[BlobAsync] Moving async handling into BlobStorageContext & quota out.

storage/browser/blob/blob_transport_host.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 <stddef.h>
+#include <stdint.h>
+
+#include <memory>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/shared_memory.h"
+#include "storage/browser/blob/blob_data_handle.h"
+#include "storage/browser/blob/blob_memory_controller.h"
+#include "storage/browser/blob/blob_storage_context.h"
+#include "storage/browser/blob/blob_transport_host.h"
+
+namespace storage {
+namespace {
+using MemoryStrategy = BlobMemoryController::Strategy;
+using MemoryItemRequest =
+    BlobAsyncTransportRequestBuilder::RendererMemoryItemRequest;
+
+bool CalculateBlobMemorySize(const std::vector<DataElement>& elements,
+                             size_t* shortcut_bytes,
+                             uint64_t* total_bytes) {
+  DCHECK(shortcut_bytes);
+  DCHECK(total_bytes);
+
+  base::CheckedNumeric<uint64_t> total_size_checked = 0;
+  base::CheckedNumeric<size_t> shortcut_size_checked = 0;
+  for (const auto& e : elements) {
+    if (e.type() == DataElement::TYPE_BYTES) {
+      total_size_checked += e.length();
+      shortcut_size_checked += e.length();
+    } else if (e.type() == DataElement::TYPE_BYTES_DESCRIPTION) {
+      total_size_checked += e.length();
+    } else {
+      continue;
+    }
+    if (!total_size_checked.IsValid() || !shortcut_size_checked.IsValid())
+      return false;
+  }
+  *shortcut_bytes = shortcut_size_checked.ValueOrDie();
+  *total_bytes = total_size_checked.ValueOrDie();
+  return true;
+}
+}  // namespace
+
+BlobTransportHost::TransportState::TransportState(
+    const std::string& uuid, const std::string& content_type,
+    const std::string& content_disposition,
+    RequestMemoryCallback request_memory_callback,
+    BlobStatusCallback completion_callback)
+    : data_builder(uuid),
+      request_memory_callback(std::move(request_memory_callback)),
+      completion_callback(std::move(completion_callback)){
+  data_builder.set_content_type(content_type);
+  data_builder.set_content_disposition(content_disposition);
+}
+
+BlobTransportHost::TransportState::~TransportState() {}
+
+BlobTransportHost::BlobTransportHost() : ptr_factory_(this) {}
+
+BlobTransportHost::~BlobTransportHost() {}
+
+void BlobTransportHost::StartBuildingBlob(
+    const std::string& uuid, const std::string& content_type,
+    const std::string& content_disposition,
+    const std::vector<DataElement>& elements, BlobStorageContext* context,
+    const RequestMemoryCallback& request_memory,
+    const BlobStatusCallback& completion_callback) {
+  DCHECK(context);
+  if (async_blob_map_.find(uuid) != async_blob_map_.end()) {
+    completion_callback.Run(BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS);
+    return;
+  }
+  // Validate that our referenced blobs aren't us.
+  for (const DataElement& e : elements) {
+    if (e.type() == DataElement::TYPE_BLOB && e.blob_uuid() == uuid) {
+      completion_callback.Run(BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS);
+      return;
+    }
+  }
+  uint64_t transport_memory_size = 0;
+  size_t shortcut_size = 0;
+  if (!CalculateBlobMemorySize(elements, &shortcut_size,
+                               &transport_memory_size)) {
+    completion_callback.Run(BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS);
+    return;
+  }
+
+  const BlobMemoryController& memory_controller = context->memory_controller();
+  MemoryStrategy memory_strategy =
+      memory_controller.DetermineStrategy(shortcut_size, transport_memory_size);
+  std::unique_ptr<TransportState> state(
+      new TransportState(uuid, content_type, content_disposition,
+                         request_memory, completion_callback));
+  std::unique_ptr<BlobDataHandle> temp_handle;
+  switch (memory_strategy) {
+    case MemoryStrategy::TOO_LARGE:
+      temp_handle =
+          context->AddBrokenBlob(uuid, content_type, content_disposition,
+                                 BlobStatus::ERR_OUT_OF_MEMORY);
+      context->IncrementBlobRefCount(uuid);
+      completion_callback.Run(BlobStatus::ERR_OUT_OF_MEMORY);
+      return;
+    case MemoryStrategy::NONE_NEEDED: {
+      for (const DataElement& e : elements) {
+        DCHECK_NE(e.type(), DataElement::TYPE_BYTES_DESCRIPTION);
+        state->data_builder.AppendIPCDataElement(e);
+      }
+      temp_handle =
+          context->BuildBlob(state->data_builder,

[michaeln, 2016/11/07 21:47:05]

naming nit: similar naming across levels might help lighten the cognitive load, 
  context->StartBuildingBlob(...)

