[BlobAsync] Patch 3: Renderer Classes & Logic

content/child/blob_storage/blob_transport_controller.cc

+// Copyright 2015 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 "content/child/blob_storage/blob_transport_controller.h"
+
+#include <vector>
+
+#include "base/containers/scoped_ptr_hash_map.h"

[michaeln, 2015/10/30 19:44:40]

is this include needed now that your using a vector instead?

[dmurph, 2015/10/30 22:55:33]

Done.

+#include "base/lazy_instance.h"
+#include "base/memory/scoped_vector.h"
+#include "base/memory/shared_memory.h"
+#include "base/stl_util.h"
+#include "content/child/blob_storage/blob_consolidation.h"
+#include "content/child/thread_safe_sender.h"
+#include "ipc/ipc_sender.h"
+#include "storage/common/blob_storage/blob_item_bytes_request.h"
+#include "storage/common/blob_storage/blob_item_bytes_response.h"
+#include "storage/common/data_element.h"
+
+using base::SharedMemory;
+using base::SharedMemoryHandle;
+using storage::BlobItemBytesRequest;
+using storage::BlobItemBytesResponse;
+using storage::IPCBlobItemRequestStrategy;
+using storage::DataElement;
+
+namespace content {
+
+using storage::IPCBlobCreationCancelCode;
+
+using ConsolidatedItem = BlobConsolidation::ConsolidatedItem;
+using ReadStatus = BlobConsolidation::ReadStatus;
+
+namespace {
+const size_t kLargeThresholdBytes = 250 * 1024;
+static base::LazyInstance<BlobTransportController> g_controller =
+    LAZY_INSTANCE_INITIALIZER;
+}  // namespace
+
+BlobTransportController* BlobTransportController::GetInstance() {
+  return g_controller.Pointer();
+}
+
+BlobTransportController::~BlobTransportController() {}
+
+void BlobTransportController::InitiateBlobTransfer(
+    const std::string& uuid,
+    const std::string& type,
+    scoped_ptr<BlobConsolidation> consolidation,
+    IPC::Sender* sender) {
+  BlobConsolidation* consolidation_ptr = consolidation.get();
+  blob_storage_.insert(uuid, consolidation.Pass());
+  std::vector<storage::DataElement> descriptions;
+  GetDescriptions(consolidation_ptr, kLargeThresholdBytes, &descriptions);
+  // TODO(dmurph): Uncomment when IPC messages are added.
+  // sender->Send(new BlobStorageMsg_StartBuildingBlob(uuid, type,
+  // descriptions));
+}
+
+void BlobTransportController::OnMemoryRequest(
+    const std::string& uuid,
+    const std::vector<storage::BlobItemBytesRequest>& requests,
+    std::vector<base::SharedMemoryHandle>* memory_handles,
+    const std::vector<IPC::PlatformFileForTransit>& file_handles,
+    IPC::Sender* sender) {
+  std::vector<storage::BlobItemBytesResponse> responses;
+  ResponsesStatus status =
+      GetResponses(uuid, requests, memory_handles, file_handles, &responses);
+
+  switch (status) {
+    case ResponsesStatus::BLOB_NOT_FOUND:
+      // sender->Send(new BlobStorageMsg_CancelBuildingBlob(uuid,
+      // IPCBlobCreationCancelCode::UNKNOWN));
+      return;
+    case ResponsesStatus::SHARED_MEMORY_MAP_FAILED:
+      // This would happen if the renderer process doesn't have enough memory
+      // to map the shared memory, which is possible if we don't have much
+      // memory. If this scenario happens often, we could delay the response
+      // until we have enough memory.  For now we just fail.
+      CHECK(false) << "Unable to map shared memory to send blob " << uuid
+                   << ".";
+      break;
+    case ResponsesStatus::SUCCESS:
+      break;
+  }
+
+  // TODO(dmurph): Uncomment when IPC messages are added.
+  // sender->Send(new BlobStorageMsg_MemoryItemResponse(uuid, responses));
+}
+
+void BlobTransportController::OnCancel(
+    const std::string& uuid,
+    storage::IPCBlobCreationCancelCode code) {
+  DVLOG(1) << "Received blob cancel for blob " << uuid << " with reason:";
+  switch (code) {
+    case IPCBlobCreationCancelCode::UNKNOWN:
+      DVLOG(1) << "Unknown.";
+      break;
+    case IPCBlobCreationCancelCode::OUT_OF_MEMORY:
+      DVLOG(1) << "Out of Memory.";
+      break;
+    case IPCBlobCreationCancelCode::FILE_WRITE_FAILED:
+      DVLOG(1) << "File Write Failed (Invalid cancel reason!).";
+      break;
+  }
+  ReleaseBlobConsolidation(uuid);
+}
+
+void BlobTransportController::OnDone(const std::string& uuid) {
+  ReleaseBlobConsolidation(uuid);
+}
+
+void BlobTransportController::Clear() {
+  blob_storage_.clear();
+}
+
+BlobTransportController::BlobTransportController() {}
+
