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Reorder the geometries by index

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This commit is contained in:
Eric Fischer 2015-03-05 16:18:01 -08:00
parent a8b2db8d5a
commit 572df8ad39
1 changed files with 91 additions and 17 deletions
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108
geojson.c
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@ -289,7 +289,8 @@ void traverse_zooms(int geomfd[4], off_t geom_size[4], char *metabase, unsigned
}
struct index {
long long fpos;
long long start;
long long end;
unsigned long long index;
};
@ -409,11 +410,6 @@ void read_json(FILE *f, const char *fname, const char *layername, int maxzoom, i
json_pull *jp = json_begin_file(f);
long long seq = 0;
/* initial tile is 0/0/0 */
serialize_int(geomfile, 0, &geompos, fname, jp);
serialize_uint(geomfile, 0, &geompos, fname, jp);
serialize_uint(geomfile, 0, &geompos, fname, jp);
while (1) {
json_object *j = json_read(jp);
if (j == NULL) {
@ -544,12 +540,6 @@ void read_json(FILE *f, const char *fname, const char *layername, int maxzoom, i
parse_geometry(t, coordinates, bbox, &geompos, geomfile, VT_MOVETO, fname, jp);
serialize_byte(geomfile, VT_END, &geompos, fname, jp);
struct index index;
index.fpos = geomstart;
index.index = encode(bbox[0] / 2 + bbox[2] / 2, bbox[1] / 2 + bbox[3] / 2);
fwrite_check(&index, sizeof(struct index), 1, indexfile, fname, jp);
indexpos += sizeof(struct index);
/*
* Note that minzoom for lines is the dimension
* of the geometry in world coordinates, but
@ -580,6 +570,13 @@ void read_json(FILE *f, const char *fname, const char *layername, int maxzoom, i
serialize_byte(geomfile, minzoom, &geompos, fname, jp);
struct index index;
index.start = geomstart;
index.end = geompos;
index.index = encode(bbox[0] / 2 + bbox[2] / 2, bbox[1] / 2 + bbox[3] / 2);
fwrite_check(&index, sizeof(struct index), 1, indexfile, fname, jp);
indexpos += sizeof(struct index);
for (i = 0; i < 2; i++) {
if (bbox[i] < file_bbox[i]) {
file_bbox[i] = bbox[i];
@ -602,9 +599,6 @@ void read_json(FILE *f, const char *fname, const char *layername, int maxzoom, i
/* XXX check for any non-features in the outer object */
}
/* end of tile */
serialize_int(geomfile, -2, &geompos, fname, jp);
json_end(jp);
fclose(metafile);
fclose(geomfile);
@ -667,13 +661,15 @@ void read_json(FILE *f, const char *fname, const char *layername, int maxzoom, i
printf("using layer name %s\n", trunc);
}
/* Sort the index by geometry */
{
int bytes = sizeof(struct index);
fprintf(stderr,
"Sorting %lld indices for %lld features\n",
"Sorting %lld indices for %lld features, %lld bytes of geometry\n",
(long long) indexpos / bytes,
seq);
seq, (long long) geomst.st_size);
int page = sysconf(_SC_PAGESIZE);
long long unit = (50 * 1024 * 1024 / bytes) * bytes;
@ -745,6 +741,84 @@ void read_json(FILE *f, const char *fname, const char *layername, int maxzoom, i
close(indexfd);
}
/* Copy geometries to a new file in index order */
indexfd = open(indexname, O_RDONLY);
if (indexfd < 0) {
perror("reopen sorted index");
exit(EXIT_FAILURE);
}
struct index *index_map = mmap(NULL, indexpos, PROT_READ, MAP_PRIVATE, indexfd, 0);
if (index_map == MAP_FAILED) {
perror("mmap index");
exit(EXIT_FAILURE);
}
unlink(indexname);
char *geom_map = mmap(NULL, geomst.st_size, PROT_READ, MAP_PRIVATE, geomfd, 0);
if (geom_map == MAP_FAILED) {
perror("mmap unsorted geometry");
exit(EXIT_FAILURE);
}
if (close(geomfd) != 0) {
perror("close unsorted geometry");
}
sprintf(geomname, "%s%s", tmpdir, "/geom.XXXXXXXX");
geomfd = mkstemp(geomname);
if (geomfd < 0) {
perror(geomname);
exit(EXIT_FAILURE);
}
geomfile = fopen(geomname, "wb");
if (geomfile == NULL) {
perror(geomname);
exit(EXIT_FAILURE);
}
{
geompos = 0;
/* initial tile is 0/0/0 */
serialize_int(geomfile, 0, &geompos, fname, jp);
serialize_uint(geomfile, 0, &geompos, fname, jp);
serialize_uint(geomfile, 0, &geompos, fname, jp);
long long i;
long long sum = 0;
for (i = 0; i < indexpos / sizeof(struct index); i++) {
fwrite_check(geom_map + index_map[i].start, sizeof(char), index_map[i].end - index_map[i].start, geomfile, fname, jp);
sum += index_map[i].end - index_map[i].start;
}
/* end of tile */
serialize_int(geomfile, -2, &geompos, fname, jp);
fclose(geomfile);
}
if (munmap(index_map, indexpos) != 0) {
perror("unmap sorted index");
}
if (munmap(geom_map, geomst.st_size) != 0) {
perror("unmap unsorted geometry");
}
if (close(indexfd) != 0) {
perror("close sorted index");
}
/* Traverse and split the geometries for each zoom level */
geomfd = open(geomname, O_RDONLY);
if (geomfd < 0) {
perror("reopen sorted geometry");
exit(EXIT_FAILURE);
}
unlink(geomname);
if (fstat(geomfd, &geomst) != 0) {
perror("stat sorted geom\n");
exit(EXIT_FAILURE);
}
int fd[4];
off_t size[4];