/src/postgis/liblwgeom/gserialized1.c

Source
/**********************************************************************
 *
 * PostGIS - Spatial Types for PostgreSQL
 * http://postgis.net
 *
 * PostGIS 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.
 *
 * PostGIS 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 PostGIS.  If not, see <http://www.gnu.org/licenses/>.
 *
 **********************************************************************
 *
 * Copyright 2009 Paul Ramsey <pramsey@cleverelephant.ca>
 * Copyright 2017 Darafei Praliaskouski <me@komzpa.net>
 *
 **********************************************************************/


#include "liblwgeom_internal.h"
#include "lwgeom_log.h"
#include "lwgeodetic.h"
#include "gserialized1.h"

#include <stddef.h>
#if defined(__has_feature)
#if __has_feature(address_sanitizer)
#define POSTGIS_ASAN_ALLOCATOR_SIZE 1
#endif
#endif
#if defined(__SANITIZE_ADDRESS__)
#define POSTGIS_ASAN_ALLOCATOR_SIZE 1
#endif
#if defined(POSTGIS_ASAN_ALLOCATOR_SIZE)
#include <sanitizer/allocator_interface.h>
#endif

/***********************************************************************
* GSERIALIZED metadata utility functions.
*/

static int gserialized1_read_gbox_p(const GSERIALIZED *g, GBOX *gbox);
static int gserialized1_payload_bounds(const GSERIALIZED *g, uint8_t **start, uint8_t **end);
static int gserialized1_validate_geometry_buffer(uint8_t *data_ptr, uint8_t *data_end, lwflags_t lwflags, size_t *size);

static size_t
gserialized1_buffer_size(const GSERIALIZED *g)
{
  size_t gsize = LWSIZE_GET(g->size);
#if defined(POSTGIS_ASAN_ALLOCATOR_SIZE)
  size_t allocated_size = __sanitizer_get_allocated_size(g);
  if (allocated_size > 0 && allocated_size < gsize)
    return allocated_size;
#endif
  return gsize;
}

lwflags_t gserialized1_get_lwflags(const GSERIALIZED *g)
{
  lwflags_t lwflags = 0;
  uint8_t gflags = g->gflags;
  FLAGS_SET_Z(lwflags, G1FLAGS_GET_Z(gflags));
  FLAGS_SET_M(lwflags, G1FLAGS_GET_M(gflags));
  FLAGS_SET_BBOX(lwflags, G1FLAGS_GET_BBOX(gflags));
  FLAGS_SET_GEODETIC(lwflags, G1FLAGS_GET_GEODETIC(gflags));
  FLAGS_SET_SOLID(lwflags, G1FLAGS_GET_SOLID(gflags));
  return lwflags;
}

uint8_t lwflags_get_g1flags(lwflags_t lwflags)
{
  uint8_t gflags = 0;
  G1FLAGS_SET_Z(gflags, FLAGS_GET_Z(lwflags));
  G1FLAGS_SET_M(gflags, FLAGS_GET_M(lwflags));
  G1FLAGS_SET_BBOX(gflags, FLAGS_GET_BBOX(lwflags));
  G1FLAGS_SET_GEODETIC(gflags, FLAGS_GET_GEODETIC(lwflags));
  G1FLAGS_SET_SOLID(gflags, FLAGS_GET_SOLID(lwflags));
  return gflags;
}


static size_t gserialized1_box_size(const GSERIALIZED *g)
{
  if (G1FLAGS_GET_GEODETIC(g->gflags))
    return 6 * sizeof(float);
  else
    return 2 * G1FLAGS_NDIMS(g->gflags) * sizeof(float);
}

/* handle missaligned uint32_t data */
static inline uint32_t gserialized1_get_uint32_t(const uint8_t *loc)
{
  return *((uint32_t*)loc);
}

uint8_t g1flags(int has_z, int has_m, int is_geodetic)
{
  uint8_t gflags = 0;
  if (has_z)
    G1FLAGS_SET_Z(gflags, 1);
  if (has_m)
    G1FLAGS_SET_M(gflags, 1);
  if (is_geodetic)
    G1FLAGS_SET_GEODETIC(gflags, 1);
  return gflags;
}

int gserialized1_has_bbox(const GSERIALIZED *gser)
{
  return G1FLAGS_GET_BBOX(gser->gflags);
}

int gserialized1_has_z(const GSERIALIZED *gser)
{
  return G1FLAGS_GET_Z(gser->gflags);
}

int gserialized1_has_m(const GSERIALIZED *gser)
{
  return G1FLAGS_GET_M(gser->gflags);
}

int gserialized1_ndims(const GSERIALIZED *gser)
{
  return G1FLAGS_NDIMS(gser->gflags);
}

int gserialized1_is_geodetic(const GSERIALIZED *gser)
{
    return G1FLAGS_GET_GEODETIC(gser->gflags);
}

uint32_t gserialized1_max_header_size(void)
{
  /* GSERIALIZED size + max bbox according gbox_serialized_size (XYZM*2) + extended flags + type */
  return offsetof(GSERIALIZED, data) + 8 * sizeof(float) + sizeof(uint32_t);
}

static uint32_t gserialized1_header_size(const GSERIALIZED *gser)
{
  uint32_t sz = 8; /* varsize (4) + srid(3) + flags (1) */

  if (gserialized1_has_bbox(gser))
    sz += gserialized1_box_size(gser);

  return sz;
}

uint32_t gserialized1_get_type(const GSERIALIZED *g)
{
  uint32_t *ptr;
  size_t hsz = gserialized1_header_size(g);
  size_t gsize = gserialized1_buffer_size(g);
  if (gsize < hsz + sizeof(uint32_t))
  {
    lwerror("%s: GSERIALIZED too small for geometry type", __func__);
    return 0;
  }
  ptr = (uint32_t*)(g->data);
  if ( G1FLAGS_GET_BBOX(g->gflags) )
  {
    ptr += (gserialized1_box_size(g) / sizeof(uint32_t));
  }
  return *ptr;
}

int32_t gserialized1_get_srid(const GSERIALIZED *s)
{
  uint32_t srid = 0;
  srid = srid | ((uint32_t)s->srid[0] << 16);
  srid = srid | ((uint32_t)s->srid[1] << 8);
  srid = srid | (uint32_t)s->srid[2];
  /* Only the first 21 bits are set. Sign-extend without signed shift UB. */
  if (srid & 0x00100000)
    srid |= 0xFFE00000;

  /* 0 is our internal unknown value. We'll map back and forth here for now */
  if ( srid == 0 )
    return SRID_UNKNOWN;
  else
    return (int32_t)srid;
}

void gserialized1_set_srid(GSERIALIZED *s, int32_t srid)
{
  LWDEBUGF(3, "%s called with srid = %d", __func__, srid);

  srid = clamp_srid(srid);

