Examples with Value org.exist.storage.btree.Value used on opensource projects

Example 1 with Value

use of org.exist.storage.btree.Value in project exist by eXist-db.

the class ConsistencyCheck method checkXMLTree.

/**
 * Check the persistent DOM of a document. The method traverses the entire node tree and checks it for consistency, including node relationships,
 * child and attribute counts etc.
 *
 * @param doc the document to check
 * @return null if the document is consistent, an error report otherwise.
 */
public ErrorReport checkXMLTree(final DocumentImpl doc) {
    final DOMFile domDb = ((NativeBroker) broker).getDOMFile();
    return new DOMTransaction<ErrorReport>(this, domDb, () -> broker.getBrokerPool().getLockManager().acquireBtreeWriteLock(domDb.getLockName()), doc) {

        public ErrorReport start() {
            EmbeddedXMLStreamReader reader = null;
            try {
                final Node root = doc.getFirstChild();
                reader = (EmbeddedXMLStreamReader) broker.getXMLStreamReader((NodeHandle) root, true);
                boolean attribsAllowed = false;
                int expectedAttribs = 0;
                int attributeCount = 0;
                while (reader.hasNext()) {
                    final int status = reader.next();
                    final NodeId nodeId = (NodeId) reader.getProperty(EmbeddedXMLStreamReader.PROPERTY_NODE_ID);
                    if ((status != XMLStreamReader.END_ELEMENT) && !elementStack.isEmpty()) {
                        final ElementNode parent = elementStack.peek();
                        parent.childCount++;
                        // test parent-child relation
                        if (!nodeId.isChildOf(parent.elem.getNodeId())) {
                            return new ErrorReport.ResourceError(ErrorReport.NODE_HIERARCHY, "Node " + nodeId + " is not a child of " + parent.elem.getNodeId());
                        }
                        // test sibling relation
                        if ((parent.prevSibling != null) && !(nodeId.isSiblingOf(parent.prevSibling) && (nodeId.compareTo(parent.prevSibling) > 0))) {
                            return new ErrorReport.ResourceError(ErrorReport.INCORRECT_NODE_ID, "Node " + nodeId + " is not a sibling of " + parent.prevSibling);
                        }
                        parent.prevSibling = nodeId;
                    }
                    switch(status) {
                        case XMLStreamReader.ATTRIBUTE:
                            {
                                attributeCount++;
                                break;
                            }
                        case XMLStreamReader.END_ELEMENT:
                            {
                                if (elementStack.isEmpty()) {
                                    return new org.exist.backup.ErrorReport.ResourceError(ErrorReport.NODE_HIERARCHY, "Error in node hierarchy: received END_ELEMENT event " + "but stack was empty!");
                                }
                                final ElementNode lastElem = elementStack.pop();
                                if (lastElem.childCount != lastElem.elem.getChildCount()) {
                                    return new ErrorReport.ResourceError(org.exist.backup.ErrorReport.NODE_HIERARCHY, "Element reports incorrect child count: expected " + lastElem.elem.getChildCount() + " but found " + lastElem.childCount);
                                }
                                break;
                            }
                        case XMLStreamReader.START_ELEMENT:
                            {
                                if (nodeId.getTreeLevel() <= defaultIndexDepth) {
                                    // check dom.dbx btree, which maps the node
                                    // id to the node's storage address
                                    // look up the node id and check if the
                                    // returned storage address is correct
                                    final NativeBroker.NodeRef nodeRef = new NativeBroker.NodeRef(doc.getDocId(), nodeId);
                                    try {
                                        final long p = domDb.findValue(nodeRef);
                                        if (p != reader.getCurrentPosition()) {
                                            final Value v = domDb.get(p);
                                            if (v == null) {
                                                return new ErrorReport.IndexError(ErrorReport.DOM_INDEX, "Failed to access node " + nodeId + " through dom.dbx index. Wrong storage address. Expected: " + p + "; got: " + reader.getCurrentPosition() + " - ", doc.getDocId());
                                            }
                                        }
                                    } catch (final Exception e) {
                                        e.printStackTrace();
                                        return new ErrorReport.IndexError(ErrorReport.DOM_INDEX, "Failed to access node " + nodeId + " through dom.dbx index.", e, doc.getDocId());
                                    }
                                }
                                final IStoredNode node = reader.getNode();
                                if (node.getNodeType() != Node.ELEMENT_NODE) {
                                    return new org.exist.backup.ErrorReport.ResourceError(ErrorReport.INCORRECT_NODE_TYPE, "Expected an element node, received node of type " + node.getNodeType());
                                }
                                elementStack.push(new ElementNode((ElementImpl) node));
                                attribsAllowed = true;
                                attributeCount = 0;
                                expectedAttribs = reader.getAttributeCount();
                                break;
                            }
                        default:
                            {
                                if (attribsAllowed) {
                                    if (attributeCount != expectedAttribs) {
                                        return new org.exist.backup.ErrorReport.ResourceError(ErrorReport.INCORRECT_NODE_TYPE, "Wrong number of attributes. Expected: " + expectedAttribs + "; found: " + attributeCount);
                                    }
                                }
                                attribsAllowed = false;
                                break;
                            }
                    }
                }
                if (!elementStack.isEmpty()) {
                    return new org.exist.backup.ErrorReport.ResourceError(ErrorReport.NODE_HIERARCHY, "Error in node hierarchy: reached end of tree but " + "stack was not empty!");
                }
                return null;
            } catch (final IOException | XMLStreamException e) {
                e.printStackTrace();
                return new org.exist.backup.ErrorReport.ResourceError(ErrorReport.RESOURCE_ACCESS_FAILED, e.getMessage(), e);
            } finally {
                elementStack.clear();
                if (reader != null) {
                    try {
                        reader.close();
                    } catch (final XMLStreamException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }.run();
}

