dbtuxnode.cpp

mysql-5.0.22.tar.gz源码包

/* Copyright (C) 2003 MySQL AB

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#define DBTUX_NODE_CPP
#include "Dbtux.hpp"

/*
 * Allocate index node in TUP.
 */
int
Dbtux::allocNode(Signal* signal, NodeHandle& node)
{
  if (ERROR_INSERTED(12007)) {
    jam();
    CLEAR_ERROR_INSERT_VALUE;
    return TuxMaintReq::NoMemError;
  }
  Frag& frag = node.m_frag;
  Uint32 pageId = NullTupLoc.getPageId();
  Uint32 pageOffset = NullTupLoc.getPageOffset();
  Uint32* node32 = 0;
  int errorCode = c_tup->tuxAllocNode(signal, frag.m_tupIndexFragPtrI, pageId, pageOffset, node32);
  jamEntry();
  if (errorCode == 0) {
    jam();
    node.m_loc = TupLoc(pageId, pageOffset);
    node.m_node = reinterpret_cast<TreeNode*>(node32);
    ndbrequire(node.m_loc != NullTupLoc && node.m_node != 0);
  } else {
    switch (errorCode) {
    case 827:
      errorCode = TuxMaintReq::NoMemError;
      break;
    }
  }
  return errorCode;
}

/*
 * Set handle to point to existing node.
 */
void
Dbtux::selectNode(NodeHandle& node, TupLoc loc)
{
  Frag& frag = node.m_frag;
  ndbrequire(loc != NullTupLoc);
  Uint32 pageId = loc.getPageId();
  Uint32 pageOffset = loc.getPageOffset();
  Uint32* node32 = 0;
  c_tup->tuxGetNode(frag.m_tupIndexFragPtrI, pageId, pageOffset, node32);
  jamEntry();
  node.m_loc = loc;
  node.m_node = reinterpret_cast<TreeNode*>(node32);
  ndbrequire(node.m_loc != NullTupLoc && node.m_node != 0);
}

/*
 * Set handle to point to new node.  Uses a pre-allocated node.
 */
void
Dbtux::insertNode(NodeHandle& node)
{
  Frag& frag = node.m_frag;
  // unlink from freelist
  selectNode(node, frag.m_freeLoc);
  frag.m_freeLoc = node.getLink(0);
  new (node.m_node) TreeNode();
#ifdef VM_TRACE
  TreeHead& tree = frag.m_tree;
  memset(node.getPref(), DataFillByte, tree.m_prefSize << 2);
  TreeEnt* entList = tree.getEntList(node.m_node);
  memset(entList, NodeFillByte, (tree.m_maxOccup + 1) * (TreeEntSize << 2));
#endif
}

/*
 * Delete existing node.  Simply put it on the freelist.
 */
void
Dbtux::deleteNode(NodeHandle& node)
{
  Frag& frag = node.m_frag;
  ndbrequire(node.getOccup() == 0);
  // link to freelist
  node.setLink(0, frag.m_freeLoc);
  frag.m_freeLoc = node.m_loc;
  // invalidate the handle
  node.m_loc = NullTupLoc;
  node.m_node = 0;
}

/*
 * Set prefix.  Copies the number of words that fits.  Includes
 * attribute headers for now.  XXX use null mask instead
 */
void
Dbtux::setNodePref(NodeHandle& node)
{
  const Frag& frag = node.m_frag;
  const TreeHead& tree = frag.m_tree;
  readKeyAttrs(frag, node.getMinMax(0), 0, c_entryKey);
  copyAttrs(frag, c_entryKey, node.getPref(), tree.m_prefSize);
}

// node operations

/*
 * Add entry at position.  Move entries greater than or equal to the old
 * one (if any) to the right.
 *
 *            X
 *            v
 *      A B C D E _ _  =>  A B C X D E _
 *      0 1 2 3 4 5 6      0 1 2 3 4 5 6
 *
 * Add list of scans at the new entry.
 */
void
Dbtux::nodePushUp(NodeHandle& node, unsigned pos, const TreeEnt& ent, Uint32 scanList)
{
  Frag& frag = node.m_frag;
  TreeHead& tree = frag.m_tree;
  const unsigned occup = node.getOccup();
  ndbrequire(occup < tree.m_maxOccup && pos <= occup);
  // fix old scans
  if (node.getNodeScan() != RNIL)
    nodePushUpScans(node, pos);
  // fix node
  TreeEnt* const entList = tree.getEntList(node.m_node);
  entList[occup] = entList[0];
  TreeEnt* const tmpList = entList + 1;
  for (unsigned i = occup; i > pos; i--) {
    jam();
    tmpList[i] = tmpList[i - 1];
  }
  tmpList[pos] = ent;
  entList[0] = entList[occup + 1];
  node.setOccup(occup + 1);
  // add new scans
  if (scanList != RNIL)
    addScanList(node, pos, scanList);
  // fix prefix
  if (occup == 0 || pos == 0)
    setNodePref(node);
}

