1 package org.simantics.acorn;
3 import java.io.FileNotFoundException;
4 import java.io.IOException;
5 import java.io.Serializable;
6 import java.nio.file.FileVisitResult;
7 import java.nio.file.Files;
8 import java.nio.file.Path;
9 import java.nio.file.SimpleFileVisitor;
10 import java.nio.file.attribute.BasicFileAttributes;
11 import java.time.ZonedDateTime;
12 import java.time.format.DateTimeFormatter;
13 import java.util.List;
14 import java.util.function.Predicate;
15 import java.util.stream.Collectors;
16 import java.util.stream.Stream;
18 import org.simantics.acorn.exception.InvalidHeadStateException;
19 import org.simantics.databoard.Bindings;
20 import org.simantics.databoard.binding.mutable.MutableVariant;
21 import org.simantics.databoard.util.binary.BinaryMemory;
22 import org.slf4j.Logger;
23 import org.slf4j.LoggerFactory;
25 public class MainState implements Serializable {
27 private static final long serialVersionUID = 6237383147637270225L;
29 private static final Logger LOGGER = LoggerFactory.getLogger(MainState.class);
31 public static final String MAIN_STATE = "main.state";
39 private MainState(int headDir) {
40 this.headDir = headDir;
43 public static MainState load(Path directory, Runnable rollbackCallback) throws IOException {
44 Files.createDirectories(directory);
45 Path mainState = directory.resolve(MAIN_STATE);
47 MainState state = (MainState) org.simantics.databoard.Files.readFile(
49 Bindings.getBindingUnchecked(MainState.class));
50 int latestRevision = state.headDir - 1;
52 HeadState.validateHeadStateIntegrity(directory.resolve(latestRevision + "/" + HeadState.HEAD_STATE));
53 archiveRevisionDirectories(directory, latestRevision, rollbackCallback);
55 } catch (InvalidHeadStateException e) {
56 LOGGER.warn("Failed to start database from revision " + latestRevision + " stored in " + mainState + ". " + HeadState.HEAD_STATE + " is invalid.");
57 return rollback(directory, rollbackCallback);
58 } catch (FileNotFoundException e) {
59 LOGGER.warn("Failed to start database from revision " + latestRevision + " stored in " + mainState + ". Revision does not contain " + HeadState.HEAD_STATE + ".");
60 return rollback(directory, rollbackCallback);
62 } catch (FileNotFoundException e) {
63 // The database may also be totally empty at this point
64 if (!listRevisionDirs(directory, true, MainState::isInteger).isEmpty())
65 return new MainState(0);
67 LOGGER.warn("Unclean exit detected, " + mainState + " not found. Initiating automatic rollback.");
68 return rollback(directory, rollbackCallback);
69 } catch (Exception e) {
70 LOGGER.warn("Unclean exit detected. Initiating automatic rollback.", e);
71 return rollback(directory, rollbackCallback);
73 Files.deleteIfExists(mainState);
77 private static MainState rollback(Path directory, Runnable rollbackCallback) throws IOException {
78 LOGGER.warn("Database rollback initiated for " + directory);
79 rollbackCallback.run();
80 Path latest = findNewHeadStateDir(directory, rollbackCallback);
81 int latestRevision = latest != null ? safeParseInt(-1, latest) : -1;
82 // +1 because we want to return the next head version to use,
83 // not the latest existing version.
