tests/SerializationTest.cpp

/*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "Resources.h"
#include "SkAnnotationKeys.h"
#include "SkCanvas.h"
#include "SkDashPathEffect.h"
#include "SkFixed.h"
#include "SkFontDescriptor.h"
#include "SkImage.h"
#include "SkImageSource.h"
#include "SkLightingShader.h"
#include "SkMakeUnique.h"
#include "SkMallocPixelRef.h"
#include "SkMatrixPriv.h"
#include "SkNormalSource.h"
#include "SkOSFile.h"
#include "SkReadBuffer.h"
#include "SkPicturePriv.h"
#include "SkPictureRecorder.h"
#include "SkShaderBase.h"
#include "SkTableColorFilter.h"
#include "SkTemplates.h"
#include "SkTextBlob.h"
#include "SkTypeface.h"
#include "SkWriteBuffer.h"
#include "SkXfermodeImageFilter.h"
#include "sk_tool_utils.h"
#include "Test.h"

static const uint32_t kArraySize = 64;
static const int kBitmapSize = 256;

class SerializationTest {
public:

template<typename T>
static void TestAlignment(T* testObj, skiatest::Reporter* reporter) {
    // Test memory read/write functions directly
    unsigned char dataWritten[1024];
    size_t bytesWrittenToMemory = testObj->writeToMemory(dataWritten);
    REPORTER_ASSERT(reporter, SkAlign4(bytesWrittenToMemory) == bytesWrittenToMemory);
    size_t bytesReadFromMemory = testObj->readFromMemory(dataWritten, bytesWrittenToMemory);
    REPORTER_ASSERT(reporter, SkAlign4(bytesReadFromMemory) == bytesReadFromMemory);
}
};

template<typename T> struct SerializationUtils {
    // Generic case for flattenables
    static void Write(SkWriteBuffer& writer, const T* flattenable) {
        writer.writeFlattenable(flattenable);
    }
    static void Read(SkReadBuffer& reader, T** flattenable) {
        *flattenable = (T*)reader.readFlattenable(T::GetFlattenableType());
    }
};

template<> struct SerializationUtils<SkMatrix> {
    static void Write(SkWriteBuffer& writer, const SkMatrix* matrix) {
        writer.writeMatrix(*matrix);
    }
    static void Read(SkReadBuffer& reader, SkMatrix* matrix) {
        reader.readMatrix(matrix);
    }
};

template<> struct SerializationUtils<SkPath> {
    static void Write(SkWriteBuffer& writer, const SkPath* path) {
        writer.writePath(*path);
    }
    static void Read(SkReadBuffer& reader, SkPath* path) {
        reader.readPath(path);
    }
};

template<> struct SerializationUtils<SkRegion> {
    static void Write(SkWriteBuffer& writer, const SkRegion* region) {
        writer.writeRegion(*region);
    }
    static void Read(SkReadBuffer& reader, SkRegion* region) {
        reader.readRegion(region);
    }
};

template<> struct SerializationUtils<SkString> {
    static void Write(SkWriteBuffer& writer, const SkString* string) {
        writer.writeString(string->c_str());
    }
    static void Read(SkReadBuffer& reader, SkString* string) {
        reader.readString(string);
    }
};

template<> struct SerializationUtils<unsigned char> {
    static void Write(SkWriteBuffer& writer, unsigned char* data, uint32_t arraySize) {
        writer.writeByteArray(data, arraySize);
    }
    static bool Read(SkReadBuffer& reader, unsigned char* data, uint32_t arraySize) {
        return reader.readByteArray(data, arraySize);
    }
};

template<> struct SerializationUtils<SkColor> {
    static void Write(SkWriteBuffer& writer, SkColor* data, uint32_t arraySize) {
        writer.writeColorArray(data, arraySize);
    }
    static bool Read(SkReadBuffer& reader, SkColor* data, uint32_t arraySize) {
        return reader.readColorArray(data, arraySize);
    }
};

