Hi Yin, I noticed you completely removed the section on community involvement in your most recent draft. In my previous note I wasn't suggesting that you delete it altogether, just that you describe your unique experience in your own words.
Engagement with the project community is important and it's a good idea for everyone to mention it in their proposal. Thanks. Michael Glavassevich XML Parser Development IBM Toronto Lab E-mail: [email protected] E-mail: [email protected] "xiaohei.leiyin" <[email protected]> wrote on 03/30/2010 10:19:16 AM: > Hi Michael, > > Thank you so much, i think i have found the solution to implement > Asynchronous LSParser and parseWithContext for Xerces, and i am sure > i can finish it well, the most important thing is that i am > interested in XML parsing job,that gives me power. I am really > really looking forward to one of Xerces committers :-) > > In addition, here is my submited proposal,if you have time, i am > looking forward to any suggestions from you > ------------------------------------------------------------------------------------------------------------------------------------- > Project Title:Implement Xerces' Asynchronous LSParser and parseWithContext > StudentName: Yin Lei > Student Email: [email protected] > Organization/Project:Apache Foundation/Xerces > > Assigned Mentor:Michael Glavassevich > Proposal Abstract: > Apache Xerces2 is a powful XML parser,at present, it implements a > collection of standard APIs for XML processing,though Xerces has a > functional DOM Level 3 LSParser,but there are a couple parts of the > spec which still need to be implemented.This project will provide an > asynchronous version for LSParse which returns from the parse method > immediately and builds the DOM tree on another thread as well as > implementing the function parseWithContext which allows a document > fragment to be parsed and attached to an existing DOM. > Detailed Description: > Apache Xerces-J is a high-performance, standard complaint processor > written in Java for parsing, validating, serializing and > manipulating XML documents. It provides a complete implementation of > the Document Object Model Level 3 Core and Document Object Model > Level 3 Load and Save Recommendations,but Xerces' implemention of > LSParser has two limitations (http://xerces.apache.org/xerces2-j/dom3.html): > 1. not support asynchronous LSParser which returns from the parse > method immediately and builds the DOM tree on another thread. > 2. not support the function parserWithContext of interface LSParser > which parse an XML fragment from a resource identified by a LSInput > and insert the content into an existing document at the position > specified with the context and action arguments. > In order to solve these two limitations, i have been researching > W3C's recommendation specification about LSParser and in the > meantime, i have downloaded Xerces2-J's source code,import it to my > Eclipse workspace, look it over and over and consider how to > implements these two specifications.At the same time,i discuss the > subject with Xerces' developers(You help me a lot,thank > you,especially dear Michael Glavassevich).Now,i have found some > ideas about the solution and did some experiments to check my > solution,this is only a global solution,and i neglect some details. > 1. interface DOMImplementationLS,Class > org.apache.xerces.dom.CoreDOMImplementationImpl implements the > interface. As described in W3C's recommendation, > DOMImplementationLS's implemention should supply a function > createLSParser which can create synchronous LSParser as well as > asynchronous LSParser,but now, we can only get the former using > CoreDOMImplementationImpl's function createLSParser. So,i should fix > this problem., > 2. interface LSParser,Class org.apache.xerces.parsers.DOMParserImpl > implements the interface, but absolutely,it supports synchronous > model only,even the function getAsync in it directly return false. > There is my solution to provide an asynchronous version for LSParser. > Step one : DOMParserImpl implements interface EventTarget as well as > interface LSParser. > It use a Vector ojbect (we name it repository) to store all the > action listeners registered in to the current LSParser object. Each > of listeners is made up of three parts,type,useCapture and event > handler function,there are only two types of event,load and > progress. My following task is to implement function > addEventListener,dispatchEvent and removeEventListener. > addEventListener : just add a action listener object in to > repository.We should notice that listener with the same parameters > can only be added once. > dispatchEvent : traverse each item of repository,if some one has the > same type value with the event and its useCapture value is > true,let's dispatch its handleEvent function. > removeEventListener : traverse each item of repository,if some one > is the same as the object in the parameter,just remove this item > from repository. > Step two : implement interface LSLoadEventIn asynchronous LSParser, > LSLoadEvent