calibre: always use custom fast parser (#12714)

Fixes #12610

plugins/calibre.koplugin/metadata.lua

@@ -11,7 +11,6 @@ of storing it.
 local lfs = require("libs/libkoreader-lfs")
 local rapidjson = require("rapidjson")
 local logger = require("logger")
-local parser = require("parser")
 local util = require("util")
 local time = require("ui/time")
 
@@ -52,10 +51,6 @@ local function slim(book, is_search)
     return slim_book
 end
 
--- This is the max file size we attempt to decode using rapidjson.
--- For larger files we use a sax parser to avoid OOM errors
-local MAX_JSON_FILESIZE = 50 * 1024 * 1024
-
 --- find calibre files for a given dir
 local function findCalibreFiles(dir)
     local function existOrLast(file)
@@ -120,15 +115,7 @@ function CalibreMetadata:loadBookList()
         logger.warn("File is invalid", self.metadata)
         return rapidjson.array({})
     end
-    local books, err
-    local impl = G_reader_settings:readSetting("calibre_json_parser") or attr.size > MAX_JSON_FILESIZE and "safe" or "fast"
-    if impl == "fast" then
-        books, err = rapidjson.load_calibre(self.metadata)
-    elseif impl == "safe" then
-         books, err = parser.parseFile(self.metadata)
-    else
-        books, err = rapidjson.load(self.metadata)
-    end
+    local books, err = rapidjson.load_calibre(self.metadata)
     if not books then
         logger.warn(string.format("Unable to load library from json file %s: \n%s",
             self.metadata, err))

plugins/calibre.koplugin/parser.lua

@@ -1,97 +0,0 @@
--- parse "metadata.calibre" files
-local lj = require("lunajson")
-local rapidjson = require("rapidjson")
-
-local array_fields = {
-    authors = true,
-    tags = true,
-    series = true,
-}
-
-local required_fields = {
-    authors = true,
-    last_modified = true,
-    lpath = true,
-    series = true,
-    series_index = true,
-    size = true,
-    tags = true,
-    title = true,
-    uuid = true,
-}
-
-local field
-local t = {}
-local function append(v)
-    -- Some fields *may* be arrays, so check whether we ran through startarray first or not
-    if t[field] then
-        table.insert(t[field], v)
-    else
-        t[field] = v
-        field = nil
-    end
-end
-
-local depth = 0
-local result = rapidjson.array({})
-local sax = {
-    startobject = function()
-        depth = depth + 1
-    end,
-    endobject = function()
-        if depth == 1 then
-            table.insert(result, rapidjson.object(t))
-            t = {}
-        end
-        depth = depth - 1
-    end,
-    startarray = function()
-        if array_fields[field] then
-            t[field] = rapidjson.array({})
-        end
-    end,
-    endarray = function()
-        if field then
-            field = nil
-        end
-    end,
-    key = function(s)
-        if required_fields[s] then
-            field = s
-        end
-    end,
-    string = function(s)
-        if field then
-            append(s)
-        end
-    end,
-    number = function(n)
-        if field then
-            append(n)
-        end
-    end,
-    boolean = function(b)
-        if field then
-            append(b)
-        end
-    end,
-}
-
-local function parse_unsafe(path)
-    local p = lj.newfileparser(path, sax)
-    p.run()
-end
-
-local parser = {}
-
-function parser.parseFile(file)
-    result = rapidjson.array({})
-    local ok, err = pcall(parse_unsafe, file)
-    field = nil
-    if not ok then
-        return nil, err
-    end
-    return result
-end
-
-return parser