Demo of projection database served over duckdbvfs barebone implementation

[carlopi]

Demo of projection database served over duckdbvfs barebone implementation.

To try this out:

1. Generate proj.db

#include <stdio.h>
#include "spatial/src/spatial/proj/proj_db.c"

int main(void)
{
    for (unsigned int i = 0; i < proj_db_len; i++)
        putchar(proj_db[i]);
    return 0;
}

g++ file.cpp -o generate_proj && ./generate_proj > proj.db
(should this part of the Makefile? Or it's already there?)

2. Launch http-server from the same folder where proj.db is

3. python3 duckdb/scripts/run_tests_one_by_one.py ./build/release/test/unittest '/Users/carlo/duckdblabs/duckdb_spatial/test/sql/*

TODO:

• Sort out context cleanup (see failure in unittester)
• Make location configurable via DuckDB option (should there be a MAP[extension_name] -> (MAP[option_name] -> option_value) to store extension options needed at load time ?
• Figure out whether proj.db should be fetched on load or anyhow proper strategy. Or maybe native have it backed in (who cares) but optionally configurable, and Wasm has it always remote

[carlopi]

Sizes for Wasm extensions [pre / post] [uncompressed / compressed]:

-rw-r--r--   1 carlo  staff  22808679 Oct  3 14:24 current_spatial.duckdb_extension.wasm
-rw-r--r--   1 carlo  staff   4420396 Oct  3 14:24 current_spatial.duckdb_extension.wasm.br
-rwxr-xr-x   1 carlo  staff  14502924 Oct  3 14:23 next_spatial.duckdb_extension.wasm
-rwxr-xr-x   1 carlo  staff   3340354 Oct  3 14:21 next_spatial.duckdb_extension.wasm.br