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koreader/frontend/docsettings.lua

298 lines
12 KiB
Lua

--[[--
This module is responsible for reading and writing `metadata.lua` files
in the so-called sidecar directory
([Wikipedia definition](https://en.wikipedia.org/wiki/Sidecar_file)).
]]
local DataStorage = require("datastorage")
local LuaSettings = require("luasettings")
local dump = require("dump")
local ffiutil = require("ffi/util")
local lfs = require("libs/libkoreader-lfs")
local logger = require("logger")
local util = require("util")
local DocSettings = LuaSettings:extend{}
local HISTORY_DIR = DataStorage:getHistoryDir()
local DOCSETTINGS_DIR = DataStorage:getDocSettingsDir()
local function buildCandidates(list)
local candidates = {}
local previous_entry_exists = false
for i, file_path in ipairs(list) do
-- Ignore missing files.
if file_path ~= "" and lfs.attributes(file_path, "mode") == "file" then
local mtime = lfs.attributes(file_path, "modification")
-- NOTE: Extra trickery: if we're inserting a "backup" file, and its primary buddy exists,
-- make sure it will *never* sort ahead of it by using the same mtime.
-- This aims to avoid weird UTC/localtime issues when USBMS is involved,
-- c.f., https://github.com/koreader/koreader/issues/9227#issuecomment-1345263324
if file_path:sub(-4) == ".old" and previous_entry_exists then
local primary_mtime = candidates[#candidates].mtime
-- Only proceed with the switcheroo when necessary, and warn about it.
if primary_mtime < mtime then
logger.warn("DocSettings: Backup", file_path, "is newer (", mtime, ") than its primary (", primary_mtime, "), fudging timestamps!")
-- Use the most recent timestamp for both (i.e., the backup's).
candidates[#candidates].mtime = mtime
end
end
table.insert(candidates, {
path = file_path,
mtime = mtime,
prio = i,
}
)
previous_entry_exists = true
else
previous_entry_exists = false
end
end
-- MRU sort, tie breaker is insertion order (higher priority locations were inserted first).
-- Iff a primary/backup pair of file both exist, of the two of them, the primary one *always* has priority,
-- regardless of mtime (c.f., NOTE above).
table.sort(candidates, function(l, r)
if l.mtime == r.mtime then
return l.prio < r.prio
else
return l.mtime > r.mtime
end
end)
return candidates
end
--- Returns path to sidecar directory (`filename.sdr`).
-- Sidecar directory is the file without _last_ suffix.
-- @string doc_path path to the document (e.g., `/foo/bar.pdf`)
-- @treturn string path to the sidecar directory (e.g., `/foo/bar.sdr`)
function DocSettings:getSidecarDir(doc_path, force_location)
if doc_path == nil or doc_path == "" then return "" end
local path = doc_path:match("(.*)%.") or doc_path -- file path without the last suffix
local location = force_location or G_reader_settings:readSetting("document_metadata_folder", "doc")
if location == "dir" then
path = DOCSETTINGS_DIR..path
end
return path..".sdr"
end
--- Returns path to `metadata.lua` file.
-- @string doc_path path to the document (e.g., `/foo/bar.pdf`)
-- @treturn string path to `/foo/bar.sdr/metadata.lua` file
function DocSettings:getSidecarFile(doc_path, force_location)
if doc_path == nil or doc_path == "" then return "" end
-- If the file does not have a suffix or we are working on a directory, we
-- should ignore the suffix part in metadata file path.
local suffix = doc_path:match(".*%.(.+)") or ""
return self:getSidecarDir(doc_path, force_location) .. "/metadata." .. suffix .. ".lua"
end
--- Returns `true` if there is a `metadata.lua` file.