+                             BlobStorageContext::PopulatationAllowedCallback());
+      context->IncrementBlobRefCount(uuid);
+      completion_callback.Run(BlobStatus::DONE);
+      return;
+    }
+    case MemoryStrategy::IPC:
+      state->strategy = IPCBlobItemRequestStrategy::IPC;
+      state->request_builder.InitializeForIPCRequests(
+          memory_controller.limits().max_ipc_memory_size, transport_memory_size,
+          elements, &(state->data_builder));
+      break;
+    case MemoryStrategy::SHARED_MEMORY:
+      state->strategy = IPCBlobItemRequestStrategy::SHARED_MEMORY;
+      state->request_builder.InitializeForSharedMemoryRequests(
+          memory_controller.limits().max_shared_memory_size,
+          transport_memory_size, elements, &(state->data_builder));
+      break;
+    case MemoryStrategy::FILE:
+      state->strategy = IPCBlobItemRequestStrategy::FILE;
+      state->request_builder.InitializeForFileRequests(
+          memory_controller.limits().max_file_size, transport_memory_size,
+          elements, &(state->data_builder));
+      break;
+  }
+  // We initialize our requests received state now that they are populated.
+  state->request_received.resize(state->request_builder.requests().size(),
+                                 false);
+  TransportState* state_ptr = state.get();
+  async_blob_map_[uuid] = std::move(state);
+  temp_handle = context->BuildBlob(
+      state_ptr->data_builder,
+      base::Bind(&BlobTransportHost::OnPopulationAllowed,
+                 ptr_factory_.GetWeakPtr(), uuid, context->AsWeakPtr()));
+  context->IncrementBlobRefCount(uuid);
+  BlobStatus status = temp_handle->GetBlobStatus();
+  if (BlobStatusIsError(status)) async_blob_map_.erase(uuid);
+
+  if (!BlobStatusIsPending(status))
+    completion_callback.Run(temp_handle->GetBlobStatus());
+
+  return;
+}
+
+BlobStatus BlobTransportHost::OnMemoryResponses(
+    const std::string& uuid,
+    const std::vector<BlobItemBytesResponse>& responses,
+    BlobStorageContext* context) {
+  AsyncBlobMap::const_iterator state_it = async_blob_map_.find(uuid);
+  if (state_it == async_blob_map_.end()) {
+    DVLOG(1) << "Could not find blob " << uuid;
+    return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+  }
+  if (responses.empty()) {
+    CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                       context);
+    return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+  }
+
+  // Validate response sanity: it should refer to a legal request number, and
+  // we shouldn't have received an answer for that request yet.
+  BlobTransportHost::TransportState* state = state_it->second.get();
+  const auto& requests = state->request_builder.requests();
+  for (const BlobItemBytesResponse& response : responses) {
+    if (response.request_number >= requests.size()) {
+      // Bad IPC, so we delete our record and ignore.
+      DVLOG(1) << "Invalid request number " << response.request_number;
+      CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                         context);
+      return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+    }
+    DCHECK_LT(response.request_number, state->request_received.size());
+    if (state->request_received[response.request_number]) {
+      // Bad IPC, so we delete our record.
+      DVLOG(1) << "Already received response for that request.";
+      CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                         context);
+      return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+    }
+    state->request_received[response.request_number] = true;
+  }
+  switch (state->strategy) {
+    case IPCBlobItemRequestStrategy::IPC:
+      return OnIPCResponses(uuid, state, responses, context);
+    case IPCBlobItemRequestStrategy::SHARED_MEMORY:
+      return OnSharedMemoryResponses(uuid, state, responses, context);
+    case IPCBlobItemRequestStrategy::FILE:
+      return OnFileResponses(uuid, state, responses, context);
+    case IPCBlobItemRequestStrategy::UNKNOWN:
+      break;
+  }
+  NOTREACHED();
+  return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+}
+
+void BlobTransportHost::CancelBuildingBlob(const std::string& uuid,
+                                              BlobStatus code,
+                                              BlobStorageContext* context) {
+  DCHECK(context);
+  DCHECK(BlobStatusIsError(code));
+  auto state_it = async_blob_map_.find(uuid);
+  if (state_it == async_blob_map_.end())
+    return;
+  // We can have the blob dereferenced by the renderer, but have it still being
+  // 'built'. In this case, it's destructed in the context, but we still have
+  // it in our map. Hence we make sure the context has the entry before
+  // calling cancel.
+  async_blob_map_.erase(state_it);
+  if (context->registry().HasEntry(uuid))
+    context->BreakAndFinishPendingBlob(uuid, code);

