Merge remote-tracking branch 'origin/v0.8'
This commit is contained in:
commit
79ae8b7ae2
@ -96,13 +96,12 @@ var server = http.createServer(function (req, res) {
|
|||||||
'Transfer-Encoding': 'chunked' });
|
'Transfer-Encoding': 'chunked' });
|
||||||
// send body in chunks
|
// send body in chunks
|
||||||
var len = body.length;
|
var len = body.length;
|
||||||
var step = ~~(len / n_chunks) || len;
|
var step = Math.floor(len / n_chunks) || 1;
|
||||||
|
|
||||||
for (var i = 0; i < len; i += step) {
|
for (var i = 0, n = (n_chunks - 1); i < n; ++i) {
|
||||||
res.write(body.slice(i, i + step));
|
res.write(body.slice(i * step, i * step + step));
|
||||||
}
|
}
|
||||||
|
res.end(body.slice((n_chunks - 1) * step));
|
||||||
res.end();
|
|
||||||
} else {
|
} else {
|
||||||
var content_length = body.length.toString();
|
var content_length = body.length.toString();
|
||||||
|
|
||||||
|
@ -77,13 +77,12 @@ var server = http.createServer(function (req, res) {
|
|||||||
"Transfer-Encoding": "chunked" });
|
"Transfer-Encoding": "chunked" });
|
||||||
// send body in chunks
|
// send body in chunks
|
||||||
var len = body.length;
|
var len = body.length;
|
||||||
var step = ~~(len / n_chunks) || len;
|
var step = Math.floor(len / n_chunks) || 1;
|
||||||
|
|
||||||
for (var i = 0; i < len; i += step) {
|
for (var i = 0, n = (n_chunks - 1); i < n; ++i) {
|
||||||
res.write(body.slice(i, i + step));
|
res.write(body.slice(i * step, i * step + step));
|
||||||
}
|
}
|
||||||
|
res.end(body.slice((n_chunks - 1) * step));
|
||||||
res.end();
|
|
||||||
} else {
|
} else {
|
||||||
var content_length = body.length.toString();
|
var content_length = body.length.toString();
|
||||||
|
|
||||||
|
579
doc/blog/feature/streams2.md
Normal file
579
doc/blog/feature/streams2.md
Normal file
@ -0,0 +1,579 @@
|
|||||||
|
title: A New Streaming API for Node v0.10
|
||||||
|
author: Isaac Z. Schlueter
|
||||||
|
date: Tue Dec 18 08:44:33 PST 2012
|
||||||
|
slug: streams2
|
||||||
|
category: feature
|
||||||
|
|
||||||
|
**tl;dr**
|
||||||
|
|
||||||
|
* Node streams are great, except for all the ways in which they're
|
||||||
|
terrible.
|
||||||
|
* A new Stream implementation is coming in 0.10, that has gotten the
|
||||||
|
nickname "streams2".
|
||||||
|
* Readable streams have a `read()` method that returns a buffer or
|
||||||
|
null.
|
||||||
|
* `'data'` events, `pause()`, and `resume()` will still work as before
|
||||||
|
(except that they'll actully work how you'd expect).
|
||||||
|
* Old programs will **almost always** work without modification, but
|
||||||
|
streams start out in a paused state, and need to be read from to be
|
||||||
|
consumed.
|
||||||
|
* **WARNING**: If you never add a `'data'` event handler, or call
|
||||||
|
`resume()`, then it'll sit in a paused state forever and never
|
||||||
|
emit `'end'`.
|
||||||
|
|
||||||
|
-------
|
||||||
|
|
||||||
|
Throughout the life of Node, we've been gradually iterating on the
|
||||||
|
ideal event-based API for handling data. Over time, this developed
|
||||||
|
into the "Stream" interface that you see throughout Node's core
|
||||||
|
modules and many of the modules in npm.
|
||||||
|
|
||||||
|
Consistent interfaces increase the portability and reliability of our
|
||||||
|
programs and libraries. Overall, the move from domain-specific events
|
||||||
|
and methods towards a unified stream interface was a huge win.
|
||||||
|
However, there are still several problems with Node's streams as of
|
||||||
|
v0.8. In a nutshell:
|
||||||
|
|
||||||
|
1. The `pause()` method doesn't pause. It is advisory-only. In
|
||||||
|
Node's implementation, this makes things much simpler, but it's
|
||||||
|
confusing to users, and doesn't do what it looks like it does.
|
||||||
|
2. `'data'` events come right away (whether you're ready or not).
|
||||||
|
This makes it unreasonably difficult to do common tasks like load a
|
||||||
|
user's session before deciding how to handle their request.
|
||||||
|
3. There is no way to consume a specific number of bytes, and then
|
||||||
|
leave the rest for some other part of the program to deal with.
