build cache prime (#327)

- Feature: zen `--boost-workers` option to builds `upload`, `download` and `validate-part` that will increase the number of worker threads, may cause computer to be less responsive
  - Feature: zen `--cache-prime-only` that uploads referenced data from a part to `--zen-cache-host` if it is not already present. Target folder will be untouched.

2 files changed, 9 insertions, 1 deletions

diff --git a/src/zenutil/include/zenutil/buildstoragecache.h b/src/zenutil/include/zenutil/buildstoragecache.h
index 08c936bf5..cab35328d 100644
--- a/src/zenutil/include/zenutil/buildstoragecache.h
+++ b/src/zenutil/include/zenutil/buildstoragecache.h
@@ -42,11 +42,16 @@ public:
 	};
 
 	virtual std::vector<BlobExistsResult> BlobsExists(const Oid& BuildId, std::span<const IoHash> BlobHashes) = 0;
+
+	virtual void Flush(
+		int32_t									  UpdateInteralMS,
+		std::function<bool(intptr_t Remaining)>&& UpdateCallback = [](intptr_t) { return true; }) = 0;
 };
 
 std::unique_ptr<BuildStorageCache> CreateZenBuildStorageCache(HttpClient&					 HttpClient,
 															  BuildStorageCache::Statistics& Stats,
 															  std::string_view				 Namespace,
 															  std::string_view				 Bucket,
-															  const std::filesystem::path&	 TempFolderPath);
+															  const std::filesystem::path&	 TempFolderPath,
+															  bool							 BoostBackgroundThreadCount);
 }  // namespace zen
diff --git a/src/zenutil/include/zenutil/workerpools.h b/src/zenutil/include/zenutil/workerpools.h
index 9683ad720..df2033bca 100644
--- a/src/zenutil/include/zenutil/workerpools.h
+++ b/src/zenutil/include/zenutil/workerpools.h
@@ -21,6 +21,9 @@ WorkerThreadPool& GetMediumWorkerPool(EWorkloadType WorkloadType);
 // Worker pool with std::thread::hardware_concurrency() / 8 worker threads, but at least one thread
 WorkerThreadPool& GetSmallWorkerPool(EWorkloadType WorkloadType);
 
+// Worker pool with minimum number of worker threads, but at least one thread
+WorkerThreadPool& GetTinyWorkerPool(EWorkloadType WorkloadType);
+
 // Special worker pool that does not use worker thread but issues all scheduled work on the calling thread
 // This is useful for debugging when multiple async thread can make stepping in debugger complicated
 WorkerThreadPool& GetSyncWorkerPool();