Example 2 with Value

use of org.exist.storage.btree.Value in project exist by eXist-db.

the class WriteOverflowPageLoggable method read.

@Override
public void read(final ByteBuffer in) {
    pageNum = in.getInt();
    nextPage = in.getInt();
    final int len = in.getShort();
    final byte[] data = new byte[len];
    in.get(data);
    value = new Value(data);
}

Example 3 with Value

use of org.exist.storage.btree.Value in project exist by eXist-db.

the class BFile method get.

/**
 * Retrieve value at logical address pointer from page
 *
 * @param page the data page
 * @param pointer the pointer to the value
 *
 * @return the value or null if there is no value
 *
 * @throws IOException if an I/O error occurs
 */
protected Value get(final DataPage page, final long pointer) throws IOException {
    final short tid = StorageAddress.tidFromPointer(pointer);
    final int offset = page.findValuePosition(tid);
    final byte[] data = page.getData();
    if (offset < 0 || offset > data.length) {
        LOG.error("wrong pointer (tid: {}{}) in file {}; offset = {}", tid, page.getPageInfo(), FileUtils.fileName(getFile()), offset);
        return null;
    }
    final int l = ByteConversion.byteToInt(data, offset);
    if (l + 6 > data.length) {
        LOG.error("{} wrong data length in page {}: expected={}; found={}", FileUtils.fileName(getFile()), page.getPageNum(), l + 6, data.length);
        return null;
    }
    dataCache.add(page.getFirstPage());
    final Value v = new Value(data, offset + 4, l);
    v.setAddress(pointer);
    return v;
}

Example 4 with Value

use of org.exist.storage.btree.Value in project exist by eXist-db.

the class RawNodeIterator method next.

