[BlobAsync] Asynchronous Blob Construction Final Patch

content/browser/blob_storage/blob_dispatcher_host.cc

Index: content/browser/blob_storage/blob_dispatcher_host.cc
diff --git a/content/browser/blob_storage/blob_dispatcher_host.cc b/content/browser/blob_storage/blob_dispatcher_host.cc
new file mode 100644
index 0000000000000000000000000000000000000000..00ef8b40f71f04826f09ac935af3516c0b318f23
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+++ b/content/browser/blob_storage/blob_dispatcher_host.cc
@@ -0,0 +1,333 @@
+// 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 "content/browser/blob_storage/blob_dispatcher_host.h"
+
+#include <algorithm>
+
+#include "base/bind.h"
+#include "content/browser/bad_message.h"
+#include "content/browser/fileapi/chrome_blob_storage_context.h"
+#include "content/common/fileapi/webblob_messages.h"
+#include "ipc/ipc_platform_file.h"
+#include "storage/browser/blob/blob_storage_context.h"
+#include "storage/browser/blob/blob_transport_result.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"
+#include "url/gurl.h"
+
+using storage::BlobStorageContext;
+using storage::BlobStorageRegistry;
+using storage::BlobTransportResult;
+using storage::IPCBlobCreationCancelCode;
+
+namespace content {
+
+BlobDispatcherHost::BlobDispatcherHost(
+    ChromeBlobStorageContext* blob_storage_context)
+    : BrowserMessageFilter(BlobMsgStart),
+      blob_storage_context_(blob_storage_context) {}
+
+BlobDispatcherHost::~BlobDispatcherHost() {
+  ClearHostFromBlobStorageContext();
+}
+
+void BlobDispatcherHost::OnChannelClosing() {
+  ClearHostFromBlobStorageContext();
+  public_blob_urls_.clear();
+  blobs_inuse_map_.clear();
+}
+
+bool BlobDispatcherHost::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(BlobDispatcherHost, message)
+    IPC_MESSAGE_HANDLER(BlobStorageMsg_RegisterBlobUUID, OnRegisterBlobUUID)
+    IPC_MESSAGE_HANDLER(BlobStorageMsg_StartBuildingBlob, OnStartBuildingBlob)
+    IPC_MESSAGE_HANDLER(BlobStorageMsg_MemoryItemResponse, OnMemoryItemResponse)
+    IPC_MESSAGE_HANDLER(BlobStorageMsg_CancelBuildingBlob, OnCancelBuildingBlob)
+    IPC_MESSAGE_HANDLER(BlobHostMsg_IncrementRefCount, OnIncrementBlobRefCount)
+    IPC_MESSAGE_HANDLER(BlobHostMsg_DecrementRefCount, OnDecrementBlobRefCount)
+    IPC_MESSAGE_HANDLER(BlobHostMsg_RegisterPublicURL, OnRegisterPublicBlobURL)
+    IPC_MESSAGE_HANDLER(BlobHostMsg_RevokePublicURL, OnRevokePublicBlobURL)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void BlobDispatcherHost::OnRegisterBlobUUID(
+    const std::string& uuid,
+    const std::string& content_type,
+    const std::string& content_disposition,
+    const std::set<std::string>& referenced_blob_uuids) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BlobStorageContext* context = this->context();
+  if (uuid.empty() || context->registry().HasEntry(uuid)) {
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_UUID_REGISTERED);
+    return;
+  }
+  blobs_inuse_map_[uuid] = 1;
+  BlobTransportResult result = async_builder_.RegisterBlobUUID(
+      uuid, content_type, content_disposition, referenced_blob_uuids, context);
+  switch (result) {
+    case BlobTransportResult::BAD_IPC:
+      blobs_inuse_map_.erase(uuid);
+      bad_message::ReceivedBadMessage(this, bad_message::BDH_INVALID_OPERATION);
+      break;
+      ;
+    case BlobTransportResult::CANCEL_REFERENCED_BLOB_BROKEN:
+      // The async builder builds the blob as broken, and we just need to send
+      // the cancel message back to the renderer.