+void BlobTransportController::CancelBlobTransfer(const std::string& uuid,
+                                                 IPCBlobCreationCancelCode code,
+                                                 IPC::Sender* sender) {
+  // TODO(dmurph): Uncomment when IPC messages are added.
+  // sender->Send(new BlobStorageMsg_CancelBuildingBlob(uuid, code));
+  ReleaseBlobConsolidation(uuid);
+}
+
+void BlobTransportController::GetDescriptions(
+    BlobConsolidation* consolidation,
+    size_t max_data_population,
+    std::vector<storage::DataElement>* out) {
+  DCHECK(out->empty());
+  DCHECK(consolidation);
+  const auto& consolidated_items = consolidation->consolidated_items();
+
+  size_t current_memory_population = 0;
+  size_t current_item = 0;
+  out->reserve(consolidated_items.size());
+  for (const ConsolidatedItem& item : consolidated_items) {
+    out->push_back(DataElement());
+    auto& element = out->back();
+
+    switch (item.type) {
+      case DataElement::TYPE_BYTES: {
+        size_t bytes_length = static_cast<size_t>(item.length);
+        if (current_memory_population + bytes_length <= max_data_population) {
+          element.SetToAllocatedBytes(bytes_length);
+          consolidation->ReadMemory(current_item, 0, bytes_length,
+                                    element.mutable_bytes());
+          current_memory_population += bytes_length;
+        } else {
+          element.SetToBytesDescription(bytes_length);
+        }
+        break;
+      }
+      case DataElement::TYPE_FILE: {
+        element.SetToFilePathRange(
+            item.path, item.offset, item.length,
+            base::Time::FromDoubleT(item.expected_modification_time));
+        break;
+      }
+      case DataElement::TYPE_BLOB: {
+        element.SetToBlobRange(item.blob_uuid, item.offset, item.length);
+        break;
+      }
+      case DataElement::TYPE_FILE_FILESYSTEM: {
+        element.SetToFileSystemUrlRange(
+            item.filesystem_url, item.offset, item.length,
+            base::Time::FromDoubleT(item.expected_modification_time));
+        break;
+      }
+      case DataElement::TYPE_DISK_CACHE_ENTRY:
+      case DataElement::TYPE_BYTES_DESCRIPTION:
+      case DataElement::TYPE_UNKNOWN:
+        NOTREACHED();
+    }
+    ++current_item;
+  }
+}
+
+BlobTransportController::ResponsesStatus BlobTransportController::GetResponses(
+    const std::string& uuid,
+    const std::vector<BlobItemBytesRequest>& requests,
+    std::vector<SharedMemoryHandle>* memory_handles,
+    const std::vector<IPC::PlatformFileForTransit>& file_handles,
+    std::vector<BlobItemBytesResponse>* out) {
+  DCHECK(out->empty());
+  auto it = blob_storage_.find(uuid);
+  if (it == blob_storage_.end())
+    return ResponsesStatus::BLOB_NOT_FOUND;
+
+  BlobConsolidation* consolidation = it->second;
+  const auto& consolidated_items = consolidation->consolidated_items();
+
+  // Since we can be writing to the same shared memory handle from multiple
+  // requests, we keep them in a vector and lazily create them.
+  ScopedVector<SharedMemory> opened_memory;
+  opened_memory.resize(memory_handles->size());
+  for (const BlobItemBytesRequest& request : requests) {
+    DCHECK_LT(request.renderer_item_index, consolidated_items.size())
+        << "Invalid item index";
+
+    const ConsolidatedItem& item =
+        consolidated_items[request.renderer_item_index];
+    DCHECK_LE(request.renderer_item_offset + request.size, item.length)
+        << "Invalid data range";
+    DCHECK_EQ(item.type, DataElement::TYPE_BYTES) << "Invalid element type";
+
+    out->push_back(BlobItemBytesResponse(request.request_number));
+    switch (request.transport_strategy) {
+      case IPCBlobItemRequestStrategy::IPC: {
+        BlobItemBytesResponse& response = out->back();
+        ReadStatus status = consolidation->ReadMemory(
+            request.renderer_item_index, request.renderer_item_offset,
+            request.size, response.allocate_mutable_data(request.size));
+        DCHECK(status == ReadStatus::OK)
+            << "Error reading from consolidated blob: "
+            << static_cast<int>(status);
+        break;
+      }
+      case IPCBlobItemRequestStrategy::SHARED_MEMORY: {
+        DCHECK_LT(request.handle_index, memory_handles->size())
+            << "Invalid handle index.";
+        SharedMemory* memory = opened_memory.get().at(request.handle_index);