[michaeln, 2016/11/07 21:47:05]

naming nit: similar naming across levels might help lighten the cognitive load, 
  context->CancelBuildingBlob()

[dmurph, 2016/11/08 21:19:59]

Done.

+}
+
+void BlobTransportHost::CancelAll(BlobStorageContext* context) {
+  DCHECK(context);
+  // If the blob still exists in the context, then we know that someone else is
+  // expecting our blob, and we need to cancel it to let the dependency know
+  // it's gone.
+  std::vector<std::unique_ptr<BlobDataHandle>> referenced_pending_blobs;
+  for (const auto& uuid_state_pair : async_blob_map_) {
+    std::unique_ptr<BlobDataHandle> handle =
+        context->GetBlobDataFromUUID(uuid_state_pair.first);
+    if (handle) {
+      referenced_pending_blobs.push_back(
+          context->GetBlobDataFromUUID(uuid_state_pair.first));
+    }
+  }
+  // We clear the map before canceling them to prevent any strange reentry into
+  // our class (see OnPopulationAllowed) if any blobs were waiting for others
+  // to construct.
+  async_blob_map_.clear();
+  for (const std::unique_ptr<BlobDataHandle>& handle :
+       referenced_pending_blobs) {
+    context->BreakAndFinishPendingBlob(handle->uuid(),
+                                       BlobStatus::ERR_SOURCE_DIED_IN_TRANSIT);
+  }
+}
+
+BlobStatus BlobTransportHost::StartRequests(
+    const std::string& uuid,
+    TransportState* state,
+    BlobStorageContext* context,
+    std::vector<BlobMemoryController::FileCreationInfo> file_infos) {
+  switch (state->strategy) {
+    case IPCBlobItemRequestStrategy::IPC:
+      DCHECK(file_infos.empty());
+      SendIPCRequests(state, context);
+      return BlobStatus::PENDING_TRANSPORT;
+    case IPCBlobItemRequestStrategy::SHARED_MEMORY:
+      DCHECK(file_infos.empty());
+      return ContinueSharedMemoryRequests(uuid, state, context);
+    case IPCBlobItemRequestStrategy::FILE:
+      DCHECK(!file_infos.empty());
+      SendFileRequests(state, context, std::move(file_infos));
+      return BlobStatus::PENDING_TRANSPORT;
+    case IPCBlobItemRequestStrategy::UNKNOWN:
+      break;
+  }
+  NOTREACHED();
+  return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+}
+
+// Note: This can be called when we cancel a blob in the context.
+void BlobTransportHost::OnPopulationAllowed(

[michaeln, 2016/11/07 21:47:05]

OnReadyForTransport()

[dmurph, 2016/11/08 21:19:58]

Done.

