Examples with JournalledPageFile suite.file.JournalledPageFile used on opensource projects

Example 1 with JournalledPageFile

use of suite.file.JournalledPageFile in project suite by stupidsing.

the class B_TreeBuilder method build.

public static <// 
Key> // 
Pair<B_Tree<Key, Integer>, KeyDataStore<Key>> build(// 
Path path, // 
boolean isNew, // 
Serializer<Key> ks, // 
Comparator<Key> cmp, // 
int pageSize, int nPages) {
    if (isNew)
        Rethrow.ex(() -> Files.deleteIfExists(path));
    JournalledPageFile jpf = JournalledFileFactory.journalled(path, pageSize);
    B_Tree<Key, Integer> b_tree = new B_TreeBuilder<>(ks, serialize.int_).build(jpf, cmp, nPages);
    if (isNew) {
        b_tree.create();
        jpf.commit();
    }
    return Pair.of(b_tree, new B_TreeStore<>(b_tree, jpf::commit));
}

Example 2 with JournalledPageFile

use of suite.file.JournalledPageFile in project suite by stupidsing.

the class JournalledFileFactory method journalled.

private static // 
JournalledPageFile journalled(// 
PageFile df, // 
PageFile jpf, // 
PageFile ppf, int pageSize) {
    Serializer<Bytes> bytesSerializer = serialize.bytes(pageSize);
    Serializer<JournalEntry> journalEntrySerializer = new Serializer<>() {

        public JournalEntry read(DataInput_ dataInput) throws IOException {
            int pointer = dataInput.readInt();
            Bytes bytes = bytesSerializer.read(dataInput);
            return new JournalEntry(pointer, bytes);
        }

        public void write(DataOutput_ dataOutput, JournalEntry journalEntry) throws IOException {
            dataOutput.writeInt(journalEntry.pointer);
            bytesSerializer.write(dataOutput, journalEntry.bytes);
        }
    };
    PageFile dataFile = df;
    SerializedPageFile<JournalEntry> journalPageFile = SerializedFileFactory.serialized(jpf, journalEntrySerializer);
    SerializedPageFile<Integer> pointerPageFile = SerializedFileFactory.serialized(ppf, serialize.int_);
    int nCommittedJournalEntries0 = pointerPageFile.load(0);
    List<JournalEntry> journalEntries = new ArrayList<>();
    for (int jp = 0; jp < nCommittedJournalEntries0; jp++) journalEntries.add(journalPageFile.load(jp));
    return new JournalledPageFile() {

        private int nCommittedJournalEntries = nCommittedJournalEntries0;

        public void close() throws IOException {
            dataFile.close();
            journalPageFile.close();
            pointerPageFile.close();
        }

        public synchronized Bytes load(int pointer) {
            IntObjPair<JournalEntry> pair = findPageInJournal(pointer);
            if (pair != null)
                return pair.t1.bytes;
            else
                return dataFile.load(pointer);
        }

        public synchronized void save(int pointer, Bytes bytes) {
            IntObjPair<JournalEntry> pair = findDirtyPageInJournal(pointer);
            int jp;
            JournalEntry journalEntry;
            if (pair != null) {
                jp = pair.t0;
                journalEntry = pair.t1;
            } else {
                jp = journalEntries.size();
                journalEntries.add(journalEntry = new JournalEntry(pointer, null));
            }
            journalEntry.bytes = bytes;
            journalPageFile.save(jp, journalEntry);
        }

        /**
         * Marks a snapshot that data can be recovered to.
         */
        public synchronized void commit() {
            while (nCommittedJournalEntries < journalEntries.size()) {
                JournalEntry journalEntry = journalEntries.get(nCommittedJournalEntries++);
                dataFile.save(journalEntry.pointer, journalEntry.bytes);
            }
            if (8 < nCommittedJournalEntries)
                saveJournal();
        }