  /* 0 is our internal unknown value.
   * We'll map back and forth here for now */
  if ( srid == SRID_UNKNOWN )
    srid = 0;

  s->srid[0] = (srid & 0x001F0000) >> 16;
  s->srid[1] = (srid & 0x0000FF00) >> 8;
  s->srid[2] = (srid & 0x000000FF);
}

static int
gserialized1_range_available(const uint8_t *ptr, const uint8_t *end, size_t len)
{
  return ptr <= end && len <= (size_t)(end - ptr);
}

static int
gserialized1_checked_mul(size_t a, size_t b, size_t *out)
{
  if (a != 0 && b > SIZE_MAX / a)
    return LW_FAILURE;
  *out = a * b;
  return LW_SUCCESS;
}

static int
gserialized1_checked_add(size_t a, size_t b, size_t *out)
{
  if (b > SIZE_MAX - a)
    return LW_FAILURE;
  *out = a + b;
  return LW_SUCCESS;
}

static int
gserialized1_payload_bounds(const GSERIALIZED *g, uint8_t **start, uint8_t **end)
{
  size_t hsz;
  size_t gsize;

  if (!g)
    return LW_FAILURE;

  hsz = gserialized1_header_size(g);
  gsize = gserialized1_buffer_size(g);
  if (gsize < hsz)
    return LW_FAILURE;

  if (start)
    *start = (uint8_t *)g + hsz;
  if (end)
    *end = (uint8_t *)g + gsize;
  return LW_SUCCESS;
}

static uint32_t
gserialized1_read_uint32_checked(uint8_t *ptr, uint8_t *end, const char *field)
{
  uint32_t value = 0;
  if (!gserialized1_range_available(ptr, end, sizeof(uint32_t)))
  {
    lwerror("%s: GSERIALIZED too small for %s", __func__, field);
    return 0;
  }
  memcpy(&value, ptr, sizeof(uint32_t));
  return value;
}

static int
gserialized1_pointarray_payload_size(uint32_t npoints, lwflags_t lwflags, size_t *nbytes)
{
  if (gserialized1_checked_mul((size_t)npoints, sizeof(double) * FLAGS_NDIMS(lwflags), nbytes) == LW_FAILURE)
  {
    lwerror("%s: GSERIALIZED point count overflows payload size", __func__);
    return LW_FAILURE;
  }
  return LW_SUCCESS;
}

static int
gserialized1_validate_geometry_buffer(uint8_t *data_ptr, uint8_t *data_end, lwflags_t lwflags, size_t *size)
{
  uint32_t type, count;
  size_t consumed = 0;

  if (!gserialized1_range_available(data_ptr, data_end, 2 * sizeof(uint32_t)))
  {
    lwerror("%s: GSERIALIZED geometry payload is too short", __func__);
    return LW_FAILURE;
  }

  type = gserialized1_read_uint32_checked(data_ptr, data_end, "geometry type");
  count = gserialized1_read_uint32_checked(data_ptr + sizeof(uint32_t), data_end, "geometry count");

  switch (type)
  {
  case POINTTYPE:
    if (count > 1)
    {
      lwerror("%s: invalid point count %u", __func__, count);
      return LW_FAILURE;
    }
    /* fall through */
  case LINETYPE:
  case CIRCSTRINGTYPE:
  case TRIANGLETYPE: {
    size_t point_bytes;
    if (gserialized1_pointarray_payload_size(count, lwflags, &point_bytes) == LW_FAILURE)
      return LW_FAILURE;
    consumed = 2 * sizeof(uint32_t) + point_bytes;
    break;
  }

  case POLYGONTYPE: {
    size_t ring_counts_size, ring_counts_padded_size, point_bytes_sum = 0;
    uint8_t *ring_counts = data_ptr + 2 * sizeof(uint32_t);
    uint32_t i;

    if (gserialized1_checked_mul((size_t)count, sizeof(uint32_t), &ring_counts_size) == LW_FAILURE)
    {
      lwerror("%s: GSERIALIZED ring count overflows payload size", __func__);
      return LW_FAILURE;
    }
    ring_counts_padded_size = ring_counts_size + ((count % 2) ? sizeof(uint32_t) : 0);
    if (!gserialized1_range_available(ring_counts, data_end, ring_counts_padded_size))
    {
      lwerror("%s: GSERIALIZED polygon ring table exceeds payload size", __func__);
      return LW_FAILURE;
    }

    for (i = 0; i < count; i++)
    {
      size_t ring_point_bytes;
      uint32_t npoints = gserialized1_read_uint32_checked(
          ring_counts + i * sizeof(uint32_t), data_end, "ring point count");
      if (gserialized1_pointarray_payload_size(npoints, lwflags, &ring_point_bytes) == LW_FAILURE)
        return LW_FAILURE;
      if (gserialized1_checked_add(point_bytes_sum, ring_point_bytes, &point_bytes_sum) == LW_FAILURE)
      {
        lwerror("%s: GSERIALIZED polygon coordinate size overflows", __func__);
        return LW_FAILURE;
      }
    }
    consumed = 2 * sizeof(uint32_t) + ring_counts_padded_size;
    if (gserialized1_checked_add(consumed, point_bytes_sum, &consumed) == LW_FAILURE)
    {
      lwerror("%s: GSERIALIZED polygon size overflows", __func__);
      return LW_FAILURE;
    }
    break;
  }

  case MULTIPOINTTYPE:
  case MULTILINETYPE:
  case MULTIPOLYGONTYPE:
  case COMPOUNDTYPE:
  case CURVEPOLYTYPE:
  case MULTICURVETYPE:
  case MULTISURFACETYPE:
  case POLYHEDRALSURFACETYPE:
  case TINTYPE:
  case COLLECTIONTYPE: {
    uint32_t i;
    uint8_t *subgeom_ptr = data_ptr + 2 * sizeof(uint32_t);
    lwflags_t subflags = lwflags;
    FLAGS_SET_BBOX(subflags, 0);
    for (i = 0; i < count; i++)
    {
      size_t subsize = 0;
      uint32_t subtype =
          gserialized1_read_uint32_checked(subgeom_ptr, data_end, "collection subtype");
      if (!lwcollection_allows_subtype(type, subtype))
      {
        lwerror("Invalid subtype (%s) for collection type (%s)",
          lwtype_name(subtype),
          lwtype_name(type));
        return LW_FAILURE;
      }
      if (gserialized1_validate_geometry_buffer(subgeom_ptr, data_end, subflags, &subsize) ==
          LW_FAILURE)
        return LW_FAILURE;
      if (subsize == 0)
      {
        lwerror("%s: GSERIALIZED collection member has zero size", __func__);
        return LW_FAILURE;
      }
      subgeom_ptr += subsize;
    }
    consumed = (size_t)(subgeom_ptr - data_ptr);
    break;
  }

  default:
    lwerror("Unknown geometry type: %d - %s", type, lwtype_name(type));
    return LW_FAILURE;
  }

  if (!gserialized1_range_available(data_ptr, data_end, consumed))
  {
    lwerror("%s: GSERIALIZED geometry payload exceeds declared size", __func__);
    return LW_FAILURE;
  }

  if (size)
    *size = consumed;
  return LW_SUCCESS;
}

static size_t gserialized1_is_empty_recurse(const uint8_t *p, int *isempty);
static size_t gserialized1_is_empty_recurse(const uint8_t *p, int *isempty)
{
  int i;
  int32_t type, num;

  memcpy(&type, p, 4);
  memcpy(&num, p+4, 4);

  if ( lwtype_is_collection(type) )
  {
    size_t lz = 8;
    for ( i = 0; i < num; i++ )
    {
      lz += gserialized1_is_empty_recurse(p+lz, isempty);
      if ( ! *isempty )
        return lz;
    }
    *isempty = LW_TRUE;
    return lz;
  }
  else
  {
    *isempty = (num == 0 ? LW_TRUE : LW_FALSE);
    return 8;
  }
}

int gserialized1_is_empty(const GSERIALIZED *g)
{
  uint8_t *p, *end;
  int isempty = 0;
  assert(g);

  if (gserialized1_payload_bounds(g, &p, &end) == LW_FAILURE)
  {
    lwerror("%s: invalid GSERIALIZED header size", __func__);
    return LW_TRUE;
  }
  if (gserialized1_validate_geometry_buffer(p, end, gserialized1_get_lwflags(g), NULL) == LW_FAILURE)
    return LW_TRUE;

  gserialized1_is_empty_recurse(p, &isempty);
  return isempty;
}


/* Prototype for lookup3.c */
/* key = the key to hash */
/* length = length of the key */
/* pc = IN: primary initval, OUT: primary hash */
/* pb = IN: secondary initval, OUT: secondary hash */
void hashlittle2(const void *key, size_t length, uint32_t *pc, uint32_t *pb);

