[BlobAsync] Asynchronous Blob Construction Final Patch

storage/browser/blob/blob_async_transport_strategy.cc

Index: storage/browser/blob/blob_async_transport_strategy.cc
diff --git a/storage/browser/blob/blob_async_transport_strategy.cc b/storage/browser/blob/blob_async_transport_strategy.cc
deleted file mode 100644
index edae52c79ed0a76bcd6d2f3a6fc3f795de470ad8..0000000000000000000000000000000000000000
--- a/storage/browser/blob/blob_async_transport_strategy.cc
+++ /dev/null
@@ -1,337 +0,0 @@
-// 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 <algorithm>
-
-#include "base/numerics/safe_math.h"
-#include "storage/browser/blob/blob_async_transport_strategy.h"
-#include "storage/common/blob_storage/blob_storage_constants.h"
-
-namespace storage {
-namespace {
-bool IsBytes(DataElement::Type type) {
-  return type == DataElement::TYPE_BYTES ||
-         type == DataElement::TYPE_BYTES_DESCRIPTION;
-}
-
-// This is the general template that each strategy below implements. See the
-// ForEachWithSegment method for a description of how these are called.
-// class BlobSegmentVisitor {
-//  public:
-//   typedef ___ SizeType;
-//   void VisitBytesSegment(size_t element_index, uint64_t element_offset,
-//                          size_t segment_index, uint64_t segment_offset,
-//                          uint64_t size);
-//   void VisitNonBytesSegment(const DataElement& element, size_t element_idx);
-//   void Done();
-// };
-
-// This class handles the logic of how transported memory is going to be
-// represented as storage in the browser.  The main idea is that all the memory
-// is now packed into file chunks, and the browser items will just reference
-// the file with offsets and sizes.
-class FileStorageStrategy {
- public:
-  FileStorageStrategy(
-      std::vector<BlobAsyncTransportStrategy::RendererMemoryItemRequest>*
-          requests,
-      BlobDataBuilder* builder)
-      : requests(requests), builder(builder), current_item_index(0) {}
-
-  ~FileStorageStrategy() {}
-
-  void VisitBytesSegment(size_t element_index,
-                         uint64_t element_offset,
-                         size_t segment_index,
-                         uint64_t segment_offset,
-                         uint64_t size) {
-    BlobAsyncTransportStrategy::RendererMemoryItemRequest request;
-    request.browser_item_index = current_item_index;
-    request.browser_item_offset = 0;
-    request.message.request_number = requests->size();
-    request.message.transport_strategy = IPCBlobItemRequestStrategy::FILE;
-    request.message.renderer_item_index = element_index;
-    request.message.renderer_item_offset = element_offset;
-    request.message.size = size;
-    request.message.handle_index = segment_index;
-    request.message.handle_offset = segment_offset;
-
-    requests->push_back(request);
-    builder->AppendFutureFile(segment_offset, size);
-    current_item_index++;
-  }
-
-  void VisitNonBytesSegment(const DataElement& element, size_t element_index) {
-    builder->AppendIPCDataElement(element);
-    current_item_index++;
-  }
-
-  void Done() {}
-
-  std::vector<BlobAsyncTransportStrategy::RendererMemoryItemRequest>* requests;
-  BlobDataBuilder* builder;
-
-  size_t current_item_index;
-};
-
-// This class handles the logic of storing memory that is transported as
-// consolidated shared memory.
