tippecanoe/geojson.c
2014-09-17 16:21:25 -07:00

453 lines
10 KiB
C

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <string.h>
#include <fcntl.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include "jsonpull.h"
#define GEOM_POINT 0 /* array of positions */
#define GEOM_MULTIPOINT 1 /* array of arrays of positions */
#define GEOM_LINESTRING 2 /* array of arrays of positions */
#define GEOM_MULTILINESTRING 3 /* array of arrays of arrays of positions */
#define GEOM_POLYGON 4 /* array of arrays of arrays of positions */
#define GEOM_MULTIPOLYGON 5 /* array of arrays of arrays of arrays of positions */
#define GEOM_TYPES 6
#define VT_END 0
#define VT_POINT 1
#define VT_LINE 2
#define VT_POLYGON 3
#define VT_MOVETO 1
#define VT_LINETO 2
#define VT_CLOSEPATH 7
#define VT_STRING 1
#define VT_NUMBER 2
#define VT_BOOLEAN 7
char *geometry_names[GEOM_TYPES] = {
"Point",
"MultiPoint",
"LineString",
"MultiLineString",
"Polygon",
"MultiPolygon",
};
int geometry_within[GEOM_TYPES] = {
-1, /* point */
GEOM_POINT, /* multipoint */
GEOM_POINT, /* linestring */
GEOM_LINESTRING, /* multilinestring */
GEOM_LINESTRING, /* polygon */
GEOM_POLYGON, /* multipolygon */
};
int mb_geometry[GEOM_TYPES] = {
VT_POINT,
VT_POINT,
VT_LINE,
VT_LINE,
VT_POLYGON,
VT_POLYGON,
};
// http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
void latlon2tile(double lat, double lon, int zoom, unsigned int *x, unsigned int *y) {
double lat_rad = lat * M_PI / 180;
unsigned long long n = 1LL << zoom;
*x = n * ((lon + 180) / 360);
*y = n * (1 - (log(tan(lat_rad) + 1/cos(lat_rad)) / M_PI)) / 2;
}
#define MAX_ZOOM 28
#define ZOOM_BITS 5
int get_bbox_zoom(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2) {
int z;
for (z = 0; z < MAX_ZOOM; z++) {
int mask = 1 << (32 - (z + 1));
if (((x1 & mask) != (x2 & mask)) ||
((y1 & mask) != (y2 & mask))) {
return z;
}
}
return MAX_ZOOM;
}
void get_bbox_tile(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, int *z, unsigned int *x, unsigned int *y) {
*z = get_bbox_zoom(x1, y1, x2, y2);
if (*z == 0) {
*x = *y = 0;
} else {
*x = x1 >> (32 - *z);
*y = y1 >> (32 - *z);
}
}
/*
* 5 bits for zoom (<< 59)
* 56 bits for interspersed yx (<< 3)
* 3 bits for tags (<< 0)
*/
unsigned long long encode_bbox(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2, int tags) {
int z = get_bbox_zoom(x1, y1, x2, y2);
long long out = ((long long) z) << (64 - ZOOM_BITS);
int i;
for (i = 0; i < MAX_ZOOM; i++) {
long long v = ((y1 >> (32 - (i + 1))) & 1) << 1;
v |= (x1 >> (32 - (i + 1))) & 1;
v = v << (64 - ZOOM_BITS - 2 * (i + 1));
out |= v;
}
return out;
}
struct index {
unsigned long long index;
long long fpos;
struct index *next;
};
int indexcmp(const void *v1, const void *v2) {
const struct index *i1 = v1;
const struct index *i2 = v2;
if (i1->index < i2->index) {
return -1;
} else if (i1->index > i2->index) {
return 1;
} else {
return 0;
}
}
size_t fwrite_check(const void *ptr, size_t size, size_t nitems, FILE *stream) {
size_t w = fwrite(ptr, size, nitems, stream);
if (w != nitems) {
fprintf(stderr, "Write failed\n");
exit(EXIT_FAILURE);
}
return w;
}
void serialize_int(FILE *out, int n, long long *fpos) {
fwrite_check(&n, sizeof(int), 1, out);
*fpos += sizeof(int);
