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      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 #ifndef SkReadBuffer_DEFINED
      9 #define SkReadBuffer_DEFINED
     10 
     11 #include "SkBitmapHeap.h"
     12 #include "SkColorFilter.h"
     13 #include "SkData.h"
     14 #include "SkDrawLooper.h"
     15 #include "SkImageFilter.h"
     16 #include "SkMaskFilter.h"
     17 #include "SkPath.h"
     18 #include "SkPathEffect.h"
     19 #include "SkPicture.h"
     20 #include "SkPixelRef.h"
     21 #include "SkRasterizer.h"
     22 #include "SkReadBuffer.h"
     23 #include "SkReader32.h"
     24 #include "SkRefCnt.h"
     25 #include "SkShader.h"
     26 #include "SkWriteBuffer.h"
     27 #include "SkXfermode.h"
     28 
     29 class SkBitmap;
     30 
     31 #if defined(SK_DEBUG) && defined(SK_BUILD_FOR_MAC)
     32     #define DEBUG_NON_DETERMINISTIC_ASSERT
     33 #endif
     34 
     35 class SkReadBuffer {
     36 public:
     37     SkReadBuffer();
     38     SkReadBuffer(const void* data, size_t size);
     39     SkReadBuffer(SkStream* stream);
     40     virtual ~SkReadBuffer();
     41 
     42     enum Version {
     43         kFilterLevelIsEnum_Version         = 23,
     44         kGradientFlippedFlag_Version       = 24,
     45         kDashWritesPhaseIntervals_Version  = 25,
     46         kColorShaderNoBool_Version         = 26,
     47         kNoUnitMappers_Version             = 27,
     48         kNoMoreBitmapFlatten_Version       = 28,
     49     };
     50 
     51     /**
     52      *  Returns true IFF the version is older than the specified version.
     53      */
     54     bool isVersionLT(Version targetVersion) const {
     55         SkASSERT(targetVersion > 0);
     56         return fVersion > 0 && fVersion < targetVersion;
     57     }
     58 
     59     /** This may be called at most once; most clients of SkReadBuffer should not mess with it. */
     60     void setVersion(int version) {
     61         SkASSERT(0 == fVersion || version == fVersion);
     62         fVersion = version;
     63     }
     64 
     65     enum Flags {
     66         kCrossProcess_Flag  = 1 << 0,
     67         kScalarIsFloat_Flag = 1 << 1,
     68         kPtrIs64Bit_Flag    = 1 << 2,
     69         kValidation_Flag    = 1 << 3,
     70     };
     71 
     72     void setFlags(uint32_t flags) { fFlags = flags; }
     73     uint32_t getFlags() const { return fFlags; }
     74 
     75     bool isCrossProcess() const {
     76         return this->isValidating() || SkToBool(fFlags & kCrossProcess_Flag);
     77     }
     78     bool isScalarFloat() const { return SkToBool(fFlags & kScalarIsFloat_Flag); }
     79     bool isPtr64Bit() const { return SkToBool(fFlags & kPtrIs64Bit_Flag); }
     80     bool isValidating() const { return SkToBool(fFlags & kValidation_Flag); }
     81 
     82     SkReader32* getReader32() { return &fReader; }
     83 
     84     size_t size() { return fReader.size(); }
     85     size_t offset() { return fReader.offset(); }
     86     bool eof() { return fReader.eof(); }
     87     virtual const void* skip(size_t size) { return fReader.skip(size); }
     88     void* readFunctionPtr() { return fReader.readPtr(); }
     89 
     90     // primitives
     91     virtual bool readBool();
     92     virtual SkColor readColor();
     93     virtual SkFixed readFixed();
     94     virtual int32_t readInt();
     95     virtual SkScalar readScalar();
     96     virtual uint32_t readUInt();
     97     virtual int32_t read32();
     98 
     99     // strings -- the caller is responsible for freeing the string contents
    100     virtual void readString(SkString* string);
    101     virtual void* readEncodedString(size_t* length, SkPaint::TextEncoding encoding);
    102 
    103     // common data structures
    104     virtual void readPoint(SkPoint* point);
    105     SkPoint readPoint() { SkPoint p; this->readPoint(&p); return p; }
    106     virtual void readMatrix(SkMatrix* matrix);
    107     virtual void readIRect(SkIRect* rect);
    108     virtual void readRect(SkRect* rect);
    109     virtual void readRegion(SkRegion* region);
    110     virtual void readPath(SkPath* path);
    111     void readPaint(SkPaint* paint) { paint->unflatten(*this); }
    112 
    113     virtual SkFlattenable* readFlattenable(SkFlattenable::Type);
    114     template <typename T> T* readFlattenable() {
    115         return (T*) this->readFlattenable(T::GetFlattenableType());
    116     }
    117     SkColorFilter* readColorFilter() { return this->readFlattenable<SkColorFilter>(); }
    118     SkDrawLooper*  readDrawLooper()  { return this->readFlattenable<SkDrawLooper>(); }
    119     SkImageFilter* readImageFilter() { return this->readFlattenable<SkImageFilter>(); }
    120     SkMaskFilter*  readMaskFilter()  { return this->readFlattenable<SkMaskFilter>(); }
    121     SkPathEffect*  readPathEffect()  { return this->readFlattenable<SkPathEffect>(); }
    122     SkPixelRef*    readPixelRef()    { return this->readFlattenable<SkPixelRef>(); }
    123     SkRasterizer*  readRasterizer()  { return this->readFlattenable<SkRasterizer>(); }
    124     SkShader*      readShader()      { return this->readFlattenable<SkShader>(); }
    125     SkXfermode*    readXfermode()    { return this->readFlattenable<SkXfermode>(); }
    126 
    127     /**
    128      *  Like readFlattenable() but explicitly just skips the data that was written for the
    129      *  flattenable (or the sentinel that there wasn't one).
