Examples with PageCursor org.neo4j.io.pagecache.PageCursor used on opensource projects

Example 21 with PageCursor

use of org.neo4j.io.pagecache.PageCursor in project neo4j by neo4j.

the class MuninnPageCacheTest method mustUnblockPageFaultersWhenEvictionGetsException.

@Test(timeout = SEMI_LONG_TIMEOUT_MILLIS)
public void mustUnblockPageFaultersWhenEvictionGetsException() throws Exception {
    writeInitialDataTo(file("a"));
    FileSystemAbstraction fs = new DelegatingFileSystemAbstraction(this.fs) {

        @Override
        public StoreChannel open(File fileName, String mode) throws IOException {
            return new DelegatingStoreChannel(super.open(fileName, mode)) {

                @Override
                public void writeAll(ByteBuffer src, long position) throws IOException {
                    throw new IOException("uh-oh...");
                }
            };
        }
    };
    MuninnPageCache pageCache = createPageCache(fs, 2, 8, PageCacheTracer.NULL, DefaultPageCursorTracerSupplier.INSTANCE);
    final PagedFile pagedFile = pageCache.map(file("a"), 8);
    // all writes.
    try (PageCursor cursor = pagedFile.io(0, PF_SHARED_WRITE_LOCK)) {
        for (int i = 0; i < 1000; i++) {
            assertTrue(cursor.next());
        }
        fail("Expected an exception at this point");
    } catch (IOException ignore) {
    // Good.
    }
}

Example 22 with PageCursor

use of org.neo4j.io.pagecache.PageCursor in project neo4j by neo4j.

the class CommonAbstractStore method extractHeaderRecord.

private void extractHeaderRecord(PagedFile pagedFile) throws IOException {
    if (getNumberOfReservedLowIds() > 0) {
        try (PageCursor pageCursor = pagedFile.io(0, PF_SHARED_READ_LOCK)) {
            if (pageCursor.next()) {
                do {
                    pageCursor.setOffset(0);
                    readHeaderAndInitializeRecordFormat(pageCursor);
                } while (pageCursor.shouldRetry());
                if (pageCursor.checkAndClearBoundsFlag()) {
                    throw new UnderlyingStorageException("Out of page bounds when reading header; page size too small: " + pageCache.pageSize() + " bytes.");
                }
            } else {
                throw new StoreNotFoundException("Fail to read header record of store file: " + storageFileName);
            }
        }
    } else {
        readHeaderAndInitializeRecordFormat(null);
    }
    recordSize = determineRecordSize();
}

Example 23 with PageCursor

use of org.neo4j.io.pagecache.PageCursor in project neo4j by neo4j.

the class CommonAbstractStore method getRawRecordData.

public byte[] getRawRecordData(long id) throws IOException {
    byte[] data = new byte[recordSize];
    long pageId = pageIdForRecord(id);
    int offset = offsetForId(id);
    try (PageCursor cursor = storeFile.io(pageId, PagedFile.PF_SHARED_READ_LOCK)) {
        if (cursor.next()) {
            do {
                cursor.setOffset(offset);
                cursor.getBytes(data);
            } while (cursor.shouldRetry());
            checkForDecodingErrors(cursor, id, CHECK);
        }
    }
    return data;
}

Example 24 with PageCursor

use of org.neo4j.io.pagecache.PageCursor in project neo4j by neo4j.

the class CommonAbstractStore method rebuildIdGenerator.

/**
     * Should rebuild the id generator from scratch.
     * <p>
     * Note: This method may be called both while the store has the store file mapped in the
     * page cache, and while the store file is not mapped. Implementers must therefore
     * map their own temporary PagedFile for the store file, and do their file IO through that,
     * if they need to access the data in the store file.
     */
final void rebuildIdGenerator() {
    int blockSize = getRecordSize();
    if (blockSize <= 0) {
        throw new InvalidRecordException("Illegal blockSize: " + blockSize);
    }
    log.info("Rebuilding id generator for[" + getStorageFileName() + "] ...");
    closeIdGenerator();
    createIdGenerator(getIdFileName());
    openIdGenerator();
    long defraggedCount = 0;
    boolean fastRebuild = isOnlyFastIdGeneratorRebuildEnabled(configuration);
    try {
        long foundHighId = scanForHighId();
        setHighId(foundHighId);
        if (!fastRebuild) {
            try (PageCursor cursor = storeFile.io(0, PF_SHARED_WRITE_LOCK | PF_READ_AHEAD)) {
                defraggedCount = rebuildIdGeneratorSlow(cursor, getRecordsPerPage(), blockSize, foundHighId);
            }
        }
    } catch (IOException e) {
        throw new UnderlyingStorageException("Unable to rebuild id generator " + getStorageFileName(), e);
    }
    log.info("[" + getStorageFileName() + "] high id=" + getHighId() + " (defragged=" + defraggedCount + ")");
    log.info(getStorageFileName() + " rebuild id generator, highId=" + getHighId() + " defragged count=" + defraggedCount);
    if (!fastRebuild) {
        closeIdGenerator();
        openIdGenerator();
    }
}

Example 25 with PageCursor

use of org.neo4j.io.pagecache.PageCursor in project neo4j by neo4j.

the class MetaDataStore method setRecord.

/**
     * Writes a record in a neostore file.
     * This method only works for neostore files of the current version.
     *
     * @param pageCache {@link PageCache} the {@code neostore} file lives in.
     * @param neoStore {@link File} pointing to the neostore.
     * @param position record {@link Position}.
     * @param value value to write in that record.
     * @return the previous value before writing.
     * @throws IOException if any I/O related error occurs.
     */
public static long setRecord(PageCache pageCache, File neoStore, Position position, long value) throws IOException {
    long previousValue = FIELD_NOT_INITIALIZED;
    int pageSize = getPageSize(pageCache);
    try (PagedFile pagedFile = pageCache.map(neoStore, pageSize)) {
        int offset = offset(position);
        try (PageCursor cursor = pagedFile.io(0, PagedFile.PF_SHARED_WRITE_LOCK)) {
            if (cursor.next()) {
                // We're overwriting a record, get the previous value
                cursor.setOffset(offset);
                byte inUse = cursor.getByte();
                long record = cursor.getLong();
                if (inUse == Record.IN_USE.byteValue()) {
                    previousValue = record;
                }
                // Write the value
                cursor.setOffset(offset);
                cursor.putByte(Record.IN_USE.byteValue());
                cursor.putLong(value);
                if (cursor.checkAndClearBoundsFlag()) {
                    MetaDataRecord neoStoreRecord = new MetaDataRecord();
                    neoStoreRecord.setId(position.id);
                    throw new UnderlyingStorageException(buildOutOfBoundsExceptionMessage(neoStoreRecord, 0, offset, RECORD_SIZE, pageSize, neoStore.getAbsolutePath()));
                }
            }
        }
    }
    return previousValue;
}