Reuse HTTP session for HTTP store transactions

src/blobsets/httpstores.nim

@@ -20,11 +20,12 @@ type
 
   HttpStore* = ref HttpStoreObj
   HttpStoreObj = object of BlobStoreObj
+    client: AsyncHttpClient
+      # TODO: keep a future that completes after the current client transaction completes,
+      # chain new streams that use the same client connection to this future
     url: Uri
 
-proc httpBlobClose(s: BlobStream) =
-  var s = (HttpBlobStream)s
-  close s.client
+proc httpBlobClose(s: BlobStream) = discard
 
 proc setPosHttp(s: BlobStream; pos: BiggestInt) =
   var s = (HttpBlobStream)s
@@ -49,7 +50,7 @@ proc httpBlobRead(s: BlobStream; buffer: pointer; len: Natural): int =
 proc httpOpenBlobStream(store: BlobStore; id: BlobId; size: BiggestInt; kind: BlobKind): BlobStream =
   var store = HttpStore(store)
   let stream = HttpBlobStream(
-    client: newAsyncHttpClient(),
+    client: store.client,
     closeImpl: httpBlobClose,
     setPosImpl: setPosHttp,
     getPosImpl: getPosHttp,
@@ -87,7 +88,7 @@ proc httpIngest(x: IngestStream; buf: pointer; len: Natural) =
 proc httpOpenIngestStream(s: BlobStore; size: BiggestInt; kind: BlobKind): IngestStream =
   var store = HttpStore(s)
   let
-    client = newAsyncHttpClient()
+    client = store.client
     url = (store.url / "ingest") / $kind
     headers = newHttpHeaders({"ingest-size": $size})
     resp = waitFor client.request($url, HttpPOST, headers=headers)
@@ -105,9 +106,15 @@ proc httpOpenIngestStream(s: BlobStore; size: BiggestInt; kind: BlobKind): Inges
   else:
     raiseAssert(resp.status)
 
+proc httpCloseStore(s: BlobStore) =
+  var s = HttpStore(s)
+  close s.client
+
 proc newHttpStore*(url: string): HttpStore =
   HttpStore(
-    url: parseUri url,
+    closeImpl: httpCloseStore,
     openBlobStreamImpl: httpOpenBlobStream,
     openIngestStreamImpl: httpOpenIngestStream,
+    client: newAsyncHttpClient(),
+    url: parseUri url,
   )