Mercurial Hosting > nabble
view src/cachingfilter/CachingResponseWrapper.java @ 35:5ea557eece1f
remove site.isNew()
author | Franklin Schmidt <fschmidt@gmail.com> |
---|---|
date | Tue, 07 Jul 2020 09:57:53 -0600 |
parents | 7ecd1a4ef557 |
children |
line wrap: on
line source
package cachingfilter; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.PrintWriter; import java.io.ObjectOutputStream; import java.io.ObjectInputStream; import java.net.URLEncoder; import java.util.Map; import java.util.HashMap; import java.util.Set; import java.util.HashSet; import java.util.List; import java.util.ArrayList; import java.util.Collections; import java.util.Iterator; import java.util.Collection; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpServletResponseWrapper; import org.slf4j.Logger; import org.slf4j.LoggerFactory; final class CachingResponseWrapper extends HttpServletResponseWrapper { private static final Logger logger = LoggerFactory.getLogger(CachingResponseWrapper.class); private static Set<String> cacheableHeaders = new HashSet<String>(); static { for( String header : new String[]{ "Last-Modified", "Etag", "Content-Type", "Cache-Control", "Content-Encoding", } ) { cacheableHeaders.add( header.toLowerCase() ); } } private final CachingFilter cachingFilter; private final CachingRequestWrapper request; private final String fullName; private boolean isCachingToFile; private CachedPage cachingFile; private ServletOutputStream outputStream; private PrintWriter writer; private int status = SC_OK; private Long lastModified = null; private String etag = null; private FileHandler fileHandler = null; private ObjectInputStream ois = null; private final List<ResponseAction> actions = new ArrayList<ResponseAction>(); private boolean isLocked = false; // for debugging private StringBuilder log = new StringBuilder(); private void log(String msg) { log.append(msg).append('\n'); } CachingResponseWrapper( CachingFilter cachingFilter, CachingRequestWrapper request, HttpServletResponse response ) { super(response); try { this.cachingFilter = cachingFilter; this.request = request; this.fullName = getFullName(); boolean ok = false; try { if( !openObjectInputStream() ) { // calls lock() ok = true; return; } Long cachedLastModified = (Long)ois.readObject(); if( cachedLastModified==null ) cachedLastModified = -1L; request.headerMap.put( CachingRequestWrapper.IF_MODIFIED_SINCE, cachedLastModified ); String cachedEtag = (String)ois.readObject(); request.headerMap.put( CachingRequestWrapper.IF_NONE_MATCH, cachedEtag ); ok = true; } finally { if( !ok && cachingFile != null ) unlock(); } } catch(ClassNotFoundException e) { throw new RuntimeException(e); } catch(IOException e) { throw new RuntimeException(e); } } private String getFullName() throws IOException { StringBuffer url = request.getRequestURL(); String queryString = request.getQueryString(); if( queryString != null ) { url.append( '?' ); url.append( queryString ); } log("url = "+url); String fullUrl = URLEncoder.encode(url.toString(),"UTF-8"); String acceptEncoding = request.getHeader("Accept-Encoding"); logger.trace("acceptEncoding = "+acceptEncoding); if( acceptEncoding == null ) return fullUrl; Set<String> knownEncodings = cachingFilter.getEncodings(); List<String> list = new ArrayList<String>(); for( String encoding : acceptEncoding.split(",") ) { encoding = encoding.trim(); if( knownEncodings.contains(encoding) ) list.add(encoding); } if( list.isEmpty() ) { request.headerMap.put( CachingRequestWrapper.ACCEPT_ENCODING, null ); return fullUrl; } String encodings = join( list, "," ); request.headerMap.put( CachingRequestWrapper.ACCEPT_ENCODING, encodings ); return fullUrl + '~' + encodings; } private void lock() { CachingFilter.locker.lock(cachingFile.name()); log("lock"); isLocked = true; } private boolean unlock() { boolean wasLocked = CachingFilter.locker.unlock(cachingFile.name()); log("unlock "+wasLocked); if( isLocked != wasLocked ) logger.error("isLocked="+isLocked+" wasLocked="+wasLocked,new Exception()); isLocked = false; return wasLocked; } private static String join(Collection<?> col,String separator) { if( col.isEmpty() ) return ""; StringBuilder sb = new StringBuilder(); Iterator<?