template<> struct SerializationUtils<SkColor4f> {
    static void Write(SkWriteBuffer& writer, SkColor4f* data, uint32_t arraySize) {
        writer.writeColor4fArray(data, arraySize);
    }
    static bool Read(SkReadBuffer& reader, SkColor4f* data, uint32_t arraySize) {
        return reader.readColor4fArray(data, arraySize);
    }
};

template<> struct SerializationUtils<int32_t> {
    static void Write(SkWriteBuffer& writer, int32_t* data, uint32_t arraySize) {
        writer.writeIntArray(data, arraySize);
    }
    static bool Read(SkReadBuffer& reader, int32_t* data, uint32_t arraySize) {
        return reader.readIntArray(data, arraySize);
    }
};

template<> struct SerializationUtils<SkPoint> {
    static void Write(SkWriteBuffer& writer, SkPoint* data, uint32_t arraySize) {
        writer.writePointArray(data, arraySize);
    }
    static bool Read(SkReadBuffer& reader, SkPoint* data, uint32_t arraySize) {
        return reader.readPointArray(data, arraySize);
    }
};

template<> struct SerializationUtils<SkScalar> {
    static void Write(SkWriteBuffer& writer, SkScalar* data, uint32_t arraySize) {
        writer.writeScalarArray(data, arraySize);
    }
    static bool Read(SkReadBuffer& reader, SkScalar* data, uint32_t arraySize) {
        return reader.readScalarArray(data, arraySize);
    }
};

template<typename T, bool testInvalid> struct SerializationTestUtils {
    static void InvalidateData(unsigned char* data) {}
};

template<> struct SerializationTestUtils<SkString, true> {
    static void InvalidateData(unsigned char* data) {
        data[3] |= 0x80; // Reverse sign of 1st integer
    }
};

template<typename T, bool testInvalid>
static void TestObjectSerializationNoAlign(T* testObj, skiatest::Reporter* reporter) {
    SkBinaryWriteBuffer writer;
    SerializationUtils<T>::Write(writer, testObj);
    size_t bytesWritten = writer.bytesWritten();
    REPORTER_ASSERT(reporter, SkAlign4(bytesWritten) == bytesWritten);

    unsigned char dataWritten[1024];
    writer.writeToMemory(dataWritten);

    SerializationTestUtils<T, testInvalid>::InvalidateData(dataWritten);

    // Make sure this fails when it should (test with smaller size, but still multiple of 4)
    SkReadBuffer buffer(dataWritten, bytesWritten - 4);
    T obj;
    SerializationUtils<T>::Read(buffer, &obj);
    REPORTER_ASSERT(reporter, !buffer.isValid());

    // Make sure this succeeds when it should
    SkReadBuffer buffer2(dataWritten, bytesWritten);
    size_t offsetBefore = buffer2.offset();
    T obj2;
    SerializationUtils<T>::Read(buffer2, &obj2);
    size_t offsetAfter = buffer2.offset();
    // This should have succeeded, since there are enough bytes to read this
    REPORTER_ASSERT(reporter, buffer2.isValid() == !testInvalid);
    // Note: This following test should always succeed, regardless of whether the buffer is valid,
    // since if it is invalid, it will simply skip to the end, as if it had read the whole buffer.
    REPORTER_ASSERT(reporter, offsetAfter - offsetBefore == bytesWritten);
}

template<typename T>
static void TestObjectSerialization(T* testObj, skiatest::Reporter* reporter) {
    TestObjectSerializationNoAlign<T, false>(testObj, reporter);
    SerializationTest::TestAlignment(testObj, reporter);
}

template<typename T>
static T* TestFlattenableSerialization(T* testObj, bool shouldSucceed,
                                       skiatest::Reporter* reporter) {
    SkBinaryWriteBuffer writer;
    SerializationUtils<T>::Write(writer, testObj);
    size_t bytesWritten = writer.bytesWritten();
    REPORTER_ASSERT(reporter, SkAlign4(bytesWritten) == bytesWritten);

    SkASSERT(bytesWritten <= 4096);
    unsigned char dataWritten[4096];
    writer.writeToMemory(dataWritten);