-class SharedMemoryStorageStrategy {
- public:
-  SharedMemoryStorageStrategy(
-      size_t max_segment_size,
-      std::vector<BlobAsyncTransportStrategy::RendererMemoryItemRequest>*
-          requests,
-      BlobDataBuilder* builder)
-      : requests(requests),
-        max_segment_size(max_segment_size),
-        builder(builder),
-        current_item_size(0),
-        current_item_index(0) {}
-  ~SharedMemoryStorageStrategy() {}
-
-  void VisitBytesSegment(size_t element_index,
-                         uint64_t element_offset,
-                         size_t segment_index,
-                         uint64_t segment_offset,
-                         uint64_t size) {
-    if (current_item_size + size > max_segment_size) {
-      builder->AppendFutureData(current_item_size);
-      current_item_index++;
-      current_item_size = 0;
-    }
-    BlobAsyncTransportStrategy::RendererMemoryItemRequest request;
-    request.browser_item_index = current_item_index;
-    request.browser_item_offset = current_item_size;
-    request.message.request_number = requests->size();
-    request.message.transport_strategy =
-        IPCBlobItemRequestStrategy::SHARED_MEMORY;
-    request.message.renderer_item_index = element_index;
-    request.message.renderer_item_offset = element_offset;
-    request.message.size = size;
-    request.message.handle_index = segment_index;
-    request.message.handle_offset = segment_offset;
-
-    requests->push_back(request);
-    current_item_size += size;
-  }
-
-  void VisitNonBytesSegment(const DataElement& element, size_t element_index) {
-    if (current_item_size != 0) {
-      builder->AppendFutureData(current_item_size);
-      current_item_index++;
-    }
-    builder->AppendIPCDataElement(element);
-    current_item_index++;
-    current_item_size = 0;
-  }
-
-  void Done() {
-    if (current_item_size != 0) {
-      builder->AppendFutureData(current_item_size);
-    }
-  }
-
-  std::vector<BlobAsyncTransportStrategy::RendererMemoryItemRequest>* requests;
-
-  size_t max_segment_size;
-  BlobDataBuilder* builder;
-  size_t current_item_size;
-  uint64_t current_item_index;
-};
-
-// This iterates of the data elements and segments the 'bytes' data into
-// the smallest number of segments given the max_segment_size.
-// The callback describes either:
-// * A non-memory item
-// * A partition of a bytes element which will be populated into a given
-//   segment and segment offset.
-// More specifically, we split each |element| into one or more |segments| of a
-// max_size, invokes the strategy to determine the request to make for each
-// |segment| produced. A |segment| can also span multiple |elements|.
-// Assumptions: All memory items are consolidated.  As in, there are no two
-//              'bytes' items next to eachother.
-template <typename Visitor>
-void ForEachWithSegment(const std::vector<DataElement>& elements,
-                        uint64_t max_segment_size,
-                        Visitor* visitor) {
-  DCHECK_GT(max_segment_size, 0ull);
-  size_t segment_index = 0;
-  uint64_t segment_offset = 0;
-  size_t elements_length = elements.size();
-  for (size_t element_index = 0; element_index < elements_length;
-       ++element_index) {
-    const auto& element = elements.at(element_index);
-    DataElement::Type type = element.type();
-    if (!IsBytes(type)) {
-      visitor->VisitNonBytesSegment(element, element_index);
-      continue;
-    }
-    uint64_t element_memory_left = element.length();
-    uint64_t element_offset = 0;
-    while (element_memory_left > 0) {
-      if (segment_offset == max_segment_size) {
-        ++segment_index;
-        segment_offset = 0;
-      }
-      uint64_t memory_writing =
-          std::min(max_segment_size - segment_offset, element_memory_left);
-      visitor->VisitBytesSegment(element_index, element_offset, segment_index,
-                                 segment_offset, memory_writing);
-      element_memory_left -= memory_writing;
-      segment_offset += memory_writing;
-      element_offset += memory_writing;
-    }
-  }
-  visitor->Done();
-}
-}  // namespace
-
-BlobAsyncTransportStrategy::RendererMemoryItemRequest::
-    RendererMemoryItemRequest()
-    : browser_item_index(0), browser_item_offset(0), received(false) {}
-
-BlobAsyncTransportStrategy::BlobAsyncTransportStrategy()
-    : error_(BlobAsyncTransportStrategy::ERROR_NONE), total_bytes_size_(0) {}
-
-BlobAsyncTransportStrategy::~BlobAsyncTransportStrategy() {}
-
-// if total_blob_size > |memory_available| (say 400MB)
-//   Request all data in files
-//   (Segment all of the existing data into
-//   file blocks, of <= |max_file_size|)
-// else if total_blob_size > |max_ipc_memory_size| (say 150KB)
-//   Request all data in shared memory
-//   (Segment all of the existing data into
-//   shared memory blocks, of <= |max_shared_memory_size|)
-// else
-//   Request all data to be sent over IPC
-void BlobAsyncTransportStrategy::Initialize(
-    size_t max_ipc_memory_size,
-    size_t max_shared_memory_size,
-    size_t max_file_size,
-    uint64_t disk_space_left,
-    size_t memory_available,
-    const std::string& uuid,
-    const std::vector<DataElement>& blob_item_infos) {
-  DCHECK(handle_sizes_.empty());
-  DCHECK(requests_.empty());
-  DCHECK(!builder_.get());
-  builder_.reset(new BlobDataBuilder(uuid));
-  error_ = BlobAsyncTransportStrategy::ERROR_NONE;
-
-  size_t memory_items = 0;
-  base::CheckedNumeric<uint64_t> total_size_checked = 0;
-  for (const auto& info : blob_item_infos) {
-    if (!IsBytes(info.type())) {
-      continue;
-    }
-    total_size_checked += info.length();
-    ++memory_items;
-  }
-
-  if (!total_size_checked.IsValid()) {
-    DVLOG(1) << "Impossible total size of all memory elements.";
-    error_ = BlobAsyncTransportStrategy::ERROR_INVALID_PARAMS;
-    return;
-  }
-
-  total_bytes_size_ = total_size_checked.ValueOrDie();
-
-  // See if we have enough memory.