-- @string doc_path path to the document (e.g., `/foo/bar.pdf`)
-- @treturn bool
function DocSettings:hasSidecarFile(doc_path)
return lfs.attributes(self:getSidecarFile(doc_path, "doc"), "mode") == "file"
or lfs.attributes(self:getSidecarFile(doc_path, "dir"), "mode") == "file"
or lfs.attributes(self:getHistoryPath(doc_path), "mode") == "file"
end
function DocSettings:getHistoryPath(doc_path)
if doc_path == nil or doc_path == "" then return "" end
return HISTORY_DIR .. "/[" .. doc_path:gsub("(.*/)([^/]+)", "%1] %2"):gsub("/", "#") .. ".lua"
end
function DocSettings:getPathFromHistory(hist_name)
if hist_name == nil or hist_name == "" then return "" end
if hist_name:sub(-4) ~= ".lua" then return "" end -- ignore .lua.old backups
-- 1. select everything included in brackets
local s = string.match(hist_name,"%b[]")
if s == nil or s == "" then return "" end
-- 2. crop the bracket-sign from both sides
-- 3. and finally replace decorative signs '#' to dir-char '/'
return string.gsub(string.sub(s, 2, -3), "#", "/")
end
function DocSettings:getNameFromHistory(hist_name)
if hist_name == nil or hist_name == "" then return "" end
if hist_name:sub(-4) ~= ".lua" then return "" end -- ignore .lua.old backups
local s = string.match(hist_name, "%b[]")
if s == nil or s == "" then return "" end
-- at first, search for path length
-- and return the rest of string without 4 last characters (".lua")
return string.sub(hist_name, string.len(s)+2, -5)
end
function DocSettings:getFileFromHistory(hist_name)
local path = self:getPathFromHistory(hist_name)
if path ~= "" then
local name = self:getNameFromHistory(hist_name)
if name ~= "" then
return ffiutil.joinPath(path, name)
end
end
end
--- Opens a document's individual settings (font, margin, dictionary, etc.)
-- @string doc_path path to the document (e.g., `/foo/bar.pdf`)
-- @treturn DocSettings object
function DocSettings:open(doc_path)
-- NOTE: Beware, our new instance is new, but self is still DocSettings!
local new = DocSettings:extend{}
new.doc_sidecar_dir = new:getSidecarDir(doc_path, "doc")
new.doc_sidecar_file = new:getSidecarFile(doc_path, "doc")
local doc_sidecar_file, legacy_sidecar_file
if lfs.attributes(new.doc_sidecar_dir, "mode") == "directory" then
doc_sidecar_file = new.doc_sidecar_file
legacy_sidecar_file = new.doc_sidecar_dir.."/"..ffiutil.basename(doc_path)..".lua"
end
new.dir_sidecar_dir = new:getSidecarDir(doc_path, "dir")
new.dir_sidecar_file = new:getSidecarFile(doc_path, "dir")
local dir_sidecar_file
if lfs.attributes(new.dir_sidecar_dir, "mode") == "directory" then
dir_sidecar_file = new.dir_sidecar_file
end
local history_file = new:getHistoryPath(doc_path)
-- Candidates list, in order of priority:
local candidates_list = {
-- New sidecar file in doc folder
doc_sidecar_file or "",
-- Backup file of new sidecar file in doc folder
doc_sidecar_file and (doc_sidecar_file..".old") or "",
-- Legacy sidecar file
legacy_sidecar_file or "",
-- New sidecar file in docsettings folder
dir_sidecar_file or "",
-- Backup file of new sidecar file in docsettings folder
dir_sidecar_file and (dir_sidecar_file..".old") or "",
-- Legacy history folder
history_file,
-- Backup file in legacy history folder
history_file..".old",
-- Legacy kpdfview setting
doc_path..".kpdfview.lua",
}
-- We get back an array of tables for *existing* candidates, sorted MRU first (insertion order breaks ties).
