Add new split subcommand

package-lock.json

@@ -328,6 +328,11 @@
 			"resolved": "https://registry.npmjs.org/shebang-regex/-/shebang-regex-3.0.0.tgz",
 			"integrity": "sha512-7++dFhtcx3353uBaq8DDR4NuxBetBzC7ZQOhmTQInHEd6bSrXdiEyzCvG07Z44UYdLShWUyXt5M/yhz8ekcb1A=="
 		},
+		"spawn-stream": {
+			"version": "1.0.2",
+			"resolved": "https://registry.npmjs.org/spawn-stream/-/spawn-stream-1.0.2.tgz",
+			"integrity": "sha1-W9VkENXISo7N6y5jEnEWytkQUMs="
+		},
 		"string-to-arraybuffer": {
 			"version": "1.0.2",
 			"resolved": "https://registry.npmjs.org/string-to-arraybuffer/-/string-to-arraybuffer-1.0.2.tgz",

package.json

@@ -37,6 +37,7 @@
 		"chroma-js": "^2.1.0",
 		"image-encode": "^1.3.0",
 		"nexline": "^1.2.1",
+		"spawn-stream": "^1.0.2",
 		"terrain50": "^1.8.2"
 	},
 	"bin": {

src/Subcommands/split/index.mjs

@@ -0,0 +1,65 @@
+"use strict";
+
+import fs from 'fs';
+import path from 'path';
+
+import Terrain50 from 'terrain50';
+import SpawnStream from 'spawn-stream';
+
+import a from '../../Helpers/Ansi.mjs';
+import l from '../../Helpers/Log.mjs';
+
+export default async function(settings) {
+	// 1: Parse settings
+	let stream_in = process.stdin;
+	if(settings.cli.input !== "-") {
+		l.log(`Reading from ${a.hicol}${settings.cli.input}${a.reset}`);
+		stream_in = fs.createReadStream(settings.cli.input);
+	}
+	else
+		l.log(`Reading from stdin`);
+	
+	if(typeof settings.cli.output != "string") {
+		l.error(`Error: No output directory specified (try the --output argument).`);
+	}
+	
+	let dir_out = settings.cli.output; 
+	if(!fs.existsSync(dir_out))
+		await fs.promises.mkdir(dir_out, { recursive: true, mode: 0o750 });
+	l.log(`Writing to ${a.hicol}${settings.cli.output}${a.reset}`);
+	
+	// ------------------------------------------------------------------------
+	
+	let i = 0;
+	for await(let next of Terrain50.ParseStream(stream_in)) {
+		// Determine the output filepath
+		let output_filename = `${i}.asc`;
+		if(!settings.cli.no_gzip) output_filename += `.gz`;
+		output_filename = path.join(dir_out, output_filename);
+		
+		// Create the output stream
+		let stream_out = fs.createWriteStream(output_filename),
+			stream_gzip = null;
+		if(!settings.cli.no_gzip) {
+			stream_gzip = SpawnStream("gzip");
+			stream_gzip.pipe(stream_out);
+		}
+		
+		
+		// Write it to the output
+		await next.serialise(stream_gzip || stream_out, true);
+		
+		// Update the user
+		l.log(`Written ${i+1} objects so far`);
+		
+		if(i >= settings.cli.count - 1) {
+			l.log(`Reached limit of ${settings.cli.count} items, stopping here`);
+			break;
+		}
+		
+		i++;
+	}
+	l.log(`Splitting complete`);
+	
+	stream_in.destroy();
+}

src/Subcommands/split/meta.toml

@@ -0,0 +1,26 @@
+description = "Split a single stream of Terrain50 objects into seprate files"
+
+[[arguments]]
+name = "input"
+description = "The input Terrain50 file (default: stdin)"
+default_value = "-"
+type = "string"
+
+[[arguments]]
+name = "output"
+description = "The output directory to write to"
+# default_value = ""
+type = "string"
+
+[[arguments]]
+name = "no-gzip"
+description = "Don't automatically gzip the output streams"
+default_value = false
+type = "boolean"
+
+
+[[arguments]]
+name = "count"
+description = "The number of objects to extract (default: Infinity)"
+default_value = inf # inf = Infinity
+type = "integer"