int32_t
gserialized1_hash(const GSERIALIZED *g1)
{
  int32_t hval;
  int32_t pb = 0, pc = 0;
  /* Point to just the type/coordinate part of buffer */
  size_t hsz1 = gserialized1_header_size(g1);
  uint8_t *b1 = (uint8_t*)g1 + hsz1;
  /* Calculate size of type/coordinate buffer */
  size_t sz1 = LWSIZE_GET(g1->size);
  size_t bsz1 = sz1 - hsz1;
  /* Calculate size of srid/type/coordinate buffer */
  int32_t srid = gserialized1_get_srid(g1);
  size_t bsz2 = bsz1 + sizeof(int);
  uint8_t *b2 = lwalloc(bsz2);
  /* Copy srid into front of combined buffer */
  memcpy(b2, &srid, sizeof(int));
  /* Copy type/coordinates into rest of combined buffer */
  memcpy(b2+sizeof(int), b1, bsz1);
  /* Hash combined buffer */
  hashlittle2(b2, bsz2, (uint32_t *)&pb, (uint32_t *)&pc);
  lwfree(b2);
  hval = pb ^ pc;
  return hval;
}

int gserialized1_read_gbox_p(const GSERIALIZED *g, GBOX *gbox)
{

  /* Null input! */
  if ( ! ( g && gbox ) ) return LW_FAILURE;
  if (gserialized1_buffer_size(g) < offsetof(GSERIALIZED, data) + gserialized1_box_size(g))
    return LW_FAILURE;

  /* Initialize the flags on the box */
  gbox->flags = gserialized1_get_lwflags(g);

  /* Has pre-calculated box */
  if ( G1FLAGS_GET_BBOX(g->gflags) )
  {
    int i = 0;
    float *fbox = (float*)(g->data);
    gbox->xmin = fbox[i++];
    gbox->xmax = fbox[i++];
    gbox->ymin = fbox[i++];
    gbox->ymax = fbox[i++];

    /* Geodetic? Read next dimension (geocentric Z) and return */
    if ( G1FLAGS_GET_GEODETIC(g->gflags) )
    {
      gbox->zmin = fbox[i++];
      gbox->zmax = fbox[i++];
      return LW_SUCCESS;
    }
    /* Cartesian? Read extra dimensions (if there) and return */
    if ( G1FLAGS_GET_Z(g->gflags) )
    {
      gbox->zmin = fbox[i++];
      gbox->zmax = fbox[i++];
    }
    if ( G1FLAGS_GET_M(g->gflags) )
    {
      gbox->mmin = fbox[i++];
      gbox->mmax = fbox[i++];
    }
    return LW_SUCCESS;
  }
  return LW_FAILURE;
}

/*
* Populate a bounding box *without* allocating an LWGEOM. Useful
* for some performance purposes.
*/
int
gserialized1_peek_gbox_p(const GSERIALIZED *g, GBOX *gbox)
{
  uint32_t type;
  uint8_t *geometry_start = NULL;
  uint8_t *geometry_end = NULL;

  if (gserialized1_payload_bounds(g, &geometry_start, &geometry_end) == LW_FAILURE)
    return LW_FAILURE;
  if (gserialized1_validate_geometry_buffer(geometry_start, geometry_end, gserialized1_get_lwflags(g), NULL) ==
      LW_FAILURE)
    return LW_FAILURE;
  type = gserialized1_get_type(g);

  /* Peeking doesn't help if you already have a box or are geodetic */
  if ( G1FLAGS_GET_GEODETIC(g->gflags) || G1FLAGS_GET_BBOX(g->gflags) )
  {
    return LW_FAILURE;
  }

  /* Boxes of points are easy peasy */
  if ( type == POINTTYPE )
  {
    int i = 1; /* Start past <pointtype><padding> */
    double *dptr = (double*)(g->data);

    /* Read the empty flag */
    int32_t *iptr = (int32_t *)(g->data);
    int isempty = (iptr[1] == 0);

    /* EMPTY point has no box */
    if ( isempty ) return LW_FAILURE;

    gbox->xmin = gbox->xmax = dptr[i++];
    gbox->ymin = gbox->ymax = dptr[i++];
    gbox->flags = gserialized1_get_lwflags(g);
    if ( G1FLAGS_GET_Z(g->gflags) )
    {
      gbox->zmin = gbox->zmax = dptr[i++];
    }
    if ( G1FLAGS_GET_M(g->gflags) )
    {
      gbox->mmin = gbox->mmax = dptr[i++];
    }
    gbox_float_round(gbox);
    return LW_SUCCESS;
  }
  /* We can calculate the box of a two-point cartesian line trivially */
  else if ( type == LINETYPE )
  {
    int ndims = G1FLAGS_NDIMS(g->gflags);
    int i = 0; /* Start at <linetype><npoints> */
    double *dptr = (double*)(g->data);
    int32_t *iptr = (int32_t *)(g->data);
    int npoints = iptr[1]; /* Read the npoints */

    /* This only works with 2-point lines */
    if ( npoints != 2 )
      return LW_FAILURE;

    /* Advance to X */
    /* Past <linetype><npoints> */
    i++;
    gbox->xmin = FP_MIN(dptr[i], dptr[i+ndims]);
    gbox->xmax = FP_MAX(dptr[i], dptr[i+ndims]);

    /* Advance to Y */
    i++;
    gbox->ymin = FP_MIN(dptr[i], dptr[i+ndims]);
    gbox->ymax = FP_MAX(dptr[i], dptr[i+ndims]);

    gbox->flags = gserialized1_get_lwflags(g);
    if ( G1FLAGS_GET_Z(g->gflags) )
    {
      /* Advance to Z */
      i++;
      gbox->zmin = FP_MIN(dptr[i], dptr[i+ndims]);
      gbox->zmax = FP_MAX(dptr[i], dptr[i+ndims]);
    }
    if ( G1FLAGS_GET_M(g->gflags) )
    {
      /* Advance to M */
      i++;
      gbox->mmin = FP_MIN(dptr[i], dptr[i+ndims]);
      gbox->mmax = FP_MAX(dptr[i], dptr[i+ndims]);
    }
    gbox_float_round(gbox);
    return LW_SUCCESS;
  }
  /* We can also do single-entry multi-points */
  else if ( type == MULTIPOINTTYPE )
  {
    int i = 0; /* Start at <multipointtype><ngeoms> */
    double *dptr = (double*)(g->data);
    int32_t *iptr = (int32_t *)(g->data);
    int ngeoms = iptr[1]; /* Read the ngeoms */
    int npoints;

    /* This only works with single-entry multipoints */
    if ( ngeoms != 1 )
      return LW_FAILURE;

    /* Npoints is at <multipointtype><ngeoms><pointtype><npoints> */
    npoints = iptr[3];

    /* The check below is necessary because we can have a MULTIPOINT
     * that contains a single, empty POINT (ngeoms = 1, npoints = 0) */
    if ( npoints != 1 )
      return LW_FAILURE;

    /* Move forward two doubles (four ints) */
    /* Past <multipointtype><ngeoms> */
    /* Past <pointtype><npoints> */
    i += 2;

    /* Read the doubles from the one point */
    gbox->xmin = gbox->xmax = dptr[i++];
    gbox->ymin = gbox->ymax = dptr[i++];
    gbox->flags = gserialized1_get_lwflags(g);
    if ( G1FLAGS_GET_Z(g->gflags) )
    {
      gbox->zmin = gbox->zmax = dptr[i++];
    }
    if ( G1FLAGS_GET_M(g->gflags) )
    {
      gbox->mmin = gbox->mmax = dptr[i++];
    }
    gbox_float_round(gbox);
    return LW_SUCCESS;
  }
  /* And we can do single-entry multi-lines with two vertices (!!!) */
  else if ( type == MULTILINETYPE )
  {
    int ndims = G1FLAGS_NDIMS(g->gflags);
    int i = 0; /* Start at <multilinetype><ngeoms> */
    double *dptr = (double*)(g->data);
    int32_t *iptr = (int32_t *)(g->data);
    int ngeoms = iptr[1]; /* Read the ngeoms */
    int npoints;