    // Make sure this fails when it should (test with smaller size, but still multiple of 4)
    SkReadBuffer buffer(dataWritten, bytesWritten - 4);
    T* obj = nullptr;
    SerializationUtils<T>::Read(buffer, &obj);
    REPORTER_ASSERT(reporter, !buffer.isValid());
    REPORTER_ASSERT(reporter, nullptr == obj);

    // Make sure this succeeds when it should
    SkReadBuffer buffer2(dataWritten, bytesWritten);
    const unsigned char* peekBefore = static_cast<const unsigned char*>(buffer2.skip(0));
    T* obj2 = nullptr;
    SerializationUtils<T>::Read(buffer2, &obj2);
    const unsigned char* peekAfter = static_cast<const unsigned char*>(buffer2.skip(0));
    if (shouldSucceed) {
        // This should have succeeded, since there are enough bytes to read this
        REPORTER_ASSERT(reporter, buffer2.isValid());
        REPORTER_ASSERT(reporter, static_cast<size_t>(peekAfter - peekBefore) == bytesWritten);
        REPORTER_ASSERT(reporter, obj2);
    } else {
        // If the deserialization was supposed to fail, make sure it did
        REPORTER_ASSERT(reporter, !buffer.isValid());
        REPORTER_ASSERT(reporter, nullptr == obj2);
    }

    return obj2; // Return object to perform further validity tests on it
}

template<typename T>
static void TestArraySerialization(T* data, skiatest::Reporter* reporter) {
    SkBinaryWriteBuffer writer;
    SerializationUtils<T>::Write(writer, data, kArraySize);
    size_t bytesWritten = writer.bytesWritten();
    // This should write the length (in 4 bytes) and the array
    REPORTER_ASSERT(reporter, (4 + kArraySize * sizeof(T)) == bytesWritten);

    unsigned char dataWritten[2048];
    writer.writeToMemory(dataWritten);

    // Make sure this fails when it should
    SkReadBuffer buffer(dataWritten, bytesWritten);
    T dataRead[kArraySize];
    bool success = SerializationUtils<T>::Read(buffer, dataRead, kArraySize / 2);
    // This should have failed, since the provided size was too small
    REPORTER_ASSERT(reporter, !success);

    // Make sure this succeeds when it should
    SkReadBuffer buffer2(dataWritten, bytesWritten);
    success = SerializationUtils<T>::Read(buffer2, dataRead, kArraySize);
    // This should have succeeded, since there are enough bytes to read this
    REPORTER_ASSERT(reporter, success);
}

static void TestBitmapSerialization(const SkBitmap& validBitmap,
                                    const SkBitmap& invalidBitmap,
                                    bool shouldSucceed,
                                    skiatest::Reporter* reporter) {
    sk_sp<SkImage> validImage(SkImage::MakeFromBitmap(validBitmap));
    sk_sp<SkImageFilter> validBitmapSource(SkImageSource::Make(std::move(validImage)));
    sk_sp<SkImage> invalidImage(SkImage::MakeFromBitmap(invalidBitmap));
    sk_sp<SkImageFilter> invalidBitmapSource(SkImageSource::Make(std::move(invalidImage)));
    sk_sp<SkImageFilter> xfermodeImageFilter(
        SkXfermodeImageFilter::Make(SkBlendMode::kSrcOver,
                                    std::move(invalidBitmapSource),
                                    std::move(validBitmapSource), nullptr));

    sk_sp<SkImageFilter> deserializedFilter(
        TestFlattenableSerialization<SkImageFilter>(
            xfermodeImageFilter.get(), shouldSucceed, reporter));

