rt_serialize.c

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/*
 *
 * WKTRaster - Raster Types for PostGIS
 * http://trac.osgeo.org/postgis/wiki/WKTRaster
 *
 * Copyright (C) 2011-2013 Regents of the University of California
 *   <bkpark@ucdavis.edu>
 * Copyright (C) 2010-2011 Jorge Arevalo <jorge.arevalo@deimos-space.com>
 * Copyright (C) 2010-2011 David Zwarg <dzwarg@azavea.com>
 * Copyright (C) 2009-2011 Pierre Racine <pierre.racine@sbf.ulaval.ca>
 * Copyright (C) 2009-2011 Mateusz Loskot <mateusz@loskot.net>
 * Copyright (C) 2008-2009 Sandro Santilli <strk@kbt.io>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
 
#include "librtcore.h"
#include "librtcore_internal.h"
#include "rt_serialize.h"
 
/******************************************************************************
* Debug and Testing Utilities
******************************************************************************/
 
#if POSTGIS_DEBUG_LEVEL > 2
 
char*
d_binary_to_hex(const uint8_t * const raw, uint32_t size, uint32_t *hexsize) {
    char* hex = NULL;
    uint32_t i = 0;
 
 
    assert(NULL != raw);
    assert(NULL != hexsize);
 
 
    *hexsize = size * 2; /* hex is 2 times bytes */
    hex = (char*) rtalloc((*hexsize) + 1);
    if (!hex) {
        rterror("d_binary_to_hex: Out of memory hexifying raw binary");
        return NULL;
    }
    hex[*hexsize] = '\0'; /* Null-terminate */
 
    for (i = 0; i < size; ++i) {
        deparse_hex(raw[i], &(hex[2 * i]));
    }
 
    assert(NULL != hex);
    assert(0 == strlen(hex) % 2);
    return hex;
}
 
void
d_print_binary_hex(const char* msg, const uint8_t * const raw, uint32_t size) {
    char* hex = NULL;
    uint32_t hexsize = 0;
 
 
    assert(NULL != msg);
    assert(NULL != raw);
 
 
    hex = d_binary_to_hex(raw, size, &hexsize);
    if (NULL != hex) {
        rtinfo("%s\t%s", msg, hex);
        rtdealloc(hex);
    }
}
 
size_t
d_binptr_to_pos(const uint8_t * const ptr, const uint8_t * const end, size_t size) {
    assert(NULL != ptr && NULL != end);
 
    return (size - (end - ptr));
}
 
#endif /* if POSTGIS_DEBUG_LEVEL > 2 */
 
 
#ifdef OPTIMIZE_SPACE
 
/*
 * Set given number of bits of the given byte,
 * starting from given bitOffset (from the first)
 * to the given value.
 *
 * Examples:
 *   char ch;
 *   ch=0; setBits(&ch, 1, 1, 0) -> ch==8
 *   ch=0; setBits(&ch, 3, 2, 1) -> ch==96 (0x60)
 *
 * Note that number of bits set must be <= 8-bitOffset
 *
 */
void
setBits(char* ch, double val, int bits, int bitOffset) {
    char mask = 0xFF >> (8 - bits);
    char ival = val;
 
 
                assert(ch != NULL);
    assert(8 - bitOffset >= bits);
 
    RASTER_DEBUGF(4, "ival:%d bits:%d mask:%hhx bitoffset:%d\n",
            ival, bits, mask, bitOffset);
 
    /* clear all but significant bits from ival */
    ival &= mask;
#if POSTGIS_RASTER_WARN_ON_TRUNCATION > 0
    if (ival != val) {
        rtwarn("Pixel value for %d-bits band got truncated"
                " from %g to %hhu", bits, val, ival);
    }
#endif /* POSTGIS_RASTER_WARN_ON_TRUNCATION */
 
    RASTER_DEBUGF(4, " cleared ival:%hhx\n", ival);
 
 
    /* Shift ival so the significant bits start at
     * the first bit */
    ival <<= (8 - bitOffset - bits);
 
    RASTER_DEBUGF(4, " ival shifted:%hhx\n", ival);
    RASTER_DEBUGF(4, "  ch:%hhx\n", *ch);
 