[michaeln, 2015/10/29 23:26:48]

Do you need the .get() to get at the scoped_vector? The the ScopedVector's
operator[]s work? If so, opened_memory[i] would be more readable.

[dmurph, 2015/10/30 22:55:33]

For some reason I didn't see these methods haha.

+        if (!memory) {
+          SharedMemoryHandle& handle = (*memory_handles)[request.handle_index];
+          DCHECK(SharedMemory::IsHandleValid(handle));
+          scoped_ptr<SharedMemory> shared_memory(
+              new SharedMemory(handle, false));
+          if (!shared_memory->Map(request.size))
+            return ResponsesStatus::SHARED_MEMORY_MAP_FAILED;
+          memory = shared_memory.get();
+          opened_memory.get()[request.handle_index] = shared_memory.release();

[michaeln, 2015/10/29 23:26:48]

ditto opened_memory[i] = x;

[dmurph, 2015/10/30 22:55:33]

Done.

+        }
+        CHECK(memory->memory()) << "Couldn't map memory for blob transfer.";
+        ReadStatus status = consolidation->ReadMemory(
+            request.renderer_item_index, request.renderer_item_offset,
+            request.size,
+            static_cast<char*>(memory->memory()) + request.handle_offset);
+        DCHECK(status == ReadStatus::OK)
+            << "Error reading from consolidated blob: "
+            << static_cast<int>(status);
+        break;
+      }
+      case IPCBlobItemRequestStrategy::FILE:
+        NOTREACHED() << "TODO(dmurph): Not implemented.";
+        break;
+      case IPCBlobItemRequestStrategy::UNKNOWN:
+        NOTREACHED();
+        break;
+    }
+  }
+  return ResponsesStatus::SUCCESS;
+}
+
+void BlobTransportController::ReleaseBlobConsolidation(
+    const std::string& uuid) {
+  auto iter = blob_storage_.find(uuid);
+  if (iter != blob_storage_.end()) {
+    BlobConsolidation* consolidation = iter->second;
+    delete consolidation;

[kinuko, 2015/10/30 02:43:38]

wait... now that we use scopedptrmap no need to manually delete, right?

[michaeln, 2015/10/30 19:44:40]

Whoa! Good catch, this would be a dbl delete, right. I'm surprised the trybots
didn't complain about it? Ah, the unit tests don't cover the basics. There
probably should be a test that covers the basic container behavior exposed via
the public methods: InitiateBlobXfer, OnDone, and OnCancel.

[dmurph, 2015/10/30 22:55:33]

Done, and added tests.

+    blob_storage_.erase(iter);
+  }
+}
+
+}  // namespace content