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tdepim/akregator/src/mk4storage/metakit/src/remap.cpp

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// remap.cpp --
// $Id$
// This is part of Metakit, the homepage is http://www.equi4.com/metakit/
/** @file
* Mapping and remapping custom viewers
*/
#include "header.h"
#include "remap.h"
#include "handler.h"
/////////////////////////////////////////////////////////////////////////////
class c4_ReadOnlyViewer : public c4_CustomViewer
{
c4_View _base;
public:
c4_ReadOnlyViewer (c4_Sequence& seq_) : _base (&seq_) { }
virtual ~c4_ReadOnlyViewer () { }
virtual c4_View GetTemplate() { return _base.Clone(); }
virtual int GetSize() { return _base.GetSize(); }
virtual int Lookup(c4_Cursor key_, int& count_)
{ int pos = 0; count_ = _base.GetSize();
return _base.RestrictSearch(*key_, pos, count_); }
virtual bool GetItem(int row_, int col_, c4_Bytes& buf_)
{ return _base.GetItem(row_, col_, buf_); }
};
/////////////////////////////////////////////////////////////////////////////
class c4_HashViewer : public c4_CustomViewer
{
c4_View _base;
c4_View _map;
int _numKeys;
c4_IntProp _pHash;
c4_IntProp _pRow;
bool KeySame(int row_, c4_Cursor cursor_) const;
t4_i32 CalcHash(c4_Cursor cursor_) const;
int LookDict(t4_i32 hash_, c4_Cursor cursor_) const;
void InsertDict(int row_);
void RemoveDict(int pos_);
bool DictResize(int minused);
int Row(int i_) const { return _pRow (_map[i_]); }
int Hash(int i_) const { return _pHash (_map[i_]); }
void SetRow(int i_, int v_) { _pRow (_map[i_]) = v_; }
void SetHash(int i_, int v_) { _pHash (_map[i_]) = v_; }
bool IsUnused(int) const;
bool IsDummy(int) const;
bool IsActive(int i_) const { return Row(i_) >= 0; }
int GetPoly() const;
void SetPoly(int v_);
int GetSpare() const;
void SetSpare(int v_);
public:
c4_HashViewer (c4_Sequence& seq_, int numKeys_,
c4_Sequence* map_=0);
virtual ~c4_HashViewer ();
virtual c4_View GetTemplate();
virtual int GetSize();
virtual int Lookup(c4_Cursor key_, int& count_);
virtual bool GetItem(int row_, int col_, c4_Bytes& buf_);
virtual bool SetItem(int row_, int col_, const c4_Bytes& buf_);
virtual bool InsertRows(int pos_, c4_Cursor value_, int count_=1);
virtual bool RemoveRows(int pos_, int count_=1);
};
/////////////////////////////////////////////////////////////////////////////
// The following contains code derived froms Python's dictionaries, hence:
// Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
// The Netherlands.
// Reduced and turned into a fast C++ class by Christian Tismer, hence:
// Copyright 1999 by Christian Tismer.
// Vectorized and reorganized further by Jean-Claude Wippler.
/////////////////////////////////////////////////////////////////////////////
// Table of irreducible polynomials to efficiently cycle through
// GF(2^n)-{0}, 2<=n<=30.