    /* This only works with 1-line multilines */
    if ( ngeoms != 1 )
      return LW_FAILURE;

    /* Npoints is at <multilinetype><ngeoms><linetype><npoints> */
    npoints = iptr[3];

    if ( npoints != 2 )
      return LW_FAILURE;

    /* Advance to X */
    /* Move forward two doubles (four ints) */
    /* Past <multilinetype><ngeoms> */
    /* Past <linetype><npoints> */
    i += 2;
    gbox->xmin = FP_MIN(dptr[i], dptr[i+ndims]);
    gbox->xmax = FP_MAX(dptr[i], dptr[i+ndims]);

    /* Advance to Y */
    i++;
    gbox->ymin = FP_MIN(dptr[i], dptr[i+ndims]);
    gbox->ymax = FP_MAX(dptr[i], dptr[i+ndims]);

    gbox->flags = gserialized1_get_lwflags(g);
    if ( G1FLAGS_GET_Z(g->gflags) )
    {
      /* Advance to Z */
      i++;
      gbox->zmin = FP_MIN(dptr[i], dptr[i+ndims]);
      gbox->zmax = FP_MAX(dptr[i], dptr[i+ndims]);
    }
    if ( G1FLAGS_GET_M(g->gflags) )
    {
      /* Advance to M */
      i++;
      gbox->mmin = FP_MIN(dptr[i], dptr[i+ndims]);
      gbox->mmax = FP_MAX(dptr[i], dptr[i+ndims]);
    }
    gbox_float_round(gbox);
    return LW_SUCCESS;
  }

  return LW_FAILURE;
}

static inline void
gserialized1_copy_point(double *dptr, lwflags_t flags, POINT4D *out_point)
{
  uint8_t dim = 0;
  out_point->x = dptr[dim++];
  out_point->y = dptr[dim++];

  if (G1FLAGS_GET_Z(flags))
  {
    out_point->z = dptr[dim++];
  }
  if (G1FLAGS_GET_M(flags))
  {
    out_point->m = dptr[dim];
  }
}

int
gserialized1_peek_first_point(const GSERIALIZED *g, POINT4D *out_point)
{
  uint8_t *geometry_start = NULL;
  uint8_t *geometry_end = NULL;

  if (gserialized1_payload_bounds(g, &geometry_start, &geometry_end) == LW_FAILURE)
    return LW_FAILURE;
  if (gserialized1_validate_geometry_buffer(geometry_start, geometry_end, gserialized1_get_lwflags(g), NULL) ==
      LW_FAILURE)
    return LW_FAILURE;

  uint32_t isEmpty = (((uint32_t *)geometry_start)[1]) == 0;
  if (isEmpty)
  {
    return LW_FAILURE;
  }

  uint32_t type = (((uint32_t *)geometry_start)[0]);
  /* Setup double_array_start depending on the geometry type */
  double *double_array_start = NULL;
  switch (type)
  {
  case (POINTTYPE):
    /* For points we only need to jump over the type and npoints 32b ints */
    double_array_start = (double *)(geometry_start + 2 * sizeof(uint32_t));
    break;

  default:
    lwerror("%s is currently not implemented for type %d", __func__, type);
    return LW_FAILURE;
  }

  gserialized1_copy_point(double_array_start, g->gflags, out_point);
  return LW_SUCCESS;
}

/**
* Read the bounding box off a serialization and calculate one if
* it is not already there.
*/
int gserialized1_get_gbox_p(const GSERIALIZED *g, GBOX *box)
{
  /* Try to just read the serialized box. */
  if ( gserialized1_read_gbox_p(g, box) == LW_SUCCESS )
  {
    return LW_SUCCESS;
  }
  /* No box? Try to peek into simpler geometries and */
  /* derive a box without creating an lwgeom */
  else if ( gserialized1_peek_gbox_p(g, box) == LW_SUCCESS )
  {
    return LW_SUCCESS;
  }
  /* Damn! Nothing for it but to create an lwgeom... */
  /* See http://trac.osgeo.org/postgis/ticket/1023 */
  else
  {
    LWGEOM *lwgeom = lwgeom_from_gserialized(g);
    int ret = lwgeom_calculate_gbox(lwgeom, box);
    gbox_float_round(box);
    lwgeom_free(lwgeom);
    return ret;
  }
}

/**
* Read the bounding box off a serialization and fail if
* it is not already there.
*/
int gserialized1_fast_gbox_p(const GSERIALIZED *g, GBOX *box)
{
  /* Try to just read the serialized box. */
  if ( gserialized1_read_gbox_p(g, box) == LW_SUCCESS )
  {
    return LW_SUCCESS;
  }
  /* No box? Try to peek into simpler geometries and */
  /* derive a box without creating an lwgeom */
  else if ( gserialized1_peek_gbox_p(g, box) == LW_SUCCESS )
  {
    return LW_SUCCESS;
  }
  else
  {
    return LW_FAILURE;
  }
}




/***********************************************************************
* Calculate the GSERIALIZED size for an LWGEOM.
*/

/* Private functions */

static size_t gserialized1_from_any_size(const LWGEOM *geom); /* Local prototype */

static size_t gserialized1_from_lwpoint_size(const LWPOINT *point)
{
  size_t size = 4; /* Type number. */

  assert(point);

  size += 4; /* Number of points (one or zero (empty)). */
  size += sizeof(double) * point->point->npoints * FLAGS_NDIMS(point->flags);

  LWDEBUGF(3, "point size = %zu", size);

  return size;
}

static size_t gserialized1_from_lwline_size(const LWLINE *line)
{
  size_t size = 4; /* Type number. */

  assert(line);

  size += 4; /* Number of points (zero => empty). */
  size += sizeof(double) * line->points->npoints * FLAGS_NDIMS(line->flags);

  LWDEBUGF(3, "linestring size = %zu", size);

  return size;
}

static size_t gserialized1_from_lwtriangle_size(const LWTRIANGLE *triangle)
{
  size_t size = 4; /* Type number. */

  assert(triangle);

  size += 4; /* Number of points (zero => empty). */
  size += sizeof(double) * triangle->points->npoints * FLAGS_NDIMS(triangle->flags);

  LWDEBUGF(3, "triangle size = %zu", size);

  return size;
}

static size_t gserialized1_from_lwpoly_size(const LWPOLY *poly)
{
  size_t size = 4; /* Type number. */
  uint32_t i = 0;

  assert(poly);

  size += 4; /* Number of rings (zero => empty). */
  if ( poly->nrings % 2 )
    size += 4; /* Padding to double alignment. */

  for ( i = 0; i < poly->nrings; i++ )
  {
    size += 4; /* Number of points in ring. */
    size += sizeof(double) * poly->rings[i]->npoints * FLAGS_NDIMS(poly->flags);
  }

  LWDEBUGF(3, "polygon size = %zu", size);

  return size;
}

static size_t gserialized1_from_lwcircstring_size(const LWCIRCSTRING *curve)
{
  size_t size = 4; /* Type number. */

  assert(curve);

  size += 4; /* Number of points (zero => empty). */
  size += sizeof(double) * curve->points->npoints * FLAGS_NDIMS(curve->flags);

  LWDEBUGF(3, "circstring size = %zu", size);

  return size;
}

static size_t gserialized1_from_lwcollection_size(const LWCOLLECTION *col)
{
  size_t size = 4; /* Type number. */
  uint32_t i = 0;

  assert(col);

  size += 4; /* Number of sub-geometries (zero => empty). */

  for ( i = 0; i < col->ngeoms; i++ )
  {
    size_t subsize = gserialized1_from_any_size(col->geoms[i]);
    size += subsize;
    LWDEBUGF(3, "lwcollection subgeom(%d) size = %zu", i, subsize);
  }