-  if (total_bytes_size_ >
-      disk_space_left + static_cast<uint64_t>(memory_available)) {
-    error_ = BlobAsyncTransportStrategy::ERROR_TOO_LARGE;
-    return;
-  }
-
-  // If we're more than the available memory, then we're going straight to disk.
-  if (total_bytes_size_ > memory_available) {
-    if (total_bytes_size_ > disk_space_left) {
-      error_ = BlobAsyncTransportStrategy::ERROR_TOO_LARGE;
-      return;
-    }
-    ComputeHandleSizes(total_bytes_size_, max_file_size, &handle_sizes_);
-    FileStorageStrategy strategy(&requests_, builder_.get());
-    ForEachWithSegment(blob_item_infos, static_cast<uint64_t>(max_file_size),
-                       &strategy);
-    return;
-  }
-
-  if (total_bytes_size_ > max_ipc_memory_size) {
-    // Note: The size must be <= std::numeric_limits<size_t>::max(). Otherwise
-    // we are guarenteed to be caught by the if statement above,
-    // |total_bytes_size_ > memory_available|.
-    ComputeHandleSizes(total_bytes_size_, max_shared_memory_size,
-                       &handle_sizes_);
-    SharedMemoryStorageStrategy strategy(max_shared_memory_size, &requests_,
-                                         builder_.get());
-    ForEachWithSegment(blob_item_infos,
-                       static_cast<uint64_t>(max_shared_memory_size),
-                       &strategy);
-    return;
-  }
-
-  // Since they can all fit in IPC memory, we don't need to segment anything,
-  // and just request them straight in IPC.
-  size_t items_length = blob_item_infos.size();
-  for (size_t i = 0; i < items_length; i++) {
-    const auto& info = blob_item_infos.at(i);
-    if (!IsBytes(info.type())) {
-      builder_->AppendIPCDataElement(info);
-      continue;
-    }
-    BlobAsyncTransportStrategy::RendererMemoryItemRequest request;
-    request.browser_item_index = i;
-    request.browser_item_offset = 0;
-    request.message.request_number = requests_.size();
-    request.message.transport_strategy = IPCBlobItemRequestStrategy::IPC;
-    request.message.renderer_item_index = i;
-    request.message.renderer_item_offset = 0;
-    request.message.size = info.length();
-    requests_.push_back(request);
-    builder_->AppendFutureData(info.length());
-  }
-}
-
-/* static */
-bool BlobAsyncTransportStrategy::ShouldBeShortcut(
-    const std::vector<DataElement>& elements,
-    size_t memory_available) {
-  base::CheckedNumeric<size_t> shortcut_bytes = 0;
-  for (const auto& element : elements) {
-    DataElement::Type type = element.type();
-    if (type == DataElement::TYPE_BYTES_DESCRIPTION) {
-      return false;
-    }
-    if (type == DataElement::TYPE_BYTES) {
-      shortcut_bytes += element.length();
-      if (!shortcut_bytes.IsValid()) {
-        return false;
-      }
-    }
-  }
-  return shortcut_bytes.ValueOrDie() <= memory_available;
-}
-
-/* static */
-void BlobAsyncTransportStrategy::ComputeHandleSizes(
-    uint64_t total_memory_size,
-    size_t max_segment_size,
-    std::vector<size_t>* segment_sizes) {
-  size_t total_max_segments =
-      static_cast<size_t>(total_memory_size / max_segment_size);
-  bool has_extra_segment = (total_memory_size % max_segment_size) > 0;
-  segment_sizes->reserve(total_max_segments + (has_extra_segment ? 1 : 0));
-  segment_sizes->insert(segment_sizes->begin(), total_max_segments,
-                        max_segment_size);
-  if (has_extra_segment) {
-    segment_sizes->push_back(total_memory_size % max_segment_size);
-  }
-}
-
-}  // namespace storage