blob: a1382d31262d5bd719246c668158d807b8b8f154 [file] [log] [blame]
// Copyright (c) 2012 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 "ui/surface/transport_dib.h"
#include <windows.h>
#include <stddef.h>
#include <stdint.h>
#include <limits>
#include <memory>
#include "base/logging.h"
#include "base/system/sys_info.h"
#include "skia/ext/platform_canvas.h"
: size_(0) {
TransportDIB::~TransportDIB() {
TransportDIB::TransportDIB(base::SharedMemoryHandle handle)
: shared_memory_(handle, false /* read write */), size_(0) {}
// static
TransportDIB* TransportDIB::Map(Handle handle) {
std::unique_ptr<TransportDIB> dib(CreateWithHandle(handle));
if (!dib->Map())
return NULL;
return dib.release();
// static
TransportDIB* TransportDIB::CreateWithHandle(Handle handle) {
return new TransportDIB(handle);
// static
bool TransportDIB::is_valid_handle(Handle dib) {
return dib.IsValid();
std::unique_ptr<SkCanvas> TransportDIB::GetPlatformCanvas(int w,
int h,
bool opaque) {
// This DIB already mapped the file into this process, but PlatformCanvas
// will map it again.
DCHECK(!memory()) << "Mapped file twice in the same process.";
// We can't check the canvas size before mapping, but it's safe because
// Windows will fail to map the section if the dimensions of the canvas
// are too large.
std::unique_ptr<SkCanvas> canvas =
w, h, opaque, shared_memory_.handle().GetHandle(),
// Calculate the size for the memory region backing the canvas.
if (canvas)
size_ = skia::PlatformCanvasStrideForWidth(w) * h;
return canvas;
bool TransportDIB::Map() {
if (!is_valid_handle(shared_memory_.handle()))
return false;
if (memory())
return true;
if (!shared_memory_.Map(0 /* map whole shared memory segment */)) {
LOG(ERROR) << "Failed to map transport DIB"
<< " handle:" << shared_memory_.handle().GetHandle()
<< " error:" << ::GetLastError();
return false;
size_ = shared_memory_.mapped_size();
return true;
void* TransportDIB::memory() const {
return shared_memory_.memory();