    130      */
    131     virtual void skipFlattenable();
    132 
    133     // binary data and arrays
    134     virtual bool readByteArray(void* value, size_t size);
    135     virtual bool readColorArray(SkColor* colors, size_t size);
    136     virtual bool readIntArray(int32_t* values, size_t size);
    137     virtual bool readPointArray(SkPoint* points, size_t size);
    138     virtual bool readScalarArray(SkScalar* values, size_t size);
    139 
    140     SkData* readByteArrayAsData() {
    141         size_t len = this->getArrayCount();
    142         if (!this->validateAvailable(len)) {
    143             return SkData::NewEmpty();
    144         }
    145         void* buffer = sk_malloc_throw(len);
    146         this->readByteArray(buffer, len);
    147         return SkData::NewFromMalloc(buffer, len);
    148     }
    149 
    150     // helpers to get info about arrays and binary data
    151     virtual uint32_t getArrayCount();
    152 
    153     /**
    154      *  Returns false if the bitmap could not be completely read. In that case, it will be set
    155      *  to have width/height, but no pixels.
    156      */
    157     bool readBitmap(SkBitmap* bitmap);
    158 
    159     virtual SkTypeface* readTypeface();
    160 
    161     void setBitmapStorage(SkBitmapHeapReader* bitmapStorage) {
    162         SkRefCnt_SafeAssign(fBitmapStorage, bitmapStorage);
    163     }
    164 
    165     void setTypefaceArray(SkTypeface* array[], int count) {
    166         fTFArray = array;
    167         fTFCount = count;
    168     }
    169 
    170     /**
    171      *  Call this with a pre-loaded array of Factories, in the same order as
    172      *  were created/written by the writer. SkPicture uses this.
    173      */
    174     void setFactoryPlayback(SkFlattenable::Factory array[], int count) {
    175         fFactoryTDArray = NULL;
    176         fFactoryArray = array;
    177         fFactoryCount = count;
    178     }
    179 
    180     /**
    181      *  Call this with an initially empty array, so the reader can cache each
    182      *  factory it sees by name. Used by the pipe code in conjunction with
    183      *  SkWriteBuffer::setNamedFactoryRecorder.
    184      */
    185     void setFactoryArray(SkTDArray<SkFlattenable::Factory>* array) {
    186         fFactoryTDArray = array;
    187         fFactoryArray = NULL;
    188         fFactoryCount = 0;
    189     }
    190 
    191     /**
    192      *  Provide a function to decode an SkBitmap from encoded data. Only used if the writer
    193      *  encoded the SkBitmap. If the proper decoder cannot be used, a red bitmap with the
    194      *  appropriate size will be used.
    195      */
    196     void setBitmapDecoder(SkPicture::InstallPixelRefProc bitmapDecoder) {
    197         fBitmapDecoder = bitmapDecoder;
    198     }
    199 
    200     // Default impelementations don't check anything.
    201     virtual bool validate(bool isValid) { return true; }
    202     virtual bool isValid() const { return true; }
    203     virtual bool validateAvailable(size_t size) { return true; }
    204 
    205 protected:
    206     SkReader32 fReader;
    207 
    208 private:
    209     bool readArray(void* value, size_t size, size_t elementSize);
    210 
    211     uint32_t fFlags;
    212     int fVersion;
    213 
    214     void* fMemoryPtr;
    215 
    216     SkBitmapHeapReader* fBitmapStorage;
    217     SkTypeface** fTFArray;
    218     int        fTFCount;
    219 
    220     SkTDArray<SkFlattenable::Factory>* fFactoryTDArray;
    221     SkFlattenable::Factory* fFactoryArray;
    222     int                     fFactoryCount;
    223 
    224     SkPicture::InstallPixelRefProc fBitmapDecoder;
    225 
    226 #ifdef DEBUG_NON_DETERMINISTIC_ASSERT
    227     // Debugging counter to keep track of how many bitmaps we
    228     // have decoded.
    229     int fDecodedBitmapIndex;
    230 #endif // DEBUG_NON_DETERMINISTIC_ASSERT
    231 };
    232 
    233 #endif // SkReadBuffer_DEFINED
    234