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Diffstat (limited to 'bundles/org.eclipse.equinox.cm/src/org/eclipse/equinox/internal/cm/reliablefile/ReliableFile.java')
| -rw-r--r-- | bundles/org.eclipse.equinox.cm/src/org/eclipse/equinox/internal/cm/reliablefile/ReliableFile.java | 840 |
1 files changed, 0 insertions, 840 deletions
diff --git a/bundles/org.eclipse.equinox.cm/src/org/eclipse/equinox/internal/cm/reliablefile/ReliableFile.java b/bundles/org.eclipse.equinox.cm/src/org/eclipse/equinox/internal/cm/reliablefile/ReliableFile.java deleted file mode 100644 index cb14d60aa..000000000 --- a/bundles/org.eclipse.equinox.cm/src/org/eclipse/equinox/internal/cm/reliablefile/ReliableFile.java +++ /dev/null @@ -1,840 +0,0 @@ -/******************************************************************************* - * Copyright (c) 2003, 2008 IBM Corporation and others. - * All rights reserved. This program and the accompanying materials - * are made available under the terms of the Eclipse Public License v1.0 - * which accompanies this distribution, and is available at - * http://www.eclipse.org/legal/epl-v10.html - * - * Contributors: - * IBM Corporation - initial API and implementation - *******************************************************************************/ - -package org.eclipse.equinox.internal.cm.reliablefile; - -import java.io.*; -import java.util.*; -import java.util.zip.CRC32; -import java.util.zip.Checksum; -import org.eclipse.equinox.internal.cm.Activator; - -//This is a copy of org.eclipse.osgi.framework.internal.reliablefile.ReliableFile - -/** - * ReliableFile class used by ReliableFileInputStream and ReliableOutputStream. - * This class encapsulates all the logic for reliable file support. - * - */ -public class ReliableFile { - /** - * Open mask. Obtain the best data stream available. If the primary data - * contents are invalid (corrupt, missing, etc.), the data for a prior - * version may be used. - * An IOException will be thrown if a valid data content can not be - * determined. - * This is mutually exclusive with <code>OPEN_FAIL_ON_PRIMARY</code>. - */ - public static final int OPEN_BEST_AVAILABLE = 0; - /** - * Open mask. Obtain only the data stream for the primary file where any other - * version will not be valid. This should be used for data streams that are - * managed as a group as a prior contents may not match the other group data. - * If the primary data is not invalid, a IOException will be thrown. - * This is mutually exclusive with <code>OPEN_BEST_AVAILABLE</code>. - */ - public static final int OPEN_FAIL_ON_PRIMARY = 1; - - /** - * Use the last generation of the file - */ - public static final int GENERATION_LATEST = 0; - /** - * Keep infinite backup files - */ - public static final int GENERATIONS_INFINITE = 0; - - /** - * Extension of tmp file used during writing. - * A reliable file with this extension should - * never be directly used. - */ - public static final String tmpExt = ".tmp"; //$NON-NLS-1$ - - /** - * Property to set the maximum size of a file that will be buffered. When calculating a ReliableFile - * checksum, if the file is this size or small, ReliableFile will read the file contents into a - * <code>BufferedInputStream</code> and reset the buffer to avoid having to read the data from the - * media twice. Since this method require memory for storage, it is limited to this size. The default - * maximum is 128-KBytes. - */ - public static final String PROP_MAX_BUFFER = "osgi.reliableFile.maxInputStreamBuffer"; //$NON-NLS-1$ - /** - * The maximum number of generations to keep as backup files in case last generation - * file is determined to be invalid. - */ - public static final String PROP_MAX_GENERATIONS = "osgi.ReliableFile.maxGenerations"; //$NON-NLS-1$ - /** - *see org.eclipse.core.runtime.internal.adaptor.BasicLocation#PROP_OSGI_LOCKING - */ - public static final String PROP_OSGI_LOCKING = "osgi.locking"; //$NON-NLS-1$ - - private static final int FILETYPE_VALID = 0; - private static final int FILETYPE_CORRUPT = 1; - private static final int FILETYPE_NOSIGNATURE = 2; - - private static final byte identifier1[] = {'.', 'c', 'r', 'c'}; - private static final byte identifier2[] = {'.', 'v', '1', '\n'}; - - private static final int BUF_SIZE = 4096; - private static final int maxInputStreamBuffer; - private