}
void serialize_uint(FILE *out, unsigned n, long long *fpos) {
fwrite_check(&n, sizeof(unsigned), 1, out);
*fpos += sizeof(unsigned);
}
void serialize_string(FILE *out, char *s, long long *fpos) {
int len = strlen(s);
serialize_int(out, len, fpos);
fwrite_check(s, sizeof(char), len, out);
*fpos += len;
}
void parse_geometry(int t, json_object *j, unsigned *bbox, long long *fpos, FILE *out, int op) {
if (j == NULL || j->type != JSON_ARRAY) {
fprintf(stderr, "expected array for type %d\n", t);
return;
}
int within = geometry_within[t];
if (within >= 0) {
int i;
for (i = 0; i < j->length; i++) {
if (within == GEOM_POINT) {
if (i == 0 || t == GEOM_MULTIPOINT) {
op = VT_MOVETO;
} else {
op = VT_LINETO;
}
}
parse_geometry(within, j->array[i], bbox, fpos, out, op);
}
} else {
if (j->length == 2 && j->array[0]->type == JSON_NUMBER && j->array[1]->type == JSON_NUMBER) {
unsigned x, y;
double lon = j->array[0]->number;
double lat = j->array[1]->number;
latlon2tile(lat, lon, 32, &x, &y);
if (bbox != NULL) {
if (x < bbox[0]) {
bbox[0] = x;
}
if (y < bbox[1]) {
bbox[1] = y;
}
if (x > bbox[2]) {
bbox[2] = x;
}
if (y > bbox[3]) {
bbox[3] = y;
}
}
serialize_int(out, op, fpos);
serialize_uint(out, x, fpos);
serialize_uint(out, y, fpos);
} else {
fprintf(stderr, "malformed point");
}
}
if (t == GEOM_POLYGON) {
serialize_int(out, VT_CLOSEPATH, fpos);
}
}
void deserialize_int(char **f, int *n) {
memcpy(n, *f, sizeof(int));
*f += sizeof(int);
}
void deserialize_string(char **f) {
int len;
deserialize_int(f, &len);
char s[len + 1];
memcpy(s, *f, len);
*f += len;
s[len] = '\0';
printf("%s", s);
}
void check(struct index *ix, long long n, char *metabase) {
int i;
for (i = 0; i < n; i++) {
printf("%llx ", ix[i].index);
char *meta = metabase + ix[i].fpos;
int m;
deserialize_int(&meta, &m);
int i;
for (i = 0; i < m; i++) {
int t;
deserialize_int(&meta, &t);
printf("(%d) ", t);
deserialize_string(&meta);
printf("=");
deserialize_string(&meta);
printf("; ");
}
int t;
deserialize_int(&meta, &t);
printf("(%d) ", t);
while (1) {
deserialize_int(&meta, &t);
if (t == VT_END) {
break;
}
printf("%d: ", t);
if (t == VT_MOVETO || t == VT_LINETO) {
int x, y;
deserialize_int(&meta, &x);
deserialize_int(&meta, &y);
printf("%x,%x ", x, y);
}
}
printf("\n");
}
}
void read_json(FILE *f) {
json_pull *jp = json_begin_file(f);
FILE *metafile = fopen("meta.out", "wb");
FILE *indexfile = fopen("index.out", "wb");
long long fpos = 0;
while (1) {
json_object *j = json_read(jp);
if (j == NULL) {
if (jp->error != NULL) {
fprintf(stderr, "%d: %s\n", jp->line, jp->error);
}
json_free(jp->root);
break;
}
json_object *type = json_hash_get(j, "type");
if (type == NULL || type->type != JSON_STRING || strcmp(type->string, "Feature") != 0) {
continue;
}
json_object *geometry = json_hash_get(j, "geometry");
if (geometry == NULL) {
fprintf(stderr, "%d: feature with no geometry\n", jp->line);
goto next_feature;
}
json_object *geometry_type = json_hash_get(geometry, "type");
if (geometry_type == NULL || geometry_type->type != JSON_STRING) {
fprintf(stderr, "%d: geometry without type string\n", jp->line);
goto next_feature;
}
json_object *properties = json_hash_get(j, "properties");
