From a9298af536e76ce922411f94a6cb4683e5da09ad Mon Sep 17 00:00:00 2001
From: Per Larsson <p3rl@protonmail.com>
Date: Mon, 15 Nov 2021 09:47:03 +0100
Subject: Handle 'partial on error' cache policy.

---
 zenserver/cache/structuredcache.cpp | 50 ++++++++++++++++++++++++++-----------
 1 file changed, 35 insertions(+), 15 deletions(-)

(limited to 'zenserver/cache/structuredcache.cpp')

diff --git a/zenserver/cache/structuredcache.cpp b/zenserver/cache/structuredcache.cpp
index eb31ce5e6..726bd7cdb 100644
--- a/zenserver/cache/structuredcache.cpp
+++ b/zenserver/cache/structuredcache.cpp
@@ -473,7 +473,7 @@ HttpStructuredCacheService::HandlePutCacheRecord(zen::HttpServerRequest& Request
 			TotalCount++;
 		});
 
-		ZEN_DEBUG("PUT - '{}/{}' {} '{}' attachments '{}/{}' (Valid/Total)",
+		ZEN_DEBUG("PUT - '{}/{}' {} '{}' attachments '{}/{}' (valid/total)",
 				  Ref.BucketSegment,
 				  Ref.HashKey,
 				  NiceBytes(Body.Size()),
@@ -552,7 +552,7 @@ HttpStructuredCacheService::HandlePutCacheRecord(zen::HttpServerRequest& Request
 			return Request.WriteResponse(HttpResponseCode::BadRequest, HttpContentType::kText, "Invalid attachment(s)"sv);
 		}
 
-		ZEN_DEBUG("PUT - '{}/{}' {} '{}', attachments '{}/{}/{}' (New/Valid/Total)",
+		ZEN_DEBUG("PUT - '{}/{}' {} '{}', attachments '{}/{}/{}' (new/valid/total)",
 				  Ref.BucketSegment,
 				  Ref.HashKey,
 				  NiceBytes(Body.GetSize()),
@@ -831,8 +831,9 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Req
 
 	CacheRecordPolicy::Load(Params["Policy"sv].AsObjectView(), Policy);
 
-	const bool SkipAttachments = (Policy.GetRecordPolicy() & CachePolicy::SkipAttachments) == CachePolicy::SkipAttachments;
-	const bool QueryRemote	   = m_UpstreamCache && ((Policy.GetRecordPolicy() & CachePolicy::QueryRemote) == CachePolicy::QueryRemote);
+	const bool PartialOnError  = Policy.HasRecordPolicy(CachePolicy::PartialOnError);
+	const bool SkipAttachments = Policy.HasRecordPolicy(CachePolicy::SkipAttachments);
+	const bool QueryRemote	   = Policy.HasRecordPolicy(CachePolicy::QueryRemote) && m_UpstreamCache;
 
 	for (CbFieldView KeyView : Params["CacheKeys"sv])
 	{
@@ -850,27 +851,36 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Req
 	for (size_t KeyIndex = 0; const CacheKey& Key : CacheKeys)
 	{
 		ZenCacheValue CacheValue;
+		uint32_t	  MissingCount = 0;
+
 		if (m_CacheStore.Get(Key.Bucket, Key.Hash, CacheValue))
 		{
 			CbObjectView CacheRecord(CacheValue.Value.Data());
 
 			if (!SkipAttachments)
 			{
-				CacheRecord.IterateAttachments([this, &RpcResponse](CbFieldView AttachmentHash) {
+				CacheRecord.IterateAttachments([this, &MissingCount, &RpcResponse](CbFieldView AttachmentHash) {
 					if (IoBuffer Chunk = m_CidStore.FindChunkByCid(AttachmentHash.AsHash()))
 					{
 						RpcResponse.AddAttachment(CbAttachment(CompressedBuffer::FromCompressed(SharedBuffer(Chunk))));
 					}
+					else
+					{
+						MissingCount++;
+					}
 				});
 			}
+		}
 
