コード例 #1
0
ファイル: QueryCompiler.java プロジェクト: dirkk/basex
  /**
   * Algorithm of Tarjan for computing the strongly connected components of a graph.
   *
   * @param v current node
   * @throws QueryException if a variable directly calls itself
   */
  private void tarjan(final int v) throws QueryException {
    final int ixv = 2 * v, llv = ixv + 1, idx = next++;
    while (list.size() <= llv) list.add(-1);
    list.set(ixv, idx);
    list.set(llv, idx);

    stack.push(v);

    for (final int w : adjacentTo(v)) {
      final int ixw = 2 * w, llw = ixw + 1;
      if (list.size() <= ixw || list.get(ixw) < 0) {
        // Successor w has not yet been visited; recurse on it
        tarjan(w);
        list.set(llv, Math.min(list.get(llv), list.get(llw)));
      } else if (stack.contains(w)) {
        // Successor w is in stack S and hence in the current SCC
        list.set(llv, Math.min(list.get(llv), list.get(ixw)));
      }
    }

    // If v is a root node, pop the stack and generate an SCC
    if (list.get(llv) == list.get(ixv)) {
      int w;
      Scope[] out = null;
      do {
        w = stack.pop();
        final Scope scp = scopes.get(w);
        out = out == null ? new Scope[] {scp} : Array.add(out, scp);
      } while (w != v);
      result.add(out);
    }
  }
コード例 #2
0
ファイル: Data.java プロジェクト: JosuaKrause/basex
  /**
   * Inserts a data instance at the specified pre value. Note that the specified data instance must
   * differ from this instance.
   *
   * @param ipre value at which to insert new data
   * @param ipar parent pre value of node
   * @param clip data clip
   */
  public final void insert(final int ipre, final int ipar, final DataClip clip) {
    meta.update();

    // update value and document indexes
    if (meta.updindex) indexBegin();
    resources.insert(ipre, clip);

    final int dsize = clip.size();
    final int buf = Math.min(dsize, IO.BLOCKSIZE >> IO.NODEPOWER);
    // resize buffer to cache more entries
    buffer(buf);

    // find all namespaces in scope to avoid duplicate declarations
    final TokenMap nsScope = nspaces.scope(ipar, this);

    // loop through all entries
    final IntList preStack = new IntList();
    final NSNode nsRoot = nspaces.current();
    final HashSet<NSNode> newNodes = new HashSet<NSNode>();
    final IntList flagPres = new IntList();

    // indicates if database only contains a dummy node
    final Data data = clip.data;
    int c = 0;
    for (int dpre = clip.start; dpre < clip.end; ++dpre, ++c) {
      if (c != 0 && c % buf == 0) insert(ipre + c - buf);

      final int pre = ipre + c;
      final int dkind = data.kind(dpre);
      final int dpar = data.parent(dpre, dkind);
      // ipar < 0 if document nodes on top level are added
      final int dis = dpar >= 0 ? dpre - dpar : ipar >= 0 ? pre - ipar : 0;
      final int par = dis == 0 ? -1 : pre - dis;

      if (c == 0) nspaces.root(par, this);

      while (!preStack.isEmpty() && preStack.peek() > par) nspaces.close(preStack.pop());

      switch (dkind) {
        case DOC:
          // add document
          nspaces.prepare();
          final int s = data.size(dpre, dkind);
          doc(pre, s, data.text(dpre, true));
          meta.ndocs++;
          preStack.push(pre);
          break;
        case ELEM:
          // add element
          nspaces.prepare();
          boolean ne = false;
          if (data.nsFlag(dpre)) {
            final Atts at = data.ns(dpre);
            for (int a = 0; a < at.size(); ++a) {
              // see if prefix has been declared/ is part of current ns scope
              final byte[] old = nsScope.get(at.name(a));
              if (old == null || !eq(old, at.value(a))) {
                // we have to keep track of all new NSNodes that are added
                // to the Namespace structure, as their pre values must not
                // be updated. I.e. if an NSNode N with pre value 3 existed
                // prior to inserting and two new nodes are inserted at
                // location pre == 3 we have to make sure N and only N gets
                // updated.
                newNodes.add(nspaces.add(at.name(a), at.value(a), pre));
                ne = true;
              }
            }
          }
          byte[] nm = data.name(dpre, dkind);
          elem(
              dis,
              tagindex.index(nm, null, false),
              data.attSize(dpre, dkind),
              data.size(dpre, dkind),
              nspaces.uri(nm, true),
              ne);
          preStack.push(pre);
          break;
        case TEXT:
        case COMM:
        case PI:
          // add text
          text(pre, dis, data.text(dpre, true), dkind);
          break;
        case ATTR:
          // add attribute
          nm = data.name(dpre, dkind);
          // check if prefix already in nsScope or not
          final byte[] attPref = prefix(nm);
          // check if prefix of attribute has already been declared, otherwise
          // add declaration to parent node
          if (data.nsFlag(dpre) && nsScope.get(attPref) == null) {
            nspaces.add(
                par,
                preStack.isEmpty() ? -1 : preStack.peek(),
                attPref,
                data.nspaces.uri(data.uri(dpre, dkind)),
                this);
            // save pre value to set ns flag later for this node. can't be done
            // here as direct table access would interfere with the buffer
            flagPres.add(par);
          }
          attr(
              pre,
              dis,
              atnindex.index(nm, null, false),
              data.text(dpre, false),
              nspaces.uri(nm, false),
              false);
          break;
      }
    }
    // finalize and update namespace structure
    while (!preStack.isEmpty()) nspaces.close(preStack.pop());
    nspaces.root(nsRoot);