static final int defaultMaxGenerations; - private static final boolean fileSharing; - //our cache of the last looked up generations for a file - private static File lastGenerationFile = null; - private static int[] lastGenerations = null; - private static final Object lastGenerationLock = new Object(); - - static { - String prop = Activator.getProperty(PROP_MAX_BUFFER); - int tmpMaxInput = 128 * 1024; //128k - if (prop != null) { - try { - tmpMaxInput = Integer.parseInt(prop); - } catch (NumberFormatException e) {/*ignore*/ - } - } - maxInputStreamBuffer = tmpMaxInput; - - int tmpDefaultMax = 2; - prop = Activator.getProperty(PROP_MAX_GENERATIONS); - if (prop != null) { - try { - tmpDefaultMax = Integer.parseInt(prop); - } catch (NumberFormatException e) {/*ignore*/ - } - } - defaultMaxGenerations = tmpDefaultMax; - - prop = Activator.getProperty(PROP_OSGI_LOCKING); - boolean tmpFileSharing = true; - if (prop != null) { - if (prop.equals("none")) { //$NON-NLS-1$ - tmpFileSharing = false; - } - } - fileSharing = tmpFileSharing; - } - - /** File object for original reference file */ - private File referenceFile; - - /** List of checksum file objects: File => specific ReliableFile generation */ - private static Hashtable cacheFiles = new Hashtable(20); - - private File inputFile = null; - private File outputFile = null; - private Checksum appendChecksum = null; - - /** - * ReliableFile object factory. This method is called by ReliableFileInputStream - * and ReliableFileOutputStream to get a ReliableFile object for a target file. - * If the object is in the cache, the cached copy is returned. - * Otherwise a new ReliableFile object is created and returned. - * The use count of the returned ReliableFile object is incremented. - * - * @param name Name of the target file. - * @return A ReliableFile object for the target file. - * @throws IOException If the target file is a directory. - */ - static ReliableFile getReliableFile(String name) throws IOException { - return getReliableFile(new File(name)); - } - - /** - * ReliableFile object factory. This method is called by ReliableFileInputStream - * and ReliableFileOutputStream to get a ReliableFile object for a target file. - * If the object is in the cache, the cached copy is returned. - * Otherwise a new ReliableFile object is created and returned. - * The use count of the returned ReliableFile object is incremented. - * - * @param file File object for the target file. - * @return A ReliableFile object for the target file. - * @throws IOException If the target file is a directory. - */ - static ReliableFile getReliableFile(File file) throws IOException { - if (file.isDirectory()) { - throw new FileNotFoundException("file is a directory"); //$NON-NLS-1$ - } - return new ReliableFile(file); - } - - /** - * Private constructor used by the static getReliableFile factory methods. - * - * @param file File object for the target file. - */ - private ReliableFile(File file) { - referenceFile = file; - } - - private static int[] getFileGenerations(File file) { - if (!fileSharing) { - synchronized (lastGenerationLock) { - if (lastGenerationFile != null) { - //shortcut maybe, only if filesharing is not supported - if (file.equals(lastGenerationFile)) - return lastGenerations; - } - } - } - int[] generations = null; - try { - String name = file.getName(); - String prefix = name + '.'; - int prefixLen = prefix.length(); - File parent = new File(file.getParent()); - String[] files = parent.list(); - if (files == null) - return null; - ArrayList list = new ArrayList(defaultMaxGenerations); - if (file.exists()) - list.add(new Integer(0)); //base file exists - for (int i = 0; i < files.length; i++) { - if (files[i].startsWith(prefix)) { - try { - int id = Integer.parseInt(files[i].substring(prefixLen)); - list.add(new Integer(id)); - } catch (NumberFormatException e) {/*ignore*/ - } - } - } - if (list.size() == 0) - return null; - Object[] array = list.toArray(); - Arrays.sort(array); - generations = new int[array.length]; - for (int i = 0, j = array.length - 1; i < array.length; i++, j--) { - generations[i] = ((Integer) array[j]).intValue(); - } - return generations; - } finally { - if (!fileSharing) { - synchronized (lastGenerationLock) { - lastGenerationFile = file; - lastGenerations = generations; - } - } - } - } - - /** - * Returns