feat: remote database backend (#7)

Cargo.toml

@@ -1,5 +1,5 @@
 [workspace]
-members = ["proto", "sqlite"]
+members = ["proto", "remote", "sqlite"]
 resolver = "2"
 
 [workspace.package]
@@ -13,15 +13,18 @@ denokv_proto = { version = "0.1.0", path = "./proto" }
 
 anyhow = "1"
 async-trait = "0.1"
+bytes = "1"
 chrono = { version = "0.4", features = ["serde"] }
 futures = "0.3.28"
 log = "0.4.20"
 num-bigint = "0.4"
 prost = "0.11"
 prost-build = "0.11"
 rand = "0.8.5"
+reqwest = { version = "0.11", features = ["json"] }
 rusqlite = { version = "0.29.0" }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1.0.107"
 tokio = { version = "1.33.0", features = ["full"] }
+url = "2"
 uuid = { version = "1.4.1", features = ["v4", "serde"] }

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2023 Deno
+Copyright (c) 2023 the Deno authors
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -5,6 +5,8 @@ This repository contains two crates:
 - `denokv_proto` (`/proto`): Shared interfaces backing KV, like definitions of
   `Key`, `Database`, and `Value`.
 - `denokv_sqlite` (`/sqlite`): An implementation of `Database` backed by SQLite.
+- `denokv_remote` (`/remote`): An implementation of `Database` backed by a
+  remote KV database, acessible via the KV Connect protocol.
 
 These crates are used by the `deno_kv` crate in the Deno repository to provide a
 JavaScript API for interacting with Deno KV.

proto/interface.rs

@@ -330,10 +330,16 @@ pub struct CommitResult {
   pub versionstamp: Versionstamp,
 }
 
+#[derive(Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct MetadataExchangeRequest {
+  #[serde(default)]
+  pub supported_versions: Vec<u64>,
+}
+
 /// The database metadata that is returned by the KV Connect metadata endpoint.
 #[derive(Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
-#[allow(dead_code)]
 pub struct DatabaseMetadata {
   pub version: u64,
   pub database_id: Uuid,

proto/kv-connect.md

@@ -103,10 +103,11 @@ exponential backoff strategy with unlimited retries.
 The client MUST verify that the response is a 200 OK, 3xx class redirect
 response, or 4xx class HTTP status response. If the response is a 3xx class
 redirect response, the client MUST follow the redirect and perform the metadata
-exchange with the new URL as the base URL. If the response is a 4xx class HTTP
-status response, the client MUST fatally abort the metadata exchange and display
-the error message to the user. If the response is a 200 OK response, the client
-MUST verify that the response body adheres to the JSON schema defined in the
+exchange with the new URL as the base URL (the client MAY impose a maximum
+redirect depth). If the response is a 4xx class HTTP status response, the client
+MUST fatally abort the metadata exchange and display the error message to the
+user. If the response is a 200 OK response, the client MUST verify that the
+response body adheres to the JSON schema defined in the
 `schema/kv-metadata-exchange-response.v<protocolversion>.json` file. If the
 response body is invalid, the client MUST fatally abort the metadata exchange
 and display the error message to the user.

proto/schema/datapath.proto

@@ -113,8 +113,8 @@ enum MutationType {
   M_UNSPECIFIED = 0;
   // Set the value.
   M_SET = 1;
-  // Clear the value.
-  M_CLEAR = 2;
+  // Delete the value.
+  M_DELETE = 2;
   // Sum the stored value with the new value. Both values must be LE64 encoded.
   M_SUM = 3;
   // Min the stored value with the new value. Both values must be LE64 encoded.

remote/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+name = "denokv_remote"
+description = "Remote (KV Connect) backend for Deno KV"
+version = "0.1.0"
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+authors.workspace = true
+
+[lib]
+path = "lib.rs"
+
+[dependencies]
+anyhow.workspace = true
+async-trait.workspace = true
+bytes.workspace = true
+chrono.workspace = true
+denokv_proto.workspace = true
+log.workspace = true
+prost.workspace = true
+rand.workspace = true
+reqwest.workspace = true
+serde_json.workspace = true
+serde.workspace = true
+tokio.workspace = true
+url.workspace = true
+uuid.workspace = true