    /* clear first bits of target */
    *ch &= ~(mask << (8 - bits - bitOffset));
 
    RASTER_DEBUGF(4, "  ch cleared:%hhx\n", *ch);
 
    /* Set the first bit of target */
    *ch |= ival;
 
    RASTER_DEBUGF(4, "  ch ored:%hhx\n", *ch);
 
}
#endif /* OPTIMIZE_SPACE */
 
void
swap_char(uint8_t *a, uint8_t *b) {
    uint8_t c = 0;
 
    assert(NULL != a && NULL != b);
 
    c = *a;
    *a = *b;
    *b = c;
}
 
void
flip_endian_16(uint8_t *d) {
    assert(NULL != d);
 
    swap_char(d, d + 1);
}
 
void
flip_endian_32(uint8_t *d) {
    assert(NULL != d);
 
    swap_char(d, d + 3);
    swap_char(d + 1, d + 2);
}
 
void
flip_endian_64(uint8_t *d) {
    assert(NULL != d);
 
    swap_char(d + 7, d);
    swap_char(d + 6, d + 1);
    swap_char(d + 5, d + 2);
    swap_char(d + 4, d + 3);
}
 
uint8_t
isMachineLittleEndian(void) {
    static int endian_check_int = 1; /* dont modify this!!! */
    /* 0=big endian|xdr --  1=little endian|ndr */
    return *((uint8_t *) & endian_check_int);
}
 
uint8_t
read_uint8(const uint8_t** from) {
    assert(NULL != from);
 
    return *(*from)++;
}
 
/* unused up to now
void
write_uint8(uint8_t** from, uint8_t v) {
    assert(NULL != from);
 
 *(*from)++ = v;
}
*/
 
int8_t
read_int8(const uint8_t** from) {
    assert(NULL != from);
 
    return (int8_t) read_uint8(from);
}
 
/* unused up to now
void
write_int8(uint8_t** from, int8_t v) {
    assert(NULL != from);
 
 *(*from)++ = v;
}
*/
 
uint16_t
read_uint16(const uint8_t** from, uint8_t littleEndian) {
    uint16_t ret = 0;
 
    assert(NULL != from);
 
    if (littleEndian) {
        ret = (*from)[0] |
                (*from)[1] << 8;
    } else {
        /* big endian */
        ret = (*from)[0] << 8 |
                (*from)[1];
    }
    *from += 2;
    return ret;
}
 
void
write_uint16(uint8_t** to, uint8_t littleEndian, uint16_t v) {
    assert(NULL != to);
 
    if (littleEndian) {
        (*to)[0] = v & 0x00FF;
        (*to)[1] = v >> 8;
    } else {
        (*to)[1] = v & 0x00FF;
        (*to)[0] = v >> 8;
    }
    *to += 2;
}
 
int16_t
read_int16(const uint8_t** from, uint8_t littleEndian) {
    assert(NULL != from);
 
    return read_uint16(from, littleEndian);
}
 
/* unused up to now
void
write_int16(uint8_t** to, uint8_t littleEndian, int16_t v) {
    assert(NULL != to);
 
    if ( littleEndian )
    {
        (*to)[0] = v & 0x00FF;
        (*to)[1] = v >> 8;
    }
    else
    {
        (*to)[1] = v & 0x00FF;
        (*to)[0] = v >> 8;
    }
 *to += 2;
}
*/
 
uint32_t
read_uint32(const uint8_t** from, uint8_t littleEndian) {
    uint32_t ret = 0;
 
    assert(NULL != from);
 
    if (littleEndian) {
        ret = (uint32_t) ((*from)[0] & 0xff) |
                (uint32_t) ((*from)[1] & 0xff) << 8 |
                (uint32_t) ((*from)[2] & 0xff) << 16 |
                (uint32_t) ((*from)[3] & 0xff) << 24;
    } else {
        /* big endian */
        ret = (uint32_t) ((*from)[3] & 0xff) |
                (uint32_t) ((*from)[2] & 0xff) << 8 |
                (uint32_t) ((*from)[1] & 0xff) << 16 |
                (uint32_t) ((*from)[0] & 0xff) << 24;
    }
 
