[BlobAsync] Disk support for blob storage

content/browser/blob_storage/blob_dispatcher_host.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 "content/browser/blob_storage/blob_dispatcher_host.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/metrics/histogram_macros.h"
 #include "content/browser/bad_message.h"
 #include "content/browser/blob_storage/chrome_blob_storage_context.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/fileapi/browser_file_system_helper.h"
 #include "content/common/fileapi/webblob_messages.h"
 #include "ipc/ipc_platform_file.h"
+#include "storage/browser/blob/blob_data_handle.h"
 #include "storage/browser/blob/blob_storage_context.h"
-#include "storage/browser/blob/blob_transport_result.h"
 #include "storage/browser/fileapi/file_system_context.h"
 #include "storage/browser/fileapi/file_system_url.h"
+#include "storage/browser/blob/internal_blob_data.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::BlobStatus;
 using storage::DataElement;
-using storage::IPCBlobCreationCancelCode;
 using storage::FileSystemURL;
 
 namespace content {
 namespace {
 
 // These are used for UMA stats, don't change.
 enum RefcountOperation {
   BDH_DECREMENT = 0,
   BDH_INCREMENT,
   BDH_TRACING_ENUM_LAST
@@ skipping 16 matching lines @@
 
 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_RegisterBlob, OnRegisterBlob)
     IPC_MESSAGE_HANDLER(BlobStorageMsg_MemoryItemResponse, OnMemoryItemResponse)
-    IPC_MESSAGE_HANDLER(BlobStorageMsg_CancelBuildingBlob, OnCancelBuildingBlob)
+    IPC_MESSAGE_HANDLER(BlobStorageMsg_SendBlobStatus, OnCancelBuildingBob)
     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(
+void BlobDispatcherHost::OnRegisterBlob(
     const std::string& uuid,
     const std::string& content_type,
     const std::string& content_disposition,
-    const std::set<std::string>& referenced_blob_uuids) {
+    const std::vector<storage::DataElement>& descriptions) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   BlobStorageContext* context = this->context();
   if (uuid.empty() || context->registry().HasEntry(uuid) ||
       async_builder_.IsBeingBuilt(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_CONSTRUCTION_FAILED);
-      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;
-  }
 
   ChildProcessSecurityPolicyImpl* security_policy =
       ChildProcessSecurityPolicyImpl::GetInstance();
   for (const DataElement& item : descriptions) {
     if (item.type() == storage::DataElement::TYPE_FILE_FILESYSTEM) {
       FileSystemURL filesystem_url(
           file_system_context_->CrackURL(item.filesystem_url()));
       if (!FileSystemURLIsValid(file_system_context_.get(), filesystem_url) ||
           !security_policy->CanReadFileSystemFile(process_id_,
                                                   filesystem_url)) {
-        async_builder_.CancelBuildingBlob(
-            uuid, IPCBlobCreationCancelCode::FILE_WRITE_FAILED, context);
-        Send(new BlobStorageMsg_CancelBuildingBlob(
-            uuid, IPCBlobCreationCancelCode::FILE_WRITE_FAILED));
+        SendFinalBlobStatus(uuid, BlobStatus::ERR_FILE_WRITE_FAILED);
         return;
       }
     }
     if (item.type() == storage::DataElement::TYPE_FILE &&
         !security_policy->CanReadFile(process_id_, item.path())) {
-      async_builder_.CancelBuildingBlob(
-          uuid, IPCBlobCreationCancelCode::FILE_WRITE_FAILED, context);
-      Send(new BlobStorageMsg_CancelBuildingBlob(
-          uuid, IPCBlobCreationCancelCode::FILE_WRITE_FAILED));
+      SendFinalBlobStatus(uuid, BlobStatus::ERR_FILE_WRITE_FAILED);
       return;
     }
   }
+  blobs_inuse_map_[uuid] = 1;
 
-  // |this| owns async_builder_ so using base::Unretained(this) is safe.
-  BlobTransportResult result = async_builder_.StartBuildingBlob(
-      uuid, descriptions, context->memory_available(), context,
+  async_builder_.RegisterBlob(
+      uuid, content_type, content_disposition, descriptions, context,
       base::Bind(&BlobDispatcherHost::SendMemoryRequest, base::Unretained(this),
-                 uuid));
-  SendIPCResponse(uuid, result);
+                 uuid),
+      base::Bind(&BlobDispatcherHost::SendFinalBlobStatus,
+                 base::Unretained(this), uuid));
 }
 
