add hw2

node_modules/get-uri/README.md

@@ -0,0 +1,109 @@
+get-uri
+=======
+### Returns a `stream.Readable` from a URI string
+
+This high-level module accepts a URI string and returns a `Readable` stream
+instance. There is built-in support for a variety of "protocols", and it's
+easily extensible with more:
+
+| Protocol  | Description                     | Example
+|:---------:|:-------------------------------:|:---------------------------------:
+| `data`    | [Data URIs][data]               | `data:text/plain;base64,SGVsbG8sIFdvcmxkIQ%3D%3D`
+| `file`    | [File URIs][file]               | `file:///c:/windows/example.ini`
+| `ftp`     | [FTP URIs][ftp]                 | `ftp://ftp.kernel.org/pub/site/README`
+| `http`    | [HTTP URIs][http]               | `http://www.example.com/path/to/name`
+| `https`   | [HTTPS URIs][https]             | `https://www.example.com/path/to/name`
+
+Example
+-------
+
+To simply get a `stream.Readable` instance from a `file:` URI, try something like:
+
+```ts
+import { getUri } from 'get-uri';
+
+// `file:` maps to a `fs.ReadStream` instance…
+const stream = await getUri('file:///Users/nrajlich/wat.json');
+stream.pipe(process.stdout);
+```
+
+
+Missing Endpoints
+-----------------
+
+When you pass in a URI in which the resource referenced does not exist on the
+destination server, then a `NotFoundError` will be thrown. The `code` of the
+error instance is set to `"ENOTFOUND"`, so you can check for that value
+to detect when a bad filename is requested:
+
+```ts
+try {
+  await getUri('http://example.com/resource.json');
+} catch (err) {
+  if (err.code === 'ENOTFOUND') {
+    // bad file path requested
+  } else {
+    // something else bad happened...
+    throw err;
+  }
+}
+```
+
+
+Cacheability
+------------
+
+When calling `getUri()` with the same URI multiple times, the `get-uri` module
+supports sending an indicator that the remote resource has not been modified
+since the last time it has been retrieved from that node process.
+
+To do this, define a `cache` property on the "options object" argument
+with the value set to the `stream.Readable` instance that was previously
+returned. If the remote resource has not been changed since the last call for
+that same URI, then a `NotModifiedError` instance will be thrown with its
+`code` property set to `"ENOTMODIFIED"`.
+
+When the `"ENOTMODIFIED"` error occurs, then you can safely re-use the
+results from the previous `getUri()` call for that same URI:
+
+``` js
+// First time fetches for real
+const stream = await getUri('http://example.com/resource.json');
+
+try {
+  // … some time later, if you need to get this same URI again, pass in the
+  // previous `stream.Readable` instance as `cache` option to potentially
+  // have an "ENOTMODIFIED" error thrown:
+  await getUri('http://example.com/resource.json', { cache: stream });
+} catch (err) {
+  if (err.code === 'ENOTMODIFIED') {
+    // source file has not been modified since last time it was requested,
+    // so you are expected to re-use results from a previous call to `getUri()`
+  } else {
+    // something else bad happened...
+    throw err;
+  }
+}
+```
+
+
+API
+---
+
+### getUri(uri: string | URL, options?: Object]): Promise<Readable>
+
+A `uri` is required. An optional `options` object may be passed in:
+
+ - `cache` - A `stream.Readable` instance from a previous call to `getUri()` with the same URI. If this option is passed in, and the destination endpoint has not been modified, then an `ENOTMODIFIED` error is thrown
+
+Any other options passed in to the `options` object will be passed through
+to the low-level connection creation functions (`http.get()`, `ftp.connect()`,
+etc).
+
+Returns a `stream.Readable` instance to read the resource at the given `uri`.
+
+[data]: http://tools.ietf.org/html/rfc2397
+[file]: http://tools.ietf.org/html/draft-hoffman-file-uri-03
+[ftp]: http://www.w3.org/Protocols/rfc959/
+[http]: http://www.w3.org/Protocols/rfc2616/rfc2616.html
+[https]: http://wikipedia.org/wiki/HTTP_Secure