250,7 @@ class Title
   end
 
   def set_cover_url(url : String)
+    @cached_cover_url = url
     TitleInfo.new @dir do |info|
       info.cover_url = url
       info.save

From 79ef7bcd1cc592b0fced32dc992295e8f90ee990 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Mon, 6 Sep 2021 03:01:21 +0000
Subject: [PATCH 21/26] Remove unused variable

---
 src/util/web.cr | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/util/web.cr b/src/util/web.cr
index 1b3a42c..5704ea8 100644
--- a/src/util/web.cr
+++ b/src/util/web.cr
@@ -120,7 +120,6 @@ macro get_and_save_sort_opt(dir)
 
     sort_opt = SortOptions.new sort_method, is_ascending
 
-    key = "#{{{dir}}}:#{username}:sort_opt"
     TitleInfo.new {{dir}} do |info|
       info.sort_by[username] = sort_opt.to_tuple
       info.save

From 51806f18db114b3878616d293f9930edb7b0906d Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Mon, 6 Sep 2021 03:35:46 +0000
Subject: [PATCH 22/26] Rename config fields and improve logging

---
 src/config.cr        |  5 +++--
 src/library/cache.cr | 31 +++++++++++++++++++------------
 2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/src/config.cr b/src/config.cr
index 69feccd..99fb5b9 100644
--- a/src/config.cr
+++ b/src/config.cr
@@ -20,8 +20,9 @@ class Config
   property plugin_path : String = File.expand_path "~/mango/plugins",
     home: true
   property download_timeout_seconds : Int32 = 30
-  property sorted_entries_cache_enable = false
-  property sorted_entries_cache_size_mbs = 50
+  property cache_enabled = false
+  property cache_size_mbs = 50
+  property cache_log_enabled = true
   property disable_login = false
   property default_username = ""
   property auth_proxy_header_name = ""
diff --git a/src/library/cache.cr b/src/library/cache.cr
index 5d3797e..496442f 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -106,23 +106,26 @@ end
 # LRU Cache
 class LRUCache
   @@limit : Int128 = Int128.new 0
+  @@should_log = true
   # key => entry
   @@cache = {} of String => CacheEntryType
 
   def self.enabled
-    Config.current.sorted_entries_cache_enable
+    Config.current.cache_enabled
   end
 
   def self.init
-    cache_size = Config.current.sorted_entries_cache_size_mbs
+    cache_size = Config.current.cache_size_mbs
     @@limit = Int128.new cache_size * 1024 * 1024 if enabled
+    @@should_log = Config.current.cache_log_enabled
   end
 
   def self.get(key : String)
     return unless enabled
     entry = @@cache[key]?
-    Logger.debug "LRUCache Cache Hit! #{key}" unless entry.nil?
-    Logger.debug "LRUCache Cache Miss #{key}" if entry.nil?
+    if @@should_log
+      Logger.debug "LRUCache #{entry.nil? ? "miss" : "hit"} #{key}"
+    end
     return entry.value unless entry.nil?
   end
 
@@ -130,8 +133,8 @@ class LRUCache
     return unless enabled
     key = cache_entry.key
     @@cache[key] = cache_entry
-    Logger.debug "LRUCache Cached #{key}"
-    remove_victim_cache
+    Logger.debug "LRUCache cached #{key}" if @@should_log
+    remove_least_recent_access
   end
 
   def self.invalidate(key : String)
@@ -140,6 +143,7 @@ class LRUCache
   end
 
   def self.print
+    return unless @@should_log
     sum = @@cache.sum { |_, entry| entry.instance_size }
     Logger.debug "---- LRU Cache ----"
     Logger.debug "Size: #{sum} Bytes"
@@ -155,14 +159,17 @@ class LRUCache
     sum > @@limit
   end
 