 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);
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_CONSTRUCTION_FAILED);
     return;
   }
   BlobStorageContext* context = this->context();
-  const BlobStorageRegistry::Entry* entry = context->registry().GetEntry(uuid);
-  if (!entry || entry->state == BlobStorageRegistry::BlobState::BROKEN) {
+  const storage::InternalBlobData* entry = context->registry().GetEntry(uuid);
+  if (!entry || BlobStatusIsError(entry->status())) {
     // 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));
+          uuid, BlobStatus::ERR_BLOB_DEREFERENCED_WHILE_BUILDING, context);
+      SendFinalBlobStatus(uuid,
+                          BlobStatus::ERR_BLOB_DEREFERENCED_WHILE_BUILDING);
     }
     return;
   }
   if (!async_builder_.IsBeingBuilt(uuid)) {
-    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_CONSTRUCTION_FAILED);
     return;
   }
-  BlobTransportResult result =
+  BlobStatus result =
       async_builder_.OnMemoryResponses(uuid, responses, context);
-  SendIPCResponse(uuid, result);
+  SendFinalBlobStatus(uuid, result);

[michaeln, 2016/08/23 01:31:55]

I thought that in some cases the result can still be PENDING? Ditto previous
comment about the builder knows when it completes and how it completes and is
probably in best position to signal completion.

 }
 
-void BlobDispatcherHost::OnCancelBuildingBlob(
-    const std::string& uuid,
-    const storage::IPCBlobCreationCancelCode code) {
+void BlobDispatcherHost::OnCancelBuildingBob(const std::string& uuid,
+                                             const storage::BlobStatus code) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (uuid.empty()) {
-    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_CONSTRUCTION_FAILED);
     return;
   }
   BlobStorageContext* context = this->context();
-  const BlobStorageRegistry::Entry* entry = context->registry().GetEntry(uuid);
-  if (!entry || entry->state == BlobStorageRegistry::BlobState::BROKEN) {
+  const storage::InternalBlobData* entry = context->registry().GetEntry(uuid);
+  if (!entry || BlobStatusIsError(entry->status())) {
     // 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.
     if (async_builder_.IsBeingBuilt(uuid)) {
       async_builder_.CancelBuildingBlob(
-          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING,
-          context);
+          uuid, BlobStatus::ERR_BLOB_DEREFERENCED_WHILE_BUILDING, context);
     }
     return;
   }
-  if (!async_builder_.IsBeingBuilt(uuid)) {
-    SendIPCResponse(uuid, BlobTransportResult::BAD_IPC);
+  // We should only get these messages for errors.
+  if (!async_builder_.IsBeingBuilt(uuid) || !storage::BlobStatusIsError(code)) {
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_CONSTRUCTION_FAILED);
     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();
@@ skipping 25 matching lines @@
   }
   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)) {

[michaeln, 2016/08/23 01:31:55]

If the final ref is dropped from a different renderer (not the one that is
building the blob), this cancelling and status sending doesn't happen. It'd be
nice if this cancellation code was agnostic about the renderer responsible for
the final dec ref.

If the builder observed status changes (via the context) for blobs it's
building, it could do this internally and it wouldn't matter which process was
the last to drop the ref.

       async_builder_.CancelBuildingBlob(
-          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING,
-          context);
-      Send(new BlobStorageMsg_CancelBuildingBlob(
-          uuid, IPCBlobCreationCancelCode::BLOB_DEREFERENCED_WHILE_BUILDING));
+          uuid, BlobStatus::ERR_BLOB_DEREFERENCED_WHILE_BUILDING, context);
+      SendFinalBlobStatus(
+          uuid, BlobStatus::ERR_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()) {
     bad_message::ReceivedBadMessage(this,
@@ skipping 24 matching lines @@
   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,
-    std::unique_ptr<std::vector<storage::BlobItemBytesRequest>> requests,
-    std::unique_ptr<std::vector<base::SharedMemoryHandle>> memory_handles,
-    std::unique_ptr<std::vector<base::File>> files) {
+    std::vector<storage::BlobItemBytesRequest> requests,
+    std::vector<base::SharedMemoryHandle> memory_handles,
+    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,
+  for (base::File& file : files) {
+    file_handles.push_back(IPC::TakePlatformFileForTransit(std::move(file)));
+  }
+  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;
+void BlobDispatcherHost::SendFinalBlobStatus(const std::string& uuid,
+                                                  BlobStatus status) {
+  if (storage::BlobStatusIsBadIPC(status)) {
+    blobs_inuse_map_.erase(uuid);
+    bad_message::ReceivedBadMessage(this, bad_message::BDH_CONSTRUCTION_FAILED);
+    return;
   }
-  NOTREACHED();
+  DCHECK(status != BlobStatus::PENDING);
+  Send(new BlobStorageMsg_SendBlobStatus(uuid, status));
 }
 
 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