|
||||||
|
4. It's unreasonably difficult to implement streams and get all the
|
||||||
|
intricacies of pause, resume, write-buffering, and data events
|
||||||
|
correct. The lack of shared classes mean that we all have to solve
|
||||||
|
the same problems repeatedly, making similar mistakes and similar
|
||||||
|
bugs.
|
||||||
|
|
||||||
|
Common simple tasks should be easy, or we aren't doing our job.
|
||||||
|
People often say that Node is better than most other platforms at this
|
||||||
|
stuff, but in my opinion, that just is an indictment of the current
|
||||||
|
state of software more than a compliment. Being better than the next
|
||||||
|
guy isn't enough; we have to be the best imaginable, and while it was
|
||||||
|
a big step in the right direction, the Streams in Node up until now
|
||||||
|
leave a lot wanting.
|
||||||
|
|
||||||
|
So, just fix it, right?
|
||||||
|
|
||||||
|
Well, we are now sitting on the results of several years of explosive
|
||||||
|
growth in the Node community, so any chnages have to be made very
|
||||||
|
carefully. If we break all the Node programs in 0.10, then no one
|
||||||
|
will ever want to upgrade to 0.10, and it's all pointless. We had
|
||||||
|
this streams conversation around 0.4, then again around 0.6, then
|
||||||
|
again around 0.8. Every time, the conclusion was "Too much work, too
|
||||||
|
hard to make backwards-compatible", and we always had other more
|
||||||
|
pressing problems to solve.
|
||||||
|
|
||||||
|
So, finally, in 0.10, we cannot put it off any longer. We've bitten
|
||||||
|
the bullet and are making a significant change to the Stream
|
||||||
|
implementation. You may have seen conversations on twitter or IRC or
|
||||||
|
the mailing list about "streams2". I also gave [a talk in
|
||||||
|
November](https://dl.dropbox.com/u/3685/presentations/streams2/streams2-ko.pdf)
|
||||||
|
about this subject. A lot of node module authors have been involved
|
||||||
|
with the development of streams2 (and of course the node core team),
|
||||||
|
and at this point, I'm confident that it's an improvement over what
|
||||||
|
we've got.
|
||||||
|
|
||||||
|
The first preview release with this change will be 0.9.4. I highly
|
||||||
|
recommend trying this release and providing feedback before it lands
|
||||||
|
in a stable version. Some polish is still required before 0.10, which
|
||||||
|
will likely be released late January, but at this point, it should be
|
||||||
|
considered feature-complete.
|
||||||
|
|
||||||
|
The feature is described pretty thoroughly in the documentation, so
|
||||||
|
I'm including it below. Please read it, especially the section on
|
||||||
|
"compatibility".
|
||||||
|
|
||||||
|
--------
|
||||||
|
|
||||||
|
# Stream
|
||||||
|
|
||||||
|
Stability: 2 - Unstable
|
||||||
|
|
||||||
|
A stream is an abstract interface implemented by various objects in
|
||||||
|
Node. For example a request to an HTTP server is a stream, as is
|
||||||
|
stdout. Streams are readable, writable, or both. All streams are
|
||||||
|
instances of EventEmitter.
|
||||||
|
|
||||||
|
You can load the Stream base classes by doing `require('stream')`.
|
||||||
|
There are base classes provided for Readable streams, Writable
|
||||||
|
streams, Duplex streams, and Transform streams.
|
||||||
|
|
||||||
|
## Compatibility
|
||||||
|
|
||||||
|
In earlier versions of Node, the Readable stream interface was
|
||||||
|
simpler, but also less powerful and less useful.
|
||||||
|
|
||||||
|
* Rather than waiting for you to call the `read()` method, `'data'`
|
||||||
|
events would start emitting immediately. If you needed to do some
|
||||||
|
I/O to decide how to handle data, then you had to store the chunks
|
||||||
|
in some kind of buffer so that they would not be lost.
|
||||||
|
* The `pause()` method was advisory, rather than guaranteed. This
|
||||||
|
meant that you still had to be prepared to receive `'data'` events
|
||||||
|
even when the stream was in a paused state.
|
||||||
|
|
||||||
|
In Node v0.10, the Readable class described below was added. For
|
||||||
|
backwards compatibility with older Node programs, Readable streams
|
||||||
|
switch into "old mode" when a `'data'` event handler is added, or when
|
||||||
|
the `pause()` or `resume()` methods are called. The effect is that,
|
||||||
|
even if you are not using the new `read()` method and `'readable'`
|
||||||
|
event, you no longer have to worry about losing `'data'` chunks.
|
||||||
|
|
||||||
|
Most programs will continue to function normally. However, this
|
||||||
|
introduces an edge case in the following conditions:
|
||||||
|
|
||||||
|
* No `'data'` event handler is added.
|
||||||
|
* The `pause()` and `resume()` methods are never called.
