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C++: throw exceptions in overflow cases

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This commit is contained in:
Brandon Liu
2022-12-22 21:55:05 +08:00
parent f9cc6a20ac
commit 58d47196c7
2 changed files with 49 additions and 9 deletions
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21
cpp/pmtiles.hpp
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@@ -311,14 +311,14 @@ void rotate(int64_t n, int64_t &x, int64_t &y, int64_t rx, int64_t ry) {
}
zxy t_on_level(uint8_t z, uint64_t pos) {
int64_t n = 1 << z;
int64_t n = 1LL << z;
int64_t rx, ry, s, t = pos;
int64_t tx = 0;
int64_t ty = 0;
for (s = 1; s < n; s *= 2) {
rx = 1 & (t / 2);
ry = 1 & (t ^ rx);
rx = 1LL & (t / 2);
ry = 1LL & (t ^ rx);
rotate(s, tx, ty, rx, ry);
tx += s * rx;
ty += s * ry;
@@ -385,28 +385,33 @@ entryv3 find_tile(const std::vector<entryv3> &entries, uint64_t tile_id) {
inline zxy tileid_to_zxy(uint64_t tileid) {
uint64_t acc = 0;
uint8_t t_z = 0;
while (true) {
for (uint8_t t_z = 0; t_z < 32; t_z++) {
uint64_t num_tiles = (1LL << t_z) * (1LL << t_z);
if (acc + num_tiles > tileid) {
return t_on_level(t_z, tileid - acc);
}
acc += num_tiles;
t_z++;
}
throw std::overflow_error("tile zoom exceeds 64-bit limit");
}
inline uint64_t zxy_to_tileid(uint8_t z, uint32_t x, uint32_t y) {
if (z > 31) {
throw std::overflow_error("tile zoom exceeds 64-bit limit");
}
if (x > (1 << z) - 1 || y > (1 << z) - 1) {
throw std::overflow_error("tile x/y outside zoom level bounds");
}
uint64_t acc = 0;
for (uint8_t t_z = 0; t_z < z; t_z++) acc += (1LL << t_z) * (1LL << t_z);
int64_t n = 1 << z;
int64_t n = 1LL << z;
int64_t rx, ry, s, d = 0;
int64_t tx = x;
int64_t ty = y;
for (s = n / 2; s > 0; s /= 2) {
rx = (tx & s) > 0;
ry = (ty & s) > 0;
d += s * s * ((3 * rx) ^ ry);
d += s * s * ((3LL * rx) ^ ry);
rotate(s, tx, ty, rx, ry);
}
return acc + d;