1 /*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "include/core/SkMallocPixelRef.h"
9
10 #include "include/core/SkAlphaType.h"
11 #include "include/core/SkColorType.h"
12 #include "include/core/SkData.h"
13 #include "include/core/SkImageInfo.h"
14 #include "include/core/SkPixelRef.h"
15 #include "include/private/base/SkMalloc.h"
16
17 #include <utility>
18
is_valid(const SkImageInfo & info)19 static bool is_valid(const SkImageInfo& info) {
20 if (info.width() < 0 || info.height() < 0 ||
21 (unsigned)info.colorType() > (unsigned)kLastEnum_SkColorType ||
22 (unsigned)info.alphaType() > (unsigned)kLastEnum_SkAlphaType)
23 {
24 return false;
25 }
26 return true;
27 }
28
MakeAllocate(const SkImageInfo & info,size_t rowBytes)29 sk_sp<SkPixelRef> SkMallocPixelRef::MakeAllocate(const SkImageInfo& info, size_t rowBytes) {
30 if (rowBytes == 0) {
31 rowBytes = info.minRowBytes();
32 // rowBytes can still be zero, if it overflowed (width * bytesPerPixel > size_t)
33 // or if colortype is unknown
34 }
35 if (!is_valid(info) || !info.validRowBytes(rowBytes)) {
36 return nullptr;
37 }
38 size_t size = info.computeByteSize(rowBytes);
39 if (SkImageInfo::ByteSizeOverflowed(size)) {
40 return nullptr;
41 }
42 #if defined(SK_BUILD_FOR_FUZZER)
43 if (size > 10000000) {
44 return nullptr;
45 }
46 #endif
47 void* addr = sk_calloc_canfail(size);
48 if (nullptr == addr) {
49 return nullptr;
50 }
51
52 struct PixelRef final : public SkPixelRef {
53 PixelRef(int w, int h, void* s, size_t r) : SkPixelRef(w, h, s, r) {}
54 ~PixelRef() override { sk_free(this->pixels()); }
55 };
56 return sk_sp<SkPixelRef>(new PixelRef(info.width(), info.height(), addr, rowBytes));
57 }
58
MakeWithData(const SkImageInfo & info,size_t rowBytes,sk_sp<SkData> data)59 sk_sp<SkPixelRef> SkMallocPixelRef::MakeWithData(const SkImageInfo& info,
60 size_t rowBytes,
61 sk_sp<SkData> data) {
62 SkASSERT(data != nullptr);
63 if (!is_valid(info)) {
64 return nullptr;
65 }
66 // TODO: what should we return if computeByteSize returns 0?
67 // - the info was empty?
68 // - we overflowed computing the size?
69 if ((rowBytes < info.minRowBytes()) || (data->size() < info.computeByteSize(rowBytes))) {
70 return nullptr;
71 }
72 struct PixelRef final : public SkPixelRef {
73 sk_sp<SkData> fData;
74 PixelRef(int w, int h, void* s, size_t r, sk_sp<SkData> d)
75 : SkPixelRef(w, h, s, r), fData(std::move(d)) {}
76 };
77 void* pixels = const_cast<void*>(data->data());
78 sk_sp<SkPixelRef> pr(new PixelRef(info.width(), info.height(), pixels, rowBytes,
79 std::move(data)));
80 pr->setImmutable(); // since we were created with (immutable) data
81 return pr;
82 }
83