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/net/blob_channel/blob_channel_bindings.h"
+
+namespace blimp {
+
+BlobChannelSender::BlobChannelSender(BlobCache* cache,
+                                     BlobSenderBindings* bindings)
+    : cache_(cache), bindings_(bindings) {
+  DCHECK(cache_);
+  DCHECK(bindings_);
+}
+
+BlobChannelSender::~BlobChannelSender() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void BlobChannelSender::Put(const std::string& id,
+                            std::unique_ptr<std::vector<uint8_t>> data) {
+  DCHECK(data);
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (cache_->Contains(id)) {
+    return;
+  }
+
+  VLOG(2) << "Put blob: " << base::HexEncode(id.data(), id.size());
+  scoped_refptr<RefCountedVector> cache_item(new RefCountedVector);
+  cache_item->data.swap(*data);
+  cache_->Put(id, cache_item);

[Wez, 2016/04/15 17:15:16]

What is the cache expected to do if it already contains item Id, but with
different content?

[Kevin M, 2016/04/15 22:42:57]

Drop it. We really don't want to support ID collisions, since it's supposed to
be content-keyed in the first place.

+}
+
+void BlobChannelSender::Push(const std::string& id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (!cache_->Contains(id)) {
+    DLOG(WARNING) << "Attempted to push invalid blob ID: "
+                  << base::HexEncode(id.data(), id.size());

[Wez, 2016/04/15 17:15:16]

Why is this only a DLOG(WARNING)? Seems worthy of DCHECK or DLOG(FATAL), since
it indicates a coding error in the caller.

[Kevin M, 2016/04/15 22:42:57]

Yeee

+    return;
+  }
+  if (client_cache_state_.find(id) != client_cache_state_.end()) {
+    DVLOG(3) << "Suppressed redundant push: "
+             << base::HexEncode(id.data(), id.size());
+    return;
+  }
+
+  VLOG(2) << "Push blob: " << base::HexEncode(id.data(), id.size());
+  bindings_->Send(id, cache_->Get(id)->data);
+  client_cache_state_.insert(id);
+}
+
+}  // namespace blimp