        /**
         * Makes sure the current snapshot of data is saved and recoverable
         * on failure, upon the return of method call.
         */
        public synchronized void sync() {
            journalPageFile.sync();
            saveJournal();
            pointerPageFile.sync();
        }

        private void saveJournal() {
            pointerPageFile.save(0, nCommittedJournalEntries);
            if (128 < nCommittedJournalEntries)
                applyJournal();
        }

        /**
         * Shortens the journal by applying them to page file.
         */
        public synchronized void applyJournal() {
            // make sure all changes are written to main file
            dataFile.sync();
            // clear all committed entries
            journalEntries.subList(0, nCommittedJournalEntries).clear();
            // reset committed pointer
            pointerPageFile.save(0, nCommittedJournalEntries = 0);
            pointerPageFile.sync();
            // write back entries for next commit
            for (int jp = 0; jp < journalEntries.size(); jp++) journalPageFile.save(jp, journalEntries.get(jp));
        }

        private IntObjPair<JournalEntry> findPageInJournal(int pointer) {
            return findPageInJournal(pointer, 0);
        }

        private IntObjPair<JournalEntry> findDirtyPageInJournal(int pointer) {
            return findPageInJournal(pointer, nCommittedJournalEntries);
        }

        private IntObjPair<JournalEntry> findPageInJournal(int pointer, int start) {
            IntObjPair<JournalEntry> pair = null;
            for (int jp = start; jp < journalEntries.size(); jp++) {
                JournalEntry journalEntry = journalEntries.get(jp);
                if (journalEntry.pointer == pointer)
                    pair = IntObjPair.of(jp, journalEntry);
            }
            return pair;
        }
    };
}

Example 3 with JournalledPageFile

use of suite.file.JournalledPageFile in project suite by stupidsing.

the class B_TreeTest method testAccess.

@Test
public void testAccess() throws IOException {
    int pageSize = 4096;
    Path path = Constants.tmp("b_tree-file");
    Files.deleteIfExists(path);
    B_TreeBuilder<Integer, String> builder = new B_TreeBuilder<>(serialize.int_, serialize.string(16));
    shuffleNumbers();
    try (JournalledPageFile jpf = JournalledFileFactory.journalled(path, pageSize);
        B_Tree<Integer, String> b_tree = builder.build(jpf, comparator, pageSize)) {
        b_tree.create();
        testStep0(b_tree);
        jpf.commit();
        jpf.sync();
    }
    shuffleNumbers();
    try (JournalledPageFile jpf = JournalledFileFactory.journalled(path, pageSize);
        B_Tree<Integer, String> b_tree = builder.build(jpf, comparator, pageSize)) {
        testStep1(b_tree);
        jpf.commit();
        jpf.sync();
    }
    try (JournalledPageFile jpf = JournalledFileFactory.journalled(path, pageSize);
        B_Tree<Integer, String> b_tree = builder.build(jpf, comparator, pageSize)) {
        testStep2(b_tree);
        jpf.commit();
        jpf.sync();
        jpf.applyJournal();
    }
}

Example 4 with JournalledPageFile

use of suite.file.JournalledPageFile in project suite by stupidsing.

the class B_TreeTest method testDump.

@Test
public void testDump() throws IOException {
    int pageSize = 4096;
    Path path = Constants.tmp("b_tree-dump");
    Files.deleteIfExists(path);
    B_TreeBuilder<Integer, String> builder = new B_TreeBuilder<>(serialize.int_, serialize.string(16));
    try (JournalledPageFile jpf = JournalledFileFactory.journalled(path, pageSize);
        B_Tree<Integer, String> b_tree = builder.build(jpf, comparator, pageSize)) {
        b_tree.create();
        for (int i = 0; i < 32; i++) b_tree.put(i, Integer.toString(i));
        b_tree.dump(System.out);
        System.out.println(To.list(b_tree.keys(3, 10)));
        jpf.commit();
    }
}