  LWDEBUGF(3, "lwcollection size = %zu", size);

  return size;
}

static size_t gserialized1_from_any_size(const LWGEOM *geom)
{
  LWDEBUGF(2, "Input type: %s", lwtype_name(geom->type));

  switch (geom->type)
  {
  case POINTTYPE:
    return gserialized1_from_lwpoint_size((LWPOINT *)geom);
  case LINETYPE:
    return gserialized1_from_lwline_size((LWLINE *)geom);
  case POLYGONTYPE:
    return gserialized1_from_lwpoly_size((LWPOLY *)geom);
  case TRIANGLETYPE:
    return gserialized1_from_lwtriangle_size((LWTRIANGLE *)geom);
  case CIRCSTRINGTYPE:
    return gserialized1_from_lwcircstring_size((LWCIRCSTRING *)geom);
  case CURVEPOLYTYPE:
  case COMPOUNDTYPE:
  case MULTIPOINTTYPE:
  case MULTILINETYPE:
  case MULTICURVETYPE:
  case MULTIPOLYGONTYPE:
  case MULTISURFACETYPE:
  case POLYHEDRALSURFACETYPE:
  case TINTYPE:
  case COLLECTIONTYPE:
    return gserialized1_from_lwcollection_size((LWCOLLECTION *)geom);
  default:
    lwerror("Unknown geometry type: %d - %s", geom->type, lwtype_name(geom->type));
    return 0;
  }
}

/* Public function */

size_t gserialized1_from_lwgeom_size(const LWGEOM *geom)
{
  size_t size = 8; /* Header overhead. */
  assert(geom);

  if (geom->bbox)
    size += gbox_serialized_size(geom->flags);

  size += gserialized1_from_any_size(geom);
  LWDEBUGF(3, "%s size = %zu", __func__, size);

  return size;
}

/***********************************************************************
* Serialize an LWGEOM into GSERIALIZED.
*/

/* Private functions */

static size_t gserialized1_from_lwgeom_any(const LWGEOM *geom, uint8_t *buf);

static size_t gserialized1_from_lwpoint(const LWPOINT *point, uint8_t *buf)
{
  uint8_t *loc;
  int ptsize = ptarray_point_size(point->point);
  int type = POINTTYPE;

  assert(point);
  assert(buf);

  if ( FLAGS_GET_ZM(point->flags) != FLAGS_GET_ZM(point->point->flags) )
    lwerror("Dimensions mismatch in lwpoint");

  LWDEBUGF(2, "%s (%p, %p) called", __func__, point, buf);

  loc = buf;

  /* Write in the type. */
  memcpy(loc, &type, sizeof(uint32_t));
  loc += sizeof(uint32_t);
  /* Write in the number of points (0 => empty). */
  memcpy(loc, &(point->point->npoints), sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Copy in the ordinates. */
  if ( point->point->npoints > 0 )
  {
    memcpy(loc, getPoint_internal(point->point, 0), ptsize);
    loc += ptsize;
  }

  return (size_t)(loc - buf);
}

static size_t gserialized1_from_lwline(const LWLINE *line, uint8_t *buf)
{
  uint8_t *loc;
  int ptsize;
  size_t size;
  int type = LINETYPE;

  assert(line);
  assert(buf);

  LWDEBUGF(2, "%s (%p, %p) called", __func__, line, buf);

  if ( FLAGS_GET_Z(line->flags) != FLAGS_GET_Z(line->points->flags) )
    lwerror("Dimensions mismatch in lwline");

  ptsize = ptarray_point_size(line->points);

  loc = buf;

  /* Write in the type. */
  memcpy(loc, &type, sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Write in the npoints. */
  memcpy(loc, &(line->points->npoints), sizeof(uint32_t));
  loc += sizeof(uint32_t);

  LWDEBUGF(3, "%s added npoints (%d)", __func__, line->points->npoints);

  /* Copy in the ordinates. */
  if ( line->points->npoints > 0 )
  {
    size = (size_t)line->points->npoints * ptsize;
    memcpy(loc, getPoint_internal(line->points, 0), size);
    loc += size;
  }
  LWDEBUGF(3, "%s copied serialized_pointlist (%d bytes)", __func__, ptsize * line->points->npoints);

  return (size_t)(loc - buf);
}

static size_t gserialized1_from_lwpoly(const LWPOLY *poly, uint8_t *buf)
{
  uint32_t i;
  uint8_t *loc;
  int ptsize;
  int type = POLYGONTYPE;

  assert(poly);
  assert(buf);

  LWDEBUGF(2, "%s called", __func__);

  ptsize = sizeof(double) * FLAGS_NDIMS(poly->flags);
  loc = buf;

  /* Write in the type. */
  memcpy(loc, &type, sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Write in the nrings. */
  memcpy(loc, &(poly->nrings), sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Write in the npoints per ring. */
  for ( i = 0; i < poly->nrings; i++ )
  {
    memcpy(loc, &(poly->rings[i]->npoints), sizeof(uint32_t));
    loc += sizeof(uint32_t);
  }

  /* Add in padding if necessary to remain double aligned. */
  if ( poly->nrings % 2 )
  {
    memset(loc, 0, sizeof(uint32_t));
    loc += sizeof(uint32_t);
  }

  /* Copy in the ordinates. */
  for ( i = 0; i < poly->nrings; i++ )
  {
    POINTARRAY *pa = poly->rings[i];
    size_t pasize;

    if ( FLAGS_GET_ZM(poly->flags) != FLAGS_GET_ZM(pa->flags) )
      lwerror("Dimensions mismatch in lwpoly");

    pasize = (size_t)pa->npoints * ptsize;
    if ( pa->npoints > 0 )
      memcpy(loc, getPoint_internal(pa, 0), pasize);
    loc += pasize;
  }
  return (size_t)(loc - buf);
}

static size_t gserialized1_from_lwtriangle(const LWTRIANGLE *triangle, uint8_t *buf)
{
  uint8_t *loc;
  int ptsize;
  size_t size;
  int type = TRIANGLETYPE;

  assert(triangle);
  assert(buf);

  LWDEBUGF(2, "%s (%p, %p) called", __func__, triangle, buf);

  if ( FLAGS_GET_ZM(triangle->flags) != FLAGS_GET_ZM(triangle->points->flags) )
    lwerror("Dimensions mismatch in lwtriangle");

  ptsize = ptarray_point_size(triangle->points);

  loc = buf;

  /* Write in the type. */
  memcpy(loc, &type, sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Write in the npoints. */
  memcpy(loc, &(triangle->points->npoints), sizeof(uint32_t));
  loc += sizeof(uint32_t);

  LWDEBUGF(3, "%s added npoints (%d)", __func__, triangle->points->npoints);

  /* Copy in the ordinates. */
  if ( triangle->points->npoints > 0 )
  {
    size = (size_t)triangle->points->npoints * ptsize;
    memcpy(loc, getPoint_internal(triangle->points, 0), size);
    loc += size;
  }
  LWDEBUGF(3, "%s copied serialized_pointlist (%d bytes)", __func__, ptsize * triangle->points->npoints);

  return (size_t)(loc - buf);
}

static size_t gserialized1_from_lwcircstring(const LWCIRCSTRING *curve, uint8_t *buf)
{
  uint8_t *loc;
  int ptsize;
  size_t size;
  int type = CIRCSTRINGTYPE;

  assert(curve);
  assert(buf);

  if (FLAGS_GET_ZM(curve->flags) != FLAGS_GET_ZM(curve->points->flags))
    lwerror("Dimensions mismatch in lwcircstring");


  ptsize = ptarray_point_size(curve->points);
  loc = buf;

