Split the server into three crates (#56)

This will make it easier to build variations on the server, or embed it
into larger projects.

.github/workflows/checks.yml

@@ -62,11 +62,24 @@ jobs:
           override: true
           minimal: true
 
-      - uses: actions-rs/[email protected]
+      - name: taskchampion-sync-server
+        uses: actions-rs/[email protected]
         with:
           command: rustdoc
           args: -p taskchampion-sync-server --all-features -- -Z unstable-options  --check -Dwarnings
 
+      - name: taskchampion-sync-server-core
+        uses: actions-rs/[email protected]
+        with:
+          command: rustdoc
+          args: -p taskchampion-sync-server-core --all-features -- -Z unstable-options  --check -Dwarnings
+
+      - name: taskchampion-sync-server-storage-sqlite
+        uses: actions-rs/[email protected]
+        with:
+          command: rustdoc
+          args: -p taskchampion-sync-server-storage-sqlite --all-features -- -Z unstable-options  --check -Dwarnings
+
   fmt:
     runs-on: ubuntu-latest
     name: "Formatting"

Cargo.toml

@@ -1,11 +1,12 @@
-[package]
-name = "taskchampion-sync-server"
-version = "0.4.1"
-authors = ["Dustin J. Mitchell <[email protected]>"]
-edition = "2021"
-publish = false
+[workspace]
+resolver = "2"
+members = [
+  "core",
+  "server",
+  "sqlite",
+]
 
-[dependencies]
+[workspace.dependencies]
 uuid = { version = "^1.11.0", features = ["serde", "v4"] }
 actix-web = "^4.9.0"
 anyhow = "1.0"
@@ -18,8 +19,6 @@ log = "^0.4.17"
 env_logger = "^0.11.5"
 rusqlite = { version = "0.32", features = ["bundled"] }
 chrono = { version = "^0.4.38", features = ["serde"] }
-
-[dev-dependencies]
 actix-rt = "2"
 tempfile = "3"
 pretty_assertions = "1"

README.md

@@ -13,6 +13,12 @@ This repository was spun off from Taskwarrior itself after the 3.0.0
 release. It is still under development and currently best described as
 a reference implementation of the Taskchampion sync protocol.
 
+It is comprised of three crates:
+
+ - `taskchampion-sync-server-core` implements the core of the protocol
+ - `taskchmpaion-sync-server-sqlite` implements an SQLite backend for the core
+ - `taskchampion-sync-server` implements a simple HTTP server for the protocol
+
 ## Installation
 
 ### From binary

core/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "taskchampion-sync-server-core"
+version = "0.4.1"
+authors = ["Dustin J. Mitchell <[email protected]>"]
+edition = "2021"
+
+[dependencies]
+uuid.workspace = true
+anyhow.workspace = true
+log.workspace = true
+env_logger.workspace = true
+chrono.workspace = true
+
+[dev-dependencies]
+pretty_assertions.workspace = true

core/README.md

@@ -0,0 +1,8 @@
+# taskchampion-sync-server-core
+
+This crate implements the core logic of the taskchampion sync protocol.
+
+This should be considered a reference implementation, with [the protocol
+documentation](https://gothenburgbitfactory.org/taskchampion/sync-protocol.html).
+representing the authoritative definition of the protocol. Other
+implementations are encouraged.

src/storage/inmemory.rs → core/src/inmemory.rs

@@ -1,6 +1,7 @@
-use super::{Client, Snapshot, Storage, StorageTxn, Uuid, Version};
+use super::{Client, Snapshot, Storage, StorageTxn, Version};
 use std::collections::HashMap;
 use std::sync::{Mutex, MutexGuard};
+use uuid::Uuid;
 
 struct Inner {
     /// Clients, indexed by client_id
@@ -16,6 +17,11 @@ struct Inner {
     children: HashMap<(Uuid, Uuid), Uuid>,
 }
 
+/// In-memory storage for testing and experimentation.
+///
+/// This is not for production use, but supports testing of sync server implementations.
+///
+/// NOTE: this does not implement transaction rollback.
 pub struct InMemoryStorage(Mutex<Inner>);
 
 impl InMemoryStorage {
@@ -32,9 +38,6 @@ impl InMemoryStorage {
 
 struct InnerTxn<'a>(MutexGuard<'a, Inner>);
 
-/// In-memory storage for testing and experimentation.
-///
-/// NOTE: this does not implement transaction rollback.
 impl Storage for InMemoryStorage {
     fn txn<'a>(&'a self) -> anyhow::Result<Box<dyn StorageTxn + 'a>> {
         Ok(Box::new(InnerTxn(self.0.lock().expect("poisoned lock"))))

core/src/lib.rs

@@ -0,0 +1,32 @@
+//! This crate implements the core logic of the taskchampion sync protocol.
+//!
+//! This should be considered a reference implementation, with [the protocol
+//! documentation](https://gothenburgbitfactory.org/taskchampion/sync-protocol.html). representing
+//! the authoritative definition of the protocol. Other implementations are encouraged.
+//!
+//! This crate uses an abstract storage backend. Note that this does not implement the
+//! HTTP-specific portions of the protocol, nor provide any storage implementations.
+//!
+//! ## API Methods
+//!
+//! The following API methods are implemented. These methods are documented in more detail in
+//! the protocol documentation.
+//!
+//! * [`add_version`]
+//! * [`get_child_version`]
+//! * [`add_snapshot`]
+//! * [`get_snapshot`]
+//!
+//! Each API method takes:
+//!
+//! * [`StorageTxn`] to access storage. Methods which modify storage will commit the transaction before returning.
+//! * [`ServerConfig`] providing basic configuration for the server's behavior.
+//! * `client_id` and a [`Client`] providing the client metadata.
+
+mod inmemory;
+mod server;
+mod storage;
+
+pub use inmemory::*;
+pub use server::*;
+pub use storage::*;