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, 615 deletions

diff --git a/src/garage/tests/list.rs b/src/garage/tests/list.rs
deleted file mode 100644
index bb03f250..00000000
--- a/src/garage/tests/list.rs
+++ /dev/null
@@ -1,615 +0,0 @@
-use crate::common;
-
-const KEYS: [&str; 8] = ["a", "a/a", "a/b", "a/c", "a/d/a", "a/é", "b", "c"];
-const KEYS_MULTIPART: [&str; 5] = ["a", "a", "c", "c/a", "c/b"];
-
-#[tokio::test]
-async fn test_listobjectsv2() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("listobjectsv2");
-
-	for k in KEYS {
-		ctx.client
-			.put_object()
-			.bucket(&bucket)
-			.key(k)
-			.send()
-			.await
-			.unwrap();
-	}
-
-	{
-		// Scoping the variable to avoid reusing it
-		// in a following assert due to copy paste
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 8);
-		assert!(r.common_prefixes.is_none());
-	}
-
-	//@FIXME aws-sdk-s3 automatically checks max-key values.
-	// If we set it to zero, it drops it, and it is probably
-	// the same behavior on values bigger than 1000.
-	// Boto and awscli do not perform these tests, we should write
-	// our own minimal library to bypass AWS SDK's tests and be
-	// sure that we behave correctly.
-
-	{
-		// With 2 elements
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.max_keys(2)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 2);
-		assert!(r.common_prefixes.is_none());
-		assert!(r.next_continuation_token.is_some());
-	}
-
-	{
-		// With pagination
-		let mut cnt = 0;
-		let mut next = None;
-		let last_idx = KEYS.len() - 1;
-
-		for i in 0..KEYS.len() {
-			let r = ctx
-				.client
-				.list_objects_v2()
-				.bucket(&bucket)
-				.set_continuation_token(next)
-				.max_keys(1)
-				.send()
-				.await
-				.unwrap();
-
-			cnt += 1;
-			next = r.next_continuation_token;
-
-			assert_eq!(r.contents.unwrap().len(), 1);
-			assert!(r.common_prefixes.is_none());
-			if i != last_idx {
-				assert!(next.is_some());
-			}
-		}
-		assert_eq!(cnt, KEYS.len());
-	}
-
-	{
-		// With a delimiter
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.delimiter("/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 3);
-		assert_eq!(r.common_prefixes.unwrap().len(), 1);
-	}
-
-	{
-		// With a delimiter and pagination
-		let mut cnt_pfx = 0;
-		let mut cnt_key = 0;
-		let mut next = None;
-
-		for _i in 0..KEYS.len() {
-			let r = ctx
-				.client
-				.list_objects_v2()
-				.bucket(&bucket)
-				.set_continuation_token(next)
-				.delimiter("/")
-				.max_keys(1)
-				.send()
-				.await
-				.unwrap();
-
-			next = r.next_continuation_token;
-			match (r.contents, r.common_prefixes) {
-				(Some(k), None) if k.len() == 1 => cnt_key += 1,
-				(None, Some(pfx)) if pfx.len() == 1 => cnt_pfx += 1,
-				_ => unreachable!("logic error"),
-			};
-			if next.is_none() {
-				break;
-			}
-		}
-		assert_eq!(cnt_key, 3);
-		assert_eq!(cnt_pfx, 1);
-	}
-
-	{
-		// With a prefix
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.prefix("a/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 5);
-		assert!(r.common_prefixes.is_none());
-	}
-
-	{
-		// With a prefix and a delimiter
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.prefix("a/")
-			.delimiter("/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 4);
-		assert_eq!(r.common_prefixes.unwrap().len(), 1);
-	}
-
-	{
-		// With a prefix, a delimiter and max_key
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.prefix("a/")
-			.delimiter("/")
-			.max_keys(1)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.as_ref().unwrap().len(), 1);
-		assert_eq!(
-			r.contents
-				.unwrap()
-				.first()
-				.unwrap()
-				.key
-				.as_ref()
-				.unwrap()
-				.as_str(),
-			"a/a"
-		);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With start_after before all keys
