First implementation of K2V (#293)

**Specification:**

View spec at [this URL](https://git.deuxfleurs.fr/Deuxfleurs/garage/src/branch/k2v/doc/drafts/k2v-spec.md)

- [x] Specify the structure of K2V triples
- [x] Specify the DVVS format used for causality detection
- [x] Specify the K2V index (just a counter of number of values per partition key)
- [x] Specify single-item endpoints: ReadItem, InsertItem, DeleteItem
- [x] Specify index endpoint: ReadIndex
- [x] Specify multi-item endpoints: InsertBatch, ReadBatch, DeleteBatch
- [x] Move to JSON objects instead of tuples
- [x] Specify endpoints for polling for updates on single values (PollItem)

**Implementation:**

- [x] Table for K2V items, causal contexts
- [x] Indexing mechanism and table for K2V index
- [x] Make API handlers a bit more generic
- [x] K2V API endpoint
- [x] K2V API router
- [x] ReadItem
- [x] InsertItem
- [x] DeleteItem
- [x] PollItem
- [x] ReadIndex
- [x] InsertBatch
- [x] ReadBatch
- [x] DeleteBatch

**Testing:**

- [x] Just a simple Python script that does some requests to check visually that things are going right (does not contain parsing of results or assertions on returned values)
- [x] Actual tests:
  - [x] Adapt testing framework
  - [x] Simple test with InsertItem + ReadItem
  - [x] Test with several Insert/Read/DeleteItem + ReadIndex
  - [x] Test all combinations of return formats for ReadItem
  - [x] Test with ReadBatch, InsertBatch, DeleteBatch
  - [x] Test with PollItem
  - [x] Test error codes
- [ ] Fix most broken stuff
  - [x] test PollItem broken randomly
  - [x] when invalid causality tokens are given, errors should be 4xx not 5xx

**Improvements:**

- [x] Descending range queries
  - [x] Specify
  - [x] Implement
  - [x] Add test
- [x] Batch updates to index counter
- [x] Put K2V behind `k2v` feature flag

Co-authored-by: Alex Auvolat <alex@adnab.me>
Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/293
Co-authored-by: Alex <alex@adnab.me>
Co-committed-by: Alex <alex@adnab.me>

