Remove per-feature compression; move minzoom back into the object

This commit is contained in:
Erica Fischer
2023-01-25 10:07:22 -08:00
parent c7393d8e2e
commit a035e4338a
+8 -23
View File
@@ -295,27 +295,12 @@ void serialize_feature(FILE *geomfile, serial_feature *sf, std::atomic<long long
serialize_long_long(s, sf->values[i]);
}
if (s.size() > 500) { // smaller than this rarely comes out smaller than it started
std::string compressed;
compress(s, compressed, false); // false for no gzip header: saves 12 bytes
if (s.size() <= compressed.size()) {
serialize_long_long(geomfile, s.size(), geompos, fname);
fwrite_check(s.c_str(), sizeof(char), s.size(), geomfile, fname);
*geompos += s.size();
} else {
serialize_long_long(geomfile, -compressed.size(), geompos, fname);
fwrite_check(compressed.c_str(), sizeof(char), compressed.size(), geomfile, fname);
*geompos += compressed.size();
}
} else {
serialize_long_long(geomfile, s.size(), geompos, fname);
fwrite_check(s.c_str(), sizeof(char), s.size(), geomfile, fname);
*geompos += s.size();
}
// MAGIC: This knows that the feature minzoom is the last byte of the feature,
serialize_byte(geomfile, sf->feature_minzoom, geompos, fname);
serialize_byte(s, sf->feature_minzoom);
serialize_long_long(geomfile, s.size(), geompos, fname);
fwrite_check(s.c_str(), sizeof(char), s.size(), geomfile, fname);
*geompos += s.size();
}
serial_feature deserialize_feature(FILE *geoms, std::atomic<long long> *geompos_in, unsigned z, unsigned tx, unsigned ty, unsigned *initial_x, unsigned *initial_y) {
@@ -406,14 +391,14 @@ serial_feature deserialize_feature(FILE *geoms, std::atomic<long long> *geompos_
sf.values.push_back(v);
}
// MAGIC: This knows that the feature minzoom is the last byte of the feature.
deserialize_byte(&cp, &sf.feature_minzoom);
if (cp != s.c_str() + len) {
fprintf(stderr, "wrong length decoding feature: used %zd, len is %llu\n", cp - s.c_str(), len);
exit(EXIT_IMPOSSIBLE);
}
// MAGIC: This knows that the feature minzoom is the last byte of the feature.
deserialize_byte_io(geoms, &sf.feature_minzoom, geompos_in);
return sf;
}