Add Zotero.File.getContentsAsync() and Zotero.File.putContentsAsync(), asynchronous versions of Zotero.File.getContents() and Zotero.File.putContents() that return Q promises.

Also make Zotero.File.getContents() slightly more efficient by increasing the blockSize.
This commit is contained in:
Simon Kornblith 2012-07-10 02:29:16 -04:00
parent 418a170f2b
commit ede39740c7

View file

@ -23,11 +23,18 @@
***** END LICENSE BLOCK *****
*/
/**
* Functions for reading files
* @namespace
*/
Zotero.File = new function(){
Components.utils.import("resource://zotero/q.jsm");
Components.utils.import("resource://gre/modules/NetUtil.jsm");
Components.utils.import("resource://gre/modules/FileUtils.jsm");
this.getExtension = getExtension;
this.getClosestDirectory = getClosestDirectory;
this.getSample = getSample;
this.getContents = getContents;
this.getContentsFromURL = getContentsFromURL;
this.putContents = putContents;
this.getValidFileName = getValidFileName;
@ -84,7 +91,15 @@ Zotero.File = new function(){
}
function getContents(file, charset, maxLength){
/**
* Get the contents of a file or input stream
* @param {nsIFile|nsIInputStream} file The file to read
* @param {String} [charset] The character set; defaults to UTF-8
* @param {Integer} [maxLength] The maximum number of bytes to read
* @return {String} The contents of the file
* @deprecated Use {@link Zotero.File.getContentsAsync} when possible
*/
this.getContents = function getContents(file, charset, maxLength){
var fis;
if(file instanceof Components.interfaces.nsIInputStream) {
fis = file;
@ -96,56 +111,59 @@ Zotero.File = new function(){
throw new Error("File is not an nsIInputStream or nsIFile");
}
if (charset){
charset = Zotero.CharacterSets.getName(charset);
}
charset = charset ? Zotero.CharacterSets.getName(charset) : "UTF-8";
if (!charset){
charset = "UTF-8";
}
var blockSize = maxLength ? Math.min(maxLength, 524288) : 524288;
const replacementChar
= Components.interfaces.nsIConverterInputStream.DEFAULT_REPLACEMENT_CHARACTER;
var is = Components.classes["@mozilla.org/intl/converter-input-stream;1"]
.createInstance(Components.interfaces.nsIConverterInputStream);
is.init(fis, charset, 4096, replacementChar);
is.init(fis, charset, blockSize, replacementChar);
var chars = 0;
var contents = [], str = {};
while (is.readString(4096, str) != 0) {
var strLen = str.value.length;
var contents = "", str = {};
while (is.readString(blockSize, str) !== 0) {
if (maxLength) {
var strLen = str.value.length;
if ((chars + strLen) > maxLength) {
var remainder = maxLength - chars;
contents.push(str.value.slice(0, remainder));
contents += str.value.slice(0, remainder);
break;
}
chars += strLen;
}
contents.push(str.value);
contents += str.value;
}
is.close();
return contents.join('');
}
return contents;
};
/**
* Return the contents of a file as a byte array
* Get the contents of a file or input stream asynchronously
* @param {nsIFile|nsIInputStream} file The file to read
* @param {String} [charset] The character set; defaults to UTF-8
* @param {Integer} [maxLength] The maximum number of characters to read
* @return {Promise} A promise that is resolved with the contents of the file
*/
this.getBinaryContents = function (bfile) {
var istream = Components.classes["@mozilla.org/network/file-input-stream;1"]
.createInstance(Components.interfaces.nsIFileInputStream);
istream.init(bfile, -1, -1, false);
var bstream = Components.classes["@mozilla.org/binaryinputstream;1"]
.createInstance(Components.interfaces.nsIBinaryInputStream);
bstream.setInputStream(istream);
return bstream.readBytes(bstream.available());
}
this.getContentsAsync = function getContentsAsync(file, charset, maxLength) {
charset = charset ? Zotero.CharacterSets.getName(charset) : "UTF-8";
var deferred = Q.defer(),
channel = NetUtil.newChannel(file, charset);
NetUtil.asyncFetch(channel, function(inputStream, status) {
if (!Components.isSuccessCode(status)) {
deferred.reject(new Components.Exception("File read operation failed", status));
return;
}
deferred.resolve(NetUtil.readInputStreamToString(inputStream, inputStream.available()));
});
return deferred.promise;
};
/*
@ -183,6 +201,34 @@ Zotero.File = new function(){
fos.close();
}
/**
* Write data to a file asynchronously
* @param {nsIFile} The file to write to
* @param {String|nsIInputStream} data The string or nsIInputStream to write to the
* file
* @param {String} [charset] The character set; defaults to UTF-8
* @return {Promise} A promise that is resolved when the file has been written
*/
this.putContentsAsync = function putContentsAsync(file, data, charset) {
// Create a stream for async stream copying
if(!(data instanceof Components.interfaces.nsIInputStream)) {
var converter = Components.classes["@mozilla.org/intl/scriptableunicodeconverter"].
createInstance(Components.interfaces.nsIScriptableUnicodeConverter);
converter.charset = charset ? Zotero.CharacterSets.getName(charset) : "UTF-8";
data = converter.convertToInputStream(data);
}
var deferred = Q.defer(),
ostream = FileUtils.openSafeFileOutputStream(file);
NetUtil.asyncCopy(data, ostream, function(inputStream, status) {
if (!Components.isSuccessCode(status)) {
deferred.reject(new Components.Exception("File write operation failed", status));
return;
}
deferred.resolve();
});
return deferred.promise;
};
function copyToUnique(file, newFile) {
newFile.createUnique(Components.interfaces.nsIFile.NORMAL_FILE_TYPE, 0644);