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, 266 deletions

diff --git a/src/garage/tests/objects.rs b/src/garage/tests/objects.rs
deleted file mode 100644
index e1175b81..00000000
--- a/src/garage/tests/objects.rs
+++ /dev/null
@@ -1,266 +0,0 @@
-use crate::common;
-use aws_sdk_s3::model::{Delete, ObjectIdentifier};
-use aws_sdk_s3::types::ByteStream;
-
-const STD_KEY: &str = "hello world";
-const CTRL_KEY: &str = "\x00\x01\x02\x00";
-const UTF8_KEY: &str = "\u{211D}\u{1F923}\u{1F44B}";
-const BODY: &[u8; 62] = b"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
-
-#[tokio::test]
-async fn test_putobject() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("putobject");
-
-	{
-		// Send an empty object (can serve as a directory marker)
-		// with a content type
-		let etag = "\"d41d8cd98f00b204e9800998ecf8427e\"";
-		let content_type = "text/csv";
-		let r = ctx
-			.client
-			.put_object()
-			.bucket(&bucket)
-			.key(STD_KEY)
-			.content_type(content_type)
-			.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);
-	}
-
-	{
-		// Key with control characters,
-		// no content type and some data
-		let etag = "\"49f68a5c8493ec2c0bf489821c21fc3b\"";
-		let data = ByteStream::from_static(b"hi");
-
-		let r = ctx
-			.client
-			.put_object()
-			.bucket(&bucket)
-			.key(CTRL_KEY)
-			.body(data)
-			.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)
-			.send()
-			.await
-			.unwrap();
-
-		assert_bytes_eq!(o.body, b"hi");
-		assert_eq!(o.e_tag.unwrap(), etag);
-		assert!(o.last_modified.is_some());
-		assert_eq!(o.content_length, 2);
-		assert_eq!(o.parts_count, 0);
-		assert_eq!(o.tag_count, 0);
-	}
-
-	{
-		// Key with UTF8 codepoints including emoji
-		let etag = "\"d41d8cd98f00b204e9800998ecf8427e\"";
-
-		let r = ctx
-			.client
-			.put_object()
-			.bucket(&bucket)
-			.key(UTF8_KEY)
-			.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(UTF8_KEY)
-			.send()
-			.await
-			.unwrap();
-
-		assert_bytes_eq!(o.body, b"");
-		assert_eq!(o.e_tag.unwrap(), etag);
-		assert!(o.last_modified.is_some());
-		assert_eq!(o.content_length, 0);
-		assert_eq!(o.parts_count, 0);
-		assert_eq!(o.tag_count, 0);
-	}
-}
-
-#[tokio::test]
-async fn test_getobject() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("getobject");
-
-	let etag = "\"46cf18a9b447991b450cad3facf5937e\"";
-	let data = ByteStream::from_static(BODY);
-
-	let r = ctx
-		.client
-		.put_object()
-		.bucket(&bucket)
-		.key(STD_KEY)
-		.body(data)
-		.send()
-		.await
-		.unwrap();
-
-	assert_eq!(r.e_tag.unwrap().as_str(), etag);
-
-	{
-		let o = ctx
-			.client
-			.get_object()
-			.bucket(&bucket)
-			.key(STD_KEY)
-			.range("bytes=1-9")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(o.content_range.unwrap().as_str(), "bytes 1-9/62");
-		assert_bytes_eq!(o.body, &BODY[1..10]);
-	}
-	{
-		let o = ctx
-			.client
-			.get_object()
-			.bucket(&bucket)
-			.key(STD_KEY)
-			.range("bytes=9-")
-			.send()
-			.await
-			.unwrap();
-		assert_eq!(o.content_range.unwrap().as_str(), "bytes 9-61/62");
-		assert_bytes_eq!(o.body, &BODY[9..]);
-	}
-	{
-		let o = ctx
-			.client
-			.get_object()
-			.bucket(&bucket)
-			.key(STD_KEY)
-			.range("bytes=-5")
-			.send()
-			.await
-			.unwrap();
-		assert_eq!(o.content_range.unwrap().as_str(), "bytes 57-61/62");
-		assert_bytes_eq!(o.body, &BODY[57..]);
-	}
-}
-
-#[tokio::test]
-async fn test_deleteobject() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("deleteobject");
-
-	let mut to_del = Delete::builder();
-
-	// add content without data
-	for i in 0..5 {
-		let k = format!("k-{}", i);
-		ctx.client
-			.put_object()
-			.bucket(&bucket)
-			.key(k.to_string())
-			.send()
-			.await
-			.unwrap();
-		if i > 0 {
-			to_del = to_del.objects(ObjectIdentifier::builder().key(k).build());
-		}
-	}
-
-	// add content with data
-	for i in 0..5 {
-		let k = format!("l-{}", i);
-		let data = ByteStream::from_static(BODY);
-		ctx.client
-			.put_object()
-			.bucket(&bucket)
-			.key(k.to_string())
-			.body(data)
-			.send()
-			.await
-			.unwrap();
-
-		if i > 0 {
-			to_del = to_del.objects(ObjectIdentifier::builder().key(k).build());
-		}
-	}
-
-	ctx.client
-		.delete_object()
-		.bucket(&bucket)
-		.key("k-0")
-		.send()
-		.await
-		.unwrap();
-
-	ctx.client
-		.delete_object()
-		.bucket(&bucket)
-		.key("l-0")
-		.send()
-		.await
-		.unwrap();
-
-	let r = ctx
-		.client
-		.delete_objects()
-		.bucket(&bucket)
-		.delete(to_del.build())
-		.send()
-		.await
-		.unwrap();
-
-	assert_eq!(r.deleted.unwrap().len(), 8);
-
-	let l = ctx
-		.client
-		.list_objects_v2()
-		.bucket(&bucket)
-		.send()
-		.await
-		.unwrap();
-
-	assert!(l.contents.is_none());
-}