    // Try to render a small bitmap using the invalid deserialized filter
    // to make sure we don't crash while trying to render it
    if (shouldSucceed) {
        SkBitmap bitmap;
        bitmap.allocN32Pixels(24, 24);
        SkCanvas canvas(bitmap);
        canvas.clear(0x00000000);
        SkPaint paint;
        paint.setImageFilter(deserializedFilter);
        canvas.clipRect(SkRect::MakeXYWH(0, 0, SkIntToScalar(24), SkIntToScalar(24)));
        canvas.drawBitmap(bitmap, 0, 0, &paint);
    }
}

static void TestColorFilterSerialization(skiatest::Reporter* reporter) {
    uint8_t table[256];
    for (int i = 0; i < 256; ++i) {
        table[i] = (i * 41) % 256;
    }
    auto colorFilter(SkTableColorFilter::Make(table));
    sk_sp<SkColorFilter> copy(
        TestFlattenableSerialization<SkColorFilter>(colorFilter.get(), true, reporter));
}

static SkBitmap draw_picture(SkPicture& picture) {
     SkBitmap bitmap;
     bitmap.allocN32Pixels(SkScalarCeilToInt(picture.cullRect().width()),
                           SkScalarCeilToInt(picture.cullRect().height()));
     SkCanvas canvas(bitmap);
     picture.playback(&canvas);
     return bitmap;
}

static void compare_bitmaps(skiatest::Reporter* reporter,
                            const SkBitmap& b1, const SkBitmap& b2) {
    REPORTER_ASSERT(reporter, b1.width() == b2.width());
    REPORTER_ASSERT(reporter, b1.height() == b2.height());

    if ((b1.width() != b2.width()) ||
        (b1.height() != b2.height())) {
        return;
    }

    int pixelErrors = 0;
    for (int y = 0; y < b2.height(); ++y) {
        for (int x = 0; x < b2.width(); ++x) {
            if (b1.getColor(x, y) != b2.getColor(x, y))
                ++pixelErrors;
        }
    }
    REPORTER_ASSERT(reporter, 0 == pixelErrors);
}
static void serialize_and_compare_typeface(sk_sp<SkTypeface> typeface, const char* text,
                                           skiatest::Reporter* reporter)
{
    // Create a paint with the typeface.
    SkPaint paint;
    paint.setColor(SK_ColorGRAY);
    paint.setTextSize(SkIntToScalar(30));
    paint.setTypeface(std::move(typeface));

    // Paint some text.
    SkPictureRecorder recorder;
    SkIRect canvasRect = SkIRect::MakeWH(kBitmapSize, kBitmapSize);
    SkCanvas* canvas = recorder.beginRecording(SkIntToScalar(canvasRect.width()),
                                               SkIntToScalar(canvasRect.height()),
                                               nullptr, 0);
    canvas->drawColor(SK_ColorWHITE);
    canvas->drawText(text, 2, 24, 32, paint);
    sk_sp<SkPicture> picture(recorder.finishRecordingAsPicture());

    // Serlialize picture and create its clone from stream.
    SkDynamicMemoryWStream stream;
    picture->serialize(&stream);
    std::unique_ptr<SkStream> inputStream(stream.detachAsStream());
    sk_sp<SkPicture> loadedPicture(SkPicture::MakeFromStream(inputStream.get()));

    // Draw both original and clone picture and compare bitmaps -- they should be identical.
    SkBitmap origBitmap = draw_picture(*picture);
    SkBitmap destBitmap = draw_picture(*loadedPicture);
    compare_bitmaps(reporter, origBitmap, destBitmap);
}

static void TestPictureTypefaceSerialization(skiatest::Reporter* reporter) {
    {
        // Load typeface from file to test CreateFromFile with index.
        auto typeface = MakeResourceAsTypeface("fonts/test.ttc", 1);
        if (!typeface) {
            INFOF(reporter, "Could not run fontstream test because test.ttc not found.");
        } else {
            serialize_and_compare_typeface(std::move(typeface), "A!", reporter);
        }
    }