    *from += 4;
    return ret;
}
 
/* unused up to now
void
write_uint32(uint8_t** to, uint8_t littleEndian, uint32_t v) {
    assert(NULL != to);
 
    if ( littleEndian )
    {
        (*to)[0] = v & 0x000000FF;
        (*to)[1] = ( v & 0x0000FF00 ) >> 8;
        (*to)[2] = ( v & 0x00FF0000 ) >> 16;
        (*to)[3] = ( v & 0xFF000000 ) >> 24;
    }
    else
    {
        (*to)[3] = v & 0x000000FF;
        (*to)[2] = ( v & 0x0000FF00 ) >> 8;
        (*to)[1] = ( v & 0x00FF0000 ) >> 16;
        (*to)[0] = ( v & 0xFF000000 ) >> 24;
    }
 *to += 4;
}
*/
 
int32_t
read_int32(const uint8_t** from, uint8_t littleEndian) {
    assert(NULL != from);
 
    return read_uint32(from, littleEndian);
}
 
/* unused up to now
void
write_int32(uint8_t** to, uint8_t littleEndian, int32_t v) {
    assert(NULL != to);
 
    if ( littleEndian )
    {
        (*to)[0] = v & 0x000000FF;
        (*to)[1] = ( v & 0x0000FF00 ) >> 8;
        (*to)[2] = ( v & 0x00FF0000 ) >> 16;
        (*to)[3] = ( v & 0xFF000000 ) >> 24;
    }
    else
    {
        (*to)[3] = v & 0x000000FF;
        (*to)[2] = ( v & 0x0000FF00 ) >> 8;
        (*to)[1] = ( v & 0x00FF0000 ) >> 16;
        (*to)[0] = ( v & 0xFF000000 ) >> 24;
    }
 *to += 4;
}
*/
 
float
read_float32(const uint8_t** from, uint8_t littleEndian) {
 
    union {
        float f;
        uint32_t i;
    } ret;
 
    ret.i = read_uint32(from, littleEndian);
 
    return ret.f;
}
 
/* unused up to now
void
write_float32(uint8_t** from, uint8_t littleEndian, float f) {
    union {
        float f;
        uint32_t i;
    } u;
 
    u.f = f;
    write_uint32(from, littleEndian, u.i);
}
*/
 
double
read_float64(const uint8_t** from, uint8_t littleEndian) {
 
    union {
        double d;
        uint64_t i;
    } ret;
 
    assert(NULL != from);
 
    if (littleEndian) {
        ret.i = (uint64_t) ((*from)[0] & 0xff) |
                (uint64_t) ((*from)[1] & 0xff) << 8 |
                (uint64_t) ((*from)[2] & 0xff) << 16 |
                (uint64_t) ((*from)[3] & 0xff) << 24 |
                (uint64_t) ((*from)[4] & 0xff) << 32 |
                (uint64_t) ((*from)[5] & 0xff) << 40 |
                (uint64_t) ((*from)[6] & 0xff) << 48 |
                (uint64_t) ((*from)[7] & 0xff) << 56;
    } else {
        /* big endian */
        ret.i = (uint64_t) ((*from)[7] & 0xff) |
                (uint64_t) ((*from)[6] & 0xff) << 8 |
                (uint64_t) ((*from)[5] & 0xff) << 16 |
                (uint64_t) ((*from)[4] & 0xff) << 24 |
                (uint64_t) ((*from)[3] & 0xff) << 32 |
                (uint64_t) ((*from)[2] & 0xff) << 40 |
                (uint64_t) ((*from)[1] & 0xff) << 48 |
                (uint64_t) ((*from)[0] & 0xff) << 56;
    }
 