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::REFERENCED_BLOB_BROKEN));
+      break;
+    case BlobTransportResult::DONE:
+      break;
+    case BlobTransportResult::CANCEL_MEMORY_FULL:
+    case BlobTransportResult::CANCEL_FILE_ERROR:
+    case BlobTransportResult::CANCEL_UNKNOWN:
+    case BlobTransportResult::PENDING_RESPONSES:
+      NOTREACHED();
+      break;
+  }
+}
+
+void BlobDispatcherHost::OnStartBuildingBlob(
+    const std::string& uuid,
+    const std::vector<storage::DataElement>& descriptions) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (uuid.empty()) {
+    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    return;
+  }
+  BlobStorageContext* context = this->context();
+  const BlobStorageRegistry::Entry* entry = context->registry().GetEntry(uuid);
+  if (!entry || entry->state == BlobStorageRegistry::BlobState::BROKEN) {
+    // We ignore messages for blobs that don't exist to handle the case where
+    // the renderer de-refs a blob that we're still constructing, and there are
+    // no references to that blob. We ignore broken as well, in the case where
+    // we decided to break a blob after RegisterBlobUUID is called.
+    // Second, if the last dereference of the blob happened on a different host,
+    // then we still haven't gotten rid of the 'building' state in the original
+    // host. So we call cancel, and send the message just in case that happens.
+    if (async_builder_.IsBeingBuilt(uuid)) {
+      async_builder_.CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING,
+          context);
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING));
+    }
+    return;
+  }
+  if (!async_builder_.IsBeingBuilt(uuid)) {
+    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    return;
+  }
+  // |this| owns async_builder_ so using base::Unretained(this) is safe.
+  BlobTransportResult result = async_builder_.StartBuildingBlob(
+      uuid, descriptions, context->memory_available(), context,
+      base::Bind(&BlobDispatcherHost::SendMemoryRequest, base::Unretained(this),
+                 uuid));
+  SendIPCResponse(uuid, result);
+}
+
+void BlobDispatcherHost::OnMemoryItemResponse(
+    const std::string& uuid,
+    const std::vector<storage::BlobItemBytesResponse>& responses) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (uuid.empty()) {
+    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    return;
+  }
+  BlobStorageContext* context = this->context();
+  const BlobStorageRegistry::Entry* entry = context->registry().GetEntry(uuid);
+  if (!entry || entry->state == BlobStorageRegistry::BlobState::BROKEN) {
+    // We ignore messages for blobs that don't exist to handle the case where
+    // the renderer de-refs a blob that we're still constructing, and there are
+    // no references to that blob. We ignore broken as well, in the case where
+    // we decided to break a blob after sending the memory request.
+    // Note: if a blob is broken, then it can't be in the async_builder.
+    // Second, if the last dereference of the blob happened on a different host,
+    // then we still haven't gotten rid of the 'building' state in the original
+    // host. So we call cancel, and send the message just in case that happens.
+    if (async_builder_.IsBeingBuilt(uuid)) {
+      async_builder_.CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING,
+          context);
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING));
+    }
+    return;
+  }
+  if (!async_builder_.IsBeingBuilt(uuid)) {
+    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    return;
+  }
+  BlobTransportResult result =
+      async_builder_.OnMemoryResponses(uuid, responses, context);
+  SendIPCResponse(uuid, result);
+}
+
+void BlobDispatcherHost::OnCancelBuildingBlob(
+    const std::string& uuid,
+    const storage::IPCBlobCreationCancelCode code) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (uuid.empty()) {
+    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    return;
+  }
+  BlobStorageContext* context = this->context();
+  const BlobStorageRegistry::Entry* entry = context->registry().GetEntry(uuid);
+  if (!entry || entry->state == BlobStorageRegistry::BlobState::BROKEN) {
+    // We ignore messages for blobs that don't exist to handle the case where
+    // the renderer de-refs a blob that we're still constructing, and there are
+    // no references to that blob. We ignore broken as well, in the case where
+    // we decided to break a blob and the renderer also decided to cancel.
+    // Note: if a blob is broken, then it can't be in the async_builder.
+    // Second, if the last dereference of the blob happened on a different host,
+    // then we still haven't gotten rid of the 'building' state in the original
+    // host. So we call cancel just in case this happens.
+    async_builder_.CancelBuildingBlob(
+        uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING,
+        context);
+    return;
+  }
+  if (!async_builder_.IsBeingBuilt(uuid)) {
+    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    return;
+  }
+  VLOG(1) << "Blob construction of " << uuid << " cancelled by renderer. "
+          << " Reason: " << static_cast<int>(code) << ".";
+  async_builder_.CancelBuildingBlob(uuid, code, context);
+}
+
+void BlobDispatcherHost::OnIncrementBlobRefCount(const std::string& uuid) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BlobStorageContext* context = this->context();
+  if (uuid.empty() || !context->registry().HasEntry(uuid)) {
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_INVALID_OPERATION);
+    return;
+  }
+  context->IncrementBlobRefCount(uuid);
+  blobs_inuse_map_[uuid] += 1;
+}
+
+void BlobDispatcherHost::OnDecrementBlobRefCount(const std::string& uuid) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (uuid.empty() || !IsInUseInHost(uuid)) {
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_INVALID_OPERATION);
+    return;
+  }
+  BlobStorageContext* context = this->context();
+  context->DecrementBlobRefCount(uuid);
+  blobs_inuse_map_[uuid] -= 1;
+  if (blobs_inuse_map_[uuid] == 0) {
+    blobs_inuse_map_.erase(uuid);
+    // If the blob has been deleted in the context and we're still building it,
+    // this means we have no references waiting to read it. Clear the building
+    // state and send a cancel message to the renderer.
