Add utils to work with Postgres ranges

lib/www/server/lib/utils/index.js

@@ -6,5 +6,6 @@ module.exports = {
 	flattenQCDefinitions: require('./flattenQCDefinitions'),
 	deepMerge: require('./deepMerge'),
 	removeNulls: require('./removeNulls'),
-	logicalPath: require('./logicalPath')
+	logicalPath: require('./logicalPath'),
+	ranges: require('./ranges')
 };

lib/www/server/lib/utils/ranges.js

@@ -0,0 +1,74 @@
+
+function parseRange (str) {
+	const rx = /^[\[(].*,.*[)\]]$/
+
+	if (rx.test(str)) {
+		const lower_inclusive = str[0] == '[';
+		const upper_inclusive = str[str.length-1] == ']';
+		const [ lower, upper ] = str.slice(1,-1).split(",");
+		return {
+			upper,
+			lower,
+			upper_inclusive,
+			lower_inclusive
+		};
+	}
+}
+
+function parseValidity (str) {
+	const range = parseRange(str);
+
+	if (range) {
+		ts0 = range.lower ? new Date(range.lower) : null;
+		ts1 = range.upper ? new Date(range.upper) : null;
+
+		return {
+			...range,
+			lower: ts0,
+			upper: ts1
+		};
+	}
+}
+
+function withinValidity (range, ts) {
+	if (!ts) {
+		ts = new Date();
+	}
+
+	if (typeof range === "string") {
+		range = parseValidity(range);
+	}
+
+	if (range.lower) {
+		if (range.lower_inclusive) {
+			if (!(range.lower <= ts)) {
+				return false;
+			}
+		} else {
+			if (!(range.lower < ts)) {
+				return false;
+			}
+		}
+	}
+
+	if (range.upper) {
+		if (range.upper_inclusive) {
+			if (!(range.upper >= ts)) {
+				return false;
+			}
+		} else {
+			if (!(range.upper > ts)) {
+				return false;
+			}
+		}
+	}
+
+	return true;
+}
+
+module.exports = {
+	parseRange,
+	parseValidity,
+	withinValidity
+}
+