> iter = col.iterator(); sb.append( iter.next() ); while( iter.hasNext() ) { sb.append( separator ).append( iter.next() ); } return sb.toString(); } private static long hashCode(String s) { final int len = s.length(); long h = 0; for( int i = 0; i < len; i++ ) { h = 31*h + s.charAt(i); } return h; } private boolean openObjectInputStream() { for( long hash = hashCode(fullName); true; hash++ ) { String s = Long.toHexString(hash); cachingFile = cachingFilter.newCachedPage(s); lock(); if( !cachingFile.exists() ) { logger.trace("couldn't find "+cachingFile); return false; } try { FileHandler fileHandler = FileHandler.factory.newInstance(cachingFile.lastFile()); ObjectInputStream ois = new ObjectInputStream(fileHandler.getInputStream()); if( ois.readUTF().equals(fullName) ) { logger.trace("found file = "+cachingFile); this.fileHandler = fileHandler; this.ois = ois; return true; } fileHandler.close(); } catch(IOException e) { logger.error("couldn't read "+cachingFile+" length="+cachingFile.lastFile().length(),e); if( !cachingFile.delete() ) logger.error("couldn't delete "+cachingFile); return false; } unlock(); } } public void setContentType(String ct) { logger.trace("setContentType "+ct); super.setContentType(ct); actions.add( new ResponseAction.SetHeader("Content-Type",ct) ); } public void setStatus(int sc, String sm) { logger.trace("setStatus2"); super.setStatus(sc,sm); this.status = sc; } public void setStatus(int sc) { logger.trace("setStatus "+sc); super.setStatus(sc); this.status = sc; } public void setHeader(String name, String value) { logger.trace("setHeader "+name+" = "+value); super.setHeader(name,value); if( "Etag".equalsIgnoreCase(name) ) etag = value; if( "Last-Modified".equalsIgnoreCase(name) ) { if( value==null ) lastModified = null; else logger.error("unsupported",new Exception()); } if( cacheableHeaders.contains(name.toLowerCase()) ) actions.add( new ResponseAction.SetHeader(name,value) ); } public void addHeader(String name, String value) { logger.trace("addHeader "+name+" = "+value); super.addHeader(name,value); if( cacheableHeaders.contains(name.toLowerCase()) ) actions.add( new ResponseAction.AddHeader(name,value) ); } public void setIntHeader(String name, int value) { logger.trace("setIntHeader "+name); super.setIntHeader(name,value); if( cacheableHeaders.contains(name.toLowerCase()) ) actions.add( new ResponseAction.SetIntHeader(name,value) ); } public void addIntHeader(String name, int value) { logger.trace("addIntHeader "+name); super.addIntHeader(name,value); if( cacheableHeaders.contains(name.toLowerCase()) ) actions.add( new ResponseAction.AddIntHeader(name,value) ); } public void setDateHeader(String name, long value) { logger.trace("setDateHeader "+name); super.setDateHeader(name,value); value = value / 1000 * 1000; // round to seconds if( "Last-Modified".equalsIgnoreCase(name) ) lastModified = value; if( cacheableHeaders.contains(name.toLowerCase()) ) actions.add( new ResponseAction.SetDateHeader(name,value) ); } public void addDateHeader(String name, long value) { logger.trace("addDateHeader "+name); super.setDateHeader(name,value); if( cacheableHeaders.contains(name.toLowerCase()) ) actions.add( new ResponseAction.AddDateHeader(name,value) ); } public void reset() { logger.trace("reset"); super.reset(); resetOutput(); status = SC_OK; lastModified = null; etag = null; actions.clear(); } public void resetBuffer() { logger.trace("resetBuffer"); super.resetBuffer(); resetOutput(); } private void resetOutput() { if( isCachingToFile ) { try { outputStream.close(); } catch(IOException e) { logger.error("resetOutput",e); } cachingFile.deleteNewFile(); isCachingToFile = false; } outputStream = null; writer = null; } public void sendError(int sc, String msg) throws IOException { logger.trace("sendError2"); this.status = sc; resetBuffer(); if( shouldSendFile() ) { sendFile(); } else { super.sendError(sc,msg); } } public void sendError(int sc) throws IOException { logger.trace("sendError"); this.status = sc; resetBuffer(); if( shouldSendFile() ) { sendFile(); } else { super.sendError(sc); } } public void sendRedirect(String location) throws IOException { logger.trace("sendRedirect"); this.status = SC_MOVED_TEMPORARILY; resetBuffer(); super.sendRedirect(location); } public void flushBuffer() throws IOException { logger.trace("flushBuffer "+isCommitted()); if( writer != null ) writer.flush(); if( outputStream != null ) outputStream.flush(); else if( shouldSendFile() ) sendFile(); else getResponse().flushBuffer(); } private boolean shouldSendFile() { if( !