75 lines
2.1 KiB
JavaScript
75 lines
2.1 KiB
JavaScript
#!/usr/bin/env node
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var fs = require("fs"),
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commander = require("commander"),
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topojson = require("../");
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commander
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.version(require("../package.json").version)
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.usage("[options] <n> [file]")
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.description("Quantizes TopoJSON.")
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.option("-o, --out <file>", "output topology file name; defaults to “-” for stdout", "-")
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.parse(process.argv);
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if (commander.args.length < 1) {
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console.error();
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console.error(" error: missing quantization parameter n");
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console.error();
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process.exit(1);
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} else if (commander.args.length > 2) {
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console.error();
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console.error(" error: multiple input files");
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console.error();
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process.exit(1);
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} else if (commander.args.length === 1) {
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commander.args.push("-");
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}
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if (!(Math.floor(commander.args[0]) >= 2)) {
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console.error();
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console.error(" error: invalid quantization parameter " + commander.args[0]);
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console.error();
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process.exit(1);
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}
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read(commander.args[1]).then(quantize).then(write(commander.out)).catch(abort);
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function read(file) {
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return new Promise(function(resolve, reject) {
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var data = [], stream = file === "-" ? process.stdin : fs.createReadStream(file);
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stream
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.on("data", function(d) { data.push(d); })
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.on("end", function() { resolve(JSON.parse(Buffer.concat(data))); })
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.on("error", reject);
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});
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}
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function quantize(topology) {
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return topojson.quantize(topology, +commander.args[0]);
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}
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function write(file) {
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var stream = (file === "-" ? process.stdout : fs.createWriteStream(file)).on("error", handleEpipe);
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return function(topology) {
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return new Promise(function(resolve, reject) {
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stream.on("error", reject)[stream === process.stdout ? "write" : "end"](JSON.stringify(topology) + "\n", function(error) {
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if (error) reject(error);
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else resolve();
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});
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});
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};
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}
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function handleEpipe(error) {
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if (error.code === "EPIPE" || error.errno === "EPIPE") {
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process.exit(0);
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}
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}
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function abort(error) {
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console.error();
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console.error(" error: " + error.message);
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console.error();
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process.exit(1);
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}
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