+    const std::string& uuid,
+    base::WeakPtr<BlobStorageContext> context,
+    BlobStatus status,
+    std::vector<BlobMemoryController::FileCreationInfo> file_infos) {
+  if (!context) {
+    async_blob_map_.erase(uuid);
+    return;
+  }
+  AsyncBlobMap::const_iterator state_it = async_blob_map_.find(uuid);
+  if (state_it == async_blob_map_.end())
+    return;
+
+  TransportState* state = state_it->second.get();
+  if (BlobStatusIsPending(status)) {
+    DCHECK(status == BlobStatus::PENDING_TRANSPORT);
+    status = StartRequests(uuid, state, context.get(), std::move(file_infos));
+    if (BlobStatusIsPending(status))
+      return;
+  }
+  BlobStatusCallback completion_callback = state->completion_callback;
+  async_blob_map_.erase(state_it);
+  completion_callback.Run(status);
+}
+
+void BlobTransportHost::SendIPCRequests(TransportState* state,
+                                           BlobStorageContext* context) {
+  const std::vector<MemoryItemRequest>& requests =
+      state->request_builder.requests();
+  std::vector<BlobItemBytesRequest> byte_requests;
+
+  DCHECK(!requests.empty());
+  for (const MemoryItemRequest& request : requests) {
+    byte_requests.push_back(request.message);
+  }
+
+  state->request_memory_callback.Run(std::move(byte_requests),
+                                     std::vector<base::SharedMemoryHandle>(),
+                                     std::vector<base::File>());
+}
+
+BlobStatus BlobTransportHost::OnIPCResponses(
+    const std::string& uuid,
+    TransportState* state,
+    const std::vector<BlobItemBytesResponse>& responses,
+    BlobStorageContext* context) {
+  const auto& requests = state->request_builder.requests();
+  size_t num_requests = requests.size();
+  for (const BlobItemBytesResponse& response : responses) {
+    const MemoryItemRequest& request = requests[response.request_number];
+    if (response.inline_data.size() < request.message.size) {
+      DVLOG(1) << "Invalid data size " << response.inline_data.size()
+               << " vs requested size of " << request.message.size;
+      CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                         context);
+      return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+    }
+    bool success = state->data_builder.PopulateFutureData(
+        request.browser_item_index, response.inline_data.data(),
+        request.browser_item_offset, request.message.size);
+    if (!success) {
+      CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                         context);
+      return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+    }
+    state->num_fulfilled_requests++;
+  }
+  if (state->num_fulfilled_requests == num_requests) {
+    FinishBuildingBlob(state, context);
+    return BlobStatus::DONE;
+  }
+  return BlobStatus::PENDING_TRANSPORT;
+}
+
+BlobStatus BlobTransportHost::ContinueSharedMemoryRequests(
+    const std::string& uuid,
+    TransportState* state,
+    BlobStorageContext* context) {
+  BlobAsyncTransportRequestBuilder& request_builder = state->request_builder;
+  const std::vector<MemoryItemRequest>& requests = request_builder.requests();
+  size_t num_requests = requests.size();
+  DCHECK_LT(state->num_fulfilled_requests, num_requests);
+  if (state->next_request == num_requests) {
+    // We are still waiting on other requests to come back.
+    return BlobStatus::PENDING_TRANSPORT;
+  }
+
+  std::vector<BlobItemBytesRequest> byte_requests;
+  std::vector<base::SharedMemoryHandle> shared_memory;
+
+  for (; state->next_request < num_requests; ++state->next_request) {
+    const MemoryItemRequest& request = requests[state->next_request];
+    bool using_shared_memory_handle = state->num_shared_memory_requests > 0;
+    if (using_shared_memory_handle &&
+        state->current_shared_memory_handle_index !=
+            request.message.handle_index) {
+      // We only want one shared memory per requesting blob.
+      break;
+    }
+    state->current_shared_memory_handle_index = request.message.handle_index;
+    state->num_shared_memory_requests++;
+
+    if (!state->shared_memory_block) {
+      state->shared_memory_block.reset(new base::SharedMemory());
+      size_t size =
+          request_builder.shared_memory_sizes()[request.message.handle_index];
+      if (!state->shared_memory_block->CreateAnonymous(size)) {
+        DVLOG(1) << "Unable to allocate shared memory for blob transfer.";
+        return BlobStatus::ERR_OUT_OF_MEMORY;
+      }
+    }
+    shared_memory.push_back(state->shared_memory_block->handle());
+    byte_requests.push_back(request.message);
+    // Since we are only using one handle at a time, transform our handle
+    // index correctly back to 0.
+    byte_requests.back().handle_index = 0;
+  }
+  DCHECK(!requests.empty());
+
+  state->request_memory_callback.Run(std::move(byte_requests),
+                                     std::move(shared_memory),
+                                     std::vector<base::File>());