1 files changed, 0 insertions, 185 deletions

diff --git a/src/garage/tests/streaming_signature.rs b/src/garage/tests/streaming_signature.rs
deleted file mode 100644
index c68f7dfc..00000000
--- a/src/garage/tests/streaming_signature.rs
+++ /dev/null
@@ -1,185 +0,0 @@
-use std::collections::HashMap;
-
-use crate::common;
-use common::custom_requester::BodySignature;
-use hyper::Method;
-
-const STD_KEY: &str = "hello-world";
-//const CTRL_KEY: &str = "\x00\x01\x02\x00";
-const BODY: &[u8; 62] = b"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
-
-#[tokio::test]
-async fn test_putobject_streaming() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("putobject-streaming");
-
-	{
-		// Send an empty object (can serve as a directory marker)
-		// with a content type
-		let etag = "\"d41d8cd98f00b204e9800998ecf8427e\"";
-		let content_type = "text/csv";
-		let mut headers = HashMap::new();
-		headers.insert("content-type".to_owned(), content_type.to_owned());
-		let _ = ctx
-			.custom_request
-			.builder(bucket.clone())
-			.method(Method::PUT)
-			.path(STD_KEY.to_owned())
-			.unsigned_headers(headers)
-			.vhost_style(true)
-			.body(vec![])
-			.body_signature(BodySignature::Streaming(10))
-			.send()
-			.await
-			.unwrap();
-
-		// assert_eq!(r.e_tag.unwrap().as_str(), etag);
-		// We return a version ID here
-		// We should check if Amazon is returning one when versioning is not enabled
-		// assert!(r.version_id.is_some());
-
-		//let _version = r.version_id.unwrap();
-
-		let o = ctx
-			.client
-			.get_object()
-			.bucket(&bucket)
-			.key(STD_KEY)
-			.send()
-			.await
-			.unwrap();
-
-		assert_bytes_eq!(o.body, b"");
-		assert_eq!(o.e_tag.unwrap(), etag);
-		// We do not return version ID
-		// We should check if Amazon is returning one when versioning is not enabled
-		// assert_eq!(o.version_id.unwrap(), _version);
-		assert_eq!(o.content_type.unwrap(), content_type);
-		assert!(o.last_modified.is_some());
-		assert_eq!(o.content_length, 0);
-		assert_eq!(o.parts_count, 0);
-		assert_eq!(o.tag_count, 0);
-	}
-
-	{
-		let etag = "\"46cf18a9b447991b450cad3facf5937e\"";
-
-		let _ = ctx
-			.custom_request
-			.builder(bucket.clone())
-			.method(Method::PUT)
-			//.path(CTRL_KEY.to_owned()) at the moment custom_request does not encode url so this
-			//fail
-			.path("abc".to_owned())
-			.vhost_style(true)
-			.body(BODY.to_vec())
-			.body_signature(BodySignature::Streaming(16))
-			.send()
-			.await
-			.unwrap();
-
-		// assert_eq!(r.e_tag.unwrap().as_str(), etag);
-		// assert!(r.version_id.is_some());
-
-		let o = ctx
-			.client
-			.get_object()
-			.bucket(&bucket)
-			//.key(CTRL_KEY)
-			.key("abc")
-			.send()
-			.await
-			.unwrap();
-
-		assert_bytes_eq!(o.body, BODY);
-		assert_eq!(o.e_tag.unwrap(), etag);
-		assert!(o.last_modified.is_some());
-		assert_eq!(o.content_length, 62);
-		assert_eq!(o.parts_count, 0);
-		assert_eq!(o.tag_count, 0);
-	}
-}
-
-#[tokio::test]
-async fn test_create_bucket_streaming() {
-	let ctx = common::context();
-	let bucket = "createbucket-streaming";
-
-	{
-		// create bucket
-		let _ = ctx
-			.custom_request
-			.builder(bucket.to_owned())
-			.method(Method::PUT)
-			.body_signature(BodySignature::Streaming(10))
-			.send()
-			.await
-			.unwrap();
-
-		// test if the bucket exists and works properly
-		let etag = "\"d41d8cd98f00b204e9800998ecf8427e\"";
-		let content_type = "text/csv";
-		let _ = ctx
-			.client
-			.put_object()
-			.bucket(bucket)
-			.key(STD_KEY)
-			.content_type(content_type)
-			.send()
-			.await
-			.unwrap();
-
-		let o = ctx
-			.client
-			.get_object()
-			.bucket(bucket)
-			.key(STD_KEY)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(o.e_tag.unwrap(), etag);
-	}
-}
-
-#[tokio::test]
-async fn test_put_website_streaming() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("putwebsite-streaming");
-
-	{
-		let website_config = r#"<?xml version="1.0" encoding="UTF-8"?>
-<WebsiteConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
-   <ErrorDocument>
-      <Key>err/error.html</Key>
-   </ErrorDocument>
-   <IndexDocument>
-      <Suffix>home.html</Suffix>
-   </IndexDocument>
-</WebsiteConfiguration>"#;
-
-		let mut query = HashMap::new();
-		query.insert("website".to_owned(), None);
-		let _ = ctx
-			.custom_request
-			.builder(bucket.clone())
-			.method(Method::PUT)
-			.query_params(query)
-			.body(website_config.as_bytes().to_vec())
-			.body_signature(BodySignature::Streaming(10))
-			.send()
-			.await
-			.unwrap();
-
-		let o = ctx
-			.client
-			.get_bucket_website()
-			.bucket(&bucket)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(o.index_document.unwrap().suffix.unwrap(), "home.html");
-		assert_eq!(o.error_document.unwrap().key.unwrap(), "err/error.html");
-	}
-}