syncthing/lib
Jakob Borg 77970d5113
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 16:50:17 +01:00
..
api refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
assets lib/assets: MIME types, time formats (#8351) 2022-05-22 22:10:18 +02:00
automaxprocs all: Use own automaxprocs package that doesn't log (ref #9436) (#9437) 2024-02-27 13:05:19 +01:00
beacon style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
build lib/sha256: Remove it (#9643) 2024-08-10 12:58:20 +01:00
config refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
connections refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
db refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
dialer style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
discover refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
events style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
fs refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
geoip lib/geoip, cmd/relaypoolsrv, cmd/ursrv: Automatically manage GeoIP updates (#9342) 2024-05-18 20:31:49 +03:00
httpcache cmd/stupgrades: Cache should apply to HEAD as well as GET 2023-02-22 12:22:52 +01:00
ignore fix(ignore): ensure normalization of patterns and paths match (fixes #9597) (#9717) 2024-09-28 17:16:44 +02:00
locations all: minimal set of changes for iOS app (#9619) 2024-07-31 07:31:14 +02:00
logger all: Use some Go 1.21 features (#9409) 2024-02-10 21:02:42 +01:00
model refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
nat style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
netutil all: Remove lib/util package (#9049) 2023-08-21 19:44:33 +02:00
osutil refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
pmp style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
protocol refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
rand all: Remove unused method receivers (#8462) 2022-07-28 17:32:45 +02:00
rc style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
relay refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
s3 feat(ursrv): new metrics based approach 2024-09-30 14:16:27 -05:00
scanner refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
semaphore all: Remove lib/util package (#9049) 2023-08-21 19:44:33 +02:00
signature lib/sha256: Remove it (#9643) 2024-08-10 12:58:20 +01:00
sliceutil refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
stats style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
stringutil all: Remove lib/util package (#9049) 2023-08-21 19:44:33 +02:00
structutil all: Remove lib/util package (#9049) 2023-08-21 19:44:33 +02:00
stun style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
svcutil all: Remove lib/util package (#9049) 2023-08-21 19:44:33 +02:00
sync lib/model: Use a single lock (phase two: cleanup) (#9276) 2023-12-11 22:06:45 +01:00
syncthing refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
testutil all: Remove lib/util package (#9049) 2023-08-21 19:44:33 +02:00
tlsutil chore: enable TLS client cache for HTTPS where appropriate (#9721) 2024-09-24 08:55:04 +02:00
upgrade style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
upnp style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00
ur refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
versioner refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
watchaggregator refactor: use modern Protobuf encoder (#9817) 2024-12-01 16:50:17 +01:00
weakhash style: gofumpt all the things (#9829) 2024-11-19 11:32:56 +01:00