+  return BlobStatus::PENDING_TRANSPORT;
+}
+
+BlobStatus BlobTransportHost::OnSharedMemoryResponses(
+    const std::string& uuid,
+    TransportState* state,
+    const std::vector<BlobItemBytesResponse>& responses,
+    BlobStorageContext* context) {
+  BlobAsyncTransportRequestBuilder& request_builder = state->request_builder;
+  const auto& requests = request_builder.requests();
+  for (const BlobItemBytesResponse& response : responses) {
+    const MemoryItemRequest& request = requests[response.request_number];
+    if (state->num_shared_memory_requests == 0) {
+      DVLOG(1) << "Received too many responses for shared memory.";
+      CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                         context);
+      return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+    }
+    state->num_shared_memory_requests--;
+    if (!state->shared_memory_block->memory()) {
+      // We just map the whole block, as we'll probably be accessing the
+      // whole thing in this group of responses.
+      size_t handle_size =
+          request_builder
+              .shared_memory_sizes()[state->current_shared_memory_handle_index];
+      if (!state->shared_memory_block->Map(handle_size)) {
+        DVLOG(1) << "Unable to map memory to size " << handle_size;
+        CancelBuildingBlob(uuid, BlobStatus::ERR_OUT_OF_MEMORY, context);
+        return BlobStatus::ERR_OUT_OF_MEMORY;
+      }
+    }
+
+    bool success = state->data_builder.PopulateFutureData(
+        request.browser_item_index,
+        static_cast<const char*>(state->shared_memory_block->memory()) +
+            request.message.handle_offset,
+        request.browser_item_offset, request.message.size);
+
+    if (!success) {
+      CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                         context);
+      return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+    }
+    state->num_fulfilled_requests++;
+  }
+  if (state->num_fulfilled_requests == requests.size()) {
+    FinishBuildingBlob(state, context);
+    return BlobStatus::DONE;
+  }
+  return ContinueSharedMemoryRequests(uuid, state, context);
+}
+
+void BlobTransportHost::SendFileRequests(
+    TransportState* state,
+    BlobStorageContext* context,
+    std::vector<BlobMemoryController::FileCreationInfo> file_infos) {
+  std::vector<base::File> files;
+
+  for (BlobMemoryController::FileCreationInfo& file_info : file_infos) {
+    state->files.push_back(std::move(file_info.file_reference));
+    files.push_back(std::move(file_info.file));
+  }
+
+  const std::vector<MemoryItemRequest>& requests =
+      state->request_builder.requests();
+  std::vector<BlobItemBytesRequest> byte_requests;
+
+  DCHECK(!requests.empty());
+  for (const MemoryItemRequest& request : requests) {
+    byte_requests.push_back(request.message);
+  }
+
+  state->request_memory_callback.Run(std::move(byte_requests),
+                                     std::vector<base::SharedMemoryHandle>(),
+                                     std::move(files));
+}
+
+BlobStatus BlobTransportHost::OnFileResponses(
+    const std::string& uuid,
+    TransportState* state,
+    const std::vector<BlobItemBytesResponse>& responses,
+    BlobStorageContext* context) {
+  BlobAsyncTransportRequestBuilder& request_builder = state->request_builder;
+  const auto& requests = request_builder.requests();
+  for (const BlobItemBytesResponse& response : responses) {
+    const MemoryItemRequest& request = requests[response.request_number];
+    const scoped_refptr<ShareableFileReference>& file_ref =
+        state->files[request.message.handle_index];
+    bool success = state->data_builder.PopulateFutureFile(
+        request.browser_item_index, file_ref, response.time_file_modified);
+    if (!success) {
+      CancelBuildingBlob(uuid, BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS,
+                         context);
+      return BlobStatus::ERR_INVALID_CONSTRUCTION_ARGUMENTS;
+    }
+    state->num_fulfilled_requests++;
+  }
+  if (state->num_fulfilled_requests == requests.size()) {
+    FinishBuildingBlob(state, context);
+    return BlobStatus::DONE;
+  }
+  return BlobStatus::PENDING_TRANSPORT;
+}
+
+void BlobTransportHost::FinishBuildingBlob(TransportState* state,

[michaeln, 2016/11/07 21:47:05]

CompleteTransport() might be more clear since the blob may or may not be
'finished' at this point.

[dmurph, 2016/11/08 21:19:58]

Done.

+                                              BlobStorageContext* context) {

[michaeln, 2016/11/07 21:47:05]

nit: indent is off

[dmurph, 2016/11/08 21:19:58]

Done.

+  std::string uuid = state->data_builder.uuid();
+  async_blob_map_.erase(state->data_builder.uuid());
+  context->OnPopulationComplete(uuid);

[michaeln, 2016/11/07 21:47:05]

it probably would be a small improvement to consistently use 'transport' at
various levels, i think it would help to lighten the cognitive load

->NotifyTransportComplete()

[dmurph, 2016/11/08 21:19:58]

Done.

+}
+
+}  // namespace storage