static long s_polys[] = {
4 + 3,
8 + 3,
16 + 3,
32 + 5,
64 + 3,
128 + 3,
256 + 29,
512 + 17,
1024 + 9,
2048 + 5,
4096 + 83,
8192 + 27,
16384 + 43,
32768 + 3,
65536 + 45,
131072 + 9,
262144 + 39,
524288 + 39,
1048576 + 9,
2097152 + 5,
4194304 + 3,
8388608 + 33,
16777216 + 27,
33554432 + 9,
67108864 + 71,
134217728 + 39,
268435456 + 9,
536870912 + 5,
1073741824 + 83,
0
};
/////////////////////////////////////////////////////////////////////////////
c4_HashViewer::c4_HashViewer (c4_Sequence& seq_, int numKeys_,
c4_Sequence* map_)
: _base (&seq_), _map (map_), _numKeys (numKeys_),
_pHash ("_H"), _pRow ("_R")
{
if (_map.GetSize() == 0)
_map.SetSize(1);
int poly = GetPoly();
if (poly == 0 || _map.GetSize() <= _base.GetSize())
DictResize(_base.GetSize());
}
c4_HashViewer::~c4_HashViewer ()
{
}
bool c4_HashViewer::IsUnused(int row_) const
{
c4_RowRef r = _map[row_];
return _pRow (r) < 0 && _pHash (r) == 0;
}
bool c4_HashViewer::IsDummy(int row_) const
{
c4_RowRef r = _map[row_];
return _pRow (r) < 0 && _pHash (r) < 0;
}
int c4_HashViewer::GetPoly() const
{
return Hash(_map.GetSize()-1);
}
void c4_HashViewer::SetPoly(int v_)
{
SetHash(_map.GetSize()-1, v_);
}
int c4_HashViewer::GetSpare() const
{
return Row(_map.GetSize()-1);
}
void c4_HashViewer::SetSpare(int v_)
{
SetRow(_map.GetSize()-1, v_);
}
bool c4_HashViewer::KeySame(int row_, c4_Cursor cursor_) const
{
for (int i = 0; i < _numKeys; ++i)
{
c4_Bytes buffer;
_base.GetItem(row_, i, buffer);
c4_Handler& h = cursor_._seq->NthHandler(i);
if (h.Compare(cursor_._index, buffer) != 0)
return false;
}
return true;
}
/// Create mapped view which is uses a second view for hashing
t4_i32 c4_HashViewer::CalcHash(c4_Cursor cursor_) const
{
c4_Bytes buffer, buf2;
const t4_i32 endian = 0x03020100;
t4_i32 hash = 0;
for (int i = 0; i < _numKeys; ++i)
{
c4_Handler& h = cursor_._seq->NthHandler(i);
cursor_._seq->Get(cursor_._index, h.PropId(), buffer);
// this code borrows from Python's stringobject.c/string_hash()
int len = buffer.Size();
if (len > 0)
{
const t4_byte* p = buffer.Contents();
// 20030218: careful to avoid endian-ness sensitivity
if (*(const t4_byte*) &endian) // true on big-endian systems
switch (h.Property().Type())
{
case 'I': case 'L': case 'F': case 'D':
{
t4_byte* q = buf2.SetBuffer(len);
for (int j = 0; j < len; ++j)
q[len-j-1] = p[j];
p = q;
}
}
long x = *p << 7;
// modifications are risky, this code avoid scanning huge blobs
if (len > 200)
len = 100;
while (--len >= 0)
x = (1000003 * x) ^ *p++;
if (buffer.Size() > 200)
{
len = 100;
p += buffer.Size() - 200;
while (--len >= 0)
x = (1000003 * x) ^ *p++;
}
x ^= buffer.Size();
hash ^= x ^ i;
}
}
if (hash == 0)
hash = -1;
return hash;
}
/*
* Types of slots:
* Unused: row = -1, hash = 0
* Dummy: row = -1, hash = -1
* Active: row >= 0
* There must be at least one Unused slot at all times.
*/
int c4_HashViewer::LookDict(t4_i32 hash_, c4_Cursor cursor_) const
{
const unsigned int mask = _map.GetSize() - 2;
/* We must come up with (i, incr) such that 0 <= i < _size
and 0 < incr < _size and both are a function of hash */
int i = mask & ~hash_;
/* We use ~hash_ instead of hash_, as degenerate hash functions, such