|
||||||
|
|
||||||
|
For example, consider the following code:
|
||||||
|
|
||||||
|
```javascript
|
||||||
|
// WARNING! BROKEN!
|
||||||
|
net.createServer(function(socket) {
|
||||||
|
|
||||||
|
// we add an 'end' method, but never consume the data
|
||||||
|
socket.on('end', function() {
|
||||||
|
// It will never get here.
|
||||||
|
socket.end('I got your message (but didnt read it)\n');
|
||||||
|
});
|
||||||
|
|
||||||
|
}).listen(1337);
|
||||||
|
```
|
||||||
|
|
||||||
|
In versions of node prior to v0.10, the incoming message data would be
|
||||||
|
simply discarded. However, in Node v0.10 and beyond, the socket will
|
||||||
|
remain paused forever.
|
||||||
|
|
||||||
|
The workaround in this situation is to call the `resume()` method to
|
||||||
|
trigger "old mode" behavior:
|
||||||
|
|
||||||
|
```javascript
|
||||||
|
// Workaround
|
||||||
|
net.createServer(function(socket) {
|
||||||
|
|
||||||
|
socket.on('end', function() {
|
||||||
|
socket.end('I got your message (but didnt read it)\n');
|
||||||
|
});
|
||||||
|
|
||||||
|
// start the flow of data, discarding it.
|
||||||
|
socket.resume();
|
||||||
|
|
||||||
|
}).listen(1337);
|
||||||
|
```
|
||||||
|
|
||||||
|
In addition to new Readable streams switching into old-mode, pre-v0.10
|
||||||
|
style streams can be wrapped in a Readable class using the `wrap()`
|
||||||
|
method.
|
||||||
|
|
||||||
|
## Class: stream.Readable
|
||||||
|
|
||||||
|
<!--type=class-->
|
||||||
|
|
||||||
|
A `Readable Stream` has the following methods, members, and events.
|
||||||
|
|
||||||
|
Note that `stream.Readable` is an abstract class designed to be
|
||||||
|
extended with an underlying implementation of the `_read(size, cb)`
|
||||||
|
method. (See below.)
|
||||||
|
|
||||||
|
### new stream.Readable([options])
|
||||||
|
|
||||||
|
* `options` {Object}
|
||||||
|
* `bufferSize` {Number} The size of the chunks to consume from the
|
||||||
|
underlying resource. Default=16kb
|
||||||
|
* `lowWaterMark` {Number} The minimum number of bytes to store in
|
||||||
|
the internal buffer before emitting `readable`. Default=0
|
||||||
|
* `highWaterMark` {Number} The maximum number of bytes to store in
|
||||||
|
the internal buffer before ceasing to read from the underlying
|
||||||
|
resource. Default=16kb
|
||||||
|
* `encoding` {String} If specified, then buffers will be decoded to
|
||||||
|
strings using the specified encoding. Default=null
|
||||||
|
|
||||||
|
In classes that extend the Readable class, make sure to call the
|
||||||
|
constructor so that the buffering settings can be properly
|
||||||
|
initialized.
|
||||||
|
|
||||||
|
### readable.\_read(size, callback)
|
||||||
|
|
||||||
|
* `size` {Number} Number of bytes to read asynchronously
|
||||||
|
* `callback` {Function} Called with an error or with data
|
||||||
|
|
||||||
|
All Readable stream implementations must provide a `_read` method
|
||||||
|
to fetch data from the underlying resource.
|
||||||
|
|
||||||
|
**This function MUST NOT be called directly.** It should be
|
||||||
|
implemented by child classes, and called by the internal Readable
|
||||||
|
class methods only.
|
||||||
|
|
||||||
|
Call the callback using the standard `callback(error, data)` pattern.
|
||||||
|
When no more data can be fetched, call `callback(null, null)` to
|
||||||
|
signal the EOF.
|
||||||
|
|
||||||
|
This method is prefixed with an underscore because it is internal to
|
||||||
|
the class that defines it, and should not be called directly by user
|
||||||
|
programs. However, you **are** expected to override this method in
|
||||||
|
your own extension classes.
|
||||||
|
|
||||||
|
|
||||||
|
### readable.wrap(stream)
|
||||||
|
|
||||||
|
* `stream` {Stream} An "old style" readable stream
|
||||||
|
|
||||||
|
If you are using an older Node library that emits `'data'` events and
|
||||||
|
has a `pause()` method that is advisory only, then you can use the
|
||||||
|
`wrap()` method to create a Readable stream that uses the old stream
|
||||||
|
as its data source.
|
||||||
|
|
||||||
|
For example:
|
||||||
|
|
||||||
|
```javascript
|
||||||
|
var OldReader = require('./old-api-module.js').OldReader;
|
||||||
|
var oreader = new OldReader;
|
||||||
|
var Readable = require('stream').Readable;
|
||||||
|
var myReader = new Readable().wrap(oreader);
|
||||||
|
|
||||||
|
myReader.on('readable', function() {
|
||||||
|
myReader.read(); // etc.
