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Diffstat (limited to 'README.adoc')
| -rw-r--r-- | README.adoc | 38 |
1 files changed, 34 insertions, 4 deletions
diff --git a/README.adoc b/README.adoc index 8636e74..9c673d9 100644 --- a/README.adoc +++ b/README.adoc @@ -8,7 +8,7 @@ hittekaart - A GPX track heatmap generator. == SYNOPSIS ---- -hittekaart [--output=...] [--min-zoom=...] [--max-zoom=...] [--threads=...] FILES... +hittekaart [--output=...] [--min-zoom=...] [--max-zoom=...] [--threads=...] [--sqlite] FILES... ---- == INSTALLATION @@ -38,6 +38,29 @@ By default, the directory `tiles/` will be used as the root directory, so a tile would be saved as `tiles/{zoom}/{x}/{y}.png`. You can change this by using the `--output/-o` option. +=== SQLITE OUTPUT + +In order to overcome storage overhead when saving many small files (see the tip +and table further below), `hittekaart` can instead output a SQLite database +with the heatmap tile data. To do so, use the `--sqlite` command line option, +and control where the SQLite file should be placed with `--output`/`-o`. + +While this does not allow you to immediately serve the tiles with a HTTP +server, it does cut down on the wasted space on non-optimal file systems. + +The generated SQLite file will have one table with the following schema: + +[source,sql] +---- +CREATE TABLE tiles ( + zoom INTEGER, + x INTEGER, + y INTEGER, + data BLOB, + PRIMARY KEY (zoom, x, y) +); +---- + === INPUT FILES `hittekaart` expects GPX track files with the `.gpx` extension. It will parse @@ -140,8 +163,8 @@ system that is optimized for a large amount of small files, for example by setting a smaller block size. Many of the PNG images are smaller than 2 KiB (half a standard block); for those 50% of storage is wasted already. -Currently, `hittekaart` does not provide a built-in way to store or serve the -tiles more efficiently. +If you don't need the tiles in separate files, you can use the SQLite output +mode. For the same data as above, the SQLite database would be 73 MiB in size. ==== == OPTIONS @@ -161,7 +184,14 @@ The following options are supported: will automatically pick a default. `-o DIRECTORY`, `--output=DIRECTORY`:: - Generate the output tiles into the given directory. Defaults to `tiles/`. + Generate the output tiles into the given directory. Defaults to `tiles/` + when generating single files, and `tiles.sqlite` when storing the tiles in + a SQLite database. + +`--sqlite`:: + Output a single SQLite file with all tiles instead of saving each tile as a + separate PNG file. In this case, `-o` can be used to set the location of + the SQLite database. The schema is described above. == EXAMPLE |