84 MainState state = new MainState( latestRevision + 1 );
85 archiveRevisionDirectories(directory, latestRevision, rollbackCallback);
86 LOGGER.warn("Database rollback completed. Restarting database from revision " + latest);
90 private byte[] toByteArray() throws IOException {
91 try (BinaryMemory rf = new BinaryMemory(4096)) {
92 Bindings.getSerializerUnchecked(Bindings.VARIANT).serialize(rf, MutableVariant.ofInstance(this));
93 return rf.toByteBuffer().array();
97 public void save(Path directory) throws IOException {
98 Path f = directory.resolve(MAIN_STATE);
99 Files.write(f, toByteArray());
103 private static int safeParseInt(int defaultValue, Path p) {
105 return Integer.parseInt(p.getFileName().toString());
106 } catch (NumberFormatException e) {
111 private static boolean isInteger(Path p) {
112 return safeParseInt(Integer.MIN_VALUE, p) != Integer.MIN_VALUE;
115 private static Predicate<Path> isGreaterThan(int i) {
117 int pi = safeParseInt(Integer.MIN_VALUE, p);
118 return pi != Integer.MIN_VALUE && pi > i;
127 * @throws IOException
129 private static Path findNewHeadStateDir(Path directory, Runnable rollbackCallback) throws IOException {
130 for (Path last : listRevisionDirs(directory, true, MainState::isInteger)) {
132 HeadState.validateHeadStateIntegrity(last.resolve(HeadState.HEAD_STATE));
134 } catch (IOException | InvalidHeadStateException e) {
135 // Cleanup is done in {@link cleanRevisionDirectories} method
136 rollbackCallback.run();
142 private static void archiveRevisionDirectories(Path directory, int greaterThanRevision, Runnable rollbackCallback) throws IOException {
143 List<Path> reverseSortedPaths = listRevisionDirs(directory, true, isGreaterThan(greaterThanRevision));
144 if (reverseSortedPaths.isEmpty())
147 // If none of the revisions to be archived are actually committed revisions
148 // then just delete them. Commitment is indicated by the head.state file.
149 if (!anyContainsHeadState(reverseSortedPaths)) {
150 for (Path p : reverseSortedPaths) {
152 LOGGER.info("Removed useless working folder " + p);
157 // Some kind of rollback is being performed. There is a possibility that
158 // indexes and virtual graphs are out of sync with the persistent database.
159 rollbackCallback.run();
161 Path recoveryFolder = getRecoveryFolder(directory);
162 Files.createDirectories(recoveryFolder);
163 LOGGER.info("Created new database recovery folder " + recoveryFolder);
164 for (Path p : reverseSortedPaths) {
165 Files.move(p, recoveryFolder.resolve(p.getFileName().toString()));
166 LOGGER.info("Archived revision " + p + " in recovery folder " + recoveryFolder);
170 private static boolean anyContainsHeadState(List<Path> paths) {
172 if (Files.exists(p.resolve(HeadState.HEAD_STATE)))
178 private static List<Path> listRevisionDirs(Path directory, boolean descending, Predicate<Path>... filters) throws IOException {
179 int coef = descending ? -1 : 1;
180 try (Stream<Path> s = Files.walk(directory, 1)) {
181 Stream<Path> fs = s.filter(p -> !p.equals(directory));
182 for (Predicate<Path> p : filters)
184 return fs.filter(Files::isDirectory)
185 .sorted((p1, p2) -> coef * Integer.compare(Integer.parseInt(p1.getFileName().toString()),
186 Integer.parseInt(p2.getFileName().toString())))
187 .collect(Collectors.toList());
191 private static void deleteAll(Path dir) throws IOException {
192 Files.walkFileTree(dir, new SimpleFileVisitor<Path>() {
194 public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
196 return FileVisitResult.CONTINUE;
199 public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
201 return FileVisitResult.CONTINUE;
206 private static final DateTimeFormatter RECOVERY_DIR_FORMAT = DateTimeFormatter.ofPattern("yyyy-M-d_HH-mm-ss");
208 private static Path getRecoveryFolder(Path directory) {
209 return findNonexistentDir(
210 directory.resolve("recovery"),
211 RECOVERY_DIR_FORMAT.format(ZonedDateTime.now()));
214 private static Path findNonexistentDir(Path inDirectory, String prefix) {
215 for (int i = 0;; ++i) {
216 Path dir = inDirectory.resolve(i == 0 ? prefix : prefix + "-" + i);
217 if (Files.notExists(dir))