|
||||||
|
});
|
||||||
|
```
|
||||||
|
|
||||||
|
### Event: 'readable'
|
||||||
|
|
||||||
|
When there is data ready to be consumed, this event will fire. The
|
||||||
|
number of bytes that are required to be considered "readable" depends
|
||||||
|
on the `lowWaterMark` option set in the constructor.
|
||||||
|
|
||||||
|
When this event emits, call the `read()` method to consume the data.
|
||||||
|
|
||||||
|
### Event: 'end'
|
||||||
|
|
||||||
|
Emitted when the stream has received an EOF (FIN in TCP terminology).
|
||||||
|
Indicates that no more `'data'` events will happen. If the stream is
|
||||||
|
also writable, it may be possible to continue writing.
|
||||||
|
|
||||||
|
### Event: 'data'
|
||||||
|
|
||||||
|
The `'data'` event emits either a `Buffer` (by default) or a string if
|
||||||
|
`setEncoding()` was used.
|
||||||
|
|
||||||
|
Note that adding a `'data'` event listener will switch the Readable
|
||||||
|
stream into "old mode", where data is emitted as soon as it is
|
||||||
|
available, rather than waiting for you to call `read()` to consume it.
|
||||||
|
|
||||||
|
### Event: 'error'
|
||||||
|
|
||||||
|
Emitted if there was an error receiving data.
|
||||||
|
|
||||||
|
### Event: 'close'
|
||||||
|
|
||||||
|
Emitted when the underlying resource (for example, the backing file
|
||||||
|
descriptor) has been closed. Not all streams will emit this.
|
||||||
|
|
||||||
|
### readable.setEncoding(encoding)
|
||||||
|
|
||||||
|
Makes the `'data'` event emit a string instead of a `Buffer`. `encoding`
|
||||||
|
can be `'utf8'`, `'utf16le'` (`'ucs2'`), `'ascii'`, or `'hex'`.
|
||||||
|
|
||||||
|
The encoding can also be set by specifying an `encoding` field to the
|
||||||
|
constructor.
|
||||||
|
|
||||||
|
### readable.read([size])
|
||||||
|
|
||||||
|
* `size` {Number | null} Optional number of bytes to read.
|
||||||
|
* Return: {Buffer | String | null}
|
||||||
|
|
||||||
|
Call this method to consume data once the `'readable'` event is
|
||||||
|
emitted.
|
||||||
|
|
||||||
|
The `size` argument will set a minimum number of bytes that you are
|
||||||
|
interested in. If not set, then the entire content of the internal
|
||||||
|
buffer is returned.
|
||||||
|
|
||||||
|
If there is no data to consume, or if there are fewer bytes in the
|
||||||
|
internal buffer than the `size` argument, then `null` is returned, and
|
||||||
|
a future `'readable'` event will be emitted when more is available.
|
||||||
|
|
||||||
|
Note that calling `stream.read(0)` will always return `null`, and will
|
||||||
|
trigger a refresh of the internal buffer, but otherwise be a no-op.
|
||||||
|
|
||||||
|
### readable.pipe(destination, [options])
|
||||||
|
|
||||||
|
* `destination` {Writable Stream}
|
||||||
|
* `options` {Object} Optional
|
||||||
|
* `end` {Boolean} Default=true
|
||||||
|
|
||||||
|
Connects this readable stream to `destination` WriteStream. Incoming
|
||||||
|
data on this stream gets written to `destination`. Properly manages
|
||||||
|
back-pressure so that a slow destination will not be overwhelmed by a
|
||||||
|
fast readable stream.
|
||||||
|
|
||||||
|
This function returns the `destination` stream.
|
||||||
|
|
||||||
|
For example, emulating the Unix `cat` command:
|
||||||
|
|
||||||
|
process.stdin.pipe(process.stdout);
|
||||||
|
|
||||||
|
By default `end()` is called on the destination when the source stream
|
||||||
|
emits `end`, so that `destination` is no longer writable. Pass `{ end:
|
||||||
|
false }` as `options` to keep the destination stream open.
|
||||||
|
|
||||||
|
This keeps `writer` open so that "Goodbye" can be written at the
|
||||||
|
end.
|
||||||
|
|
||||||
|
reader.pipe(writer, { end: false });
|
||||||
|
reader.on("end", function() {
|
||||||
|
writer.end("Goodbye\n");
|
||||||
|
});
|
||||||
|
|
||||||
|
Note that `process.stderr` and `process.stdout` are never closed until
|
||||||
|
the process exits, regardless of the specified options.