as for ints <sigh>, can have lots of leading zeros. It's not
really a performance risk, but better safe than sorry. */
if (IsUnused(i) || Hash(i) == hash_ && KeySame(Row(i), cursor_))
return i;
int freeslot = IsDummy(i) ? i : -1;
/* Derive incr from hash_, just to make it more arbitrary. Note that
incr must not be 0, or we will get into an infinite loop.*/
unsigned incr = (hash_ ^ ((unsigned long) hash_ >> 3)) & mask;
if (!incr)
incr = mask;
int poly = GetPoly();
for (;;)
{
i = (i+incr) & mask;
if (IsUnused(i))
break;
if (Hash(i) == hash_ && KeySame(Row(i), cursor_))
return i;
if (freeslot == -1 && IsDummy(i))
freeslot = i;
/* Cycle through GF(2^n)-{0} */
incr = incr << 1;
if (incr > mask)
incr ^= poly; /* This will implicitely clear the highest bit */
}
return freeslot != -1 ? freeslot : i;
}
void c4_HashViewer::InsertDict(int row_)
{
c4_Cursor cursor = &_base[row_];
t4_i32 hash = CalcHash(cursor);
int i = LookDict(hash, cursor);
if (IsDummy(i))
{
int n = GetSpare();
d4_assert(n > 0);
SetSpare(n - 1);
}
SetHash(i, hash);
SetRow(i, row_);
}
void c4_HashViewer::RemoveDict(int pos_)
{
c4_Cursor key = &_base[pos_];
t4_i32 hash = CalcHash(key);
int i = LookDict(hash, key);
d4_assert(i >= 0);
d4_assert(Row(i) == pos_);
SetHash(i, -1);
SetRow(i, -1);
SetSpare(GetSpare() + 1);
}
bool c4_HashViewer::DictResize(int minused)
{
int i, newsize, newpoly;
for (i = 0, newsize = 4; ; i++, newsize <<= 1) {
if (s_polys[i] == 0)
return false;
else if (newsize > minused) {
newpoly = s_polys[i];
break;
}
}
_map.SetSize(0);
c4_Row empty;
_pRow (empty) = -1;
_map.InsertAt(0, empty, newsize + 1);
SetPoly(newpoly);
SetSpare(0);
for (int j = 0; j < _base.GetSize(); ++j)
InsertDict(j);
return true;
}
c4_View c4_HashViewer::GetTemplate()
{
return _base.Clone();
}
int c4_HashViewer::GetSize()
{
return _base.GetSize();
}
int c4_HashViewer::Lookup(c4_Cursor key_, int& count_)
{
// can only use hashing if the properties match the query
// XXX it appears that this loop takes some 300 uS!
c4_View kv = (*key_).Container();
for (int k = 0; k < _numKeys; ++k)
if (kv.FindProperty(_base.NthProperty(k).GetId()) < 0)
return -1;
t4_i32 hash = CalcHash(key_); // TODO should combine with above loop
int i = LookDict(hash, key_);
int row = Row(i);
count_ = row >= 0 && KeySame(row, key_) ? 1 : 0;
return count_ ? row : 0; // don't return -1, we *know* it's not there
}
bool c4_HashViewer::GetItem(int row_, int col_, c4_Bytes& buf_)
{
return _base.GetItem(row_, col_, buf_);
}
bool c4_HashViewer::SetItem(int row_, int col_, const c4_Bytes& buf_)
{
if (col_ < _numKeys)
{
c4_Bytes temp;
_base.GetItem(row_, col_, temp);
if (buf_ == temp)
return true; // this call will have no effect, just ignore it
RemoveDict(row_);
}
_base.SetItem(row_, col_, buf_);
if (col_ < _numKeys)
{
// careful if changing a key to one which is already present:
// in that case, delete the other row to preserve uniqueness
//
// Note: this is a tricky and confusing issue, because now the
// mere act of *setting* a property value can *delete* a row!
//
// The big problem here is that setting the rest of the values
// in a loop can end up *wrong*, if the row has moved down!!!