    {
        // Load typeface as stream to create with axis settings.
        std::unique_ptr<SkStreamAsset> distortable(GetResourceAsStream("fonts/Distortable.ttf"));
        if (!distortable) {
            INFOF(reporter, "Could not run fontstream test because Distortable.ttf not found.");
        } else {
            SkFixed axis = SK_FixedSqrt2;
            sk_sp<SkTypeface> typeface(SkTypeface::MakeFromFontData(
                skstd::make_unique<SkFontData>(std::move(distortable), 0, &axis, 1)));
            if (!typeface) {
                INFOF(reporter, "Could not run fontstream test because Distortable.ttf not created.");
            } else {
                serialize_and_compare_typeface(std::move(typeface), "abc", reporter);
            }
        }
    }
}

static void setup_bitmap_for_canvas(SkBitmap* bitmap) {
    bitmap->allocN32Pixels(kBitmapSize, kBitmapSize);
}

static void make_checkerboard_bitmap(SkBitmap& bitmap) {
    setup_bitmap_for_canvas(&bitmap);

    SkCanvas canvas(bitmap);
    canvas.clear(0x00000000);
    SkPaint darkPaint;
    darkPaint.setColor(0xFF804020);
    SkPaint lightPaint;
    lightPaint.setColor(0xFF244484);
    const int i = kBitmapSize / 8;
    const SkScalar f = SkIntToScalar(i);
    for (int y = 0; y < kBitmapSize; y += i) {
        for (int x = 0; x < kBitmapSize; x += i) {
            canvas.save();
            canvas.translate(SkIntToScalar(x), SkIntToScalar(y));
            canvas.drawRect(SkRect::MakeXYWH(0, 0, f, f), darkPaint);
            canvas.drawRect(SkRect::MakeXYWH(f, 0, f, f), lightPaint);
            canvas.drawRect(SkRect::MakeXYWH(0, f, f, f), lightPaint);
            canvas.drawRect(SkRect::MakeXYWH(f, f, f, f), darkPaint);
            canvas.restore();
        }
    }
}

static void draw_something(SkCanvas* canvas) {
    SkPaint paint;
    SkBitmap bitmap;
    make_checkerboard_bitmap(bitmap);

    canvas->save();
    canvas->scale(0.5f, 0.5f);
    canvas->drawBitmap(bitmap, 0, 0, nullptr);
    canvas->restore();

    paint.setAntiAlias(true);

    paint.setColor(SK_ColorRED);
    canvas->drawCircle(SkIntToScalar(kBitmapSize/2), SkIntToScalar(kBitmapSize/2), SkIntToScalar(kBitmapSize/3), paint);
    paint.setColor(SK_ColorBLACK);
    paint.setTextSize(SkIntToScalar(kBitmapSize/3));
    canvas->drawString("Picture", SkIntToScalar(kBitmapSize/2), SkIntToScalar(kBitmapSize/4), paint);
}

DEF_TEST(Serialization, reporter) {
    // Test matrix serialization
    {
        SkMatrix matrix = SkMatrix::I();
        TestObjectSerialization(&matrix, reporter);
    }

    // Test path serialization
    {
        SkPath path;
        TestObjectSerialization(&path, reporter);
    }

    // Test region serialization
    {
        SkRegion region;
        TestObjectSerialization(&region, reporter);
    }

    // Test color filter serialization
    {
        TestColorFilterSerialization(reporter);
    }

    // Test string serialization
    {
        SkString string("string");
        TestObjectSerializationNoAlign<SkString, false>(&string, reporter);
        TestObjectSerializationNoAlign<SkString, true>(&string, reporter);
    }

    // Test rrect serialization
    {
        // SkRRect does not initialize anything.
        // An uninitialized SkRRect can be serialized,
        // but will branch on uninitialized data when deserialized.
        SkRRect rrect;
        SkRect rect = SkRect::MakeXYWH(1, 2, 20, 30);
        SkVector corners[4] = { {1, 2}, {2, 3}, {3,4}, {4,5} };
        rrect.setRectRadii(rect, corners);
        SerializationTest::TestAlignment(&rrect, reporter);
    }

    // Test readByteArray
    {
        unsigned char data[kArraySize] = { 1, 2, 3 };
        TestArraySerialization(data, reporter);
    }

    // Test readColorArray
    {
        SkColor data[kArraySize] = { SK_ColorBLACK, SK_ColorWHITE, SK_ColorRED };
        TestArraySerialization(data, reporter);
    }

