From 4bff8b23cb3a78ebbfeffa9f3da0218dd470a3f7 Mon Sep 17 00:00:00 2001
From: David Kagan <david.kagan07@gmail.com>
Date: Thu, 30 Mar 2023 14:26:11 -0400
Subject: [PATCH] WIP on DeleteShard, currently still nop

---
 api.go           | 17 +++++++++++++++++
 api_directive.go |  9 ++++-----
 index.go         | 13 +++++++++++++
 3 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/api.go b/api.go
index b7c155db8..35a8ae6ad 100644
--- a/api.go
+++ b/api.go
@@ -760,7 +760,22 @@ func (api *API) DeleteField(ctx context.Context, indexName string, fieldName str
 	return nil
 }
 
+// DeleteShard deletes a given shard in an index.
 func (api *API) DeleteShard(_ context.Context, indexName string, shardID uint64) error {
+	if err := api.validate(apiDeleteShard); err != nil {
+		return errors.Wrap(err, "validating api method")
+	}
+
+	// Find index.
+	idx := api.holder.Index(indexName)
+	if idx == nil {
+		return newNotFoundError(ErrIndexNotFound, indexName)
+	}
+
+	// Get views of shards
+	// ??? sv := idx.fieldView2shard().removeField()
+	// ??? maybe just use the api.DeleteField() method?
+
 	return nil
 }
 
@@ -3187,6 +3202,7 @@ const (
 	apiCreateField
 	apiCreateIndex
 	apiDeleteField
+	apiDeleteShard
 	apiDeleteAvailableShard
 	apiDeleteIndex
 	apiDeleteView
@@ -3257,6 +3273,7 @@ var methodsNormal = map[apiMethod]struct{}{
 	apiCreateField:          {},
 	apiCreateIndex:          {},
 	apiDeleteField:          {},
+	apiDeleteShard:          {},
 	apiDeleteAvailableShard: {},
 	apiDeleteIndex:          {},
 	apiDeleteView:           {},
diff --git a/api_directive.go b/api_directive.go
index 0d917558d..5e78f6059 100644
--- a/api_directive.go
+++ b/api_directive.go
@@ -341,7 +341,8 @@ func (api *API) pushJobsTableKeys(ctx context.Context, jobs chan<- directiveJobT
 
 			//maybe start with shards, since multiple shards belong to a partition
 			api.Holder().Index(string(tkey)).TranslateStore(int(partition)) //.Delete(records *roaring.Bitmap)
-			// maybe need to do this since it's local disk? os.RemoveAll(pathname) maybe partition path?
+
+			// this implementation is going to be much more difficult
 		}
 	}
 
@@ -433,14 +434,12 @@ func (api *API) pushJobsFieldKeys(ctx context.Context, jobs chan<- directiveJobT
 	fieldComp := newFieldsComparer(fromD.TranslateFieldsMap(), toD.TranslateFieldsMap())
 
 	// Remove any field keys which are no longer assigned to this worker.
-	// TODO(tlt): currently, this is just removing the file lock on the
-	// resource; it's not actually removing the resource from the local
-	// computer. We should do that.
 	for tkey, fields := range fieldComp.removed() {
 		qtid := tkey.QualifiedTableID()
 		for _, field := range fields {
 			api.serverlessStorage.RemoveFieldKeyResource(qtid, field)
 
+			// deleting field from disk
 			err := api.DeleteField(ctx, string(tkey), string(field))
 			if err != nil {
 				errors.Wrapf(err, "error deleting field")
@@ -541,7 +540,7 @@ func (api *API) pushJobsShards(ctx context.Context, jobs chan<- directiveJobType
 		for _, shard := range shards {
 			partition := dax.PartitionNum(disco.ShardToShardPartition(string(tkey), uint64(shard), disco.DefaultPartitionN))
 			api.serverlessStorage.RemoveShardResource(qtid, partition, shard)
-			
+
 			//this is a noop implementation of DeleteShard for now
 			err := api.DeleteShard(ctx, string(tkey), uint64(shard))
 			if err != nil {
diff --git a/index.go b/index.go
index 5887d2a41..ea7c94a62 100644
--- a/index.go
+++ b/index.go
@@ -1016,6 +1016,19 @@ func (i *Index) DeleteField(name string) error {
 	return i.translationSyncer.Reset()
 }
 
+func (i *Index) DeleteShard(shardName string) error {
+	i.mu.Lock()
+	defer i.mu.Unlock()
+
+	// Confirm shard exists.
+	// Delete shard
+	// --> need to make schemator DeleteShard too?
+	// ???
+	// profit
+
+	return nil
+}
+
 // SetTranslatePartitions sets the cached value: translatePartitions.
 //
 // There's already logic in api_directive.go which creates a new index with