int n;
int i = Lookup(&_base[row_], n);
if (i >= 0 && n > 0)
{
RemoveRows(i, 1);
if (i < row_)
--row_;
}
InsertDict(row_);
}
return true;
}
bool c4_HashViewer::InsertRows(int pos_, c4_Cursor value_, int count_)
{
d4_assert(count_ > 0);
int n;
int i = Lookup(value_, n);
if (i >= 0 && n > 0)
{
_base.SetAt(i, *value_); // replace existing
return true;
}
// adjust row numbers if the insertion is not at the end
//
// TODO this could be optimized to go through the rows which
// were moved up, and then adjusting the map through a lookup
// (probably better than full scan if pos_ is relatively high)
if (pos_ < _base.GetSize())
{
for (int r = 0; r < _map.GetSize() - 1; ++r)
{
int n2 = Row(r);
if (n2 >= pos_)
SetRow(r, n2 + 1);
}
}
_base.InsertAt(pos_, *value_);
InsertDict(pos_);
int used = _base.GetSize();
int fill = used + GetSpare();
if (fill * 3 >= (_map.GetSize() - 1) * 2 && !DictResize(used * 2))
return false; // bail out
d4_assert(_base.GetSize() + GetSpare() < _map.GetSize() - 1);
return true;
}
bool c4_HashViewer::RemoveRows(int pos_, int count_)
{
while (--count_ >= 0)
{
// since the map persists, be somewhat more aggressive than the
// original code in resizing down when the map is getting empty
if (_base.GetSize() * 3 < _map.GetSize() - 1 &&
!DictResize(_base.GetSize()))
return false; // bail out
RemoveDict(pos_);
// move rows down for now
//
// optionally: consider replacing with last entry (much faster)
for (int r = 0; r < _map.GetSize() - 1; ++r)
{
int n = Row(r);
if (n > pos_)
SetRow(r, n - 1);
}
_base.RemoveAt(pos_, 1);
}
return true;
}
/////////////////////////////////////////////////////////////////////////////
class c4_BlockedViewer : public c4_CustomViewer
{
enum { kLimit = 1000 };
c4_View _base;
c4_ViewProp _pBlock;
c4_DWordArray _offsets;
int Slot(int& pos_);
void Split(int block_, int row_);
void Merge(int block_);
void Validate() const;
public:
c4_BlockedViewer (c4_Sequence& seq_);
virtual ~c4_BlockedViewer ();
virtual c4_View GetTemplate();
virtual int GetSize();
virtual bool GetItem(int row_, int col_, c4_Bytes& buf_);
virtual bool SetItem(int row_, int col_, const c4_Bytes& buf_);
virtual bool InsertRows(int pos_, c4_Cursor value_, int count_=1);
virtual bool RemoveRows(int pos_, int count_=1);
};
/////////////////////////////////////////////////////////////////////////////
#if q4_CHECK
// debugging version to verify that the internal data is consistent
void c4_BlockedViewer::Validate() const
{
d4_assert(_base.GetSize() >= 2);
int n = _base.GetSize() - 1;
d4_assert(_offsets.GetSize() == n);
int total = 0;
for (int i = 0; i < n; i++)
{
c4_View bv = _pBlock (_base[i]);
d4_assert(bv.GetSize() > 0 || i == 0);
total += bv.GetSize();
d4_assert((int) _offsets.GetAt(i) == total++);
}
c4_View be = _pBlock (_base[n]);
d4_assert(be.GetSize() == n - 1);
}
#else
// nothing, so inline this thing to avoid even the calling overhead
d4_inline void c4_BlockedViewer::Validate() const
{
}
#endif
c4_BlockedViewer::c4_BlockedViewer (c4_Sequence& seq_)
: _base (&seq_), _pBlock ("_B")
{
if (_base.GetSize() < 2)
_base.SetSize(2);
int n = _base.GetSize() - 1;
_offsets.SetSize(n);
int total = 0;
for (int i = 0; i < n; i++)
{
c4_View bv = _pBlock (_base[i]);
total += bv.GetSize();
_offsets.SetAt(i, total++);