    *from += 8;
    return ret.d;
}
 
/* unused up to now
void
write_float64(uint8_t** to, uint8_t littleEndian, double v) {
    union {
        double d;
        uint64_t i;
    } u;
 
    assert(NULL != to);
 
    u.d = v;
 
    if ( littleEndian )
    {
        (*to)[0] =   u.i & 0x00000000000000FFULL;
        (*to)[1] = ( u.i & 0x000000000000FF00ULL ) >> 8;
        (*to)[2] = ( u.i & 0x0000000000FF0000ULL ) >> 16;
        (*to)[3] = ( u.i & 0x00000000FF000000ULL ) >> 24;
        (*to)[4] = ( u.i & 0x000000FF00000000ULL ) >> 32;
        (*to)[5] = ( u.i & 0x0000FF0000000000ULL ) >> 40;
        (*to)[6] = ( u.i & 0x00FF000000000000ULL ) >> 48;
        (*to)[7] = ( u.i & 0xFF00000000000000ULL ) >> 56;
    }
    else
    {
        (*to)[7] =   u.i & 0x00000000000000FFULL;
        (*to)[6] = ( u.i & 0x000000000000FF00ULL ) >> 8;
        (*to)[5] = ( u.i & 0x0000000000FF0000ULL ) >> 16;
        (*to)[4] = ( u.i & 0x00000000FF000000ULL ) >> 24;
        (*to)[3] = ( u.i & 0x000000FF00000000ULL ) >> 32;
        (*to)[2] = ( u.i & 0x0000FF0000000000ULL ) >> 40;
        (*to)[1] = ( u.i & 0x00FF000000000000ULL ) >> 48;
        (*to)[0] = ( u.i & 0xFF00000000000000ULL ) >> 56;
    }
 *to += 8;
}
*/
 
static uint32_t
rt_raster_serialized_size(rt_raster raster) {
        uint32_t size = sizeof (struct rt_raster_serialized_t);
        uint16_t i = 0;
 
        assert(NULL != raster);
 
        RASTER_DEBUGF(3, "Serialized size with just header:%d - now adding size of %d bands",
                size, raster->numBands);
 
        for (i = 0; i < raster->numBands; ++i) {
                rt_band band = raster->bands[i];
                rt_pixtype pixtype = band->pixtype;
                int pixbytes = rt_pixtype_size(pixtype);
 
                if (pixbytes < 1) {
                        rterror("rt_raster_serialized_size: Corrupted band: unknown pixtype");
                        return 0;
                }
 
                /* Add space for band type, hasnodata flag and data padding */
                size += pixbytes;
 
                /* Add space for nodata value */
                size += pixbytes;
 
                if (band->offline) {
                        /* Add space for band number */
                        size += 1;
 
                        /* Add space for null-terminated path */
                        size += strlen(band->data.offline.path) + 1;
                }
                else {
                        /* Add space for raster band data */
                        size += pixbytes * raster->width * raster->height;
                }
 
                RASTER_DEBUGF(3, "Size before alignment is %d", size);
 
                /* Align size to 8-bytes boundary (trailing padding) */
                /* XXX jorgearevalo: bug here. If the size is actually 8-bytes aligned,
                   this line will add 8 bytes trailing padding, and it's not necessary */
                /*size += 8 - (size % 8);*/
                if (size % 8)
                        size += 8 - (size % 8);
 
                RASTER_DEBUGF(3, "Size after alignment is %d", size);
        }
 
        return size;
}
 
void*
rt_raster_serialize(rt_raster raster) {
        uint32_t size = 0;
        uint8_t* ret = NULL;
        uint8_t* ptr = NULL;
        uint16_t i = 0;
 
        assert(NULL != raster);
 
        size = rt_raster_serialized_size(raster);
        ret = (uint8_t*) rtalloc(size);
        if (!ret) {
                rterror("rt_raster_serialize: Out of memory allocating %d bytes for serializing a raster", size);
                return NULL;
        }
        memset(ret, '-', size);
        ptr = ret;
 
        RASTER_DEBUGF(3, "sizeof(struct rt_raster_serialized_t):%u",
                sizeof (struct rt_raster_serialized_t));
        RASTER_DEBUGF(3, "sizeof(struct rt_raster_t):%u",
                sizeof (struct rt_raster_t));
        RASTER_DEBUGF(3, "serialized size:%lu", (long unsigned) size);
 
