Blimp: Add BlobChannelSender implementation

blimp/net/blob_channel/blob_channel_sender.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "blimp/net/blob_channel/blob_channel_sender.h"
+
+#include "base/strings/string_number_conversions.h"
+#include "blimp/common/blob_cache/blob_cache.h"
+#include "blimp/common/blob_cache/id_util.h"
+
+namespace blimp {
+
+BlobChannelSender::BlobChannelSender(std::unique_ptr<BlobCache> cache,
+                                     std::unique_ptr<Delegate> delegate)
+    : cache_(std::move(cache)), delegate_(std::move(delegate)) {
+  DCHECK(cache_);
+  DCHECK(delegate_);
+}
+
+BlobChannelSender::~BlobChannelSender() {}
+
+void BlobChannelSender::Put(const BlobId& id, BlobDataPtr data) {
+  DCHECK(data);
+  DCHECK(!id.empty());
+
+  if (cache_->Contains(id)) {
+    return;
+  }
+
+  VLOG(2) << "Put blob: " << FormatBlobId(id);
+  cache_->Put(id, data);
+}
+
+void BlobChannelSender::DeliverBlob(const BlobId& id) {
+  if (!cache_->Contains(id)) {
+    DLOG(FATAL) << "Attempted to push unknown blob: "
+                << FormatBlobId(id);
+    return;
+  }
+
+  if (receiver_cache_contents_.find(id) != receiver_cache_contents_.end()) {
+    DVLOG(3) << "Suppressed redundant push: " << FormatBlobId(id);
+    return;
+  }
+
+  VLOG(2) << "Deliver blob: " << FormatBlobId(id);
+  delegate_->DeliverBlob(id, cache_->Get(id));
+  receiver_cache_contents_.insert(id);

[Wez, 2016/05/03 22:11:05]

nit: Suggest moving this to come immediately after the if() check against
receiver_cache_contents, since logically the two belong together - if an item is
in there then we know we already have delivered it, or are about to.

[Kevin M, 2016/05/03 22:42:57]

Done.

+}
+
+}  // namespace blimp