if (properties == NULL || properties->type != JSON_HASH) {
fprintf(stderr, "%d: feature without properties hash\n", jp->line);
goto next_feature;
}
json_object *coordinates = json_hash_get(geometry, "coordinates");
if (coordinates == NULL || coordinates->type != JSON_ARRAY) {
fprintf(stderr, "%d: feature without coordinates array\n", jp->line);
goto next_feature;
}
int t;
for (t = 0; t < GEOM_TYPES; t++) {
if (strcmp(geometry_type->string, geometry_names[t]) == 0) {
break;
}
}
if (t >= GEOM_TYPES) {
fprintf(stderr, "%d: Can't handle geometry type %s\n", jp->line, geometry_type->string);
goto next_feature;
}
/* scope for variable-length arrays */
{
long long start = fpos;
char *metakey[properties->length];
char *metaval[properties->length];
int metatype[properties->length];
int m = 0;
int i;
for (i = 0; i < properties->length; i++) {
if (properties->keys[i]->type == JSON_STRING) {
metakey[m] = properties->keys[i]->string;
if (properties->values[i] != NULL && properties->values[i]->type == JSON_STRING) {
metatype[m] = VT_STRING;
metaval[m] = properties->values[i]->string;
m++;
} else if (properties->values[i] != NULL && properties->values[i]->type == JSON_NUMBER) {
metatype[m] = VT_NUMBER;
metaval[m] = properties->values[i]->string;
m++;
} else if (properties->values[i] != NULL && (properties->values[i]->type == JSON_TRUE || properties->values[i]->type == JSON_FALSE)) {
metatype[m] = VT_BOOLEAN;
metaval[m] = properties->values[i]->string;
m++;
} else {
fprintf(stderr, "%d: Unsupported metafile type\n", jp->line);
goto next_feature;
}
}
}
serialize_int(metafile, m, &fpos);
for (i = 0; i < m; i++) {
serialize_int(metafile, metatype[i], &fpos);
serialize_string(metafile, metakey[i], &fpos);
serialize_string(metafile, metaval[i], &fpos);
}
unsigned bbox[] = { UINT_MAX, UINT_MAX, 0, 0 };
serialize_int(metafile, t, &fpos);
parse_geometry(t, coordinates, bbox, &fpos, metafile, VT_MOVETO);
serialize_int(metafile, VT_END, &fpos);
// printf("bbox %x %x %x %x\n", bbox[0], bbox[1], bbox[2], bbox[3]);
struct index ix;
ix.index = encode_bbox(bbox[0], bbox[1], bbox[2], bbox[3], 0);
ix.fpos = start;
fwrite_check(&ix, sizeof(struct index), 1, indexfile);
}
next_feature:
json_free(j);
/* XXX check for any non-features in the outer object */
}
json_end(jp);
fclose(metafile);
fclose(indexfile);
int fd = open("index.out", O_RDWR);
struct stat st;
fstat(fd, &st);
struct index *index = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
if (index == MAP_FAILED) {
perror("mmap index");
exit(EXIT_FAILURE);
}
int mfd = open("meta.out", O_RDWR);
struct stat mst;
fstat(mfd, &mst);
char *meta = mmap(NULL, mst.st_size, PROT_READ, MAP_PRIVATE, mfd, 0);
if (meta == MAP_FAILED) {
perror("mmap meta");
exit(EXIT_FAILURE);
}
qsort(index, st.st_size / sizeof(struct index), sizeof(struct index), indexcmp);
check(index, st.st_size / sizeof(struct index), meta);
munmap(index, st.st_size);
munmap(meta, mst.st_size);
close(fd);
close(mfd);
}
int main(int argc, char **argv) {
if (argc > 1) {
int i;
for (i = 1; i < argc; i++) {
FILE *f = fopen(argv[i], "r");
if (f == NULL) {
fprintf(stderr, "%s: %s: %s\n", argv[0], argv[i], strerror(errno));
} else {
read_json(f);
fclose(f);
}
}
} else {
read_json(stdin);
}
return 0;
}