        /* Set size */
        /* NOTE: Value of rt_raster.size may be updated in
         * returned object, for instance, by rt_pg layer to
         * store value calculated by SET_VARSIZE.
         */
        raster->size = size;
 
        /* Set version */
        raster->version = 0;
 
        /* Copy header */
        memcpy(ptr, raster, sizeof (struct rt_raster_serialized_t));
 
        RASTER_DEBUG(3, "Start hex dump of raster being serialized using 0x2D to mark non-written bytes");
 
#if POSTGIS_DEBUG_LEVEL > 2
        uint8_t* dbg_ptr = ptr;
        d_print_binary_hex("HEADER", dbg_ptr, size);
#endif
 
        ptr += sizeof (struct rt_raster_serialized_t);
 
        /* Serialize bands now */
        for (i = 0; i < raster->numBands; ++i) {
                rt_band band = raster->bands[i];
                assert(NULL != band);
 
                rt_pixtype pixtype = band->pixtype;
                int pixbytes = rt_pixtype_size(pixtype);
                if (pixbytes < 1) {
                        rterror("rt_raster_serialize: Corrupted band: unknown pixtype");
                        rtdealloc(ret);
                        return NULL;
                }
 
                /* Add band type */
                *ptr = band->pixtype;
                if (band->offline) {
#ifdef POSTGIS_RASTER_DISABLE_OFFLINE
      rterror("rt_raster_serialize: offdb raster support disabled at compile-time");
      return NULL;
#endif
                        *ptr |= BANDTYPE_FLAG_OFFDB;
                }
                if (band->hasnodata) {
                        *ptr |= BANDTYPE_FLAG_HASNODATA;
                }
 
                if (band->isnodata) {
                        *ptr |= BANDTYPE_FLAG_ISNODATA;
                }
 
#if POSTGIS_DEBUG_LEVEL > 2
                d_print_binary_hex("PIXTYPE", dbg_ptr, size);
#endif
 
                ptr += 1;
 
                /* Add padding (if needed) */
                if (pixbytes > 1) {
                        memset(ptr, '\0', pixbytes - 1);
                        ptr += pixbytes - 1;
                }
 
#if POSTGIS_DEBUG_LEVEL > 2
                d_print_binary_hex("PADDING", dbg_ptr, size);
#endif
 
                /* Consistency checking (ptr is pixbytes-aligned) */
                assert(!((ptr - ret) % pixbytes));
 
                /* Add nodata value */
                switch (pixtype) {
                        case PT_1BB:
                        case PT_2BUI:
                        case PT_4BUI:
                        case PT_8BUI: {
                                uint8_t v = band->nodataval;
                                *ptr = v;
                                ptr += 1;
                                break;
                        }
                        case PT_8BSI: {
                                int8_t v = band->nodataval;
                                *ptr = v;
                                ptr += 1;
                                break;
                        }
                        case PT_16BSI: {
                                int16_t v = band->nodataval;
                                memcpy(ptr, &v, 2);
                                ptr += 2;
                                break;
                        }
                        case PT_16BUI: {
                                uint16_t v = band->nodataval;
                                memcpy(ptr, &v, 2);
                                ptr += 2;
                                break;
                        }
                        case PT_32BSI: {
                                int32_t v = band->nodataval;
                                memcpy(ptr, &v, 4);
                                ptr += 4;
                                break;
                        }
                        case PT_32BUI: {
                                uint32_t v = band->nodataval;
                                memcpy(ptr, &v, 4);
                                ptr += 4;
                                break;
                        }
                        case PT_32BF: {
                                float v = band->nodataval;
                                memcpy(ptr, &v, 4);
                                ptr += 4;
                                break;
                        }
                        case PT_64BF: {
                                memcpy(ptr, &band->nodataval, 8);
                                ptr += 8;
                                break;
                        }
                        default:
                                rterror("rt_raster_serialize: Fatal error caused by unknown pixel type. Aborting.");
                                rtdealloc(ret);
                                return NULL;
                }
 
                /* Consistency checking (ptr is pixbytes-aligned) */
                assert(!((ptr - ret) % pixbytes));
 
