From 5bf6b589283cfdb340a4d975f3c170644ceb31d0 Mon Sep 17 00:00:00 2001
From: "Zeyi (Rice) Fan" <zeyi@fb.com>
Date: Tue, 5 May 2020 20:55:16 -0700
Subject: [PATCH] clean up HgQueuedBackingStore

Summary: split functions up.

Reviewed By: chadaustin

Differential Revision: D20808045

fbshipit-source-id: 3160566deb763c888a0bf34557d934feccc5ae3b
---
 eden/fs/store/hg/HgImportRequest.h        |  5 ++
 eden/fs/store/hg/HgQueuedBackingStore.cpp | 60 ++++++++++++++++-------
 eden/fs/store/hg/HgQueuedBackingStore.h   |  4 ++
 3 files changed, 50 insertions(+), 19 deletions(-)

diff --git a/eden/fs/store/hg/HgImportRequest.h b/eden/fs/store/hg/HgImportRequest.h
index 0a5241c821..f64de57c82 100644
--- a/eden/fs/store/hg/HgImportRequest.h
+++ b/eden/fs/store/hg/HgImportRequest.h
@@ -84,6 +84,11 @@ class HgImportRequest {
     return std::get_if<T>(&request_);
   }
 
+  template <typename T>
+  bool isType() const noexcept {
+    return std::holds_alternative<T>(request_);
+  }
+
   size_t getType() const noexcept {
     return request_.index();
   }
diff --git a/eden/fs/store/hg/HgQueuedBackingStore.cpp b/eden/fs/store/hg/HgQueuedBackingStore.cpp
index 0ce0d32ebf..971f104266 100644
--- a/eden/fs/store/hg/HgQueuedBackingStore.cpp
+++ b/eden/fs/store/hg/HgQueuedBackingStore.cpp
@@ -44,6 +44,39 @@ HgQueuedBackingStore::~HgQueuedBackingStore() {
   }
 }
 
+void HgQueuedBackingStore::processBlobImportRequests(
+    std::vector<HgImportRequest>&& requests) {
+  for (auto& request : requests) {
+    auto parameter = request.getRequest<HgImportRequest::BlobImport>();
+    request.setWith<HgImportRequest::BlobImport>(
+        [store = backingStore_.get(), hash = parameter->hash]() {
+          return store->getBlob(hash).getTry();
+        });
+  }
+}
+
+void HgQueuedBackingStore::processTreeImportRequests(
+    std::vector<HgImportRequest>&& requests) {
+  for (auto& request : requests) {
+    auto parameter = request.getRequest<HgImportRequest::TreeImport>();
+    request.setWith<HgImportRequest::TreeImport>(
+        [store = backingStore_.get(), hash = parameter->hash]() {
+          return store->getTree(hash).getTry();
+        });
+  }
+}
+
+void HgQueuedBackingStore::processPrefetchRequests(
+    std::vector<HgImportRequest>&& requests) {
+  for (auto& request : requests) {
+    auto parameter = request.getRequest<HgImportRequest::Prefetch>();
+    request.setWith<HgImportRequest::Prefetch>(
+        [store = backingStore_.get(), hashes = parameter->hashes]() {
+          return store->prefetchBlobs(hashes).getTry();
+        });
+  }
+}
+
 void HgQueuedBackingStore::processRequest() {
   for (;;) {
     auto requests = queue_.dequeue(FLAGS_hg_queue_batch_size);
@@ -52,25 +85,14 @@ void HgQueuedBackingStore::processRequest() {
       break;
     }
 
-    for (auto& request : requests) {
-      if (auto parameter = request.getRequest<HgImportRequest::BlobImport>()) {
-        request.setWith<HgImportRequest::BlobImport>(
-            [store = backingStore_.get(), hash = parameter->hash]() {
-              return store->getBlob(hash).getTry();
-            });
-      } else if (
-          auto parameter = request.getRequest<HgImportRequest::TreeImport>()) {
-        request.setWith<HgImportRequest::TreeImport>(
-            [store = backingStore_.get(), hash = parameter->hash]() {
-              return store->getTree(hash).getTry();
-            });
-      } else if (
-          auto parameter = request.getRequest<HgImportRequest::Prefetch>()) {
-        request.setWith<HgImportRequest::Prefetch>(
-            [store = backingStore_.get(), hashes = parameter->hashes]() {
-              return store->prefetchBlobs(hashes).getTry();
-            });
-      }
+    const auto& first = requests.at(0);
+
+    if (first.isType<HgImportRequest::BlobImport>()) {
+      processBlobImportRequests(std::move(requests));
+    } else if (first.isType<HgImportRequest::TreeImport>()) {
+      processTreeImportRequests(std::move(requests));
+    } else if (first.isType<HgImportRequest::Prefetch>()) {
+      processPrefetchRequests(std::move(requests));
     }
   }
 }
diff --git a/eden/fs/store/hg/HgQueuedBackingStore.h b/eden/fs/store/hg/HgQueuedBackingStore.h
index 3a2434921d..e89c58b7e0 100644
--- a/eden/fs/store/hg/HgQueuedBackingStore.h
+++ b/eden/fs/store/hg/HgQueuedBackingStore.h
@@ -78,6 +78,10 @@ class HgQueuedBackingStore : public BackingStore {
   HgQueuedBackingStore(const HgQueuedBackingStore&) = delete;
   HgQueuedBackingStore& operator=(const HgQueuedBackingStore&) = delete;
 
+  void processBlobImportRequests(std::vector<HgImportRequest>&& requests);
+  void processTreeImportRequests(std::vector<HgImportRequest>&& requests);
+  void processPrefetchRequests(std::vector<HgImportRequest>&& requests);
+
   /**
    * The worker runloop function.
    */