is used to inform the parser that the parse function has > finished parse job. We can achieve it by dispatching LSParser's > dispatchEvent function which will receive LSLoadEvent as a parameter. > Step three : implement interface LSProgressEventIn asynchronous > LSParser,the parse thread will trigger a LSProgressEvent when it > finish a entity node parsing job,the triggered LSProgressEvent will > tell LSParser current parse position. If it can see more external > resource reference, it may also change totalSize value. > Step four : implement asynchronous mechanismDOMParserImpl has a > attribute which mark its model,synchronous or asynchronous. We can > get its parse model from the function getAsynoc. If the parser is in > asynchronous, when LSParser instance's parse() function is > dispatched,set busy value true, start a Thread to parse XML document > in LSInput,and then return null value. When XML parse thread finish > its parse job,set busy value false,create a LSLoadEvent instance > with type value load,dispatch function dispatchEvent(Event evt).If > user register any actionlistener for load event,dispatchEvent > function will finish jobs defined in actionlistener's handleEvent function. > 3. function parseWithContext(LSInput input, Node contextArg, short action) > This function parse an XML fragment from a resource identified by a > LSInput and insert the content into an existing document at the > position specified with the context and action arguments. This XML > fragment is a special data structure, I need contruct a new class > named XMLFragment to store it. Then, i should do the following jobs: > Parse the XML fragment into a XMLFragment object,mark it whether a > complete XML document, any error happens,throw an exception. These > classes can help me: > a . org.apache.xerces.impl.XMLDocumentFragmentScannerImpl > b . org.apache.xerces.impl.XMLDocumentScannerImpl.FragmentContentDispatcher > c . org.apache.xerces.impl.XMLEntityScanner > I can use some functions in these classes and start the parsing job > by consult function startEntity in class > org.apache.xerces.impl.XMLDocumentScannerImpl and function > scanDocument in class > org.apache.xerces.impl.XMLDocumentFragmentScannerImpl. Here is the > basic implement idea (in fact, this is a recursion process): > 1. Create a XMLFragment instance,there is a very importmant > attribute in it, we named it fCurrentNode; > 2. Start read characters from the LSInput stream.If catch Node start > character such as "<" from the input stream,go tostep 3; If catch > Node end character such as "/" from the input stream,go to step 4; > If catch file end up character,go to step 5. > 3. A begin EVENT happens, usually, instance a Node object,append the > Node instance in to fCurrentNode's child node list,change > fCurrentNode to this Node,then go to step 2. > 4. A end EVENT happens,usually,we should change fCurrentNode to its > father node,then go to step 2. > 5. Parsing job ends. > Start add the XMLFragment in to the place indicated by the parameter > action. In this phase, we have lots of validate jobs to do, > including four aspects: Basic Validation, Namespace Validate, DTD > Validation and Schema Validateoin. > 1. Basic Validation: > I should validate whether this merge job is legal, for example,if > the context Node is document root element, and the parameter action > is not ACTION_REPLACE_CHILDREN,in this situation,an error should be thrown up. > I should confirm the merge result XML document is well-formed,for > example, the DOM should have only one root element and Entity > declaration must be at the beginning part of the document etc. > 2. Namespace Validation: I should validate both Element namespace > and Attribute namespace of the merge result XML document > 3. DTD Validationa: > Validate whether the merge result XML document is in keeping with > Element Type Declarationb. > Validate whether the merge result XML document is in keeping with > Entity Declarationc. > Validate whether the merge result XML document is in keeping with > Attribute Declaration, for example, if DTD file includes default > attribute declaration,i should add default attributes for the > elements which are root in LSInput Fragment. > 4. Schema Validation,This section includes validations demands in > DTD Validation, and it has some more validation requests: > Validate data type of elements and attributes > Three kinds of annotation declaration validation > If everything is OK,return the result Node,otherwise if an error > occurs, the caller is notified through the ErrorHandler instance > associated with the "error-handler" parameter of the > DOMConfiguration.As the new data is inserted into the document, at > least one mutation event is fired per new immediate child or sibling > of the context node. > Additional Information: > My development plan: > > 1st week in 1st month(May 24 - Jun 1) > > Read Xerces-J source code and get familiar with its > architecture,thus what I have done will comply with its philosophy > > 2st week in 1st month(Jun 1 - Jun 8) > > Do some change