File	Doc	Category	Size	Date	Package
CompoundFileWriter.java	API Doc	Apache Lucene 1.4.3	7844	Tue Mar 30 00:48:02 BST 2004	org.apache.lucene.index

CompoundFileWriter

• java.lang.Object

Fields Summary
private Directory	directory
private String	fileName
private HashSet	ids
private LinkedList	entries
private boolean	merged

Constructors Summary
public CompoundFileWriter(Directory dir, String name) Create the compound stream in the specified file. The file name is the entire name (no extensions are added). if (dir == null) throw new IllegalArgumentException("Missing directory"); if (name == null) throw new IllegalArgumentException("Missing name"); directory = dir; fileName = name; ids = new HashSet(); entries = new LinkedList();

Methods Summary
public void	addFile(java.lang.String file) Add a source stream. If sourceDir is null, it is set to the same value as the directory where this compound stream exists. The id is the string by which the sub-stream will be know in the compound stream. The caller must ensure that the ID is unique. If the id is null, it is set to the name of the source file. if (merged) throw new IllegalStateException( "Can't add extensions after merge has been called"); if (file == null) throw new IllegalArgumentException( "Missing source file"); if (! ids.add(file)) throw new IllegalArgumentException( "File " + file + " already added"); FileEntry entry = new FileEntry(); entry.file = file; entries.add(entry);
public void	close() Merge files with the extensions added up to now. All files with these extensions are combined sequentially into the compound stream. After successful merge, the source files are deleted. if (merged) throw new IllegalStateException( "Merge already performed"); if (entries.isEmpty()) throw new IllegalStateException( "No entries to merge have been defined"); merged = true; // open the compound stream OutputStream os = null; try { os = directory.createFile(fileName); // Write the number of entries os.writeVInt(entries.size()); // Write the directory with all offsets at 0. // Remember the positions of directory entries so that we can // adjust the offsets later Iterator it = entries.iterator(); while(it.hasNext()) { FileEntry fe = (FileEntry) it.next(); fe.directoryOffset = os.getFilePointer(); os.writeLong(0); // for now os.writeString(fe.file); } // Open the files and copy their data into the stream. // Remeber the locations of each file's data section. byte buffer[] = new byte[1024]; it = entries.iterator(); while(it.hasNext()) { FileEntry fe = (FileEntry) it.next(); fe.dataOffset = os.getFilePointer(); copyFile(fe, os, buffer); } // Write the data offsets into the directory of the compound stream it = entries.iterator(); while(it.hasNext()) { FileEntry fe = (FileEntry) it.next(); os.seek(fe.directoryOffset); os.writeLong(fe.dataOffset); } // Close the output stream. Set the os to null before trying to // close so that if an exception occurs during the close, the // finally clause below will not attempt to close the stream // the second time. OutputStream tmp = os; os = null; tmp.close(); } finally { if (os != null) try { os.close(); } catch (IOException e) { } }
private void	copyFile(org.apache.lucene.index.CompoundFileWriter$FileEntry source, org.apache.lucene.store.OutputStream os, byte[] buffer) Copy the contents of the file with specified extension into the provided output stream. Use the provided buffer for moving data to reduce memory allocation. InputStream is = null; try { long startPtr = os.getFilePointer(); is = directory.openFile(source.file); long length = is.length(); long remainder = length; int chunk = buffer.length; while(remainder > 0) { int len = (int) Math.min(chunk, remainder); is.readBytes(buffer, 0, len); os.writeBytes(buffer, len); remainder -= len; } // Verify that remainder is 0 if (remainder != 0) throw new IOException( "Non-zero remainder length after copying: " + remainder + " (id: " + source.file + ", length: " + length + ", buffer size: " + chunk + ")"); // Verify that the output length diff is equal to original file long endPtr = os.getFilePointer(); long diff = endPtr - startPtr; if (diff != length) throw new IOException( "Difference in the output file offsets " + diff + " does not match the original file length " + length); } finally { if (is != null) is.close(); }
public org.apache.lucene.store.Directory	getDirectory() Returns the directory of the compound file. return directory;
public java.lang.String	getName() Returns the name of the compound file. return fileName;