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/SkData.h"
11#include "include/core/SkImageInfo.h"
12#include "include/private/SkMalloc.h"
13
14static bool is_valid(const SkImageInfo& info) {
15    if (info.width() < 0 || info.height() < 0 ||
16        (unsigned)info.colorType() > (unsigned)kLastEnum_SkColorType ||
17        (unsigned)info.alphaType() > (unsigned)kLastEnum_SkAlphaType)
18    {
19        return false;
20    }
21    return true;
22}
23
24sk_sp<SkPixelRef> SkMallocPixelRef::MakeAllocate(const SkImageInfo& info, size_t rowBytes) {
25    if (rowBytes == 0) {
26        rowBytes = info.minRowBytes();
27        // rowBytes can still be zero, if it overflowed (width * bytesPerPixel > size_t)
28        // or if colortype is unknown
29    }
30    if (!is_valid(info) || !info.validRowBytes(rowBytes)) {
31        return nullptr;
32    }
33    size_t size = info.computeByteSize(rowBytes);
34    if (SkImageInfo::ByteSizeOverflowed(size)) {
35        return nullptr;
36    }
37#if defined(SK_BUILD_FOR_FUZZER)
38    if (size > 100000) {
39        return nullptr;
40    }
41#endif
42    void* addr = sk_calloc_canfail(size);
43    if (nullptr == addr) {
44        return nullptr;
45    }
46
47    struct PixelRef final : public SkPixelRef {
48        PixelRef(int w, int h, void* s, size_t r) : SkPixelRef(w, h, s, r) {}
49        ~PixelRef() override { sk_free(this->pixels()); }
50    };
51    return sk_sp<SkPixelRef>(new PixelRef(info.width(), info.height(), addr, rowBytes));
52}
53
54sk_sp<SkPixelRef> SkMallocPixelRef::MakeWithData(const SkImageInfo& info,
55                                                 size_t rowBytes,
56                                                 sk_sp<SkData> data) {
57    SkASSERT(data != nullptr);
58    if (!is_valid(info)) {
59        return nullptr;
60    }
61    // TODO: what should we return if computeByteSize returns 0?
62    // - the info was empty?
63    // - we overflowed computing the size?
64    if ((rowBytes < info.minRowBytes()) || (data->size() < info.computeByteSize(rowBytes))) {
65        return nullptr;
66    }
67    struct PixelRef final : public SkPixelRef {
68        sk_sp<SkData> fData;
69        PixelRef(int w, int h, void* s, size_t r, sk_sp<SkData> d)
70            : SkPixelRef(w, h, s, r), fData(std::move(d)) {}
71    };
72    void* pixels = const_cast<void*>(data->data());
73    sk_sp<SkPixelRef> pr(new PixelRef(info.width(), info.height(), pixels, rowBytes,
74                                      std::move(data)));
75    pr->setImmutable(); // since we were created with (immutable) data
76    return pr;
77}
78