void
Dbtux::nodePushUpScans(NodeHandle& node, unsigned pos)
{
  const unsigned occup = node.getOccup();
  ScanOpPtr scanPtr;
  scanPtr.i = node.getNodeScan();
  do {
    jam();
    c_scanOpPool.getPtr(scanPtr);
    TreePos& scanPos = scanPtr.p->m_scanPos;
    ndbrequire(scanPos.m_loc == node.m_loc && scanPos.m_pos < occup);
    if (scanPos.m_pos >= pos) {
      jam();
#ifdef VM_TRACE
      if (debugFlags & DebugScan) {
        debugOut << "Fix scan " << scanPtr.i << " " << *scanPtr.p << endl;
        debugOut << "At pushUp pos=" << pos << " " << node << endl;
      }
#endif
      scanPos.m_pos++;
    }
    scanPtr.i = scanPtr.p->m_nodeScan;
  } while (scanPtr.i != RNIL);
}

/*
 * Remove and return entry at position.  Move entries greater than the
 * removed one to the left.  This is the opposite of nodePushUp.
 *
 *                               D
 *            ^                  ^
 *      A B C D E F _  =>  A B C E F _ _
 *      0 1 2 3 4 5 6      0 1 2 3 4 5 6
 *
 * Scans at removed entry are returned if non-zero location is passed or
 * else moved forward.
 */
void
Dbtux::nodePopDown(NodeHandle& node, unsigned pos, TreeEnt& ent, Uint32* scanList)
{
  Frag& frag = node.m_frag;
  TreeHead& tree = frag.m_tree;
  const unsigned occup = node.getOccup();
  ndbrequire(occup <= tree.m_maxOccup && pos < occup);
  if (node.getNodeScan() != RNIL) {
    // remove or move scans at this position
    if (scanList == 0)
      moveScanList(node, pos);
    else
      removeScanList(node, pos, *scanList);
    // fix other scans
    if (node.getNodeScan() != RNIL)
      nodePopDownScans(node, pos);
  }
  // fix node
  TreeEnt* const entList = tree.getEntList(node.m_node);
  entList[occup] = entList[0];
  TreeEnt* const tmpList = entList + 1;
  ent = tmpList[pos];
  for (unsigned i = pos; i < occup - 1; i++) {
    jam();
    tmpList[i] = tmpList[i + 1];
  }
  entList[0] = entList[occup - 1];
  node.setOccup(occup - 1);
  // fix prefix
  if (occup != 1 && pos == 0)
    setNodePref(node);
}

void
Dbtux::nodePopDownScans(NodeHandle& node, unsigned pos)
{
  const unsigned occup = node.getOccup();
  ScanOpPtr scanPtr;
  scanPtr.i = node.getNodeScan();
  do {
    jam();
    c_scanOpPool.getPtr(scanPtr);
    TreePos& scanPos = scanPtr.p->m_scanPos;
    ndbrequire(scanPos.m_loc == node.m_loc && scanPos.m_pos < occup);
    // handled before
    ndbrequire(scanPos.m_pos != pos);
    if (scanPos.m_pos > pos) {
      jam();
#ifdef VM_TRACE
      if (debugFlags & DebugScan) {
        debugOut << "Fix scan " << scanPtr.i << " " << *scanPtr.p << endl;
        debugOut << "At popDown pos=" << pos << " " << node << endl;
      }
#endif
      scanPos.m_pos--;
    }
    scanPtr.i = scanPtr.p->m_nodeScan;
  } while (scanPtr.i != RNIL);
}

/*
 * Add entry at existing position.  Move entries less than or equal to
 * the old one to the left.  Remove and return old min entry.
 *
 *            X            A
 *      ^     v            ^
 *      A B C D E _ _  =>  B C D X E _ _
 *      0 1 2 3 4 5 6      0 1 2 3 4 5 6
 *
 * Return list of scans at the removed position 0.
 */
void
Dbtux::nodePushDown(NodeHandle& node, unsigned pos, TreeEnt& ent, Uint32& scanList)
{
  Frag& frag = node.m_frag;
  TreeHead& tree = frag.m_tree;
  const unsigned occup = node.getOccup();
  ndbrequire(occup <= tree.m_maxOccup && pos < occup);
  if (node.getNodeScan() != RNIL) {
    // remove scans at 0
    removeScanList(node, 0, scanList);
    // fix other scans
    if (node.getNodeScan() != RNIL)
      nodePushDownScans(node, pos);
  }
  // fix node
  TreeEnt* const entList = tree.getEntList(node.m_node);
  entList[occup] = entList[0];
  TreeEnt* const tmpList = entList + 1;
  TreeEnt oldMin = tmpList[0];
  for (unsigned i = 0; i < pos; i++) {
    jam();
    tmpList[i] = tmpList[i + 1];
  }
  tmpList[pos] = ent;
  ent = oldMin;
  entList[0] = entList[occup];
  // fix prefix
  if (true)
    setNodePref(node);
}