|
||||||
|
|
||||||
|
### readable.unpipe([destination])
|
||||||
|
|
||||||
|
* `destination` {Writable Stream} Optional
|
||||||
|
|
||||||
|
Undo a previously established `pipe()`. If no destination is
|
||||||
|
provided, then all previously established pipes are removed.
|
||||||
|
|
||||||
|
### readable.pause()
|
||||||
|
|
||||||
|
Switches the readable stream into "old mode", where data is emitted
|
||||||
|
using a `'data'` event rather than being buffered for consumption via
|
||||||
|
the `read()` method.
|
||||||
|
|
||||||
|
Ceases the flow of data. No `'data'` events are emitted while the
|
||||||
|
stream is in a paused state.
|
||||||
|
|
||||||
|
### readable.resume()
|
||||||
|
|
||||||
|
Switches the readable stream into "old mode", where data is emitted
|
||||||
|
using a `'data'` event rather than being buffered for consumption via
|
||||||
|
the `read()` method.
|
||||||
|
|
||||||
|
Resumes the incoming `'data'` events after a `pause()`.
|
||||||
|
|
||||||
|
|
||||||
|
## Class: stream.Writable
|
||||||
|
|
||||||
|
<!--type=class-->
|
||||||
|
|
||||||
|
A `Writable` Stream has the following methods, members, and events.
|
||||||
|
|
||||||
|
Note that `stream.Writable` is an abstract class designed to be
|
||||||
|
extended with an underlying implementation of the `_write(chunk, cb)`
|
||||||
|
method. (See below.)
|
||||||
|
|
||||||
|
### new stream.Writable([options])
|
||||||
|
|
||||||
|
* `options` {Object}
|
||||||
|
* `highWaterMark` {Number} Buffer level when `write()` starts
|
||||||
|
returning false. Default=16kb
|
||||||
|
* `lowWaterMark` {Number} The buffer level when `'drain'` is
|
||||||
|
emitted. Default=0
|
||||||
|
* `decodeStrings` {Boolean} Whether or not to decode strings into
|
||||||
|
Buffers before passing them to `_write()`. Default=true
|
||||||
|
|
||||||
|
In classes that extend the Writable class, make sure to call the
|
||||||
|
constructor so that the buffering settings can be properly
|
||||||
|
initialized.
|
||||||
|
|
||||||
|
### writable.\_write(chunk, callback)
|
||||||
|
|
||||||
|
* `chunk` {Buffer | Array} The data to be written
|
||||||
|
* `callback` {Function} Called with an error, or null when finished
|
||||||
|
|
||||||
|
All Writable stream implementations must provide a `_write` method to
|
||||||
|
send data to the underlying resource.
|
||||||
|
|
||||||
|
**This function MUST NOT be called directly.** It should be
|
||||||
|
implemented by child classes, and called by the internal Writable
|
||||||
|
class methods only.
|
||||||
|
|
||||||
|
Call the callback using the standard `callback(error)` pattern to
|
||||||
|
signal that the write completed successfully or with an error.
|
||||||
|
|
||||||
|
If the `decodeStrings` flag is set in the constructor options, then
|
||||||
|
`chunk` will be an array rather than a Buffer. This is to support
|
||||||
|
implementations that have an optimized handling for certain string
|
||||||
|
data encodings.
|
||||||
|
|
||||||
|
This method is prefixed with an underscore because it is internal to
|
||||||
|
the class that defines it, and should not be called directly by user
|
||||||
|
programs. However, you **are** expected to override this method in
|
||||||
|
your own extension classes.
|
||||||
|
|
||||||
|
|
||||||
|
### writable.write(chunk, [encoding], [callback])
|
||||||
|
|
||||||
|
* `chunk` {Buffer | String} Data to be written
|
||||||
|
* `encoding` {String} Optional. If `chunk` is a string, then encoding
|
||||||
|
defaults to `'utf8'`
|
||||||
|
* `callback` {Function} Optional. Called when this chunk is
|
||||||
|
successfully written.
|
||||||
|
* Returns {Boolean}
|
||||||
|
|
||||||
|
Writes `chunk` to the stream. Returns `true` if the data has been
|
||||||
|
flushed to the underlying resource. Returns `false` to indicate that
|
||||||
|
the buffer is full, and the data will be sent out in the future. The
|
||||||
|
`'drain'` event will indicate when the buffer is empty again.
|
||||||
|
|
||||||
|
The specifics of when `write()` will return false, and when a
|
||||||
|
subsequent `'drain'` event will be emitted, are determined by the
|
||||||
|
`highWaterMark` and `lowWaterMark` options provided to the
|
||||||
|
constructor.
|
||||||
|
|
||||||
|
### writable.end([chunk], [encoding])
|
||||||
|
|
||||||
|
* `chunk` {Buffer | String} Optional final data to be written
|
||||||
|
* `encoding` {String} Optional. If `chunk` is a string, then encoding
|
||||||
|
defaults to `'utf8'`
|
||||||
|
|
||||||
|
Call this method to signal the end of the data being written to the
|
||||||
|
stream.
