syncthing/lib/fs/types.go

// Copyright (C) 2016 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.

package fs

type FilesystemType int32

const (
	FilesystemTypeBasic FilesystemType = 0
	FilesystemTypeFake  FilesystemType = 1
)

func (t FilesystemType) String() string {
	switch t {
	case FilesystemTypeBasic:
		return "basic"
	case FilesystemTypeFake:
		return "fake"
	default:
		return "unknown"
	}
}
all: Convert folders to use filesystem abstraction GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4228 2017-08-19 14:36:56 +00:00			`// Copyright (C) 2016 The Syncthing Authors.`
			`//`
			`// This Source Code Form is subject to the terms of the Mozilla Public`
			`// License, v. 2.0. If a copy of the MPL was not distributed with this file,`
			`// You can obtain one at https://mozilla.org/MPL/2.0/.`

			`package fs`

refactor: use modern Protobuf encoder (#9817) At a high level, this is what I've done and why: - I'm moving the protobuf generation for the `protocol`, `discovery` and `db` packages to the modern alternatives, and using `buf` to generate because it's nice and simple. - After trying various approaches on how to integrate the new types with the existing code, I opted for splitting off our own data model types from the on-the-wire generated types. This means we can have a `FileInfo` type with nicer ergonomics and lots of methods, while the protobuf generated type stays clean and close to the wire protocol. It does mean copying between the two when required, which certainly adds a small amount of inefficiency. If we want to walk this back in the future and use the raw generated type throughout, that's possible, this however makes the refactor smaller (!) as it doesn't change everything about the type for everyone at the same time. - I have simply removed in cold blood a significant number of old database migrations. These depended on previous generations of generated messages of various kinds and were annoying to support in the new fashion. The oldest supported database version now is the one from Syncthing 1.9.0 from Sep 7, 2020. - I changed config structs to be regular manually defined structs. For the sake of discussion, some things I tried that turned out not to work... ### Embedding / wrapping Embedding the protobuf generated structs in our existing types as a data container and keeping our methods and stuff: ``` package protocol type FileInfo struct { generated.FileInfo } ``` This generates a lot of problems because the internal shape of the generated struct is quite different (different names, different types, more pointers), because initializing it doesn't work like you'd expect (i.e., you end up with an embedded nil pointer and a panic), and because the types of child types don't get wrapped. That is, even if we also have a similar wrapper around a `Vector`, that's not the type you get when accessing `someFileInfo.Version`, you get the `generated.Vector` that doesn't have methods, etc. ### Aliasing ``` package protocol type FileInfo = generated.FileInfo ``` Doesn't help because you can't attach methods to it, plus all the above. ### Generating the types into the target package like we do now and attaching methods This fails because of the different shape of the generated type (as in the embedding case above) plus the generated struct already has a bunch of methods that we can't necessarily override properly (like `String()` and a bunch of getters). ### Methods to functions I considered just moving all the methods we attach to functions in a specific package, so that for example ``` package protocol func (f FileInfo) Equal(other FileInfo) bool ``` would become ``` package fileinfos func Equal(a, b generated.FileInfo) bool ``` and this would mostly work, but becomes quite verbose and cumbersome, and somewhat limits discoverability (you can't see what methods are available on the type in auto completions, etc). In the end I did this in some cases, like in the database layer where a lot of things like `func (fv FileVersion) IsEmpty() bool` becomes `func fvIsEmpty(fv *generated.FileVersion)` because they were anyway just internal methods. Fixes #8247 2024-12-01 15:50:17 +00:00			`type FilesystemType int32`

			`const (`
			`FilesystemTypeBasic FilesystemType = 0`
			`FilesystemTypeFake FilesystemType = 1`
			`)`

all: Convert folders to use filesystem abstraction GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4228 2017-08-19 14:36:56 +00:00			`func (t FilesystemType) String() string {`
			`switch t {`
			`case FilesystemTypeBasic:`
			`return "basic"`
lib/fs: Add fakefs (#5235) * lib/fs: Add fakefs This adds a new fake filesystem type. It's described rather extensively in fakefs.go, but the main point is that it's for testing: when you want to spin up a Syncthing and have a terabyte or two of random files that can be synced somewhere, or an inifitely large filesystem to sync files into. It has pseudorandom properties such that data read from one fakefs can be written into another fakefs and read back and it will look consistent, without any of the data actually being stored. To use: <folder id="default" path="whatever" ...> <filesystemType>fake</filesystemType> This will create an empty fake filesystem. You can also specify that it should be prefilled with files: <folder id="default" path="whatever?size=2000000" ...> <filesystemType>fake</filesystemType> This will create a filesystem filled with 2TB of random data that can be scanned and synced. There are more options, see fakefs.go. Prefilled data is based on a deterministic seed, so you can index the data and restart Syncthing and the index is still correct for all the stored data. 2018-10-02 18:29:06 +00:00			`case FilesystemTypeFake:`
			`return "fake"`
all: Convert folders to use filesystem abstraction GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4228 2017-08-19 14:36:56 +00:00			`default:`
			`return "unknown"`
			`}`
			`}`