  /* Write in the type. */
  memcpy(loc, &type, sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Write in the npoints. */
  memcpy(loc, &curve->points->npoints, sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Copy in the ordinates. */
  if ( curve->points->npoints > 0 )
  {
    size = (size_t)curve->points->npoints * ptsize;
    memcpy(loc, getPoint_internal(curve->points, 0), size);
    loc += size;
  }

  return (size_t)(loc - buf);
}

static size_t gserialized1_from_lwcollection(const LWCOLLECTION *coll, uint8_t *buf)
{
  size_t subsize = 0;
  uint8_t *loc;
  uint32_t i;
  int type;

  assert(coll);
  assert(buf);

  type = coll->type;
  loc = buf;

  /* Write in the type. */
  memcpy(loc, &type, sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Write in the number of subgeoms. */
  memcpy(loc, &coll->ngeoms, sizeof(uint32_t));
  loc += sizeof(uint32_t);

  /* Serialize subgeoms. */
  for ( i=0; i<coll->ngeoms; i++ )
  {
    if (FLAGS_GET_ZM(coll->flags) != FLAGS_GET_ZM(coll->geoms[i]->flags))
      lwerror("Dimensions mismatch in lwcollection");
    subsize = gserialized1_from_lwgeom_any(coll->geoms[i], loc);
    loc += subsize;
  }

  return (size_t)(loc - buf);
}

static size_t gserialized1_from_lwgeom_any(const LWGEOM *geom, uint8_t *buf)
{
  assert(geom);
  assert(buf);

  LWDEBUGF(2, "Input type (%d) %s, hasz: %d hasm: %d",
    geom->type, lwtype_name(geom->type),
    FLAGS_GET_Z(geom->flags), FLAGS_GET_M(geom->flags));
  LWDEBUGF(2, "LWGEOM(%p) uint8_t(%p)", geom, buf);

  switch (geom->type)
  {
  case POINTTYPE:
    return gserialized1_from_lwpoint((LWPOINT *)geom, buf);
  case LINETYPE:
    return gserialized1_from_lwline((LWLINE *)geom, buf);
  case POLYGONTYPE:
    return gserialized1_from_lwpoly((LWPOLY *)geom, buf);
  case TRIANGLETYPE:
    return gserialized1_from_lwtriangle((LWTRIANGLE *)geom, buf);
  case CIRCSTRINGTYPE:
    return gserialized1_from_lwcircstring((LWCIRCSTRING *)geom, buf);
  case CURVEPOLYTYPE:
  case COMPOUNDTYPE:
  case MULTIPOINTTYPE:
  case MULTILINETYPE:
  case MULTICURVETYPE:
  case MULTIPOLYGONTYPE:
  case MULTISURFACETYPE:
  case POLYHEDRALSURFACETYPE:
  case TINTYPE:
  case COLLECTIONTYPE:
    return gserialized1_from_lwcollection((LWCOLLECTION *)geom, buf);
  default:
    lwerror("Unknown geometry type: %d - %s", geom->type, lwtype_name(geom->type));
    return 0;
  }
  return 0;
}

static size_t gserialized1_from_gbox(const GBOX *gbox, uint8_t *buf)
{
  uint8_t *loc = buf;
  float f;
  size_t return_size;

  assert(buf);

  f = next_float_down(gbox->xmin);
  memcpy(loc, &f, sizeof(float));
  loc += sizeof(float);

  f = next_float_up(gbox->xmax);
  memcpy(loc, &f, sizeof(float));
  loc += sizeof(float);

  f = next_float_down(gbox->ymin);
  memcpy(loc, &f, sizeof(float));
  loc += sizeof(float);

  f = next_float_up(gbox->ymax);
  memcpy(loc, &f, sizeof(float));
  loc += sizeof(float);

  if ( FLAGS_GET_GEODETIC(gbox->flags) )
  {
    f = next_float_down(gbox->zmin);
    memcpy(loc, &f, sizeof(float));
    loc += sizeof(float);

    f = next_float_up(gbox->zmax);
    memcpy(loc, &f, sizeof(float));
    loc += sizeof(float);

    return_size = (size_t)(loc - buf);
    LWDEBUGF(4, "returning size %zu", return_size);
    return return_size;
  }

  if ( FLAGS_GET_Z(gbox->flags) )
  {
    f = next_float_down(gbox->zmin);
    memcpy(loc, &f, sizeof(float));
    loc += sizeof(float);

    f = next_float_up(gbox->zmax);
    memcpy(loc, &f, sizeof(float));
    loc += sizeof(float);

  }

  if ( FLAGS_GET_M(gbox->flags) )
  {
    f = next_float_down(gbox->mmin);
    memcpy(loc, &f, sizeof(float));
    loc += sizeof(float);

    f = next_float_up(gbox->mmax);
    memcpy(loc, &f, sizeof(float));
    loc += sizeof(float);
  }
  return_size = (size_t)(loc - buf);
  LWDEBUGF(4, "returning size %zu", return_size);
  return return_size;
}

/* Public function */

GSERIALIZED* gserialized1_from_lwgeom(LWGEOM *geom, size_t *size)
{
  size_t expected_size = 0;
  size_t return_size = 0;
  uint8_t *serialized = NULL;
  uint8_t *ptr = NULL;
  GSERIALIZED *g = NULL;
  assert(geom);

  /*
  ** See if we need a bounding box, add one if we don't have one.
  */
  if ( (! geom->bbox) && lwgeom_needs_bbox(geom) && (!lwgeom_is_empty(geom)) )
  {
    lwgeom_add_bbox(geom);
  }

  /*
  ** Harmonize the flags to the state of the lwgeom
  */
  if ( geom->bbox )
    FLAGS_SET_BBOX(geom->flags, 1);
  else
    FLAGS_SET_BBOX(geom->flags, 0);

  /* Set up the uint8_t buffer into which we are going to write the serialized geometry. */
  expected_size = gserialized1_from_lwgeom_size(geom);
  serialized = lwalloc(expected_size);
  ptr = serialized;

  /* Move past size, srid and flags. */
  ptr += 8;

  /* Write in the serialized form of the gbox, if necessary. */
  if ( geom->bbox )
    ptr += gserialized1_from_gbox(geom->bbox, ptr);

  /* Write in the serialized form of the geometry. */
  ptr += gserialized1_from_lwgeom_any(geom, ptr);

  /* Calculate size as returned by data processing functions. */
  return_size = ptr - serialized;

  if ( expected_size != return_size ) /* Uh oh! */
  {
    lwerror("Return size (%zu) not equal to expected size (%zu)!", return_size, expected_size);
    return NULL;
  }

  if ( size ) /* Return the output size to the caller if necessary. */
    *size = return_size;

  g = (GSERIALIZED*)serialized;

  /*
  ** We are aping PgSQL code here, PostGIS code should use
  ** VARSIZE to set this for real.
  */
  g->size = return_size << 2;