#if POSTGIS_DEBUG_LEVEL > 2
                d_print_binary_hex("nodata", dbg_ptr, size);
#endif
 
                if (band->offline) {
                        /* Write band number */
                        *ptr = band->data.offline.bandNum;
                        ptr += 1;
 
                        /* Write path */
                        strcpy((char*) ptr, band->data.offline.path);
                        ptr += strlen(band->data.offline.path) + 1;
                }
                else {
                        /* Write data */
                        uint32_t datasize = raster->width * raster->height * pixbytes;
                        memcpy(ptr, band->data.mem, datasize);
                        ptr += datasize;
                }
 
#if POSTGIS_DEBUG_LEVEL > 2
                d_print_binary_hex("BAND", dbg_ptr, size);
#endif
 
                /* Pad up to 8-bytes boundary */
                while ((ptr-ret) % 8) {
                        *ptr = 0;
                        ++ptr;
                }
 
                /* Consistency checking (ptr is pixbytes-aligned) */
                assert(!((ptr - ret) % pixbytes));
        } /* for-loop over bands */
 
#if POSTGIS_DEBUG_LEVEL > 2
                d_print_binary_hex("SERIALIZED RASTER", dbg_ptr, size);
#endif
        return ret;
}
 
rt_raster
rt_raster_deserialize(void* serialized, int header_only) {
        rt_raster rast = NULL;
        const uint8_t *ptr = NULL;
        const uint8_t *beg = NULL;
        uint16_t i = 0;
        uint16_t j = 0;
        uint8_t littleEndian = isMachineLittleEndian();
 
        assert(NULL != serialized);
 
        RASTER_DEBUG(2, "rt_raster_deserialize: Entering...");
 
        /* NOTE: Value of rt_raster.size may be different
         * than actual size of raster data being read.
         * See note on SET_VARSIZE in rt_raster_serialize function above.
         */
 
        /* Allocate memory for deserialized raster header */
        RASTER_DEBUG(3, "rt_raster_deserialize: Allocating memory for deserialized raster header");
        rast = (rt_raster) rtalloc(sizeof (struct rt_raster_t));
        if (!rast) {
                rterror("rt_raster_deserialize: Out of memory allocating raster for deserialization");
                return NULL;
        }
 
        /* Deserialize raster header */
        RASTER_DEBUG(3, "rt_raster_deserialize: Deserialize raster header");
        memcpy(rast, serialized, sizeof (struct rt_raster_serialized_t));
 
        if (0 == rast->numBands || header_only) {
                rast->bands = 0;
                return rast;
        }
 
        beg = (const uint8_t*) serialized;
 
        /* Allocate registry of raster bands */
        RASTER_DEBUG(3, "rt_raster_deserialize: Allocating memory for bands");
        rast->bands = rtalloc(rast->numBands * sizeof (rt_band));
        if (rast->bands == NULL) {
                rterror("rt_raster_deserialize: Out of memory allocating bands");
                rtdealloc(rast);
                return NULL;
        }
 
        RASTER_DEBUGF(3, "rt_raster_deserialize: %d bands", rast->numBands);
 
        /* Move to the beginning of first band */
        ptr = beg;
        ptr += sizeof (struct rt_raster_serialized_t);
 
        /* Deserialize bands now */
        for (i = 0; i < rast->numBands; ++i) {
                rt_band band = NULL;
                uint8_t type = 0;
                int pixbytes = 0;
 
                band = rtalloc(sizeof(struct rt_band_t));
                if (!band) {
                        rterror("rt_raster_deserialize: Out of memory allocating rt_band during deserialization");
                        for (j = 0; j < i; j++) rt_band_destroy(rast->bands[j]);
                        rt_raster_destroy(rast);
                        return NULL;
                }
 
                rast->bands[i] = band;
 
                type = *ptr;
                ptr++;
                band->pixtype = type & BANDTYPE_PIXTYPE_MASK;
 