|
||||||
|
|
||||||
|
### Event: 'drain'
|
||||||
|
|
||||||
|
Emitted when the stream's write queue empties and it's safe to write
|
||||||
|
without buffering again. Listen for it when `stream.write()` returns
|
||||||
|
`false`.
|
||||||
|
|
||||||
|
### Event: 'close'
|
||||||
|
|
||||||
|
Emitted when the underlying resource (for example, the backing file
|
||||||
|
descriptor) has been closed. Not all streams will emit this.
|
||||||
|
|
||||||
|
### Event: 'pipe'
|
||||||
|
|
||||||
|
* `source` {Readable Stream}
|
||||||
|
|
||||||
|
Emitted when the stream is passed to a readable stream's pipe method.
|
||||||
|
|
||||||
|
### Event 'unpipe'
|
||||||
|
|
||||||
|
* `source` {Readable Stream}
|
||||||
|
|
||||||
|
Emitted when a previously established `pipe()` is removed using the
|
||||||
|
source Readable stream's `unpipe()` method.
|
||||||
|
|
||||||
|
## Class: stream.Duplex
|
||||||
|
|
||||||
|
<!--type=class-->
|
||||||
|
|
||||||
|
A "duplex" stream is one that is both Readable and Writable, such as a
|
||||||
|
TCP socket connection.
|
||||||
|
|
||||||
|
Note that `stream.Duplex` is an abstract class designed to be
|
||||||
|
extended with an underlying implementation of the `_read(size, cb)`
|
||||||
|
and `_write(chunk, callback)` methods as you would with a Readable or
|
||||||
|
Writable stream class.
|
||||||
|
|
||||||
|
Since JavaScript doesn't have multiple prototypal inheritance, this
|
||||||
|
class prototypally inherits from Readable, and then parasitically from
|
||||||
|
Writable. It is thus up to the user to implement both the lowlevel
|
||||||
|
`_read(n,cb)` method as well as the lowlevel `_write(chunk,cb)` method
|
||||||
|
on extension duplex classes.
|
||||||
|
|
||||||
|
### new stream.Duplex(options)
|
||||||
|
|
||||||
|
* `options` {Object} Passed to both Writable and Readable
|
||||||
|
constructors. Also has the following fields:
|
||||||
|
* `allowHalfOpen` {Boolean} Default=true. If set to `false`, then
|
||||||
|
the stream will automatically end the readable side when the
|
||||||
|
writable side ends and vice versa.
|
||||||
|
|
||||||
|
In classes that extend the Duplex class, make sure to call the
|
||||||
|
constructor so that the buffering settings can be properly
|
||||||
|
initialized.
|
||||||
|
|
||||||
|
## Class: stream.Transform
|
||||||
|
|
||||||
|
A "transform" stream is a duplex stream where the output is causally
|
||||||
|
connected in some way to the input, such as a zlib stream or a crypto
|
||||||
|
stream.
|
||||||
|
|
||||||
|
There is no requirement that the output be the same size as the input,
|
||||||
|
the same number of chunks, or arrive at the same time. For example, a
|
||||||
|
Hash stream will only ever have a single chunk of output which is
|
||||||
|
provided when the input is ended. A zlib stream will either produce
|
||||||
|
much smaller or much larger than its input.
|
||||||
|
|
||||||
|
Rather than implement the `_read()` and `_write()` methods, Transform
|
||||||
|
classes must implement the `_transform()` method, and may optionally
|
||||||
|
also implement the `_flush()` method. (See below.)
|
||||||
|
|
||||||
|
### new stream.Transform([options])
|
||||||
|
|
||||||
|
* `options` {Object} Passed to both Writable and Readable
|
||||||
|
constructors.
|
||||||
|
|
||||||
|
In classes that extend the Transform class, make sure to call the
|
||||||
|
constructor so that the buffering settings can be properly
|
||||||
|
initialized.
|
||||||
|
|
||||||
|
### transform.\_transform(chunk, outputFn, callback)
|
||||||
|
|
||||||
|
* `chunk` {Buffer} The chunk to be transformed.
|
||||||
|
* `outputFn` {Function} Call this function with any output data to be
|
||||||
|
passed to the readable interface.
|
||||||
|
* `callback` {Function} Call this function (optionally with an error
|
||||||
|
argument) when you are done processing the supplied chunk.
|
||||||
|
|
||||||
|
All Transform stream implementations must provide a `_transform`
|
||||||
|
method to accept input and produce output.
|
||||||
|
|
||||||
|
**This function MUST NOT be called directly.** It should be
|
||||||
|
implemented by child classes, and called by the internal Transform
|
||||||
|
class methods only.