    if (bp != 0) insert(ipre + c - 1 - (c - 1) % buf);
    // reset buffer to old size
    buffer(1);

    // set ns flags
    for (int f = 0; f < flagPres.size(); f++) {
      final int fl = flagPres.get(f);
      table.write2(fl, 1, name(fl) | 1 << 15);
    }

    // increase size of ancestors
    int p = ipar;
    while (p >= 0) {
      final int k = kind(p);
      size(p, k, size(p, k) + dsize);
      p = parent(p, k);
    }

    if (meta.updindex) {
      // add the entries to the ID -> PRE mapping:
      idmap.insert(ipre, id(ipre), dsize);
      indexEnd();
    }

    if (!cache) updateDist(ipre + dsize, dsize);

    // propagate PRE value shifts to namespaces
    if (ipar != -1) nspaces.insert(ipre, dsize, newNodes);
  }
コード例 #3
0
ファイル: Optimize.java プロジェクト: james-jw/basex
  /**
   * Optimizes the structures of a database.
   *
   * @param data data
   * @param enforceText enforce creation or deletion of text index
   * @param enforceAttr enforce creation or deletion of attribute index
   * @param enforceToken enforce creation or deletion of token index
   * @param enforceFt enforce creation or deletion of full-text index
   * @param cmd calling command instance (may be {@code null})
   * @throws IOException I/O Exception during index rebuild
   */
  public static void optimize(
      final Data data,
      final boolean enforceText,
      final boolean enforceAttr,
      final boolean enforceToken,
      final boolean enforceFt,
      final Optimize cmd)
      throws IOException {

    // initialize structural indexes
    final MetaData md = data.meta;
    if (!md.uptodate) {
      data.paths.init();
      data.elemNames.init();
      data.attrNames.init();
      md.dirty = true;

      final IntList pars = new IntList(), elms = new IntList();
      int n = 0;

      for (int pre = 0; pre < md.size; ++pre) {
        final byte kind = (byte) data.kind(pre);
        final int par = data.parent(pre, kind);
        while (!pars.isEmpty() && pars.peek() > par) {
          pars.pop();
          elms.pop();
        }

        final int level = pars.size();
        if (kind == Data.DOC) {
          data.paths.put(0, Data.DOC, level);
          pars.push(pre);
          elms.push(0);
          ++n;
        } else if (kind == Data.ELEM) {
          final int id = data.nameId(pre);
          data.elemNames.index(data.elemNames.key(id), null, true);
          data.paths.put(id, Data.ELEM, level);
          pars.push(pre);
          elms.push(id);
        } else if (kind == Data.ATTR) {
          final int id = data.nameId(pre);
          final byte[] val = data.text(pre, false);
          data.attrNames.index(data.attrNames.key(id), val, true);
          data.paths.put(id, Data.ATTR, level, val, md);
        } else {
          final byte[] val = data.text(pre, true);
          if (kind == Data.TEXT && level > 1) data.elemNames.index(elms.peek(), val);
          data.paths.put(0, kind, level, val, md);
        }
        if (cmd != null) cmd.pre = pre;
      }
      md.ndocs = n;
      md.uptodate = true;
    }

    // rebuild value indexes
    optimize(IndexType.TEXT, data, md.createtext, md.textindex, enforceText, cmd);
    optimize(IndexType.ATTRIBUTE, data, md.createattr, md.attrindex, enforceAttr, cmd);
    optimize(IndexType.TOKEN, data, md.createtoken, md.tokenindex, enforceToken, cmd);
    optimize(IndexType.FULLTEXT, data, md.createft, md.ftindex, enforceFt, cmd);
  }