}
Validate();
}
c4_BlockedViewer::~c4_BlockedViewer ()
{
}
int c4_BlockedViewer::Slot(int& pos_)
{
d4_assert(_offsets.GetSize() > 0);
d4_assert(pos_ <= (int) _offsets.GetAt(_offsets.GetSize() - 1));
#if 0
const int n = _offsets.GetSize();
int h;
for (h = 0; h < n; ++h)
if (pos_ <= (t4_i32) _offsets.GetAt(h))
break;
#else
// switch to binary search, adapted from code by Zhang Dehua, 28-3-2002
// slows down some 5%, but said to be much better with 5 million rows
int l = 0, h = _offsets.GetSize() - 1;
while (l < h) {
int m = l + (h - l) / 2;
if ((t4_i32) _offsets.GetAt(m) < pos_)
l = m + 1;
else
h = m;
}
#endif
if (h > 0)
pos_ -= _offsets.GetAt(h-1) + 1;
return h;
}
void c4_BlockedViewer::Split(int bno_, int row_)
{
int z = _base.GetSize() - 1;
d4_assert(bno_ < z);
c4_View bz = _pBlock (_base[z]);
c4_View bv = _pBlock (_base[bno_]);
d4_assert(row_ < bv.GetSize());
_offsets.InsertAt(bno_, _offsets.GetAt(bno_) - bv.GetSize() + row_);
_base.InsertAt(bno_+1, c4_Row ());
c4_View bn = _pBlock (_base[bno_+1]);
bv.RelocateRows(row_ + 1, -1, bn, 0);
bv.RelocateRows(row_, 1, bz, bno_);
Validate();
}
void c4_BlockedViewer::Merge(int bno_)
{
int z = _base.GetSize() - 1;
c4_View bz = _pBlock (_base[z]);
c4_View bv1 = _pBlock (_base[bno_]);
c4_View bv2 = _pBlock (_base[bno_+1]);
_offsets.RemoveAt(bno_);
bz.RelocateRows(bno_, 1, bv1, -1);
bv2.RelocateRows(0, -1, bv1, -1);
_base.RemoveAt(bno_+1);
Validate();
}
c4_View c4_BlockedViewer::GetTemplate()
{
c4_View bv = _pBlock (_base[0]);
return bv.Clone();
}
int c4_BlockedViewer::GetSize()
{
int n = _offsets.GetAt(_offsets.GetSize() - 1);
d4_assert(n >= 0);
return n;
}
bool c4_BlockedViewer::GetItem(int row_, int col_, c4_Bytes& buf_)
{
int orig = row_;
int i = Slot(row_);
d4_assert(0 <= i && i < _base.GetSize() - 1);
if ((t4_i32) _offsets.GetAt(i) == orig)
{
row_ = i;
i = _base.GetSize() - 1;
}
c4_View bv = _pBlock (_base[i]);
return bv.GetItem(row_, col_, buf_);
}
bool c4_BlockedViewer::SetItem(int row_, int col_, const c4_Bytes& buf_)
{
int orig = row_;
int i = Slot(row_);
d4_assert(0 <= i && i < _base.GetSize() - 1);
if ((t4_i32) _offsets.GetAt(i) == orig)
{
row_ = i;
i = _base.GetSize() - 1;
}
c4_View bv = _pBlock (_base[i]);
bv.SetItem(row_, col_, buf_);
return true;
}
bool c4_BlockedViewer::InsertRows(int pos_, c4_Cursor value_, int count_)
{
d4_assert(count_ > 0);
bool atEnd = pos_ == GetSize();
int z = _base.GetSize() - 1;
int i = Slot(pos_);
d4_assert(0 <= i && i < z);
c4_View bv = _pBlock (_base[i]);
d4_assert(0 <= pos_ && pos_ <= bv.GetSize());
bv.InsertAt(pos_, *value_, count_);
for (int j = i; j < z; ++j)
_offsets.SetAt(j, _offsets.GetAt(j) + count_);
// massive insertions are first split off
while (bv.GetSize() >= 2 * kLimit)
Split(i, bv.GetSize() - kLimit - 2);
if (bv.GetSize() > kLimit )
Split(i, atEnd ? kLimit - 1 : bv.GetSize() / 2); // 23-3-2002, from MB
Validate();
return true;
}
bool c4_BlockedViewer::RemoveRows(int pos_, int count_)
{
d4_assert(count_ > 0);
d4_assert(pos_ + count_ <= GetSize());
int z = _base.GetSize() - 1;
int i = Slot(pos_);
d4_assert(0 <= i && i < z);
c4_View bv = _pBlock (_base[i]);
d4_assert(0 <= pos_ && pos_ <= bv.GetSize());
int todo = count_;
// optimize if the deletion goes past the end of this block...