    // Test readColor4fArray
    {
        SkColor4f data[kArraySize] = {
            SkColor4f::FromColor(SK_ColorBLACK),
            SkColor4f::FromColor(SK_ColorWHITE),
            SkColor4f::FromColor(SK_ColorRED),
            { 1.f, 2.f, 4.f, 8.f }
        };
        TestArraySerialization(data, reporter);
    }

    // Test readIntArray
    {
        int32_t data[kArraySize] = { 1, 2, 4, 8 };
        TestArraySerialization(data, reporter);
    }

    // Test readPointArray
    {
        SkPoint data[kArraySize] = { {6, 7}, {42, 128} };
        TestArraySerialization(data, reporter);
    }

    // Test readScalarArray
    {
        SkScalar data[kArraySize] = { SK_Scalar1, SK_ScalarHalf, SK_ScalarMax };
        TestArraySerialization(data, reporter);
    }

    // Test invalid deserializations
    {
        SkImageInfo info = SkImageInfo::MakeN32Premul(kBitmapSize, kBitmapSize);

        SkBitmap validBitmap;
        validBitmap.setInfo(info);

        // Create a bitmap with a really large height
        SkBitmap invalidBitmap;
        invalidBitmap.setInfo(info.makeWH(info.width(), 1000000000));

        // The deserialization should succeed, and the rendering shouldn't crash,
        // even when the device fails to initialize, due to its size
        TestBitmapSerialization(validBitmap, invalidBitmap, true, reporter);
    }

    // Test simple SkPicture serialization
    {
        SkPictureRecorder recorder;
        draw_something(recorder.beginRecording(SkIntToScalar(kBitmapSize),
                                               SkIntToScalar(kBitmapSize),
                                               nullptr, 0));
        sk_sp<SkPicture> pict(recorder.finishRecordingAsPicture());

        // Serialize picture
        SkBinaryWriteBuffer writer;
        SkPicturePriv::Flatten(pict, writer);
        size_t size = writer.bytesWritten();
        SkAutoTMalloc<unsigned char> data(size);
        writer.writeToMemory(static_cast<void*>(data.get()));

        // Deserialize picture
        SkReadBuffer reader(static_cast<void*>(data.get()), size);
        sk_sp<SkPicture> readPict(SkPicturePriv::MakeFromBuffer(reader));
        REPORTER_ASSERT(reporter, reader.isValid());
        REPORTER_ASSERT(reporter, readPict.get());
    }

    TestPictureTypefaceSerialization(reporter);

    // Test SkLightingShader/NormalMapSource serialization
    {
        const int kTexSize = 2;

        SkLights::Builder builder;

        builder.add(SkLights::Light::MakeDirectional(SkColor3f::Make(1.0f, 1.0f, 1.0f),
                                                     SkVector3::Make(1.0f, 0.0f, 0.0f)));
        builder.setAmbientLightColor(SkColor3f::Make(0.2f, 0.2f, 0.2f));

        sk_sp<SkLights> fLights = builder.finish();

        SkBitmap diffuse = sk_tool_utils::create_checkerboard_bitmap(
                kTexSize, kTexSize,
                0x00000000,
                sk_tool_utils::color_to_565(0xFF804020),
                8);

        SkRect bitmapBounds = SkRect::MakeIWH(diffuse.width(), diffuse.height());

        SkMatrix matrix;
        SkRect r = SkRect::MakeWH(SkIntToScalar(kTexSize), SkIntToScalar(kTexSize));
        matrix.setRectToRect(bitmapBounds, r, SkMatrix::kFill_ScaleToFit);