(status==SC_NOT_MODIFIED && ois!=null) ) return false; if( request.isCacheable() ) return false; // no need return true; } private void sendFile() throws IOException { CachingResponseWrapper.super.setHeader("Via","cache-yes"); sendFile2(); } private void sendFile2() throws IOException { logger.trace("sendFile"); unlock(); setStatus(SC_OK); HttpServletResponse response = (HttpServletResponse)getResponse(); try { @SuppressWarnings("unchecked") List<ResponseAction> cachedActions = (List<ResponseAction>)ois.readObject(); for( ResponseAction cachedAction : cachedActions ) { cachedAction.apply(response); } } catch(ClassNotFoundException e) { throw new RuntimeException(e); } ServletOutputStream out = response.getOutputStream(); fileHandler.writeTo(out); } public ServletOutputStream getOutputStream() { logger.trace("getOutputStream"); if (outputStream==null) { newOutputStream(); } else if (writer!=null) throw new IllegalStateException("getWriter() called"); return outputStream; } public PrintWriter getWriter() throws IOException { logger.trace("getWriter"); if (writer==null) { if (outputStream!=null) throw new IllegalStateException("getOutputStream() called"); newOutputStream(); String encoding = getCharacterEncoding(); writer = encoding==null ? new PrintWriter(outputStream) : new PrintWriter(new OutputStreamWriter(outputStream,encoding)); } return writer; } private boolean isCacheable() { if( getResponse().isCommitted() ) { logger.trace("!isCacheable - isCommitted"); return false; } if( status != SC_OK ) { logger.trace("!isCacheable - status="+status); return false; } if( lastModified==null && etag==null ) { logger.trace("!isCacheable - no lastModified,etag"); return false; } return true; } private void newOutputStream() { outputStream = new ProxyServletOutputStream() { protected OutputStream newOutputStream() throws IOException { CachingResponseWrapper.super.setHeader("Via","cache-no"); ServletOutputStream out = getResponse().getOutputStream(); if( !isCacheable() ) { unlock(); logger.trace("return getResponse().getOutputStream() "+out.getClass()); return out; } try { File newFile = cachingFile.newFile(); logger.trace("write to cache"); isCachingToFile = true; OutputStream outFile = new BufferedOutputStream(new FileOutputStream(newFile)); ObjectOutputStream oos = new ObjectOutputStream(outFile); oos.writeUTF(fullName); oos.writeObject(lastModified); oos.writeObject(etag); oos.writeObject(actions); oos.flush(); return outFile; } catch(IOException e) { throw new RuntimeException(e); } } }; } void finish(boolean isDone) throws IOException { try { log("finish a"); if( fileHandler != null ) { fileHandler.close(); logger.trace("closed fileHandler"); } if( outputStream == null || !isDone && !isCachingToFile ) unlock(); if( isDone ) { if( writer != null ) writer.flush(); if( outputStream != null ) { try { outputStream.flush(); } catch(IOException e) { logger.trace("",e); isDone = false; } } } if( isCachingToFile ) { log("finish b"); try { outputStream.close(); } catch(IOException e) { logger.trace("",e); isDone = false; } if( isDone ) { log("finish c"); try { log("file size = "+cachingFile.lastFile().length()); fileHandler = FileHandler.factory.newInstance(cachingFile.lastFile()); ois = new ObjectInputStream(fileHandler.getInputStream()); ois.readUTF(); // full name ois.readObject(); // lastModified ois.readObject(); // etag } catch(ClassNotFoundException e) { throw new RuntimeException(e); } catch(IOException e) { cachingFile.deleteNewFile(); throw new RuntimeException(e); } CachingResponseWrapper.super.setHeader("Via","cache-write"); try { log("finish d"); sendFile2(); log("finish e"); } catch(IOException e) { unlock(); throw e; } fileHandler.close(); } else { cachingFile.deleteNewFile(); unlock(); } } log("finish z"); } catch(RuntimeException e) { log("finish RuntimeException"); logger.error("RuntimeException in finish()",e); throw e; } catch(Error e) { log("finish Error"); logger.error("Error in finish()",e); throw e; } finally { if( unlock() ) { logger.error("still locked isDone="+isDone+" isCachingToFile="+isCachingToFile+" outputStream="+(outputStream!=null)); logger.error("log:\n"+log); } } } }