move rfwfs into rt

src/rt/rfwfs/index.ts

@@ -0,0 +1,78 @@
+import { type FsList, type FsEntry } from "./core"
+
+interface SearchResult<T> {
+	item: T,
+	binary_index: number
+}
+interface Search {
+	binary_fs: (cloned_list: FsList, file_name: string) => SearchResult<FsEntry> | undefined,
+	binary_nsort: <T>(list: T[], find: T, start: number, end: number) => SearchResult<T> | undefined,
+	binary: <T>(list: T[], find: T) => SearchResult<T> | undefined,
+	linear: <T>(list: T[], find: T) => SearchResult<T> | undefined,
+}
+
+function wrap_result<T>(item: T, binary_index: number): SearchResult<T> {
+	return { item: item, binary_index: binary_index }
+}
+
+const search = {} as Search
+
+search.binary = function(list, find) {
+	list.sort()
+	let start = 0
+	let end = list.length-1
+	while (start<=end) {
+		const median = (start+end)>>1
+		if (list[median] === find) {
+			return wrap_result(list[median], median)
+		} else if (list[median]<find) {
+			start = median+1
+		} else {
+			end = median-1
+		}
+	}
+	return
+}
+
+search.binary_nsort = function(list, find, start = 0, end = list.length-1) {
+	if (start>end) { return }
+	const median = (start+end)>>1
+	if (list[median] === find) {
+		return wrap_result(list[median], median)
+	}
+	if (list[median]>find) {
+		return this.binary_nsort(list, find, start, median-1)
+	} else {
+		return this.binary_nsort(list, find, median+1, end)
+	}
+}
+
+search.binary_fs = function(cloned_list, file_name) {
+	cloned_list.sort((a,z) => a.name.localeCompare(z.name))
+	let start = 0
+	let end = cloned_list.length-1
+	while (start<=end) {
+		const median = (start+end)>>1
+		const median_name = cloned_list[median].name
+
+		if (median_name === file_name) {
+			return wrap_result(cloned_list[median], median)
+		} else if (median_name<file_name) {
+			start = median+1
+		} else {
+			end = median-1
+		}
+	}
+	return
+}
+
+search.linear = function(list, find) {
+	for (let ind = 0; ind<list.length; ind++) {
+		if (list[ind] === find) {
+			return wrap_result(list[ind], ind)
+		}
+	}
+	return
+}
+
+export default search