  /* Set the SRID! */
  gserialized1_set_srid(g, geom->srid);

  g->gflags = lwflags_get_g1flags(geom->flags);

  return g;
}

/***********************************************************************
* De-serialize GSERIALIZED into an LWGEOM.
*/

static LWGEOM* lwgeom_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *size);

static LWPOINT* lwpoint_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *size)
{
  uint8_t *start_ptr = data_ptr;
  LWPOINT *point;
  uint32_t npoints = 0;

  assert(data_ptr);

  point = (LWPOINT*)lwalloc(sizeof(LWPOINT));
  point->srid = SRID_UNKNOWN; /* Default */
  point->bbox = NULL;
  point->type = POINTTYPE;
  point->flags = lwflags;

  data_ptr += 4; /* Skip past the type. */
  npoints = gserialized1_get_uint32_t(data_ptr); /* Zero => empty geometry */
  data_ptr += 4; /* Skip past the npoints. */

  if ( npoints > 0 )
    point->point = ptarray_construct_reference_data(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), 1, data_ptr);
  else
    point->point = ptarray_construct(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), 0); /* Empty point */

  data_ptr += sizeof(double) * npoints * FLAGS_NDIMS(lwflags);

  if ( size )
    *size = data_ptr - start_ptr;

  return point;
}

static LWLINE* lwline_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *size)
{
  uint8_t *start_ptr = data_ptr;
  LWLINE *line;
  uint32_t npoints = 0;

  assert(data_ptr);

  line = (LWLINE*)lwalloc(sizeof(LWLINE));
  line->srid = SRID_UNKNOWN; /* Default */
  line->bbox = NULL;
  line->type = LINETYPE;
  line->flags = lwflags;

  data_ptr += 4; /* Skip past the type. */
  npoints = gserialized1_get_uint32_t(data_ptr); /* Zero => empty geometry */
  data_ptr += 4; /* Skip past the npoints. */

  if ( npoints > 0 )
    line->points = ptarray_construct_reference_data(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), npoints, data_ptr);

  else
    line->points = ptarray_construct(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), 0); /* Empty linestring */

  data_ptr += sizeof(double) * FLAGS_NDIMS(lwflags) * npoints;

  if ( size )
    *size = data_ptr - start_ptr;

  return line;
}

static LWPOLY* lwpoly_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *size)
{
  uint8_t *start_ptr = data_ptr;
  LWPOLY *poly;
  uint8_t *ordinate_ptr;
  uint32_t nrings = 0;
  uint32_t i = 0;

  assert(data_ptr);

  poly = (LWPOLY*)lwalloc(sizeof(LWPOLY));
  poly->srid = SRID_UNKNOWN; /* Default */
  poly->bbox = NULL;
  poly->type = POLYGONTYPE;
  poly->flags = lwflags;

  data_ptr += 4; /* Skip past the polygontype. */
  nrings = gserialized1_get_uint32_t(data_ptr); /* Zero => empty geometry */
  poly->nrings = nrings;
  LWDEBUGF(4, "nrings = %d", nrings);
  data_ptr += 4; /* Skip past the nrings. */

  ordinate_ptr = data_ptr; /* Start the ordinate pointer. */
  if ( nrings > 0)
  {
    poly->rings = (POINTARRAY**)lwalloc( sizeof(POINTARRAY*) * nrings );
    poly->maxrings = nrings;
    ordinate_ptr += nrings * 4; /* Move past all the npoints values. */
    if ( nrings % 2 ) /* If there is padding, move past that too. */
      ordinate_ptr += 4;
  }
  else /* Empty polygon */
  {
    poly->rings = NULL;
    poly->maxrings = 0;
  }

  for ( i = 0; i < nrings; i++ )
  {
    uint32_t npoints = 0;

    /* Read in the number of points. gserialized1_validate_geometry_buffer() has
     * already bounds-checked every ring's declared point count against the
     * remaining buffer and rejected overflowing byte sizes; a ring with fewer
     * than four points is geometrically invalid but not a memory-safety
     * problem, and PostGIS intentionally stores and reports such rings (see
     * Trac #408, #4470). */
    npoints = gserialized1_get_uint32_t(data_ptr);
    data_ptr += 4;

    /* Make a point array for the ring, and move the ordinate pointer past the ring ordinates. */
    poly->rings[i] = ptarray_construct_reference_data(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), npoints, ordinate_ptr);

    ordinate_ptr += sizeof(double) * FLAGS_NDIMS(lwflags) * npoints;
  }

  if ( size )
    *size = ordinate_ptr - start_ptr;

  return poly;
}

static LWTRIANGLE* lwtriangle_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *size)
{
  uint8_t *start_ptr = data_ptr;
  LWTRIANGLE *triangle;
  uint32_t npoints = 0;

  assert(data_ptr);

  triangle = (LWTRIANGLE*)lwalloc(sizeof(LWTRIANGLE));
  triangle->srid = SRID_UNKNOWN; /* Default */
  triangle->bbox = NULL;
  triangle->type = TRIANGLETYPE;
  triangle->flags = lwflags;

  data_ptr += 4; /* Skip past the type. */
  npoints = gserialized1_get_uint32_t(data_ptr); /* Zero => empty geometry */
  data_ptr += 4; /* Skip past the npoints. */

  if ( npoints > 0 )
    triangle->points = ptarray_construct_reference_data(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), npoints, data_ptr);
  else
    triangle->points = ptarray_construct(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), 0); /* Empty triangle */

  data_ptr += sizeof(double) * FLAGS_NDIMS(lwflags) * npoints;

  if ( size )
    *size = data_ptr - start_ptr;

  return triangle;
}

static LWCIRCSTRING* lwcircstring_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *size)
{
  uint8_t *start_ptr = data_ptr;
  LWCIRCSTRING *circstring;
  uint32_t npoints = 0;

  assert(data_ptr);

  circstring = (LWCIRCSTRING*)lwalloc(sizeof(LWCIRCSTRING));
  circstring->srid = SRID_UNKNOWN; /* Default */
  circstring->bbox = NULL;
  circstring->type = CIRCSTRINGTYPE;
  circstring->flags = lwflags;

  data_ptr += 4; /* Skip past the circstringtype. */
  npoints = gserialized1_get_uint32_t(data_ptr); /* Zero => empty geometry */
  data_ptr += 4; /* Skip past the npoints. */

  if ( npoints > 0 )
    circstring->points = ptarray_construct_reference_data(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), npoints, data_ptr);
  else
    circstring->points = ptarray_construct(FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), 0); /* Empty circularstring */

  data_ptr += sizeof(double) * FLAGS_NDIMS(lwflags) * npoints;

  if ( size )
    *size = data_ptr - start_ptr;

  return circstring;
}

static LWCOLLECTION* lwcollection_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *size)
{
  uint32_t type;
  uint8_t *start_ptr = data_ptr;
  LWCOLLECTION *collection;
  uint32_t ngeoms = 0;
  uint32_t i = 0;

  assert(data_ptr);

  type = gserialized1_get_uint32_t(data_ptr);
  data_ptr += 4; /* Skip past the type. */

  collection = (LWCOLLECTION*)lwalloc(sizeof(LWCOLLECTION));
  collection->srid = SRID_UNKNOWN; /* Default */
  collection->bbox = NULL;
  collection->type = type;
  collection->flags = lwflags;

  ngeoms = gserialized1_get_uint32_t(data_ptr);
  collection->ngeoms = ngeoms; /* Zero => empty geometry */
  data_ptr += 4; /* Skip past the ngeoms. */

  if ( ngeoms > 0 )
  {
    collection->geoms = lwalloc(sizeof(LWGEOM*) * ngeoms);
    collection->maxgeoms = ngeoms;
  }
  else
  {
    collection->geoms = NULL;
    collection->maxgeoms = 0;
  }

  /* Sub-geometries are never de-serialized with boxes (#1254) */
  FLAGS_SET_BBOX(lwflags, 0);

  for ( i = 0; i < ngeoms; i++ )
  {
    uint32_t subtype = gserialized1_get_uint32_t(data_ptr);
    size_t subsize = 0;

    if ( ! lwcollection_allows_subtype(type, subtype) )
    {
      lwerror("Invalid subtype (%s) for collection type (%s)", lwtype_name(subtype), lwtype_name(type));
      lwfree(collection);
      return NULL;
    }
    collection->geoms[i] = lwgeom_from_gserialized1_buffer(data_ptr, lwflags, &subsize);
    data_ptr += subsize;
  }

  if ( size )
    *size = data_ptr - start_ptr;

  return collection;
}

LWGEOM* lwgeom_from_gserialized1_buffer(uint8_t *data_ptr, lwflags_t lwflags, size_t *g_size)
{
  uint32_t type;

  assert(data_ptr);

  type = gserialized1_get_uint32_t(data_ptr);

