mirror of
https://github.com/nodejs/node.git
synced 2024-12-01 16:10:02 +01:00
88644eaa2d
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.
119 lines
3.4 KiB
JavaScript
119 lines
3.4 KiB
JavaScript
// Copyright Joyent, Inc. and other Node contributors.
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a
|
|
// copy of this software and associated documentation files (the
|
|
// "Software"), to deal in the Software without restriction, including
|
|
// without limitation the rights to use, copy, modify, merge, publish,
|
|
// distribute, sublicense, and/or sell copies of the Software, and to permit
|
|
// persons to whom the Software is furnished to do so, subject to the
|
|
// following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included
|
|
// in all copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
|
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
|
|
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
|
|
// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
|
|
// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
|
|
// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
|
|
// USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
|
|
var common = require('../common');
|
|
var assert = require('assert');
|
|
|
|
var Readable = require('stream').Readable;
|
|
|
|
test1();
|
|
test2();
|
|
|
|
function test1() {
|
|
var r = new Readable();
|
|
|
|
// should not end when we get a Buffer(0) or '' as the _read result
|
|
// that just means that there is *temporarily* no data, but to go
|
|
// ahead and try again later.
|
|
//
|
|
// note that this is very unusual. it only works for crypto streams
|
|
// because the other side of the stream will call read(0) to cycle
|
|
// data through openssl. that's why we set the timeouts to call
|
|
// r.read(0) again later, otherwise there is no more work being done
|
|
// and the process just exits.
|
|
|
|
var buf = new Buffer(5);
|
|
buf.fill('x');
|
|
var reads = 5;
|
|
r._read = function(n) {
|
|
switch (reads--) {
|
|
case 0:
|
|
return r.push(null); // EOF
|
|
case 1:
|
|
return r.push(buf);
|
|
case 2:
|
|
setTimeout(r.read.bind(r, 0), 10);
|
|
return r.push(new Buffer(0)); // Not-EOF!
|
|
case 3:
|
|
setTimeout(r.read.bind(r, 0), 10);
|
|
return process.nextTick(function() {
|
|
return r.push(new Buffer(0));
|
|
});
|
|
case 4:
|
|
setTimeout(r.read.bind(r, 0), 10);
|
|
return setTimeout(function() {
|
|
return r.push(new Buffer(0));
|
|
});
|
|
case 5:
|
|
return setTimeout(function() {
|
|
return r.push(buf);
|
|
});
|
|
default:
|
|
throw new Error('unreachable');
|
|
}
|
|
};
|
|
|
|
var results = [];
|
|
function flow() {
|
|
var chunk;
|
|
while (null !== (chunk = r.read()))
|
|
results.push(chunk + '');
|
|
}
|
|
r.on('readable', flow);
|
|
r.on('end', function() {
|
|
results.push('EOF');
|
|
});
|
|
flow();
|
|
|
|
process.on('exit', function() {
|
|
assert.deepEqual(results, [ 'xxxxx', 'xxxxx', 'EOF' ]);
|
|
console.log('ok');
|
|
});
|
|
}
|
|
|
|
function test2() {
|
|
var r = new Readable({ encoding: 'base64' });
|
|
var reads = 5;
|
|
r._read = function(n) {
|
|
if (!reads--)
|
|
return r.push(null); // EOF
|
|
else
|
|
return r.push(new Buffer('x'));
|
|
};
|
|
|
|
var results = [];
|
|
function flow() {
|
|
var chunk;
|
|
while (null !== (chunk = r.read()))
|
|
results.push(chunk + '');
|
|
}
|
|
r.on('readable', flow);
|
|
r.on('end', function() {
|
|
results.push('EOF');
|
|
});
|
|
flow();
|
|
|
|
process.on('exit', function() {
|
|
assert.deepEqual(results, [ 'eHh4', 'eHg=', 'EOF' ]);
|
|
console.log('ok');
|
|
});
|
|
}
|