SkTiffUtility.cpp File Reference

#include "src/codec/SkTiffUtility.h"
#include "include/core/SkData.h"
#include "src/codec/SkCodecPriv.h"
#include <cstddef>
#include <utility>

Go to the source code of this file.

Functions
static const uint8_t *	get_entry_address (const SkData *data, uint32_t ifdOffset, uint16_t entryIndex)
static bool	validate_ifd (const SkData *data, bool littleEndian, uint32_t ifdOffset, uint16_t *outNumEntries, uint32_t *outNextIfdOffset)

Variables
constexpr size_t	kSizeEntry = 12
constexpr size_t	kSizeShort = 2
constexpr size_t	kSizeLong = 4

Function Documentation

get_entry_address()

static const uint8_t * get_entry_address ( const SkData *  data, uint32_t  ifdOffset, uint16_t  entryIndex  )

static

Definition at line 53 of file SkTiffUtility.cpp.

                                                             {
    return data->bytes() +           // Base address
           ifdOffset +               // IFD offset
           kSizeShort +              // IFD number of entries
           kSizeEntry * entryIndex;  // Entries
}

validate_ifd()

static bool validate_ifd ( const SkData *  data, bool  littleEndian, uint32_t  ifdOffset, uint16_t *  outNumEntries, uint32_t *  outNextIfdOffset  )

static

Definition at line 64 of file SkTiffUtility.cpp.

                                                     {
    const uint8_t* dataCurrent = data->bytes();
    size_t dataSize = data->size();
 
    // Seek to the IFD offset.
    if (dataSize < ifdOffset) {
        SkCodecPrintf("IFD offset is too large.\n");
        return false;
    }
    dataCurrent += ifdOffset;
    dataSize -= ifdOffset;
 
    // Read the number of entries.
    if (dataSize < kSizeShort) {
        SkCodecPrintf("Insufficient space to store number of entries.\n");
        return false;
    }
    uint16_t numEntries = get_endian_short(dataCurrent, littleEndian);
    dataCurrent += kSizeShort;
    dataSize -= kSizeShort;
 
    // Check that there is enough space for all entries.
    if (dataSize < kSizeEntry * numEntries) {
        SkCodecPrintf("Insufficient space (%u) to store all %u entries.\n",
                      static_cast<uint32_t>(data->size()),
                      numEntries);
        return false;
    }
 
    // Save the number of entries.
    *outNumEntries = numEntries;
 
    // Seek past the entries.
    dataCurrent += kSizeEntry * numEntries;
    dataSize -= kSizeEntry * numEntries;
 
    // Read the next IFD offset.
    if (dataSize < kSizeLong) {
        SkCodecPrintf("Insufficient space to store next IFD offset.\n");
        return false;
    }
 
    // Save the next IFD offset.
    *outNextIfdOffset = get_endian_int(dataCurrent, littleEndian);
    return true;
}

Variable Documentation

kSizeEntry

constexpr size_t kSizeEntry = 12

constexpr

Definition at line 16 of file SkTiffUtility.cpp.

kSizeLong

constexpr size_t kSizeLong = 4

constexpr

Definition at line 18 of file SkTiffUtility.cpp.

kSizeShort

constexpr size_t kSizeShort = 2

constexpr

Definition at line 17 of file SkTiffUtility.cpp.