  LWDEBUGF(2, "Got type %d (%s), hasz=%d hasm=%d geodetic=%d hasbox=%d", type, lwtype_name(type),
    FLAGS_GET_Z(lwflags), FLAGS_GET_M(lwflags), FLAGS_GET_GEODETIC(lwflags), FLAGS_GET_BBOX(lwflags));

  switch (type)
  {
  case POINTTYPE:
    return (LWGEOM *)lwpoint_from_gserialized1_buffer(data_ptr, lwflags, g_size);
  case LINETYPE:
    return (LWGEOM *)lwline_from_gserialized1_buffer(data_ptr, lwflags, g_size);
  case CIRCSTRINGTYPE:
    return (LWGEOM *)lwcircstring_from_gserialized1_buffer(data_ptr, lwflags, g_size);
  case POLYGONTYPE:
    return (LWGEOM *)lwpoly_from_gserialized1_buffer(data_ptr, lwflags, g_size);
  case TRIANGLETYPE:
    return (LWGEOM *)lwtriangle_from_gserialized1_buffer(data_ptr, lwflags, g_size);
  case MULTIPOINTTYPE:
  case MULTILINETYPE:
  case MULTIPOLYGONTYPE:
  case COMPOUNDTYPE:
  case CURVEPOLYTYPE:
  case MULTICURVETYPE:
  case MULTISURFACETYPE:
  case POLYHEDRALSURFACETYPE:
  case TINTYPE:
  case COLLECTIONTYPE:
    return (LWGEOM *)lwcollection_from_gserialized1_buffer(data_ptr, lwflags, g_size);
  default:
    lwerror("Unknown geometry type: %d - %s", type, lwtype_name(type));
    return NULL;
  }
}

LWGEOM* lwgeom_from_gserialized1(const GSERIALIZED *g)
{
  lwflags_t lwflags = 0;
  int32_t srid = 0;
  uint32_t lwtype = 0;
  uint8_t *data_ptr = NULL;
  LWGEOM *lwgeom = NULL;
  GBOX bbox;
  size_t size = 0;

  assert(g);

  srid = gserialized1_get_srid(g);
  lwflags = gserialized1_get_lwflags(g);

  if (gserialized1_payload_bounds(g, &data_ptr, NULL) == LW_FAILURE)
  {
    lwerror("%s: invalid GSERIALIZED header size", __func__);
    return NULL;
  }
  if (gserialized1_validate_geometry_buffer(
    data_ptr, (uint8_t *)g + gserialized1_buffer_size(g), lwflags, NULL) == LW_FAILURE)
    return NULL;
  lwtype = gserialized1_get_type(g);

  LWDEBUGF(4, "Got type %d (%s), srid=%d", lwtype, lwtype_name(lwtype), srid);

  lwgeom = lwgeom_from_gserialized1_buffer(data_ptr, lwflags, &size);

  if ( ! lwgeom )
  {
    lwerror("%s: unable create geometry", __func__); /* Ooops! */
    return NULL;
  }

  lwgeom->type = lwtype;
  lwgeom->flags = lwflags;

  if ( gserialized1_read_gbox_p(g, &bbox) == LW_SUCCESS )
  {
    lwgeom->bbox = gbox_copy(&bbox);
  }
  else if ( lwgeom_needs_bbox(lwgeom) && (lwgeom_calculate_gbox(lwgeom, &bbox) == LW_SUCCESS) )
  {
    lwgeom->bbox = gbox_copy(&bbox);
  }
  else
  {
    lwgeom->bbox = NULL;
  }

  lwgeom_set_srid(lwgeom, srid);

  return lwgeom;
}

const float * gserialized1_get_float_box_p(const GSERIALIZED *g, size_t *ndims)
{
  if (ndims)
    *ndims = G1FLAGS_NDIMS_BOX(g->gflags);
  if (!g) return NULL;
  if (!G1FLAGS_GET_BBOX(g->gflags)) return NULL;
  if (gserialized1_buffer_size(g) < offsetof(GSERIALIZED, data) + gserialized1_box_size(g))
    return NULL;
  return (const float *)(g->data);
}

/**
* Update the bounding box of a #GSERIALIZED, allocating a fresh one
* if there is not enough space to just write the new box in.
* <em>WARNING</em> if a new object needs to be created, the
* input pointer will have to be freed by the caller! Check
* to see if input == output. Returns null if there's a problem
* like mismatched dimensions.
*/
GSERIALIZED* gserialized1_set_gbox(GSERIALIZED *g, GBOX *gbox)
{

  int g_ndims = G1FLAGS_NDIMS_BOX(g->gflags);
  int box_ndims = FLAGS_NDIMS_BOX(gbox->flags);
  GSERIALIZED *g_out = NULL;
  size_t box_size = 2 * g_ndims * sizeof(float);
  float *fbox;
  int fbox_pos = 0;

  /* The dimensionality of the inputs has to match or we are SOL. */
  if ( g_ndims != box_ndims )
  {
    return NULL;
  }

  /* Serialized already has room for a box. */
  if (G1FLAGS_GET_BBOX(g->gflags))
  {
    g_out = g;
  }
  /* Serialized has no box. We need to allocate enough space for the old
     data plus the box, and leave a gap in the memory segment to write
     the new values into.
  */
  else
  {
    size_t varsize_new = LWSIZE_GET(g->size) + box_size;
    uint8_t *ptr;
    g_out = lwalloc(varsize_new);
    /* Copy the head of g into place */
    memcpy(g_out, g, 8);
    /* Copy the body of g into place after leaving space for the box */
    ptr = g_out->data;
    ptr += box_size;
    memcpy(ptr, g->data, LWSIZE_GET(g->size) - 8);
    G1FLAGS_SET_BBOX(g_out->gflags, 1);
    LWSIZE_SET(g_out->size, varsize_new);
  }

  /* Move bounds to nearest float values */
  gbox_float_round(gbox);
  /* Now write the float box values into the memory segment */
  fbox = (float*)(g_out->data);
  /* Copy in X/Y */
  fbox[fbox_pos++] = gbox->xmin;
  fbox[fbox_pos++] = gbox->xmax;
  fbox[fbox_pos++] = gbox->ymin;
  fbox[fbox_pos++] = gbox->ymax;
  /* Optionally copy in higher dims */
  if(gserialized1_has_z(g) || gserialized1_is_geodetic(g))
  {
    fbox[fbox_pos++] = gbox->zmin;
    fbox[fbox_pos++] = gbox->zmax;
  }
  if(gserialized1_has_m(g) && ! gserialized1_is_geodetic(g))
  {
    fbox[fbox_pos++] = gbox->mmin;
    fbox[fbox_pos++] = gbox->mmax;
  }

  return g_out;
}


/**
* Remove the bounding box from a #GSERIALIZED. Returns a freshly
* allocated #GSERIALIZED every time.
*/
GSERIALIZED* gserialized1_drop_gbox(GSERIALIZED *g)
{
  int g_ndims = G1FLAGS_NDIMS_BOX(g->gflags);
  size_t box_size = 2 * g_ndims * sizeof(float);
  size_t g_out_size = LWSIZE_GET(g->size) - box_size;
  GSERIALIZED *g_out = lwalloc(g_out_size);

  /* Copy the contents while omitting the box */
  if ( G1FLAGS_GET_BBOX(g->gflags) )
  {
    uint8_t *outptr = (uint8_t*)g_out;
    uint8_t *inptr = (uint8_t*)g;
    /* Copy the header (size+type) of g into place */
    memcpy(outptr, inptr, 8);
    outptr += 8;
    inptr += 8 + box_size;
    /* Copy parts after the box into place */
    memcpy(outptr, inptr, g_out_size - 8);
    G1FLAGS_SET_BBOX(g_out->gflags, 0);
    LWSIZE_SET(g_out->size, g_out_size);
  }
  /* No box? Nothing to do but copy and return. */
  else
  {
    memcpy(g_out, g, g_out_size);
  }

  return g_out;
}

Coverage Report

Created: 2026-11-12 07:15