|
||||||
|
|
||||||
|
`_transform` should do whatever has to be done in this specific
|
||||||
|
Transform class, to handle the bytes being written, and pass them off
|
||||||
|
to the readable portion of the interface. Do asynchronous I/O,
|
||||||
|
process things, and so on.
|
||||||
|
|
||||||
|
Call the callback function only when the current chunk is completely
|
||||||
|
consumed. Note that this may mean that you call the `outputFn` zero
|
||||||
|
or more times, depending on how much data you want to output as a
|
||||||
|
result of this chunk.
|
||||||
|
|
||||||
|
This method is prefixed with an underscore because it is internal to
|
||||||
|
the class that defines it, and should not be called directly by user
|
||||||
|
programs. However, you **are** expected to override this method in
|
||||||
|
your own extension classes.
|
||||||
|
|
||||||
|
### transform.\_flush(outputFn, callback)
|
||||||
|
|
||||||
|
* `outputFn` {Function} Call this function with any output data to be
|
||||||
|
passed to the readable interface.
|
||||||
|
* `callback` {Function} Call this function (optionally with an error
|
||||||
|
argument) when you are done flushing any remaining data.
|
||||||
|
|
||||||
|
**This function MUST NOT be called directly.** It MAY be implemented
|
||||||
|
by child classes, and if so, will be called by the internal Transform
|
||||||
|
class methods only.
|
||||||
|
|
||||||
|
In some cases, your transform operation may need to emit a bit more
|
||||||
|
data at the end of the stream. For example, a `Zlib` compression
|
||||||
|
stream will store up some internal state so that it can optimally
|
||||||
|
compress the output. At the end, however, it needs to do the best it
|
||||||
|
can with what is left, so that the data will be complete.
|
||||||
|
|
||||||
|
In those cases, you can implement a `_flush` method, which will be
|
||||||
|
called at the very end, after all the written data is consumed, but
|
||||||
|
before emitting `end` to signal the end of the readable side. Just
|
||||||
|
like with `_transform`, call `outputFn` zero or more times, as
|
||||||
|
appropriate, and call `callback` when the flush operation is complete.
|
||||||
|
|
||||||
|
This method is prefixed with an underscore because it is internal to
|
||||||
|
the class that defines it, and should not be called directly by user
|
||||||
|
programs. However, you **are** expected to override this method in
|
||||||
|
your own extension classes.
|
||||||
|
|
||||||
|
|
||||||
|
## Class: stream.PassThrough
|
||||||
|
|
||||||
|
This is a trivial implementation of a `Transform` stream that simply
|
||||||
|
passes the input bytes across to the output. Its purpose is mainly
|
||||||
|
for examples and testing, but there are occasionally use cases where
|
||||||
|
it can come in handy.
|
@ -186,6 +186,8 @@
|
|||||||
Spanish<br>
|
Spanish<br>
|
||||||
<a href="http://nodejskr.org">OctoberSkyJs</a> Korea Node.js
|
<a href="http://nodejskr.org">OctoberSkyJs</a> Korea Node.js
|
||||||
community<br>
|
community<br>
|
||||||
|
<a href="https://plus.google.com/communities/113346206415381691435">FR . Node.js</a>
|
||||||
|
Google+ Community of Node.js French users
|
||||||
<a href="http://www.nodejstr.com/">Node.js Türkiye</a>
|
<a href="http://www.nodejstr.com/">Node.js Türkiye</a>
|
||||||
Node.js in Turkish
|
Node.js in Turkish
|
||||||
</p>
|
</p>
|
||||||
|
67
lib/http.js
67
lib/http.js
@ -756,6 +756,10 @@ OutgoingMessage.prototype.addTrailers = function(headers) {
|
|||||||
};
|
};
|
||||||
|
|
||||||
|
|
||||||
|
var zero_chunk_buf = new Buffer('\r\n0\r\n');
|
||||||
|
var crlf_buf = new Buffer('\r\n');
|
||||||
|
|
||||||
|
|
||||||
OutgoingMessage.prototype.end = function(data, encoding) {
|
OutgoingMessage.prototype.end = function(data, encoding) {
|
||||||
if (this.finished) {
|
if (this.finished) {
|
||||||
return false;
|
return false;
|
||||||
@ -773,8 +777,7 @@ OutgoingMessage.prototype.end = function(data, encoding) {
|
|||||||
var ret;
|
var ret;
|
||||||
|
|
||||||
var hot = this._headerSent === false &&
|
var hot = this._headerSent === false &&
|
||||||
typeof(data) === 'string' &&
|
(data && data.length > 0) &&
|
||||||
data.length > 0 &&
|
|
||||||
this.output.length === 0 &&
|
this.output.length === 0 &&
|
||||||
this.connection &&
|
this.connection &&
|
||||||
this.connection.writable &&
|
this.connection.writable &&
|
||||||
@ -786,6 +789,7 @@ OutgoingMessage.prototype.end = function(data, encoding) {
|
|||||||
// res.end(blah);
|
// res.end(blah);
|
||||||
// HACKY.