local candidates = buildCandidates(candidates_list)
local ok, stored
for _, t in ipairs(candidates) do
local candidate_path = t.path
-- Ignore empty files
if lfs.attributes(candidate_path, "size") > 0 then
ok, stored = pcall(dofile, candidate_path)
-- Ignore empty tables
if ok and next(stored) ~= nil then
logger.dbg("DocSettings: data is read from", candidate_path)
break
end
end
logger.dbg("DocSettings:", candidate_path, "is invalid, removed.")
os.remove(candidate_path)
end
if ok and stored then
new.data = stored
new.candidates = candidates
else
new.data = {}
end
new.data.doc_path = doc_path
return new
end
--- Serializes settings and writes them to `metadata.lua`.
function DocSettings:flush(data)
-- Depending on the settings, doc_settings are saved to the book folder or
-- to koreader/docsettings folder. The latter is also a fallback for read-only book storage.
local serials = G_reader_settings:readSetting("document_metadata_folder", "doc") == "doc"
and { {self.doc_sidecar_dir, self.doc_sidecar_file},
{self.dir_sidecar_dir, self.dir_sidecar_file}, }
or { {self.dir_sidecar_dir, self.dir_sidecar_file}, }
local s_out = dump(data or self.data, nil, true)
for _, s in ipairs(serials) do
util.makePath(s[1])
local sidecar_file = s[2]
local directory_updated = false
if lfs.attributes(sidecar_file, "mode") == "file" then
-- As an additional safety measure (to the ffiutil.fsync* calls used below),
-- we only backup the file to .old when it has not been modified in the last 60 seconds.
-- This should ensure in the case the fsync calls are not supported
-- that the OS may have itself sync'ed that file content in the meantime.
local mtime = lfs.attributes(sidecar_file, "modification")
if mtime < os.time() - 60 then
logger.dbg("DocSettings: Renamed", sidecar_file, "to", sidecar_file .. ".old")
os.rename(sidecar_file, sidecar_file .. ".old")
directory_updated = true -- fsync directory content too below
end
end
logger.dbg("DocSettings: Writing to", sidecar_file)
local f_out = io.open(sidecar_file, "w")
if f_out ~= nil then
f_out:write("-- we can read Lua syntax here!\nreturn ")
f_out:write(s_out)
f_out:write("\n")
ffiutil.fsyncOpenedFile(f_out) -- force flush to the storage device
f_out:close()
if directory_updated then
-- Ensure the file renaming is flushed to storage device
ffiutil.fsyncDirectory(sidecar_file)
end
self:purge(sidecar_file) -- remove old candidates and empty sidecar folders
break
end
end
end
--- Purges (removes) sidecar directory.
function DocSettings:purge(sidecar_to_keep)
-- Remove any of the old ones we may consider as candidates in DocSettings:open()
if self.candidates then
for _, t in ipairs(self.candidates) do
local candidate_path = t.path
if lfs.attributes(candidate_path, "mode") == "file" then
if (not sidecar_to_keep)
or (candidate_path ~= sidecar_to_keep and candidate_path ~= sidecar_to_keep..".old") then
os.remove(candidate_path)
logger.dbg("DocSettings: purged:", candidate_path)
end
end
end
end
if lfs.attributes(self.doc_sidecar_dir, "mode") == "directory" then
os.remove(self.doc_sidecar_dir) -- keep parent folders
end
if lfs.attributes(self.dir_sidecar_dir, "mode") == "directory" then
util.removePath(self.dir_sidecar_dir) -- remove empty parent folders
end
end
--- Updates sidecar info for file rename/copy/move/delete operations.
function DocSettings:update(doc_path, new_doc_path, copy)
if self:hasSidecarFile(doc_path) then
local doc_settings = DocSettings:open(doc_path)
if new_doc_path then
local new_doc_settings = DocSettings:open(new_doc_path)
new_doc_settings:flush(doc_settings.data) -- with current "Book metadata folder" setting
else
local cache_file_path = doc_settings:readSetting("cache_file_path")
if cache_file_path then
os.remove(cache_file_path)
end
end
if not copy then
doc_settings:purge()
end
end
end
return DocSettings