+		if (CacheValue.Value && (MissingCount == 0 || PartialOnError))
+		{
 			ZEN_DEBUG("HIT - '{}/{}' {} '{}' (LOCAL)",
 					  Key.Bucket,
 					  Key.Hash,
 					  NiceBytes(CacheValue.Value.Size()),
 					  ToString(CacheValue.Value.GetContentType()));
 
-			CacheValues[KeyIndex] = CacheValue.Value;
+			CacheValues[KeyIndex] = std::move(CacheValue.Value);
 			m_CacheStats.HitCount++;
 		}
 		else if (QueryRemote)
@@ -879,7 +889,7 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Req
 		}
 		else
 		{
-			ZEN_DEBUG("MISS - '{}/{}'", Key.Bucket, Key.Hash);
+			ZEN_DEBUG("MISS - '{}/{}' {}", Key.Bucket, Key.Hash, MissingCount ? "(partial)"sv : ""sv);
 			m_CacheStats.MissCount++;
 		}
 
@@ -889,10 +899,14 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Req
 	if (!UpstreamRequests.empty() && m_UpstreamCache)
 	{
 		const auto OnCacheRecordGetComplete =
-			[this, &CacheKeys, &CacheValues, &RpcResponse, SkipAttachments](CacheRecordGetCompleteParams&& Params) {
+			[this, &CacheKeys, &CacheValues, &RpcResponse, PartialOnError, SkipAttachments](CacheRecordGetCompleteParams&& Params) {
+				ZEN_ASSERT(Params.KeyIndex < CacheValues.size());
+
+				IoBuffer		CacheValue;
+				AttachmentCount Count;
+
 				if (Params.Record)
 				{
-					AttachmentCount Count;
 					Params.Record.IterateAttachments([this, &RpcResponse, SkipAttachments, &Params, &Count](CbFieldView HashView) {
 						if (const CbAttachment* Attachment = Params.Package.FindAttachment(HashView.AsHash()))
 						{
@@ -926,18 +940,23 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Req
 						Count.Total++;
 					});
 
-					ZEN_DEBUG("HIT - '{}/{}' {} '{}' attachments '{}/{}/{}' (New/Valid/Total) (UPSTREAM)",
+					if ((Count.Valid == Count.Total) || PartialOnError)
+					{
+						CacheValue = CbObject::Clone(Params.Record).GetBuffer().AsIoBuffer();
+					}
+				}
+
+				if (CacheValue)
+				{
+					ZEN_DEBUG("HIT - '{}/{}' {} '{}' attachments '{}/{}/{}' (new/valid/total) (UPSTREAM)",
 							  Params.CacheKey.Bucket,
 							  Params.CacheKey.Hash,
-							  NiceBytes(Params.Record.GetView().GetSize()),
+							  NiceBytes(CacheValue.GetSize()),
 							  ToString(HttpContentType::kCbPackage),
 							  Count.New,
 							  Count.Valid,
 							  Count.Total);
 
-					ZEN_ASSERT(Params.KeyIndex < CacheValues.size());
-
-					IoBuffer CacheValue = CbObject::Clone(Params.Record).GetBuffer().AsIoBuffer();
 					CacheValue.SetContentType(ZenContentType::kCbObject);
 
 					CacheValues[Params.KeyIndex] = CacheValue;
@@ -948,7 +967,8 @@ HttpStructuredCacheService::HandleRpcGetCacheRecords(zen::HttpServerRequest& Req
 				}
 				else
 				{
-					ZEN_DEBUG("MISS - '{}/{}'", Params.CacheKey.Bucket, Params.CacheKey.Hash);
+					const bool IsPartial = Count.Valid != Count.Total;
+					ZEN_DEBUG("MISS - '{}/{}' {}", Params.CacheKey.Bucket, Params.CacheKey.Hash, IsPartial ? "(partial)"sv : ""sv);
 					m_CacheStats.MissCount++;
 				}
 			};
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