an InputStream object for reading the target file. - * - * @param generation the maximum generation to evaluate - * @param openMask mask used to open data. - * are invalid (corrupt, missing, etc). - * @return An InputStream object which can be used to read the target file. - * @throws IOException If an error occurs preparing the file. - */ - InputStream getInputStream(int generation, int openMask) throws IOException { - if (inputFile != null) { - throw new IOException("Input stream already open"); //$NON-NLS-1$ - } - int[] generations = getFileGenerations(referenceFile); - if (generations == null) { - throw new FileNotFoundException("File not found"); //$NON-NLS-1$ - } - String name = referenceFile.getName(); - File parent = new File(referenceFile.getParent()); - - boolean failOnPrimary = (openMask & OPEN_FAIL_ON_PRIMARY) != 0; - if (failOnPrimary && generation == GENERATIONS_INFINITE) - generation = generations[0]; - - File textFile = null; - InputStream textIS = null; - for (int idx = 0; idx < generations.length; idx++) { - if (generation != 0) { - if (generations[idx] > generation || (failOnPrimary && generations[idx] != generation)) - continue; - } - File file; - if (generations[idx] != 0) - file = new File(parent, name + '.' + generations[idx]); - else - file = referenceFile; - InputStream is = null; - CacheInfo info; - synchronized (cacheFiles) { - info = (CacheInfo) cacheFiles.get(file); - long timeStamp = file.lastModified(); - if (info == null || timeStamp != info.timeStamp) { - try { - is = new FileInputStream(file); - if (is.available() < maxInputStreamBuffer) - is = new BufferedInputStream(is); - Checksum cksum = getChecksumCalculator(); - int filetype = getStreamType(is, cksum); - info = new CacheInfo(filetype, cksum, timeStamp); - cacheFiles.put(file, info); - } catch (IOException e) {/*ignore*/ - } - } - } - - // if looking for a specific generation only, only look at one - // and return the result. - if (failOnPrimary) { - if (info != null && info.filetype == FILETYPE_VALID) { - inputFile = file; - if (is != null) - return is; - return new FileInputStream(file); - } - throw new IOException("ReliableFile is corrupt"); //$NON-NLS-1$ - } - - // if error, ignore this file & try next - if (info == null) - continue; - - // we're not looking for a specific version, so let's pick the best case - switch (info.filetype) { - case FILETYPE_VALID : - inputFile = file; - if (is != null) - return is; - return new FileInputStream(file); - - case FILETYPE_NOSIGNATURE : - if (textFile == null) { - textFile = file; - textIS = is; - } - break; - } - } - - // didn't find any valid files, if there are any plain text files - // use it instead - if (textFile != null) { - inputFile = textFile; - if (textIS != null) - return textIS; - return new FileInputStream(textFile); - } - throw new IOException("ReliableFile is corrupt"); //$NON-NLS-1$ - } - - /** - * Returns an OutputStream object for writing the target file. - * - * @param append append new data to an existing file. - * @param appendGeneration specific generation of file to append from. - * @return An OutputStream object which can be used to write the target file. - * @throws IOException IOException If an error occurs preparing the file. - */ - OutputStream getOutputStream(boolean append, int appendGeneration) throws IOException { - if (outputFile != null) - throw new IOException("Output stream is already open"); //$NON_NLS-1$ //$NON-NLS-1$ - String name = referenceFile.getName(); - File parent = new File(referenceFile.getParent()); - File tmpFile = File.createTempFile(name, tmpExt, parent); - - if (!append) { - OutputStream os = new FileOutputStream(tmpFile); - outputFile = tmpFile; - return os; - } - - InputStream is; - try { - is = getInputStream(appendGeneration, OPEN_BEST_AVAILABLE); - } catch (FileNotFoundException e) { - OutputStream os = new FileOutputStream(tmpFile); - outputFile = tmpFile; - return os; - } - - try { - CacheInfo info = (CacheInfo) cacheFiles.get(inputFile); - appendChecksum = info.checksum; - OutputStream os = new FileOutputStream(tmpFile); - if (info.filetype == FILETYPE_NOSIGNATURE) { - cp(is, os, 0); - } else { - cp(is, os, 16); // don't copy checksum signature - } - outputFile = tmpFile; - return os; - } finally { - closeInputFile(); - } - } - - /** - * Close the target file for