int overshoot = pos_ + count_ - bv.GetSize();
if (overshoot > 0) {
// first, delete blocks which are going away completely
while (i+1 < _offsets.GetSize()) {
int nextsize = _offsets.GetAt(i+1) - _offsets.GetAt(i);
if (overshoot < nextsize)
break;
todo -= nextsize;
overshoot -= nextsize;
// drop the block and forget it ever existed
for (int j = i+1; j < z; ++j)
_offsets.SetAt(j, _offsets.GetAt(j) - nextsize);
_offsets.RemoveAt(i+1);
_base.RemoveAt(i+1);
--z;
c4_View bz = _pBlock (_base[z]);
bz.RemoveAt(i);
Validate();
}
// delete before merging, to avoid useless copying
if (overshoot > 1) {
c4_View bv2 = _pBlock (_base[i+1]);
bv2.RemoveAt(0, overshoot - 1);
todo -= overshoot - 1;
for (int j = i+1; j < z; ++j)
_offsets.SetAt(j, _offsets.GetAt(j) - (overshoot - 1));
// if the next block is filled enough, rotate the separator
// this avoids an expensive and unnecessary merge + split
if (bv2.GetSize() > kLimit / 2) {
c4_View bz = _pBlock (_base[z]);
bz[i] = bv2[0];
bv2.RemoveAt(0);
--todo;
d4_assert(pos_ + todo <= bv.GetSize());
d4_assert(i < _offsets.GetSize());
for (int j = i+1; j < z; ++j)
_offsets.SetAt(j, _offsets.GetAt(j) - 1);
}
}
// merge into one block
if (pos_ + todo > bv.GetSize()) {
d4_assert(i < z - 1);
Merge(i);
--z;
}
}
d4_assert(pos_ + todo <= bv.GetSize());
// now remove the rows and adjust offsets
if (todo > 0)
bv.RemoveAt(pos_, todo);
for (int j = i; j < z; ++j)
_offsets.SetAt(j, _offsets.GetAt(j) - todo);
// if the block underflows, merge it
if (bv.GetSize() < kLimit / 2) {
if (i > 0) // merge with predecessor, preferably
bv = _pBlock (_base[--i]);
if (i >= z - 1) // unless there is no successor to merge with
return true;
Merge(i);
}
// if the block overflows, split it
if (bv.GetSize() > kLimit )
Split(i, bv.GetSize() / 2);
Validate();
return true;
}
/////////////////////////////////////////////////////////////////////////////
class c4_OrderedViewer : public c4_CustomViewer
{
c4_View _base;
int _numKeys;
int KeyCompare(int row_, c4_Cursor cursor_) const;
public:
c4_OrderedViewer (c4_Sequence& seq_, int numKeys_);
virtual ~c4_OrderedViewer ();
virtual c4_View GetTemplate();
virtual int GetSize();
virtual int Lookup(c4_Cursor key_, int& count_);
virtual bool GetItem(int row_, int col_, c4_Bytes& buf_);
virtual bool SetItem(int row_, int col_, const c4_Bytes& buf_);
virtual bool InsertRows(int pos_, c4_Cursor value_, int count_=1);
virtual bool RemoveRows(int pos_, int count_=1);
};
/////////////////////////////////////////////////////////////////////////////
c4_OrderedViewer::c4_OrderedViewer (c4_Sequence& seq_, int numKeys_)
: _base (&seq_), _numKeys (numKeys_)
{
}
c4_OrderedViewer::~c4_OrderedViewer ()
{
}
int c4_OrderedViewer::KeyCompare(int row_, c4_Cursor cursor_) const
{
for (int i = 0; i < _numKeys; ++i)
{
c4_Bytes buffer;
_base.GetItem(row_, i, buffer);
c4_Handler& h = cursor_._seq->NthHandler(i);
int f = h.Compare(cursor_._index, buffer);
if (f != 0)
return f;
}
return 0;
}
c4_View c4_OrderedViewer::GetTemplate()
{
return _base.Clone();
}
int c4_OrderedViewer::GetSize()
{
return _base.GetSize();
}
int c4_OrderedViewer::Lookup(c4_Cursor key_, int& count_)
{
// can only use bsearch if the properties match the query
// XXX with ord1.tcl (dict words), this loop takes 300 uS!
c4_View kv = (*key_).Container();
for (int k = 0; k < _numKeys; ++k)
if (kv.FindProperty(_base.NthProperty(k).GetId()) < 0)
return -1;
#if 0 // Locate gets the count wrong, it seems 2000-06-15
int pos;
count_ = _base.Locate(*key_, &pos);
#else
int pos = _base.Search(*key_);
count_ = pos < _base.GetSize() && KeyCompare(pos, key_) == 0 ? 1 : 0;
#endif
return pos;
}
bool c4_OrderedViewer::GetItem(int row_, int col_, c4_Bytes& buf_)
{
return _base.GetItem(row_, col_, buf_);
}
bool c4_OrderedViewer::SetItem(int row_, int col_, const c4_Bytes& buf_)
{
if (col_ < _numKeys)
{
c4_Bytes temp;
_base.GetItem(row_, col_, temp);
if (buf_ == temp)
return true; // this call will have no effect, just ignore it
}
_base.SetItem(row_, col_, buf_);
if (col_ < _numKeys)
{
c4_Row copy = _base[row_];
// have to remove the row because it messes up searching
// it would be more efficient to search *around* this row
// or perhaps figure out new pos before changing any data
RemoveRows(row_);
InsertRows(0, &copy); // position is ignored
}
return true;
}
bool c4_OrderedViewer::InsertRows(int, c4_Cursor value_, int count_)
{
d4_assert(count_ > 0);
int n;
int i = Lookup(value_, n);
// XXX if the lookup does not work, then insert as first element (!?)
