A LineReader, because this kind of stuff should just exist already. ;P

This commit is contained in:
Ryan McGrath 2011-09-19 00:13:16 -04:00
parent 2aa050b815
commit 5476c463c8
3 changed files with 57 additions and 14 deletions

View file

@ -187,3 +187,40 @@ exports.copyDirRecursive = function copyDirRecursive(srcDir, newDir, clbk) {
});
});
};
exports.LineReader = function(filename, bufferSize) {
this.bufferSize = bufferSize || 8192;
this.buffer = "";
this.fd = fs.openSync(filename, "r");
this.currentPosition = 0;
}
exports.LineReader.prototype = {
getBufferAndSetCurrentPosition: function(position) {
var res = fs.readSync(this.fd, this.bufferSize, position, "ascii");
this.buffer += res[0];
if(res[1] === 0) return -1;
this.currentPosition = position + res[1];
return this.currentPosition;
},
hasNextLine: function() {
while(this.buffer.indexOf('\n') === -1) {
this.getBufferAndSetCurrentPosition(this.currentPosition);
if(this.currentPosition === -1) return false;
}
if(this.buffer.indexOf("\n") > -1) return true;
return false;
},
getNextLine: function() {
var lineEnd = this.buffer.indexOf("\n"),
result = this.buffer.substring(0, lineEnd);
this.buffer = this.buffer.substring(result.length + 1, this.buffer.length);
return result;
}
};

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@ -1,7 +1,7 @@
{
"name": "wrench",
"description": "Recursive filesystem operations that Node *should* have.",
"version": "1.1.0",
"description": "Recursive filesystem (and other) operations that Node *should* have.",
"version": "1.2.0",
"author": "Ryan McGrath <ryan@venodesigns.net>",
"repository": {

View file

@ -1,8 +1,8 @@
wrench.js - Recursive file operations in Node.js
----------------------------------------------------------------------------
While I love Node.js, I've found myself missing some functions. Things like
recursively deleting/chmodding a directory (or even deep copying a directory)
shouldn't need to be re-invented time and time again.
recursively deleting/chmodding a directory (or even deep copying a directory),
or even a basic line reader, shouldn't need to be re-invented time and time again.
That said, here's my attempt at a re-usable solution, at least until something
more formalized gets integrated into Node.js (*hint hint*). wrench.js is fairly simple
@ -15,19 +15,25 @@ Installation
Usage
-----------------------------------------------------------------------------
var wrench = require("./wrench");
``` javascript
var wrench = require('./wrench'),
util = require('util');
// Recursively delete the entire sub-tree of a directory, then kill the directory
wrench.rmdirSyncRecursive("my_directory_name");
// Recursively delete the entire sub-tree of a directory, then kill the directory
wrench.rmdirSyncRecursive('my_directory_name');
// Recursively chmod the entire sub-tree of a directory
wrench.chmodSyncRecursive("my_directory_name", 0755);
// Recursively chmod the entire sub-tree of a directory
wrench.chmodSyncRecursive('my_directory_name', 0755);
// Deep-copy an existing directory
wrench.copyDirSyncRecursive("directory_to_copy", "location_where_copy_should_end_up");
// Deep-copy an existing directory
wrench.copyDirSyncRecursive('directory_to_copy', 'location_where_copy_should_end_up');
It should be noted that these are all currently synchronous operations. I'll be adding
asynchronous versions of chmod/copy in the near future, but rmdir is one that really can't
exist in an asynchronous fashion.
// Read lines in from a file until you hit the end
var f = new wrench.LineReader('x.txt');
while(f.hasNextLine()) {
util.puts(x.getNextLine());
}
```
It should be noted that these are all currently synchronous operations.
Questions, comments? Hit me up. (ryan [at] venodesigns.net | http://twitter.com/ryanmcgrath)