Add capability to load tiled geojsons, eventually as overpass-cache

scripts/generateCache.ts

@@ -0,0 +1,176 @@
+/**
+ * Generates a collection of geojson files based on an overpass query for a given theme
+ */
+import {TileRange, Utils} from "../Utils";
+
+Utils.runningFromConsole = true
+import {Overpass} from "../Logic/Osm/Overpass";
+import {writeFileSync, existsSync, readFileSync} from "fs";
+import {TagsFilter} from "../Logic/Tags/TagsFilter";
+import {Or} from "../Logic/Tags/Or";
+import LayoutConfig from "../Customizations/JSON/LayoutConfig";
+import {AllKnownLayouts} from "../Customizations/AllKnownLayouts";
+import ScriptUtils from "./ScriptUtils";
+import ExtractRelations from "../Logic/Osm/ExtractRelations";
+import * as OsmToGeoJson from "osmtogeojson";
+import {Script} from "vm";
+
+function createOverpassObject(theme: LayoutConfig) {
+    let filters: TagsFilter[] = [];
+    let extraScripts: string[] = [];
+    for (const layer of theme.layers) {
+        if (typeof (layer) === "string") {
+            throw "A layer was not expanded!"
+        }
+        if (layer.doNotDownload) {
+            continue;
+        }
+        if (layer.source.geojsonSource !== undefined) {
+            // Not our responsibility to download this layer!
+            continue;
+        }
+
+
+        // Check if data for this layer has already been loaded
+        if (layer.source.overpassScript !== undefined) {
+            extraScripts.push(layer.source.overpassScript)
+        } else {
+            filters.push(layer.source.osmTags);
+        }
+    }
+    filters = Utils.NoNull(filters)
+    extraScripts = Utils.NoNull(extraScripts)
+    if (filters.length + extraScripts.length === 0) {
+        throw "Nothing to download! The theme doesn't declare anything to download"
+    }
+    return new Overpass(new Or(filters), extraScripts);
+}
+
+function saveResponse(chunks: string[], targetDir: string) {
+    const contents = chunks.join("")
+    if (contents.startsWith("<?xml")) {
+        // THis is an error message
+        console.error("Failed to create ", targetDir, "probably over quota")
+        return;
+    }
+    writeFileSync(targetDir, contents)
+}
+
+function rawJsonName(targetDir: string, x: number, y: number, z: number): string {
+    return targetDir + "_" + z + "_" + x + "_" + y + ".json"
+}
+
+function geoJsonName(targetDir: string, x: number, y: number, z: number): string {
+    return targetDir + "_" + z + "_" + x + "_" + y + ".geojson"
+}
+
+function metaJsonName(targetDir: string, x: number, y: number, z: number): string {
+    return targetDir + "_" + z + "_" + x + "_" + y + ".meta.json"
+}
+
+async function downloadRaw(targetdir: string,  r: TileRange, overpass: Overpass) {
+    let downloaded = 0
+    for (let x = r.xstart; x <= r.xend; x++) {
+        for (let y = r.ystart; y <= r.yend; y++) {
+            console.log("x:", (x - r.xstart), "/", (r.xend - r.xstart), "; y:", (y - r.ystart), "/", (r.yend - r.ystart), "; total: ", downloaded, "/", r.total)
+            downloaded++;
+            const filename = rawJsonName(targetdir, x, y, r.zoomlevel)
+            if (existsSync(filename)) {
+                console.log("Already exists: ", filename)
+                continue;
+            }
+
+            const boundsArr = Utils.tile_bounds(r.zoomlevel, x, y)
+            const bounds = {
+                north: Math.max(boundsArr[0][0], boundsArr[1][0]),
+                south: Math.min(boundsArr[0][0], boundsArr[1][0]),
+                east: Math.max(boundsArr[0][1], boundsArr[1][1]),
+                west: Math.min(boundsArr[0][1], boundsArr[1][1])
+            }
+            console.log("Downloading tile", r.zoomlevel, x, y, "with bounds", bounds)
+            const url = overpass.buildQuery("[bbox:" + bounds.south + "," + bounds.west + "," + bounds.north + "," + bounds.east + "]")
+
+            ScriptUtils.DownloadJSON(url,
+                chunks => {
+                    saveResponse(chunks, filename)
+                })
+
+            await ScriptUtils.sleep(10000)
+            console.debug("Waking up")
+
+        }
+    }
+}
+
+async function postProcess(targetdir: string, r: TileRange) {
+    let processed = 0;
+    for (let x = r.xstart; x <= r.xend; x++) {
+        for (let y = r.ystart; y <= r.yend; y++) {
+            processed++;
+            const filename = rawJsonName(targetdir, x, y, r.zoomlevel)
+            console.log(" Post processing", processed, "/",r. total, filename)
+            if (!existsSync(filename)) {
+                throw "Not found - and not downloaded. Run this script again!: " + filename
+            }
+
+            // We read the raw OSM-file and convert it to a geojson
+            const rawOsm = JSON.parse(readFileSync(filename, "UTF8"))
+
+            // Create and save the geojson file - which is the main chunk of the data
+            const geojson = OsmToGeoJson.default(rawOsm);
+            writeFileSync(geoJsonName(targetdir, x, y, r.zoomlevel), JSON.stringify(geojson))
+
+            // Extract the relationship information
+            const relations = ExtractRelations.GetRelationElements(rawOsm)
+            const osmTime = new Date(rawOsm.osm3s.timestamp_osm_base);
+
+            const meta = {
+                freshness: osmTime,
+                relations: relations
+            }
+
+            writeFileSync(
+                metaJsonName(targetdir, x, y, r.zoomlevel),
+                JSON.stringify(meta)
+            )
+        }
+    }
+}
+
+async function main(args: string[]) {
+
+    if (args.length == 0) {
+        console.error("Expected arguments are: theme zoomlevel targetdirectory lat0 lon0 lat1 lon1")
+        return;
+    }
+    const themeName = args[0]
+    const zoomlevel = Number(args[1])
+    const targetdir = args[2]
+    const lat0 = Number(args[3])
+    const lon0 = Number(args[4])
+    const lat1 = Number(args[5])
+    const lon1 = Number(args[6])
+
+    const tileRange = Utils.TileRangeBetween(zoomlevel, lat0, lon0, lat1, lon1)
+
+    const theme = AllKnownLayouts.allKnownLayouts.get(themeName)
+    if (theme === undefined) {
+        const keys = []
+        AllKnownLayouts.allKnownLayouts.forEach((_, key) => {
+            keys.push(key)
+        })
+        console.error("The theme " + theme + " was not found; try one of ", keys);
+        return
+    }
+
+    const overpass = createOverpassObject(theme)
+
+
+    await downloadRaw(targetdir, tileRange, overpass)
+    await postProcess(targetdir, tileRange)
+}
+
+
+let args = [...process.argv]
+args.splice(0, 2)
+main(args);