                RASTER_DEBUGF(3, "rt_raster_deserialize: band %d with pixel type %s", i, rt_pixtype_name(band->pixtype));
 
                band->offline = BANDTYPE_IS_OFFDB(type) ? 1 : 0;
                band->hasnodata = BANDTYPE_HAS_NODATA(type) ? 1 : 0;
                band->isnodata = band->hasnodata ? (BANDTYPE_IS_NODATA(type) ? 1 : 0) : 0;
                band->width = rast->width;
                band->height = rast->height;
                band->ownsdata = 0; /* we do NOT own this data!!! */
                band->raster = rast;
 
                /* Advance by data padding */
                pixbytes = rt_pixtype_size(band->pixtype);
                ptr += pixbytes - 1;
 
                /* Read nodata value */
                switch (band->pixtype) {
                        case PT_1BB: {
                                band->nodataval = ((int) read_uint8(&ptr)) & 0x01;
                                break;
                        }
                        case PT_2BUI: {
                                band->nodataval = ((int) read_uint8(&ptr)) & 0x03;
                                break;
                        }
                        case PT_4BUI: {
                                band->nodataval = ((int) read_uint8(&ptr)) & 0x0F;
                                break;
                        }
                        case PT_8BSI: {
                                band->nodataval = read_int8(&ptr);
                                break;
                        }
                        case PT_8BUI: {
                                band->nodataval = read_uint8(&ptr);
                                break;
                        }
                        case PT_16BSI: {
                                band->nodataval = read_int16(&ptr, littleEndian);
                                break;
                        }
                        case PT_16BUI: {
                                band->nodataval = read_uint16(&ptr, littleEndian);
                                break;
                        }
                        case PT_32BSI: {
                                band->nodataval = read_int32(&ptr, littleEndian);
                                break;
                        }
                        case PT_32BUI: {
                                band->nodataval = read_uint32(&ptr, littleEndian);
                                break;
                        }
                        case PT_32BF: {
                                band->nodataval = read_float32(&ptr, littleEndian);
                                break;
                        }
                        case PT_64BF: {
                                band->nodataval = read_float64(&ptr, littleEndian);
                                break;
                        }
                        default: {
                                rterror("rt_raster_deserialize: Unknown pixeltype %d", band->pixtype);
                                for (j = 0; j <= i; j++) rt_band_destroy(rast->bands[j]);
                                rt_raster_destroy(rast);
                                return NULL;
                        }
                }
 
                RASTER_DEBUGF(3, "rt_raster_deserialize: has nodata flag %d", band->hasnodata);
                RASTER_DEBUGF(3, "rt_raster_deserialize: nodata value %g", band->nodataval);
 
                /* Consistency checking (ptr is pixbytes-aligned) */
                assert(!((ptr - beg) % pixbytes));
 
                if (band->offline) {
                        int pathlen = 0;
 
                        /* Read band number */
                        band->data.offline.bandNum = *ptr;
                        ptr += 1;
 
                        /* Register path */
                        pathlen = strlen((char*) ptr);
                        band->data.offline.path = rtalloc(sizeof(char) * (pathlen + 1));
                        if (band->data.offline.path == NULL) {
                                rterror("rt_raster_deserialize: Could not allocate memory for offline band path");
                                for (j = 0; j <= i; j++) rt_band_destroy(rast->bands[j]);
                                rt_raster_destroy(rast);
                                return NULL;
                        }
 
                        memcpy(band->data.offline.path, ptr, pathlen);
                        band->data.offline.path[pathlen] = '\0';
                        ptr += pathlen + 1;
 
                        band->data.offline.mem = NULL;
                }
                else {
                        /* Register data */
                        const uint32_t datasize = rast->width * rast->height * pixbytes;
                        band->data.mem = (uint8_t*) ptr;
                        ptr += datasize;
                }
 
                /* Skip bytes of padding up to 8-bytes boundary */
#if POSTGIS_DEBUG_LEVEL > 0
                const uint8_t *padbeg = ptr;
#endif
                while (0 != ((ptr - beg) % 8)) {
                        ++ptr;
                }
 
                RASTER_DEBUGF(3, "rt_raster_deserialize: skip %d bytes of 8-bytes boundary padding", ptr - padbeg);
 
                /* Consistency checking (ptr is pixbytes-aligned) */
                assert(!((ptr - beg) % pixbytes));
        }
 
        return rast;
}