reading. - * - * @param checksum Checksum of the file contents - * @throws IOException If an error occurs closing the file. - */ - void closeOutputFile(Checksum checksum) throws IOException { - if (outputFile == null) - throw new IOException("Output stream is not open"); //$NON-NLS-1$ - int[] generations = getFileGenerations(referenceFile); - String name = referenceFile.getName(); - File parent = new File(referenceFile.getParent()); - File newFile; - if (generations == null) - newFile = new File(parent, name + ".1"); //$NON-NLS-1$ - else - newFile = new File(parent, name + '.' + (generations[0] + 1)); - - mv(outputFile, newFile); // throws IOException if problem - outputFile = null; - appendChecksum = null; - CacheInfo info = new CacheInfo(FILETYPE_VALID, checksum, newFile.lastModified()); - cacheFiles.put(newFile, info); - cleanup(generations, true); - lastGenerationFile = null; - lastGenerations = null; - } - - /** - * Abort the current output stream and do not update the reliable file table. - * - */ - void abortOutputFile() { - if (outputFile == null) - return; - outputFile.delete(); - outputFile = null; - appendChecksum = null; - } - - File getOutputFile() { - return outputFile; - } - - /** - * Close the target file for reading. - */ - void closeInputFile() { - inputFile = null; - } - - private void cleanup(int[] generations, boolean generationAdded) { - if (generations == null) - return; - String name = referenceFile.getName(); - File parent = new File(referenceFile.getParent()); - int generationCount = generations.length; - // if a base file is in the list (0 in generations[]), we will - // never delete these files, so don't count them in the old - // generation count. - if (generations[generationCount - 1] == 0) - generationCount--; - // assume here that the int[] does not include a file just created - int rmCount = generationCount - defaultMaxGenerations; - if (generationAdded) - rmCount++; - if (rmCount < 1) - return; - synchronized (cacheFiles) { - // first, see if any of the files not deleted are known to - // be corrupt. If so, be sure to keep not to delete good - // backup files. - for (int idx = 0, count = generationCount - rmCount; idx < count; idx++) { - File file = new File(parent, name + '.' + generations[idx]); - CacheInfo info = (CacheInfo) cacheFiles.get(file); - if (info != null) { - if (info.filetype == FILETYPE_CORRUPT) - rmCount--; - } - } - for (int idx = generationCount - 1; rmCount > 0; idx--, rmCount--) { - File rmFile = new File(parent, name + '.' + generations[idx]); - rmFile.delete(); - cacheFiles.remove(rmFile); - } - } - } - - /** - * Rename a file. - * - * @param from The original file. - * @param to The new file name. - * @throws IOException If the rename failed. - */ - private static void mv(File from, File to) throws IOException { - if (!from.renameTo(to)) { - throw new IOException("rename failed"); //$NON-NLS-1$ - } - } - - /** - * Copy a file. - * - * @throws IOException If the copy failed. - */ - private static void cp(InputStream in, OutputStream out, int truncateSize) throws IOException { - try { - int length = in.available(); - if (truncateSize > length) - length = 0; - else - length -= truncateSize; - if (length > 0) { - int bufferSize; - if (length > BUF_SIZE) { - bufferSize = BUF_SIZE; - } else { - bufferSize = length; - } - - byte buffer[] = new byte[bufferSize]; - int size = 0; - int count; - while ((count = in.read(buffer, 0, length)) > 0) { - if ((size + count) >= length) - count = length - size; - out.write(buffer, 0, count); - size += count; - } - } - } finally { - try { - in.close(); - } catch (IOException e) {/*ignore*/ - } - out.close(); - } - } - - /** - * Answers a boolean indicating whether or not the specified reliable file - * exists on the underlying file system. This call only returns if a file - * exists and not if the file contents are valid. - * @param file returns true if the specified reliable file exists; otherwise false is returned - * - * @return <code>true</code> if the specified reliable file exists, - * <code>false</code> otherwise. - */ - public static boolean exists(File file) { - String prefix = file.getName() + '.'; - File parent = new File(file.getParent()); - int prefixLen = prefix.length(); - String[] files = parent.list(); - if (files == null) - return false; - for (int i = 0; i < files.length; i++) { - if (files[i].startsWith(prefix)) { - try { - Integer.parseInt(files[i].substring(prefixLen)); - return true; - } catch (NumberFormatException e) {/*ignore*/ - } - } - } - return file.exists(); - } - - /** - * Returns the time that the reliable file was last modified. Only the time - * of the last file generation is returned. - * @param file the file to determine the time of. - * @return time the file was last modified (see java.io.File.lastModified()). - */ - public static long lastModified(File file) { - int[] generations = getFileGenerations(file); - if (generations == null) - return 0L; - if (generations[0] == 0) - return file.lastModified(); - String name = file.getName(); - File parent = new File(file.getParent()); - File newFile = new File(parent, name + '.' + generations[0]); - return newFile.lastModified(); - } - - /** - * Returns the time that this ReliableFile was last modified. This method is only valid - * after requesting an input stream and the time of the actual input file is returned. - * - * @return time the file was last modified (see java.io.File.lastModified()) or - * 0L if an input stream is not open. - */ - public long lastModified() { - if (inputFile != null) { - return inputFile.lastModified(); - } - return 0L; - } - - /** - * Returns the a version number of a reliable managed file. The version can be expected - * to be unique for each successful file update. - * - * @param file the file to determine the version of. - * @return a unique version of this current file. A value of -1 indicates the file does - * not exist or an error occurred. - */ - public static int lastModifiedVersion(File file) { - int[] generations = getFileGenerations(file); - if (generations == null) - return -1; - return generations[0]; - } - - /** - * Delete the specified reliable file on the underlying file system. - * @param deleteFile the reliable file to delete - * - * @return <code>true</code> if the specified reliable file was deleted, - * <code>false</code> otherwise. - */ - public static boolean delete(File deleteFile) { - int[] generations = getFileGenerations(deleteFile); - if (generations == null) - return false; - String name = deleteFile.getName(); - File parent = new File(deleteFile.getParent()); - synchronized (cacheFiles) { - for (int idx = 0; idx < generations.length; idx++) { - // base files (.0 in generations[]) will never be deleted - if (generations[idx] == 0) - continue; - File file = new File(parent, name + '.' + generations[idx]); - if (file.exists()) { - file.delete(); - } - cacheFiles.remove(file); - } - } - return true; - } - - /** - * Get a list of ReliableFile base names in a given directory. Only files with a valid - * ReliableFile generation are included. - * @param directory the directory to inquire. - * @return an array of ReliableFile names in the directory. - * @throws IOException if an error occurs. - */ - public static String[] getBaseFiles(File directory) throws IOException { - if (!directory.isDirectory()) - throw new IOException("Not a valid directory"); //$NON-NLS-1$ - String files[] = directory.list(); - HashSet list = new HashSet(files.length / 2); - for (int idx = 0; idx < files.length; idx++) { - String file = files[idx]; - int pos = file.lastIndexOf('.'); - if (pos == -1) - continue; - String ext = file.substring(pos + 1); - int generation = 0; - try { - generation = Integer.parseInt(ext); - } catch (NumberFormatException e) {/*skip*/ - } - if (generation == 0) - continue; - String base = file.substring(0, pos); - list.add(base); - } - files = new String[list.size()]; - int idx = 0; - for (Iterator iter = list.iterator(); iter.hasNext();) { - files[idx++] = (String) iter.next(); - } - return files; - } - - /** - * Delete any old excess generations of a given reliable file. - * @param base realible file. - */ - public static void cleanupGenerations(File base) { - ReliableFile rf = new ReliableFile(base); - int[] generations = getFileGenerations(base); - rf.cleanup(generations, false); - lastGenerationFile = null; - lastGenerations = null; - } - - /** - * Inform ReliableFile that a file has been updated outside of - * ReliableFile. - * @param file - */ - public static void fileUpdated(File file) { - lastGenerationFile = null; - lastGenerations = null; - } - - /** - * Append a checksum value to the end of