PostGIS 3.0.6dev-r@@SVN_REVISION@@
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◆ ptarray_from_wkb_state()

static POINTARRAY * ptarray_from_wkb_state ( wkb_parse_state s)
static

POINTARRAY Read a dynamically sized point array and advance the parse state forward.

First read the number of points, then read the points.

Definition at line 340 of file lwin_wkb.c.

341{
342 POINTARRAY *pa = NULL;
343 size_t pa_size;
344 uint32_t ndims = 2;
345 uint32_t npoints = 0;
346 static uint32_t maxpoints = UINT_MAX / WKB_DOUBLE_SIZE / 4;
347
348 /* Calculate the size of this point array. */
349 npoints = integer_from_wkb_state(s);
350 if (s->error)
351 return NULL;
352 if (npoints > maxpoints)
353 {
354 lwerror("Pointarray length (%d) is too large");
355 return NULL;
356 }
357
358 LWDEBUGF(4,"Pointarray has %d points", npoints);
359
360 if( s->has_z ) ndims++;
361 if( s->has_m ) ndims++;
362 pa_size = npoints * ndims * WKB_DOUBLE_SIZE;
363
364 /* Empty! */
365 if( npoints == 0 )
366 return ptarray_construct(s->has_z, s->has_m, npoints);
367
368 /* Does the data we want to read exist? */
369 wkb_parse_state_check(s, pa_size);
370 if (s->error)
371 return NULL;
372
373 /* If we're in a native endianness, we can just copy the data directly! */
374 if( ! s->swap_bytes )
375 {
376 pa = ptarray_construct_copy_data(s->has_z, s->has_m, npoints, (uint8_t*)s->pos);
377 s->pos += pa_size;
378 }
379 /* Otherwise we have to read each double, separately. */
380 else
381 {
382 uint32_t i = 0;
383 double *dlist;
384 pa = ptarray_construct(s->has_z, s->has_m, npoints);
385 dlist = (double*)(pa->serialized_pointlist);
386 for( i = 0; i < npoints * ndims; i++ )
387 {
388 dlist[i] = double_from_wkb_state(s);
389 }
390 }
391
392 return pa;
393}
char * s
Definition cu_in_wkt.c:23
POINTARRAY * ptarray_construct_copy_data(char hasz, char hasm, uint32_t npoints, const uint8_t *ptlist)
Construct a new POINTARRAY, copying in the data from ptlist.
Definition ptarray.c:305
POINTARRAY * ptarray_construct(char hasz, char hasm, uint32_t npoints)
Construct an empty pointarray, allocating storage and setting the npoints, but not filling in any inf...
Definition ptarray.c:51
#define WKB_DOUBLE_SIZE
Well-Known Binary (WKB) Output Variant Types.
#define LWDEBUGF(level, msg,...)
Definition lwgeom_log.h:88
void lwerror(const char *fmt,...)
Write a notice out to the error handler.
Definition lwutil.c:190
static uint32_t integer_from_wkb_state(wkb_parse_state *s)
Int32 Read 4-byte integer and advance the parse state forward.
Definition lwin_wkb.c:278
static void wkb_parse_state_check(wkb_parse_state *s, size_t next)
Check that we are not about to read off the end of the WKB array.
Definition lwin_wkb.c:131
static double double_from_wkb_state(wkb_parse_state *s)
Double Read an 8-byte double and advance the parse state forward.
Definition lwin_wkb.c:310
uint8_t * serialized_pointlist
Definition liblwgeom.h:420

References double_from_wkb_state(), integer_from_wkb_state(), LWDEBUGF, lwerror(), ptarray_construct(), ptarray_construct_copy_data(), s, POINTARRAY::serialized_pointlist, WKB_DOUBLE_SIZE, and wkb_parse_state_check().

Referenced by lwcircstring_from_wkb_state(), lwline_from_wkb_state(), lwpoly_from_wkb_state(), and lwtriangle_from_wkb_state().

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