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// Copyright Joyent, Inc. and other Node contributors.
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//
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// Permission is hereby granted, free of charge, to any person obtaining a
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// copy of this software and associated documentation files (the
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// "Software"), to deal in the Software without restriction, including
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// without limitation the rights to use, copy, modify, merge, publish,
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// distribute, sublicense, and/or sell copies of the Software, and to permit
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// persons to whom the Software is furnished to do so, subject to the
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// following conditions:
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//
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// The above copyright notice and this permission notice shall be included
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// in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
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// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
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// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
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// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
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// USE OR OTHER DEALINGS IN THE SOFTWARE.
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var common = require('../common');
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var assert = require('assert');
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var Stream = require('stream');
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var Readable = Stream.Readable;
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var r = new Readable();
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var N = 256;
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var reads = 0;
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stream: There is no _read cb, there is only push
This makes it so that `stream.push(chunk)` is the only way to signal the
end of reading, removing the confusing disparity between the
callback-style _read method, and the fact that most real-world streams
do not have a 1:1 corollation between the "please give me data" event,
and the actual arrival of a chunk of data.
It is still possible, of course, to implement a `CallbackReadable` on
top of this. Simply provide a method like this as the callback:
function readCallback(er, chunk) {
if (er)
stream.emit('error', er);
else
stream.push(chunk);
}
However, *only* fs streams actually would behave in this way, so it
makes not a lot of sense to make TCP, TLS, HTTP, and all the rest have
to bend into this uncomfortable paradigm.
12 years ago
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r._read = function(n) {
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return r.push(++reads === N ? null : new Buffer(1));
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};
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var rended = false;
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r.on('end', function() {
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rended = true;
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});
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var w = new Stream();
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w.writable = true;
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var writes = 0;
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var buffered = 0;
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w.write = function(c) {
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writes += c.length;
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buffered += c.length;
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process.nextTick(drain);
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return false;
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};
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function drain() {
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assert(buffered <= 2);
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buffered = 0;
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w.emit('drain');
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}
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var wended = false;
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w.end = function() {
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wended = true;
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};
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// Just for kicks, let's mess with the drain count.
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// This verifies that even if it gets negative in the
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// pipe() cleanup function, we'll still function properly.
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r.on('readable', function() {
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w.emit('drain');
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});
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r.pipe(w);
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process.on('exit', function() {
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assert(rended);
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assert(wended);
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console.error('ok');
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});
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