an output stream. - * @param out the output stream. - * @param checksum the checksum value to append to the file. - * @throws IOException if a write error occurs. - */ - void writeChecksumSignature(OutputStream out, Checksum checksum) throws IOException { - // tag on our signature and checksum - out.write(ReliableFile.identifier1); - out.write(intToHex((int) checksum.getValue())); - out.write(ReliableFile.identifier2); - } - - /** - * Returns the size of the ReliableFile signature + CRC at the end of the file. - * This method should be called only after calling getInputStream() or - * getOutputStream() methods. - * - * @return <code>int</code> size of the ReliableFIle signature + CRC appended - * to the end of the file. - * @throws IOException if getInputStream() or getOutputStream has not been - * called. - */ - int getSignatureSize() throws IOException { - if (inputFile != null) { - CacheInfo info = (CacheInfo) cacheFiles.get(inputFile); - if (info != null) { - switch (info.filetype) { - case FILETYPE_VALID : - case FILETYPE_CORRUPT : - return 16; - case FILETYPE_NOSIGNATURE : - return 0; - } - } - } - throw new IOException("ReliableFile signature size is unknown"); //$NON-NLS-1$ - } - - /** - * Returns a Checksum object for the current file contents. This method - * should be called only after calling getInputStream() or - * getOutputStream() methods. - * - * @return Object implementing Checksum interface initialized to the - * current file contents. - * @throws IOException if getOutputStream for append has not been called. - */ - Checksum getFileChecksum() throws IOException { - if (appendChecksum == null) - throw new IOException("Checksum is invalid!"); //$NON-NLS-1$ - return appendChecksum; - } - - /** - * Create a checksum implementation used by ReliableFile. - * - * @return Object implementing Checksum interface used to calculate - * a reliable file checksum - */ - Checksum getChecksumCalculator() { - // Using CRC32 because Adler32 isn't in the eeMinimum library. - return new CRC32(); - } - - /** - * Determine if a File is a valid ReliableFile - * - * @return <code>true</code> if the file is a valid ReliableFile - * @throws IOException If an error occurs verifying the file. - */ - private int getStreamType(InputStream is, Checksum crc) throws IOException { - boolean markSupported = is.markSupported(); - if (markSupported) - is.mark(is.available()); - try { - int len = is.available(); - if (len < 16) { - if (crc != null) { - byte data[] = new byte[16]; - int num = is.read(data); - if (num > 0) - crc.update(data, 0, num); - } - return FILETYPE_NOSIGNATURE; - } - len -= 16; - - int pos = 0; - byte data[] = new byte[BUF_SIZE]; - - while (pos < len) { - int read = data.length; - if (pos + read > len) - read = len - pos; - - int num = is.read(data, 0, read); - if (num == -1) { - throw new IOException("Unable to read entire file."); //$NON-NLS-1$ - } - - crc.update(data, 0, num); - pos += num; - } - - int num = is.read(data); // read last 16-byte signature - if (num != 16) { - throw new IOException("Unable to read entire file."); //$NON-NLS-1$ - } - - int i, j; - for (i = 0; i < 4; i++) - if (identifier1[i] != data[i]) { - crc.update(data, 0, 16); // update crc w/ sig bytes - return FILETYPE_NOSIGNATURE; - } - for (i = 0, j = 12; i < 4; i++, j++) - if (identifier2[i] != data[j]) { - crc.update(data, 0, 16); // update crc w/ sig bytes - return FILETYPE_NOSIGNATURE; - } - long crccmp; - try { - crccmp = Long.valueOf(new String(data, 4, 8, "UTF-8"), 16).longValue(); //$NON-NLS-1$ - } catch (UnsupportedEncodingException e) { - crccmp = Long.valueOf(new String(data, 4, 8), 16).longValue(); - } - if (crccmp == crc.getValue()) { - return FILETYPE_VALID; - } - // do not update CRC - return FILETYPE_CORRUPT; - } finally { - if (markSupported) - is.reset(); - } - } - - private static byte[] intToHex(int l) { - byte[] buffer = new byte[8]; - int count = 8; - - do { - int ch = (l & 0xf); - if (ch > 9) - ch = ch - 10 + 'a'; - else - ch += '0'; - buffer[--count] = (byte) ch; - l >>= 4; - } while (count > 0); - return buffer; - } - - private class CacheInfo { - int filetype; - Checksum checksum; - long timeStamp; - - CacheInfo(int filetype, Checksum checksum, long timeStamp) { - this.filetype = filetype; - this.checksum = checksum; - this.timeStamp = timeStamp; - } - } -} |