Initial commit

node_modules/pg-numeric/index.js

@@ -0,0 +1,125 @@
+'use strict';
+
+const readDigit = (buffer, index) => {
+	const digit = buffer.readUInt16BE(8 + 2 * index);
+
+	if (digit > 9999) {
+		throw new RangeError('Invalid numeric digit: ' + digit);
+	}
+
+	return digit;
+};
+
+const readNumeric = buffer => {
+	const ndigits = buffer.readUInt16BE(0);
+	let weight = buffer.readInt16BE(2);
+	const sign = buffer.readUInt16BE(4);
+	const dscale = buffer.readUInt16BE(6);
+	let signText;
+	let isNegativeZero;
+
+	switch (sign) {
+	case 0x0000:
+		signText = '';
+		isNegativeZero = false;
+		break;
+
+	case 0x4000:
+		signText = '-';
+		isNegativeZero = true;
+		break;
+
+	case 0xc000:
+		return 'NaN';
+
+	default:
+		throw new RangeError('Invalid numeric sign: 0x' + sign.toString(16));
+	}
+
+	if (2 * ndigits !== buffer.length - 8) {
+		throw new RangeError('Invalid numeric length: ' + buffer.length + ' bytes of data representing ' + ndigits + ' digits');
+	}
+
+	if (dscale > 0x3fff) {
+		throw new RangeError('Invalid numeric dscale: 0x' + dscale.toString(16));
+	}
+
+	let result = signText;
+	let i = 0;
+
+	integerPart: {
+		for (;;) {
+			if (i >= ndigits) {
+				// no non-zero digits
+				weight = -1;
+			}
+			if (weight < 0) {
+				result += '0';
+				break integerPart;
+			}
+
+			const digit = readDigit(buffer, i);
+			i++;
+			weight--;
+
+			if (digit !== 0) {
+				isNegativeZero = false;
+				result += String(digit);
+				break;
+			}
+		}
+
+		while (weight >= 0 && i < ndigits) {
+			const digit = readDigit(buffer, i);
+			i++;
+			weight--;
+
+			result += String(10000 + digit).substring(1);
+		}
+
+		while (weight >= 0) {
+			result += '0000';
+			weight--;
+		}
+	}
+
+	fractionalPart: if (dscale !== 0) {
+		result += '.';
+
+		const omitted = -1 - weight;
+
+		if (omitted > 0) {
+			if (4 * omitted > dscale) {
+				result += '0'.repeat(dscale);
+				break fractionalPart;
+			}
+
+			result += '0'.repeat(4 * omitted);
+		}
+
+		while (-4 * weight <= dscale) {
+			const digit = i < ndigits ? readDigit(buffer, i) : 0;
+			i++;
+			weight--;
+
+			if (isNegativeZero && digit !== 0) {
+				isNegativeZero = false;
+			}
+
+			result += String(10000 + digit).substring(1);
+		}
+
+		{
+			const digit = i < ndigits ? readDigit(buffer, i) : 0;
+			result += String(10000 + digit).substr(1, dscale % 4);
+
+			if (isNegativeZero && digit >= Math.pow(10, 4 - dscale % 4)) {
+				isNegativeZero = false;
+			}
+		}
+	}
+
+	return isNegativeZero ? result.substring(1) : result;
+};
+
+module.exports = readNumeric;