Files
tippecanoe/memfile.cpp
Erica Fischer e2a7a409c7 Improve tiling speed (#195)
* Add a way to run tippecanoe single-threaded for profiling

* Do less work when the tilestats sample values list is already full

* Save a copy when retrieving the attribute key

* Fewer atomic operations

* Move string hashing from mbtiles to text

* Only do approximate attribute deduplication when writing tiles

* Feature dropping tests are sensitive to exact tile size

* All tile creators now create a string pool for the tile

* Features clipped away to nothing should not participate in that tile

* Revert "Only do approximate attribute deduplication when writing tiles"

This reverts commit c42b34b498.

* Also revert the related test changes

* Revert "Revert "Only do approximate attribute deduplication when writing tiles""

This reverts commit 18509876c3.

* Be more specific about the string hash function

* Use fnv1a instead of std::hash for everything

* Reduce the chance of hash collisions

* Stick a hash search on the front of the tree search in addpool

* Eliminate repeated hashing of the same string

* Switch instead of ifs in json parsing

* A few more cases to populate the hash in addpool

* Store the hash in the tree instead of recalculating

* Add explanatory comment for mysterious argument

* Fewer copies in attribute stringification

* Clean up ancient weirdness in JSON attribute stringification

* More serial_val cleanup

* Pass a serial_feature to rewrite instead of many broken-down arguments

* Get rid of the multiple geometries within `partial`

* Revert "Pass a serial_feature to rewrite instead of many broken-down arguments"

This reverts commit 6f4ab9b725.

* Goodbye, struct coalesce

* Revert "Features clipped away to nothing should not participate in that tile"

This reverts commit 124462fbdc.

* Migrating fields from partial to serial_feature

* Name reconciliation between serial_feature and partial

* Replace struct partial with an augmented serial_feature

* Fix some overzealous search-and-replace renaming

* Don't say struct so often

* Remove more of the former partial construction

* Commenting and cleaning up

* Trying again to avoid all these arguments to rewrite

* I swear I did this same thing before and it didn't work.

* More rewrite cleanup

* Exile --detect-shared-borders to its own file

* Add missing headers

* More commenting and cleanup

* More comments

* Sprinkle consts around

* Emplacing and std::moving

* More cleanup

* That shouldn't have worked after a std::move

* Don't need to allocate memory to compare keys

* Reduce use of the global string pool in tiling

* Another avoidable mvt_value construction

* Further reduction to explicit string pool passing

* These reverses are no longer optimizations

* These layernames can all be references

* Don't drag an unused layername string around with every feature

* Heed a compiler warning about potential buffer overflow

* Fix my confusion about which feature's string pool is relevant

* Avoid some unnecessary allocations in attribute accumulation

* Maybe faster serialization?

* Eliminate a comparison

* Do the same here

* Save a couple of allocations when parsing numbers in JSON

* Immediately assign features to layers instead of subdividing later

* Maintain tilestats for tippecanoe:retain_points_multiplier_sequence

* Crunch out more duplicate attribute values when writing out the tile

* Do tilestats for tippecanoe:retain_points_multiplier_first too

* Shell filters need to be real threads, even if nothing else does

* Simplify tippecanoe_minzoom/maxzoom representation

* Update version and changelog
2024-02-07 17:50:35 -08:00

92 lines
1.9 KiB
C++

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <errno.h>
#include "memfile.hpp"
#define INCREMENT 131072
#define INITIAL 256
struct memfile *memfile_open(int fd) {
if (ftruncate(fd, INITIAL) != 0) {
return NULL;
}
struct memfile *mf = new memfile;
if (mf == NULL) {
return NULL;
}
mf->fd = fd;
mf->tree = 0;
mf->off = 0;
return mf;
}
int memfile_close(struct memfile *file) {
// If it isn't full yet, flush out the string to the file now.
// If it is full, close out the buffered file writer.
if (file->fp == NULL) {
if (write(file->fd, file->map.c_str(), file->map.size()) != (ssize_t) file->map.size()) {
return -1;
}
if (file->fd >= 0) {
if (close(file->fd) != 0) {
return -1;
}
}
} else {
if (fclose(file->fp) != 0) {
return -1;
}
}
delete file;
return 0;
}
int memfile_write(struct memfile *file, void *s, long long len, bool &in_memory) {
// If it is full, append to the file.
// If it is not full yet, append to the string in memory.
in_memory = false;
if (file->fp != NULL) {
if (fwrite(s, sizeof(char), len, file->fp) != (size_t) len) {
return 0;
}
file->off += len;
} else {
file->map.append(std::string((char *) s, len));
file->off += len;
in_memory = true;
}
return len;
}
void memfile_full(struct memfile *file) {
// The file is full. Write out a copy of whatever has accumulated in memory
// to the file, and switch to appending to the file. Existing references
// into the memory still work.
if (file->fp != NULL) {
fprintf(stderr, "memfile marked full twice\n");
exit(EXIT_IMPOSSIBLE);
}
file->fp = fdopen(file->fd, "wb");
if (file->fp == NULL) {
fprintf(stderr, "fdopen memfile: %s\n", strerror(errno));
exit(EXIT_OPEN);
}
if (fwrite(file->map.c_str(), sizeof(char), file->map.size(), file->fp) != file->map.size()) {
fprintf(stderr, "memfile write: %s\n", strerror(errno));
exit(EXIT_WRITE);
}
}