|
// HACKY.
|
||||||
|
|
||||||
|
if (typeof data === 'string') {
|
||||||
if (this.chunkedEncoding) {
|
if (this.chunkedEncoding) {
|
||||||
var l = Buffer.byteLength(data, encoding).toString(16);
|
var l = Buffer.byteLength(data, encoding).toString(16);
|
||||||
ret = this.connection.write(this._header + l + CRLF +
|
ret = this.connection.write(this._header + l + CRLF +
|
||||||
@ -794,6 +798,65 @@ OutgoingMessage.prototype.end = function(data, encoding) {
|
|||||||
} else {
|
} else {
|
||||||
ret = this.connection.write(this._header + data, encoding);
|
ret = this.connection.write(this._header + data, encoding);
|
||||||
}
|
}
|
||||||
|
} else if (Buffer.isBuffer(data)) {
|
||||||
|
if (this.chunkedEncoding) {
|
||||||
|
var chunk_size = data.length.toString(16);
|
||||||
|
|
||||||
|
// Skip expensive Buffer.byteLength() calls; only ISO-8859-1 characters
|
||||||
|
// are allowed in HTTP headers. Therefore:
|
||||||
|
//
|
||||||
|
// this._header.length == Buffer.byteLength(this._header.length)
|
||||||
|
// this._trailer.length == Buffer.byteLength(this._trailer.length)
|
||||||
|
//
|
||||||
|
var header_len = this._header.length;
|
||||||
|
var chunk_size_len = chunk_size.length;
|
||||||
|
var data_len = data.length;
|
||||||
|
var trailer_len = this._trailer.length;
|
||||||
|
|
||||||
|
var len = header_len
|
||||||
|
+ chunk_size_len
|
||||||
|
+ 2 // '\r\n'.length
|
||||||
|
+ data_len
|
||||||
|
+ 5 // '\r\n0\r\n'.length
|
||||||
|
+ trailer_len
|
||||||
|
+ 2; // '\r\n'.length
|
||||||
|
|
||||||
|
var buf = new Buffer(len);
|
||||||
|
var off = 0;
|
||||||
|
|
||||||
|
buf.write(this._header, off, header_len, 'ascii');
|
||||||
|
off += header_len;
|
||||||
|
|
||||||
|
buf.write(chunk_size, off, chunk_size_len, 'ascii');
|
||||||
|
off += chunk_size_len;
|
||||||
|
|
||||||
|
crlf_buf.copy(buf, off);
|
||||||
|
off += 2;
|
||||||
|
|
||||||
|
data.copy(buf, off);
|
||||||
|
off += data_len;
|
||||||
|
|
||||||
|
zero_chunk_buf.copy(buf, off);
|
||||||
|
off += 5;
|
||||||
|
|
||||||
|
if (trailer_len > 0) {
|
||||||
|
buf.write(this._trailer, off, trailer_len, 'ascii');
|
||||||
|
off += trailer_len;
|
||||||
|
}
|
||||||
|
|
||||||
|
crlf_buf.copy(buf, off);
|
||||||
|
|
||||||
|
ret = this.connection.write(buf);
|
||||||
|
} else {
|
||||||
|
var header_len = this._header.length;
|
||||||
|
var buf = new Buffer(header_len + data.length);
|
||||||
|
buf.write(this._header, 0, header_len, 'ascii');
|
||||||
|
data.copy(buf, header_len);
|
||||||
|
ret = this.connection.write(buf);
|
||||||
|
}
|
||||||
|
} else {
|
||||||
|
throw new TypeError('first argument must be a string or Buffer');
|
||||||
|
}
|
||||||
this._headerSent = true;
|
this._headerSent = true;
|
||||||
|
|
||||||
} else if (data) {
|
} else if (data) {
|
||||||
|
@ -122,7 +122,7 @@ def files(action):
|
|||||||
# with dtrace support now (oracle's "unbreakable" linux)
|
# with dtrace support now (oracle's "unbreakable" linux)
|
||||||
action(['src/node.d'], 'lib/dtrace/')
|
action(['src/node.d'], 'lib/dtrace/')
|
||||||
|
|
||||||
if 'freebsd' in sys.platform:
|
if 'freebsd' in sys.platform or 'openbsd' in sys.platform:
|
||||||
action(['doc/node.1'], 'man/man1/')
|
action(['doc/node.1'], 'man/man1/')
|
||||||
else:
|
else:
|
||||||
action(['doc/node.1'], 'share/man/man1/')
|
action(['doc/node.1'], 'share/man/man1/')
|
||||||
|
Loading…
x
Reference in New Issue
Block a user