@Override
public Value next() {
    Value nextValue = null;
    try (final ManagedLock<ReentrantLock> domFileLock = lockManager.acquireBtreeReadLock(db.getLockName())) {
        db.setOwnerObject(broker);
        long backLink = 0;
        do {
            final DOMFile.DOMFilePageHeader pageHeader = page.getPageHeader();
            // Next value larger than length of the current page?
            if (offset >= pageHeader.getDataLength()) {
                // Load next page in chain
                long nextPage = pageHeader.getNextDataPage();
                if (nextPage == Paged.Page.NO_PAGE) {
                    SanityCheck.TRACE("Bad link to next page " + page.page.getPageInfo() + "; previous: " + pageHeader.getPreviousDataPage() + "; offset = " + offset + "; lastTupleID = " + lastTupleID);
                    // TODO : throw exception here ? -pb
                    return null;
                }
                pageNum = nextPage;
                page = db.getDOMPage(nextPage);
                db.addToBuffer(page);
                offset = 0;
            }
            // Extract the tuple id
            lastTupleID = ByteConversion.byteToShort(page.data, offset);
            offset += DOMFile.LENGTH_TID;
            // Check if this is just a link to a relocated node
            if (ItemId.isLink(lastTupleID)) {
                // Skip this
                offset += DOMFile.LENGTH_FORWARD_LOCATION;
                continue;
            }
            // Read data length
            short valueLength = ByteConversion.byteToShort(page.data, offset);
            offset += DOMFile.LENGTH_DATA_LENGTH;
            if (valueLength < 0) {
                LOG.error("Got negative length{} at offset {}!!!", valueLength, offset);
                LOG.debug(db.debugPageContents(page));
            // TODO : throw an exception right now ?
            }
            if (ItemId.isRelocated(lastTupleID)) {
                // found a relocated node. Read the original address
                backLink = ByteConversion.byteToLong(page.data, offset);
                offset += DOMFile.LENGTH_ORIGINAL_LOCATION;
            }
            // Overflow page? load the overflow value
            if (valueLength == DOMFile.OVERFLOW) {
                valueLength = DOMFile.LENGTH_OVERFLOW_LOCATION;
                final long overflow = ByteConversion.byteToLong(page.data, offset);
                offset += DOMFile.LENGTH_OVERFLOW_LOCATION;
                try {
                    final byte[] odata = db.getOverflowValue(overflow);
                    nextValue = new Value(odata);
                } catch (final Exception e) {
                    LOG.error("Exception while loading overflow value: {}; originating page: {}", e.getMessage(), page.page.getPageInfo());
                }
            // normal node
            } else {
                try {
                    nextValue = new Value(page.data, offset, valueLength);
                    offset += valueLength;
                } catch (final Exception e) {
                    LOG.error("Error while deserializing node: {}", e.getMessage(), e);
                    LOG.error("Reading from offset: {}; len = {}", offset, valueLength);
                    LOG.debug(db.debugPageContents(page));
                    throw new RuntimeException(e);
                }
            }
            if (nextValue == null) {
                LOG.error("illegal node on page {}; tupleID = {}; next = {}; prev = {}; offset = {}; len = {}", page.getPageNum(), ItemId.getId(lastTupleID), page.getPageHeader().getNextDataPage(), page.getPageHeader().getPreviousDataPage(), offset - valueLength, page.getPageHeader().getDataLength());
                // TODO : throw exception here ? -pb
                return null;
            }
            if (ItemId.isRelocated(lastTupleID)) {
                nextValue.setAddress(backLink);
            } else {
                nextValue.setAddress(StorageAddress.createPointer((int) pageNum, ItemId.getId(lastTupleID)));
            }
        } while (nextValue == null);
        return nextValue;
    } catch (final LockException e) {
        LOG.error("Failed to acquire read lock on {}", FileUtils.fileName(db.getFile()));
        // TODO : throw exception here ? -pb
        return null;
    }
}

Example 5 with Value

use of org.exist.storage.btree.Value in project exist by eXist-db.

the class EmbeddedXMLStreamReader method readAttributes.

private void readAttributes() {
    if (attributes == null) {
        final ElementEvent parent = elementStack.peek();
        final int count = getAttributeCount();
        attributes = new AttrList();
        for (int i = 0; i < count; i++) {
            final Value v = iterator.next();
            AttrImpl.addToList(broker, v.data(), v.start(), v.getLength(), attributes);
            parent.incrementChild();
        }
    }
}