        SkMatrix ctm;
        ctm.setRotate(45);
        SkBitmap normals;
        normals.allocN32Pixels(kTexSize, kTexSize);

        sk_tool_utils::create_frustum_normal_map(&normals, SkIRect::MakeWH(kTexSize, kTexSize));
        sk_sp<SkShader> normalMap = SkShader::MakeBitmapShader(normals, SkShader::kClamp_TileMode,
                SkShader::kClamp_TileMode, &matrix);
        sk_sp<SkNormalSource> normalSource = SkNormalSource::MakeFromNormalMap(std::move(normalMap),
                                                                               ctm);
        sk_sp<SkShader> diffuseShader = SkShader::MakeBitmapShader(diffuse,
                SkShader::kClamp_TileMode, SkShader::kClamp_TileMode, &matrix);

        sk_sp<SkShader> lightingShader = SkLightingShader::Make(diffuseShader,
                                                                normalSource,
                                                                fLights);
        sk_sp<SkShader>(TestFlattenableSerialization(as_SB(lightingShader.get()), true, reporter));

        lightingShader = SkLightingShader::Make(std::move(diffuseShader),
                                                nullptr,
                                                fLights);
        sk_sp<SkShader>(TestFlattenableSerialization(as_SB(lightingShader.get()), true, reporter));

        lightingShader = SkLightingShader::Make(nullptr,
                                                std::move(normalSource),
                                                fLights);
        sk_sp<SkShader>(TestFlattenableSerialization(as_SB(lightingShader.get()), true, reporter));

        lightingShader = SkLightingShader::Make(nullptr,
                                                nullptr,
                                                fLights);
        sk_sp<SkShader>(TestFlattenableSerialization(as_SB(lightingShader.get()), true, reporter));
    }
}

///////////////////////////////////////////////////////////////////////////////////////////////////
#include "SkAnnotation.h"

static sk_sp<SkPicture> copy_picture_via_serialization(SkPicture* src) {
    SkDynamicMemoryWStream wstream;
    src->serialize(&wstream);
    std::unique_ptr<SkStreamAsset> rstream(wstream.detachAsStream());
    return SkPicture::MakeFromStream(rstream.get());
}

struct AnnotationRec {
    const SkRect    fRect;
    const char*     fKey;
    sk_sp<SkData>   fValue;
};

class TestAnnotationCanvas : public SkCanvas {
    skiatest::Reporter*     fReporter;
    const AnnotationRec*    fRec;
    int                     fCount;
    int                     fCurrIndex;

public:
    TestAnnotationCanvas(skiatest::Reporter* reporter, const AnnotationRec rec[], int count)
        : SkCanvas(100, 100)
        , fReporter(reporter)
        , fRec(rec)
        , fCount(count)
        , fCurrIndex(0)
    {}

    ~TestAnnotationCanvas() {
        REPORTER_ASSERT(fReporter, fCount == fCurrIndex);
    }

protected:
    void onDrawAnnotation(const SkRect& rect, const char key[], SkData* value) {
        REPORTER_ASSERT(fReporter, fCurrIndex < fCount);
        REPORTER_ASSERT(fReporter, rect == fRec[fCurrIndex].fRect);
        REPORTER_ASSERT(fReporter, !strcmp(key, fRec[fCurrIndex].fKey));
        REPORTER_ASSERT(fReporter, value->equals(fRec[fCurrIndex].fValue.get()));
        fCurrIndex += 1;
    }
};

/*
 *  Test the 3 annotation types by recording them into a picture, serializing, and then playing
 *  them back into another canvas.
 */
DEF_TEST(Annotations, reporter) {
    SkPictureRecorder recorder;
    SkCanvas* recordingCanvas = recorder.beginRecording(SkRect::MakeWH(100, 100));

    const char* str0 = "rect-with-url";
    const SkRect r0 = SkRect::MakeWH(10, 10);
    sk_sp<SkData> d0(SkData::MakeWithCString(str0));
    SkAnnotateRectWithURL(recordingCanvas, r0, d0.get());

    const char* str1 = "named-destination";
    const SkRect r1 = SkRect::MakeXYWH(5, 5, 0, 0); // collapsed to a point
    sk_sp<SkData> d1(SkData::MakeWithCString(str1));
    SkAnnotateNamedDestination(recordingCanvas, {r1.x(), r1.y()}, d1.get());

    const char* str2 = "link-to-destination";
    const SkRect r2 = SkRect::MakeXYWH(20, 20, 5, 6);
    sk_sp<SkData> d2(SkData::MakeWithCString(str2));
    SkAnnotateLinkToDestination(recordingCanvas, r2, d2.get());

    const AnnotationRec recs[] = {
        { r0, SkAnnotationKeys::URL_Key(),                  std::move(d0) },
        { r1, SkAnnotationKeys::Define_Named_Dest_Key(),    std::move(d1) },
        { r2, SkAnnotationKeys::Link_Named_Dest_Key(),      std::move(d2) },
    };

    sk_sp<SkPicture> pict0(recorder.finishRecordingAsPicture());
    sk_sp<SkPicture> pict1(copy_picture_via_serialization(pict0.get()));

