API: Modularize data source loaders

src/api/data-sources/lsblk.js

@@ -0,0 +1,52 @@
+"use strict";
+
+const Promise = require("bluebird");
+const memoizee = require("memoizee");
+
+const lsblk = require("../../wrappers/lsblk");
+const All = require("../../graphql/symbols/all");
+
+function linearizeDevices(devices) {
+	let linearizedDevices = [];
+
+	function add(list) {
+		for (let device of list) {
+			linearizedDevices.push(device);
+
+			if (device.children != null) {
+				add(device.children);
+			}
+		}
+	}
+
+	add(devices);
+	
+	return linearizedDevices;
+}
+
+module.exports = function () {
+	let lsblkOnce = memoizee(() => {
+		return Promise.try(() => {
+			return lsblk();
+		}).then((devices) => {
+			return {
+				tree: devices,
+				list: linearizeDevices(devices)
+			};
+		});
+	});
+
+	return function (names) {
+		return Promise.try(() => {
+			return lsblkOnce();
+		}).then(({tree, list}) => {
+			return names.map((name) => {
+				if (name === All) {
+					return tree;
+				} else {
+					return list.find((device) => device.name === name);
+				}
+			});
+		});
+	};
+};

src/api/data-sources/lvm/physical-volumes.js

@@ -0,0 +1,25 @@
+"use strict";
+
+const Promise = require("bluebird");
+const memoizee = require("memoizee");
+
+const lvm = require("../../../wrappers/lvm");
+const All = require("../../../graphql/symbols/all");
+
+module.exports = function () {
+	let getPhysicalVolumesOnce = memoizee(lvm.getPhysicalVolumes);
+
+	return function (paths) {
+		return Promise.try(() => {
+			return getPhysicalVolumesOnce();
+		}).then((volumes) => {
+			return paths.map((path) => {
+				if (path === All) {
+					return volumes;
+				} else {
+					return volumes.find((device) => device.path === path);
+				}
+			});
+		});
+	};
+};

src/api/data-sources/smartctl/attributes.js

@@ -0,0 +1,12 @@
+"use strict";
+
+const Promise = require("bluebird");
+const smartctl = require("../../../wrappers/smartctl");
+
+module.exports = function () {
+	return function (paths) {
+		return Promise.map(paths, (path) => {
+			return smartctl.attributes({ devicePath: path });
+		});
+	};
+};

src/api/data-sources/smartctl/info.js

@@ -0,0 +1,12 @@
+"use strict";
+
+const Promise = require("bluebird");
+const smartctl = require("../../../wrappers/smartctl");
+
+module.exports = function () {
+	return function (paths) {
+		return Promise.map(paths, (path) => {
+			return smartctl.info({ devicePath: path });
+		});
+	};
+};

src/api/data-sources/smartctl/scan.js

@@ -0,0 +1,25 @@
+"use strict";
+
+const Promise = require("bluebird");
+const memoizee = require("memoizee");
+
+const smartctl = require("../../../wrappers/smartctl");
+const All = require("../../../graphql/symbols/all");
+
+module.exports = function () {
+	let scanOnce = memoizee(smartctl.scan);
+	
+	return function (paths) {
+		return Promise.try(() => {
+			return scanOnce();
+		}).then((devices) => {
+			return paths.map((path) => {
+				if (path === All) {
+					return devices;
+				} else {
+					return devices.find((device) => device.path === path);
+				}
+			});
+		});
+	};
+};

src/api/loaders.js

@@ -1,98 +1,21 @@
 "use strict";
 
-const Promise = require("bluebird");
-const memoizee = require("memoizee");
 const DataLoader = require("dataloader");
+const mapObj = require("map-obj");
 
-const lvm = require("../wrappers/lvm");
-const smartctl = require("../wrappers/smartctl");
-const lsblk = require("../wrappers/lsblk");
-const findmnt = require("../wrappers/findmnt");
-const All = require("../graphql/symbols/all");
-
-function linearizeDevices(devices) {
-	let linearizedDevices = [];
-
-	function add(list) {
-		for (let device of list) {
-			linearizedDevices.push(device);
-
-			if (device.children != null) {
-				add(device.children);
-			}
-		}
-	}
-
-	add(devices);
-	
-	return linearizedDevices;
-}
+let dataSourceFactories = {
+	lsblk: require("./data-sources/lsblk"),
+	smartctlInfo: require("./data-sources/smartctl/info"),
+	smartctlScan: require("./data-sources/smartctl/scan"),
+	smartctlAttributes: require("./data-sources/smartctl/attributes"),
+	lvmPhysicalVolumes: require("./data-sources/lvm/physical-volumes"),
+};
 
 module.exports = function createLoaders() {
-	/* The below is to ensure that commands that produce a full list of all possible items, only ever get called and processed *once* per query, no matter what data is requested. */
-	let smartctlScanOnce = memoizee(smartctl.scan);
-	let lvmGetPhysicalVolumesOnce = memoizee(lvm.getPhysicalVolumes);
-
-	let lsblkOnce = memoizee(() => {
-		return Promise.try(() => {
-			return lsblk();
-		}).then((devices) => {
-			return {
-				tree: devices,
-				list: linearizeDevices(devices)
-			};
-		});
+	return mapObj(dataSourceFactories, (name, factory) => {
+		return [
+			name,
+			new DataLoader(factory())
+		];
 	});
-
-	return {
-		lsblk: new DataLoader((names) => {
-			return Promise.try(() => {
-				return lsblkOnce();
-			}).then(({tree, list}) => {
-				return names.map((name) => {
-					if (name === All) {
-						return tree;
-					} else {
-						return list.find((device) => device.name === name);
-					}
-				});
-			});
-		}),
-		smartctlScan: new DataLoader((paths) => {
-			return Promise.try(() => {
-				return smartctlScanOnce();
-			}).then((devices) => {
-				return paths.map((path) => {
-					if (path === All) {
-						return devices;
-					} else {
-						return devices.find((device) => device.path === path);
-					}
-				});
-			});
-		}),
-		smartctlInfo: new DataLoader((paths) => {
-			return Promise.map(paths, (path) => {
-				return smartctl.info({ devicePath: path });
-			});
-		}),
-		smartctlAttributes: new DataLoader((paths) => {
-			return Promise.map(paths, (path) => {
-				return smartctl.attributes({ devicePath: path });
-			});
-		}),
-		lvmPhysicalVolumes: new DataLoader((paths) => {
-			return Promise.try(() => {
-				return lvmGetPhysicalVolumesOnce();
-			}).then((volumes) => {
-				return paths.map((path) => {
-					if (path === All) {
-						return volumes;
-					} else {
-						return volumes.find((device) => device.path === path);
-					}
-				});
-			});
-		}),
-	};
 };