job to DOMImplementationLS and DOMParserImpl,make > DOMImplementationLS can create asynchronous LSParser and add some > basic attribute for DOMParserImpl such as asynchronous flag and so on > > 3st week in 1st month(Jun 9 - Jun 16) > > Construct DOMParserImpl's structure to implement interface > EventTarget,implement addActionListener,dispatchEvent and > removeActionListener > > 4st week in 1st month(Jun 17 - Jun 24) > > Implement LSParser parse() and parseURI() function, add > asynochronous support implement LSParser function abort() implement > LSParser function getAsync() implement LSParser function getBusy() > > 1st week in 2st month(Jun 25 - Jul 2) > > Implement interface LSLoadEvent and LSProgressEvent,finish the whole > asynchronous parse cycle and some unit test) > > 2st week in 2st month(Jul 3- Jul 10) > > finish sub task of function parseWithContext() -- parse the LSInput > into a XMLFragment instance > > 3st week in 2st month(Jul 11- Jul 18) > > start merge context Node and XML fragment document,finish Basic > Validation and Namespace Validation > > 4st week in 2st month(Jul 19- Jul 26) > > finish the merge job of context DOM tree and the XMLFragment,finish > DTD Validation and Schema Validation > > 1st week in 3rd month(Jul 27- Aug 3) > > Test My asynchronous LSParser and function parseWithContext > > last 2 weeks in 3rd month(Aug 3 - Aug 20) > > submit all codes and documents > > Who i am ? > Hi,everyone,My name is Yin Lei. I am a postgraduate student of > University of Science and Technology Beijing,China. My major is > computer scienece and technology. During my six years Java > development experience, Apache help me so much, many projects such > as Struts,Tomcat,Xerces,Xalan,HttpClient,Common > FileUpload,JavaMail,POI play important part of my research projects. > So, i am eager to participate in open source community and become a > long term commiter of that project, in my daily work, i use Xerces > as my XML parser, so, i found its lacking and want to improve it to > make it perfect :-) > My work experience and relative rewards: > 2007.7 - 2008.5 : work in SUN Microsystem Inc. as a intern > 2008.7 - 2009.12 : work in IBM China Development Laborary as a intern > 2008.9 : won excellent team member of 2008 IBM blue pathway program > 2009.11: won Lotus Innovation Award of IBM Asia Pacific > Also,i did some open source job before,the first experience I had in > open source development is building a Eclipse plugin for Apache > SCXML engine, and also attempt to add a new feature for SCXML engine > to make it support multi-thread operation.I can code in C++, Java > and some script language such as JaveScript and ActionScript. In > addition to these things, I'm familiar with XML,DOM,SAX,JDOM and > Dom4j,I want to improve existing XML parsing tools through my job. > > 2010-03-30 > > xiaohei.leiyin > > 发件人： Michael Glavassevich > 发送时间： 2010-03-30 20:10:21 > 收件人： xiaohei.leiyin > 抄送： > 主题： Re: GSoC proposal about "Asynchronous LSParser and parseWithContext " > Hi Yin, > > Yes, that's fine. If your proposal is accepted for GSoC I would > mentor you and I think that's what they're looking for there on the GSoC site. > > There are usually several hundred proposals submitted to Apache > every year for the various projects across the organization. It can > be very competitive depending on the number of spots that Google > actually awards to Apache and the number of good proposals submitted > by students. I wish you good luck in the selection process. > > Thanks. > > Michael Glavassevich > XML Parser Development > IBM Toronto Lab > E-mail: [email protected] > E-mail: [email protected] > > "xiaohei.leiyin" <[email protected]> wrote on 03/30/2010 01:02:31 AM: > > > Dear Michael, > > > > I have modify my proposal follow your advise, and submit it in the > > GSoC web site, i noticed that there is a item "Organization/ > > Project:Assigned Mentor:" in the content section of the proposal > > submit page. So, can i fill it "Organization/Project:Apache > > Foundation/Xerces Assigned Mentor:Michael Glavassevich", is it ok ? > > I mean that can i take you as my assigned mentor ? If you think it > > is ok, i will maintain, if you do not like it due to some > > reasons,please let me know, i will alter it ( it is ok, i must > > respect you, in Chinese culture,you are my teacher already,respct > > teach is a Chinese culture of long standing and well established, we > > call it 尊师重教[zun shi zhong jiao] ). > > > > During these days,when i was researching Xerces' architect and > > discovering how to implement Asynchronous LSParser and > > parseWithContext for Xerces, i found i got lots of knowledge, made a > > full-grown progress. When i came across some difficulties, you > > helped me a lot, in fact ,you are my mentor in my heart. Thank you > > so so so so much ! I think i have won knowledge no matter GSoC > > receive my proposal or not, i will finish this project, once i began > > it, i want to finish it, for you, for open source. > > > > Your student : Yin Lei from China > > > > 2010-03-30 > > > > xiaohei.leiyin