    TestAnnotationCanvas canvas(reporter, recs, SK_ARRAY_COUNT(recs));
    canvas.drawPicture(pict1);
}

DEF_TEST(WriteBuffer_storage, reporter) {
    enum {
        kSize = 32
    };
    int32_t storage[kSize/4];
    char src[kSize];
    sk_bzero(src, kSize);

    SkBinaryWriteBuffer writer(storage, kSize);
    REPORTER_ASSERT(reporter, writer.usingInitialStorage());
    REPORTER_ASSERT(reporter, writer.bytesWritten() == 0);
    writer.write(src, kSize - 4);
    REPORTER_ASSERT(reporter, writer.usingInitialStorage());
    REPORTER_ASSERT(reporter, writer.bytesWritten() == kSize - 4);
    writer.writeInt(0);
    REPORTER_ASSERT(reporter, writer.usingInitialStorage());
    REPORTER_ASSERT(reporter, writer.bytesWritten() == kSize);

    writer.reset(storage, kSize-4);
    REPORTER_ASSERT(reporter, writer.usingInitialStorage());
    REPORTER_ASSERT(reporter, writer.bytesWritten() == 0);
    writer.write(src, kSize - 4);
    REPORTER_ASSERT(reporter, writer.usingInitialStorage());
    REPORTER_ASSERT(reporter, writer.bytesWritten() == kSize - 4);
    writer.writeInt(0);
    REPORTER_ASSERT(reporter, !writer.usingInitialStorage());   // this is the change
    REPORTER_ASSERT(reporter, writer.bytesWritten() == kSize);
}

DEF_TEST(WriteBuffer_external_memory_textblob, reporter) {
    SkPaint font;
    font.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
    font.setTypeface(SkTypeface::MakeDefault());

    SkTextBlobBuilder builder;
    int glyph_count = 5;
    const auto& run = builder.allocRun(font, glyph_count, 1.2f, 2.3f);
    // allocRun() allocates only the glyph buffer.
    std::fill(run.glyphs, run.glyphs + glyph_count, 0);
    auto blob = builder.make();
    SkSerialProcs procs;
    SkAutoTMalloc<uint8_t> storage;
    size_t blob_size = 0u;
    size_t storage_size = 0u;

    blob_size = SkAlign4(blob->serialize(procs)->size());
    REPORTER_ASSERT(reporter, blob_size > 4u);
    storage_size = blob_size - 4;
    storage.realloc(storage_size);
    REPORTER_ASSERT(reporter, blob->serialize(procs, storage.get(), storage_size) == 0u);
    storage_size = blob_size;
    storage.realloc(storage_size);
    REPORTER_ASSERT(reporter, blob->serialize(procs, storage.get(), storage_size) != 0u);
}

DEF_TEST(WriteBuffer_external_memory_flattenable, reporter) {
    SkScalar intervals[] = {1.f, 1.f};
    auto path_effect = SkDashPathEffect::Make(intervals, 2, 0);
    size_t path_size = SkAlign4(path_effect->serialize()->size());
    REPORTER_ASSERT(reporter, path_size > 4u);
    SkAutoTMalloc<uint8_t> storage;

    size_t storage_size = path_size - 4;
    storage.realloc(storage_size);
    REPORTER_ASSERT(reporter, path_effect->serialize(storage.get(), storage_size) == 0u);

    storage_size = path_size;
    storage.realloc(storage_size);
    REPORTER_ASSERT(reporter, path_effect->serialize(storage.get(), storage_size) != 0u);
}