+    if (async_builder_.IsBeingBuilt(uuid) &&
+        !context->registry().HasEntry(uuid)) {
+      async_builder_.CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING,
+          context);
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING));
+    }
+  }
+}
+
+void BlobDispatcherHost::OnRegisterPublicBlobURL(const GURL& public_url,
+                                                 const std::string& uuid) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BlobStorageContext* context = this->context();
+  if (uuid.empty() || !IsInUseInHost(uuid) ||
+      context->registry().IsURLMapped(public_url)) {
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_INVALID_OPERATION);
+    return;
+  }
+  context->RegisterPublicBlobURL(public_url, uuid);
+  public_blob_urls_.insert(public_url);
+}
+
+void BlobDispatcherHost::OnRevokePublicBlobURL(const GURL& public_url) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (!IsUrlRegisteredInHost(public_url)) {
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_INVALID_OPERATION);
+    return;
+  }
+  context()->RevokePublicBlobURL(public_url);
+  public_blob_urls_.erase(public_url);
+}
+
+storage::BlobStorageContext* BlobDispatcherHost::context() {
+  return blob_storage_context_->context();
+}
+
+void BlobDispatcherHost::SendMemoryRequest(
+    const std::string& uuid,
+    scoped_ptr<std::vector<storage::BlobItemBytesRequest>> requests,
+    scoped_ptr<std::vector<base::SharedMemoryHandle>> memory_handles,
+    scoped_ptr<std::vector<base::File>> files) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  std::vector<IPC::PlatformFileForTransit> file_handles;
+  // TODO(dmurph): Support file-backed blob transportation.
+  DCHECK(files->empty());
+  Send(new BlobStorageMsg_RequestMemoryItem(uuid, *requests, *memory_handles,
+                                            file_handles));
+}
+
+void BlobDispatcherHost::SendIPCResponse(const std::string& uuid,
+                                         storage::BlobTransportResult result) {
+  switch (result) {
+    case BlobTransportResult::BAD_IPC:
+      bad_message::ReceivedBadMessage(this,
+                                      bad_message::BDH_CONSTRUCTION_FAILED);
+      return;
+    case BlobTransportResult::CANCEL_MEMORY_FULL:
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::OUT_OF_MEMORY));
+      return;
+    case BlobTransportResult::CANCEL_FILE_ERROR:
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::FILE_WRITE_FAILED));
+      return;
+    case BlobTransportResult::CANCEL_REFERENCED_BLOB_BROKEN:
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::REFERENCED_BLOB_BROKEN));
+      return;
+    case BlobTransportResult::CANCEL_UNKNOWN:
+      Send(new BlobStorageMsg_CancelBuildingBlob(
+          uuid, IPCBlobCreationCancelCode::UNKNOWN));
+      return;
+    case BlobTransportResult::PENDING_RESPONSES:
+      return;
+    case BlobTransportResult::DONE:
+      Send(new BlobStorageMsg_DoneBuildingBlob(uuid));
+      return;
+  }
+  NOTREACHED();
+}
+
+bool BlobDispatcherHost::IsInUseInHost(const std::string& uuid) {
+  return blobs_inuse_map_.find(uuid) != blobs_inuse_map_.end();
+}
+
+bool BlobDispatcherHost::IsUrlRegisteredInHost(const GURL& blob_url) {
+  return public_blob_urls_.find(blob_url) != public_blob_urls_.end();
+}
+
+void BlobDispatcherHost::ClearHostFromBlobStorageContext() {
+  BlobStorageContext* context = this->context();
+  for (const auto& url : public_blob_urls_) {
+    context->RevokePublicBlobURL(url);
+  }
+  for (const auto& uuid_refnum_pair : blobs_inuse_map_) {
+    for (int i = 0; i < uuid_refnum_pair.second; ++i)
+      context->DecrementBlobRefCount(uuid_refnum_pair.first);
+  }
+  async_builder_.CancelAll(context);
+}
+
+}  // namespace content