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Diffstat (limited to 'storage/ndb/src/kernel/blocks/dbtux/DbtuxCmp.cpp')
| -rw-r--r-- | storage/ndb/src/kernel/blocks/dbtux/DbtuxCmp.cpp | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/storage/ndb/src/kernel/blocks/dbtux/DbtuxCmp.cpp b/storage/ndb/src/kernel/blocks/dbtux/DbtuxCmp.cpp new file mode 100644 index 00000000000..cf815b14c1a --- /dev/null +++ b/storage/ndb/src/kernel/blocks/dbtux/DbtuxCmp.cpp @@ -0,0 +1,175 @@ +/* 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_CMP_CPP +#include "Dbtux.hpp" + +/* + * Search key vs node prefix or entry. + * + * The comparison starts at given attribute position. The position is + * updated by number of equal initial attributes found. The entry data + * may be partial in which case CmpUnknown may be returned. + * + * The attributes are normalized and have variable size given in words. + */ +int +Dbtux::cmpSearchKey(const Frag& frag, unsigned& start, ConstData searchKey, ConstData entryData, unsigned maxlen) +{ + const unsigned numAttrs = frag.m_numAttrs; + const DescEnt& descEnt = getDescEnt(frag.m_descPage, frag.m_descOff); + // skip to right position in search key only + for (unsigned i = 0; i < start; i++) { + jam(); + searchKey += AttributeHeaderSize + searchKey.ah().getDataSize(); + } + // number of words of entry data left + unsigned len2 = maxlen; + int ret = 0; + while (start < numAttrs) { + if (len2 <= AttributeHeaderSize) { + jam(); + ret = NdbSqlUtil::CmpUnknown; + break; + } + len2 -= AttributeHeaderSize; + if (! searchKey.ah().isNULL()) { + if (! entryData.ah().isNULL()) { + jam(); + // verify attribute id + const DescAttr& descAttr = descEnt.m_descAttr[start]; + ndbrequire(searchKey.ah().getAttributeId() == descAttr.m_primaryAttrId); + ndbrequire(entryData.ah().getAttributeId() == descAttr.m_primaryAttrId); + // sizes + const unsigned size1 = searchKey.ah().getDataSize(); + const unsigned size2 = min(entryData.ah().getDataSize(), len2); + len2 -= size2; + // compare + NdbSqlUtil::Cmp* const cmp = c_sqlCmp[start]; + const Uint32* const p1 = &searchKey[AttributeHeaderSize]; + const Uint32* const p2 = &entryData[AttributeHeaderSize]; + const bool full = (maxlen == MaxAttrDataSize); + ret = (*cmp)(0, p1, size1 << 2, p2, size2 << 2, full); + if (ret != 0) { + jam(); + break; + } + } else { + jam(); + // not NULL > NULL + ret = +1; + break; + } + } else { + if (! entryData.ah().isNULL()) { + jam(); + // NULL < not NULL + ret = -1; + break; + } + } + searchKey += AttributeHeaderSize + searchKey.ah().getDataSize(); + entryData += AttributeHeaderSize + entryData.ah().getDataSize(); + start++; + } + return ret; +} + +/* + * Scan bound vs node prefix or entry. + * + * Compare lower or upper bound and index entry data. The entry data + * may be partial in which case CmpUnknown may be returned. Otherwise + * returns -1 if the bound is to the left of the entry and +1 if the + * bound is to the right of the entry. + * + * The routine is similar to cmpSearchKey, but 0 is never returned. + * Suppose all attributes compare equal. Recall that all bounds except + * possibly the last one are non-strict. Use the given bound direction + * (0-lower 1-upper) and strictness of last bound to return -1 or +1. + * + * Following example illustrates this. We are at (a=2, b=3). + * + * idir bounds strict return + * 0 a >= 2 and b >= 3 no -1 + * 0 a >= 2 and b > 3 yes +1 + * 1 a <= 2 and b <= 3 no +1 + * 1 a <= 2 and b < 3 yes -1 + * + * The attributes are normalized and have variable size given in words. + */ +int +Dbtux::cmpScanBound(const Frag& frag, unsigned idir, ConstData boundInfo, unsigned boundCount, ConstData entryData, unsigned maxlen) +{ + const DescEnt& descEnt = getDescEnt(frag.m_descPage, frag.m_descOff); + // direction 0-lower 1-upper + ndbrequire(idir <= 1); + // number of words of data left + unsigned len2 = maxlen; + // in case of no bounds, init last type to something non-strict + unsigned type = 4; + while (boundCount != 0) { + if (len2 <= AttributeHeaderSize) { + jam(); + return NdbSqlUtil::CmpUnknown; + } + len2 -= AttributeHeaderSize; + // get and skip bound type (it is used after the loop) + type = boundInfo[0]; + boundInfo += 1; + if (! boundInfo.ah().isNULL()) { + if (! entryData.ah().isNULL()) { + jam(); + // verify attribute id + const Uint32 index = boundInfo.ah().getAttributeId(); + ndbrequire(index < frag.m_numAttrs); + const DescAttr& descAttr = descEnt.m_descAttr[index]; + ndbrequire(entryData.ah().getAttributeId() == descAttr.m_primaryAttrId); + // sizes + const unsigned size1 = boundInfo.ah().getDataSize(); + const unsigned size2 = min(entryData.ah().getDataSize(), len2); + len2 -= size2; + // compare + NdbSqlUtil::Cmp* const cmp = c_sqlCmp[index]; + const Uint32* const p1 = &boundInfo[AttributeHeaderSize]; + const Uint32* const p2 = &entryData[AttributeHeaderSize]; + const bool full = (maxlen == MaxAttrDataSize); + int ret = (*cmp)(0, p1, size1 << 2, p2, size2 << 2, full); + if (ret != 0) { + jam(); + return ret; + } + } else { + jam(); + // not NULL > NULL + return +1; + } + } else { + jam(); + if (! entryData.ah().isNULL()) { + jam(); + // NULL < not NULL + return -1; + } + } + boundInfo += AttributeHeaderSize + boundInfo.ah().getDataSize(); + entryData += AttributeHeaderSize + entryData.ah().getDataSize(); + boundCount -= 1; + } + // all attributes were equal + const int strict = (type & 0x1); + return (idir == 0 ? (strict == 0 ? -1 : +1) : (strict == 0 ? +1 : -1)); +} |