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.start_after("Z")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 8);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With start_after after all keys
-		let r = ctx
-			.client
-			.list_objects_v2()
-			.bucket(&bucket)
-			.start_after("c")
-			.send()
-			.await
-			.unwrap();
-
-		assert!(r.contents.is_none());
-		assert!(r.common_prefixes.is_none());
-	}
-}
-
-#[tokio::test]
-async fn test_listobjectsv1() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("listobjects");
-
-	for k in KEYS {
-		ctx.client
-			.put_object()
-			.bucket(&bucket)
-			.key(k)
-			.send()
-			.await
-			.unwrap();
-	}
-
-	{
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 8);
-		assert!(r.common_prefixes.is_none());
-	}
-
-	{
-		// With 2 elements
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.max_keys(2)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 2);
-		assert!(r.common_prefixes.is_none());
-		assert!(r.next_marker.is_some());
-	}
-
-	{
-		// With pagination
-		let mut cnt = 0;
-		let mut next = None;
-		let last_idx = KEYS.len() - 1;
-
-		for i in 0..KEYS.len() {
-			let r = ctx
-				.client
-				.list_objects()
-				.bucket(&bucket)
-				.set_marker(next)
-				.max_keys(1)
-				.send()
-				.await
-				.unwrap();
-
-			cnt += 1;
-			next = r.next_marker;
-
-			assert_eq!(r.contents.unwrap().len(), 1);
-			assert!(r.common_prefixes.is_none());
-			if i != last_idx {
-				assert!(next.is_some());
-			}
-		}
-		assert_eq!(cnt, KEYS.len());
-	}
-
-	{
-		// With a delimiter
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.delimiter("/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 3);
-		assert_eq!(r.common_prefixes.unwrap().len(), 1);
-	}
-
-	{
-		// With a delimiter and pagination
-		let mut cnt_pfx = 0;
-		let mut cnt_key = 0;
-		let mut next = None;
-
-		for _i in 0..KEYS.len() {
-			let r = ctx
-				.client
-				.list_objects()
-				.bucket(&bucket)
-				.delimiter("/")
-				.set_marker(next)
-				.max_keys(1)
-				.send()
-				.await
-				.unwrap();
-
-			next = r.next_marker;
-			match (r.contents, r.common_prefixes) {
-				(Some(k), None) if k.len() == 1 => cnt_key += 1,
-				(None, Some(pfx)) if pfx.len() == 1 => cnt_pfx += 1,
-				_ => unreachable!("logic error"),
-			};
-			if next.is_none() {
-				break;
-			}
-		}
-		assert_eq!(cnt_key, 3);
-		// We have no optimization to skip the whole prefix
-		// on listobjectsv1 so we return the same one 5 times,
-		// for each element. It is up to the client to merge its result.
-		// This is compliant with AWS spec.
-		assert_eq!(cnt_pfx, 5);
-	}
-
-	{
-		// With a prefix
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.prefix("a/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 5);
-		assert!(r.common_prefixes.is_none());
-	}
-
-	{
-		// With a prefix and a delimiter
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.prefix("a/")
-			.delimiter("/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 4);
-		assert_eq!(r.common_prefixes.unwrap().len(), 1);
-	}
-
-	{
-		// With a prefix, a delimiter and max_key
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.prefix("a/")
-			.delimiter("/")
-			.max_keys(1)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.as_ref().unwrap().len(), 1);
-		assert_eq!(
-			r.contents
-				.unwrap()
-				.first()
-				.unwrap()
-				.key
-				.as_ref()
-				.unwrap()
-				.as_str(),
-			"a/a"
-		);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With marker before all keys
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.marker("Z")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.contents.unwrap().len(), 8);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With start_after after all keys