-  private def self.remove_victim_cache
+  private def self.remove_least_recent_access
+    Logger.debug "Removing entries from LRUCache" if @@should_log
     while is_cache_full && @@cache.size > 0
-      Logger.debug "LRUCache Cache Full! Remove LRU"
-      min = @@cache.min_by? { |_, entry| entry.atime }
+      min_tuple = @@cache.min_by { |_, entry| entry.atime }
+      min_key = min_tuple[0]
+      min_entry = min_tuple[1]
+
       Logger.debug "  \
-        Target: #{min[0]}, \
-        Last Access Time: #{min[1].atime}" if min
-      invalidate min[0] if min
+        Target: #{min_key}, \
+        Last Access Time: #{min_entry.atime}" if @@should_log
+      invalidate min_key
     end
   end
 end

From 15a54f4f23038ce16cf58b607a7042d1ec6efe41 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Mon, 6 Sep 2021 08:10:13 +0000
Subject: [PATCH 23/26] Add `:sorted_entries` suffix to `gen_key`

---
 src/library/cache.cr | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 496442f..37359f2 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -63,10 +63,11 @@ class SortedEntriesCacheEntry < CacheEntry(Array(String), Array(Entry))
 
   def self.gen_key(book_id : String, username : String,
                    entries : Array(Entry), opt : SortOptions?)
-    sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
+    entries_sig = Digest::SHA1.hexdigest (entries.map &.id).to_s
     user_context = opt && opt.method == SortMethod::Progress ? username : ""
-    Digest::SHA1.hexdigest (book_id + sig + user_context +
-                            (opt ? opt.to_tuple.to_s : "nil"))
+    sig = Digest::SHA1.hexdigest (book_id + entries_sig + user_context +
+                                  (opt ? opt.to_tuple.to_s : "nil"))
+    "#{sig}:sorted_entries"
   end
 end
 

From 44d9c51ff9e86da4b45e552797d4e379556c5dc4 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Mon, 6 Sep 2021 08:10:42 +0000
Subject: [PATCH 24/26] Fix logging

---
 src/library/cache.cr | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 37359f2..0784363 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -161,7 +161,9 @@ class LRUCache
   end
 
   private def self.remove_least_recent_access
-    Logger.debug "Removing entries from LRUCache" if @@should_log
+    if @@should_log && is_cache_full
+      Logger.debug "Removing entries from LRUCache"
+    end
     while is_cache_full && @@cache.size > 0
       min_tuple = @@cache.min_by { |_, entry| entry.atime }
       min_key = min_tuple[0]

From ca1e221b10459775569d93cd1816efe5e462e880 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Mon, 6 Sep 2021 08:23:31 +0000
Subject: [PATCH 25/26] Rename `ids2entries` -> `ids_to_entries`

---
 src/library/cache.cr | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 0784363..05529fb 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -39,10 +39,10 @@ class SortedEntriesCacheEntry < CacheEntry(Array(String), Array(Entry))
   end
 
   def self.to_return_t(value : Array(String))
-    ids2entries value
+    ids_to_entries value
   end
 
-  private def self.ids2entries(ids : Array(String))
+  private def self.ids_to_entries(ids : Array(String))
     e_map = Library.default.deep_entries.to_h { |entry| {entry.id, entry} }
     entries = [] of Entry
     begin

From d809c21ee13429872950c7f5f299da236feb7ba7 Mon Sep 17 00:00:00 2001
From: Alex Ling <hkalexling@gmail.com>
Date: Mon, 6 Sep 2021 08:23:54 +0000
Subject: [PATCH 26/26] Document `CacheEntry`

---
 src/library/cache.cr | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/library/cache.cr b/src/library/cache.cr
index 05529fb..d0d3f01 100644
--- a/src/library/cache.cr
+++ b/src/library/cache.cr
@@ -3,6 +3,16 @@ require "digest"
 require "./entry"
 require "./types"
 
+# Base class for an entry in the LRU cache.
+# There are two ways to use it:
+#   1. Use it as it is by instantiating with the appropriate `SaveT` and
+#     `ReturnT`. Note that in this case, `SaveT` and `ReturnT` must be the
+#     same type. That is, the input value will be stored as it is without
+#     any transformation.
+#   2. You can also subclass it and provide custom implementations for
+#     `to_save_t` and `to_return_t`. This allows you to transform and store
+#     the input value to a different type. See `SortedEntriesCacheEntry` as
+#     an example.
 private class CacheEntry(SaveT, ReturnT)
   getter key : String, atime : Time