-		let r = ctx
-			.client
-			.list_objects()
-			.bucket(&bucket)
-			.marker("c")
-			.send()
-			.await
-			.unwrap();
-
-		assert!(r.contents.is_none());
-		assert!(r.common_prefixes.is_none());
-	}
-}
-
-#[tokio::test]
-async fn test_listmultipart() {
-	let ctx = common::context();
-	let bucket = ctx.create_bucket("listmultipartuploads");
-
-	for k in KEYS_MULTIPART {
-		ctx.client
-			.create_multipart_upload()
-			.bucket(&bucket)
-			.key(k)
-			.send()
-			.await
-			.unwrap();
-	}
-
-	{
-		// Default
-		let r = ctx
-			.client
-			.list_multipart_uploads()
-			.bucket(&bucket)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.uploads.unwrap().len(), 5);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With pagination
-		let mut next = None;
-		let mut upnext = None;
-		let last_idx = KEYS_MULTIPART.len() - 1;
-
-		for i in 0..KEYS_MULTIPART.len() {
-			let r = ctx
-				.client
-				.list_multipart_uploads()
-				.bucket(&bucket)
-				.set_key_marker(next)
-				.set_upload_id_marker(upnext)
-				.max_uploads(1)
-				.send()
-				.await
-				.unwrap();
-
-			next = r.next_key_marker;
-			upnext = r.next_upload_id_marker;
-
-			assert_eq!(r.uploads.unwrap().len(), 1);
-			assert!(r.common_prefixes.is_none());
-			if i != last_idx {
-				assert!(next.is_some());
-			}
-		}
-	}
-	{
-		// With delimiter
-		let r = ctx
-			.client
-			.list_multipart_uploads()
-			.bucket(&bucket)
-			.delimiter("/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.uploads.unwrap().len(), 3);
-		assert_eq!(r.common_prefixes.unwrap().len(), 1);
-	}
-	{
-		// With delimiter and pagination
-		let mut next = None;
-		let mut upnext = None;
-		let mut upcnt = 0;
-		let mut pfxcnt = 0;
-		let mut loopcnt = 0;
-
-		while loopcnt < KEYS_MULTIPART.len() {
-			let r = ctx
-				.client
-				.list_multipart_uploads()
-				.bucket(&bucket)
-				.delimiter("/")
-				.max_uploads(1)
-				.set_key_marker(next)
-				.set_upload_id_marker(upnext)
-				.send()
-				.await
-				.unwrap();
-
-			next = r.next_key_marker;
-			upnext = r.next_upload_id_marker;
-
-			loopcnt += 1;
-			upcnt += r.uploads.unwrap_or_default().len();
-			pfxcnt += r.common_prefixes.unwrap_or_default().len();
-
-			if next.is_none() {
-				break;
-			}
-		}
-
-		assert_eq!(upcnt + pfxcnt, loopcnt);
-		assert_eq!(upcnt, 3);
-		assert_eq!(pfxcnt, 1);
-	}
-	{
-		// With prefix
-		let r = ctx
-			.client
-			.list_multipart_uploads()
-			.bucket(&bucket)
-			.prefix("c")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.uploads.unwrap().len(), 3);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With prefix and delimiter
-		let r = ctx
-			.client
-			.list_multipart_uploads()
-			.bucket(&bucket)
-			.prefix("c")
-			.delimiter("/")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.uploads.unwrap().len(), 1);
-		assert_eq!(r.common_prefixes.unwrap().len(), 1);
-	}
-	{
-		// With prefix, delimiter and max keys
-		let r = ctx
-			.client
-			.list_multipart_uploads()
-			.bucket(&bucket)
-			.prefix("c")
-			.delimiter("/")
-			.max_uploads(1)
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.uploads.unwrap().len(), 1);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With starting token before the first element
-		let r = ctx
-			.client
-			.list_multipart_uploads()
-			.bucket(&bucket)
-			.key_marker("ZZZZZ")
-			.send()
-			.await
-			.unwrap();
-
-		assert_eq!(r.uploads.unwrap().len(), 5);
-		assert!(r.common_prefixes.is_none());
-	}
-	{
-		// With starting token after the last element
-		let r = ctx
-			.client
-			.list_multipart_uploads()
-			.bucket(&bucket)
-			.key_marker("d")
-			.send()
-			.await
-			.unwrap();
-
-		assert!(r.uploads.is_none());
-		assert!(r.common_prefixes.is_none());
-	}
-}