d4_assert(i >= 0);
if (i < 0)
i = 0;
if (n == 0)
_base.InsertAt(i, *value_);
else
{
d4_assert(i < _base.GetSize());
_base.SetAt(i, *value_); // replace existing
}
return true;
}
bool c4_OrderedViewer::RemoveRows(int pos_, int count_)
{
_base.RemoveAt(pos_, count_);
return true;
}
/////////////////////////////////////////////////////////////////////////////
class c4_IndexedViewer : public c4_CustomViewer
{
c4_View _base;
c4_View _map;
c4_View _props;
bool _unique;
c4_IntProp _mapProp;
int KeyCompare(int row_, c4_Cursor cursor_) const;
public:
c4_IndexedViewer (c4_Sequence& seq_, c4_Sequence& map_,
const c4_View& props_, bool unique_);
virtual ~c4_IndexedViewer ();
virtual c4_View GetTemplate();
virtual int GetSize();
virtual int Lookup(c4_Cursor key_, int& count_);
virtual bool GetItem(int row_, int col_, c4_Bytes& buf_);
virtual bool SetItem(int row_, int col_, const c4_Bytes& buf_);
virtual bool InsertRows(int pos_, c4_Cursor value_, int count_=1);
virtual bool RemoveRows(int pos_, int count_=1);
};
/////////////////////////////////////////////////////////////////////////////
c4_IndexedViewer::c4_IndexedViewer (c4_Sequence& seq_, c4_Sequence& map_,
const c4_View& props_, bool unique_)
: _base (&seq_), _map (&map_), _props (props_), _unique (unique_),
_mapProp ((const c4_IntProp&) _map.NthProperty(0))
{
int n = _base.GetSize();
if (_map.GetSize() != n)
{
c4_View sorted = _base.SortOn(_props);
_map.SetSize(n);
for (int i = 0; i < n; ++i)
_mapProp (_map[i]) = _base.GetIndexOf(sorted[i]);
}
}
c4_IndexedViewer::~c4_IndexedViewer ()
{
}
int c4_IndexedViewer::KeyCompare(int row_, c4_Cursor cursor_) const
{
int n = _props.NumProperties();
for (int i = 0; i < n; ++i)
{
c4_Bytes buffer;
_base.GetItem(row_, i, buffer);
c4_Handler& h = cursor_._seq->NthHandler(i);
int f = h.Compare(cursor_._index, buffer);
if (f != 0)
return f;
}
return 0;
}
c4_View c4_IndexedViewer::GetTemplate()
{
return _base.Clone();
}
int c4_IndexedViewer::GetSize()
{
return _base.GetSize();
}
int c4_IndexedViewer::Lookup(c4_Cursor key_, int& count_)
{
// can only use bsearch if the properties match the query
// XXX with ord1.tcl (dict words), this loop takes 300 uS!
c4_View kv = (*key_).Container();
int n = _props.NumProperties();
for (int k = 0; k < n; ++k)
if (kv.FindProperty(_props.NthProperty(k).GetId()) < 0)
return -1;
#if 0 // Locate gets the count wrong, it seems 2000-06-15
int pos;
count_ = _base.Locate(*key_, &pos);
#else
int pos = _base.Search(*key_);
count_ = pos < _base.GetSize() && KeyCompare(pos, key_) == 0 ? 1 : 0;
#endif
return pos;
}
bool c4_IndexedViewer::GetItem(int row_, int col_, c4_Bytes& buf_)
{
return _base.GetItem(row_, col_, buf_);
}
bool c4_IndexedViewer::SetItem(int row_, int col_, const c4_Bytes& buf_)
{
const int id = _base.NthProperty(col_).GetId();
const bool keyMod = _props.FindProperty(id) >= 0;
if (keyMod)
{
c4_Bytes temp;
_base.GetItem(row_, col_, temp);
if (buf_ == temp)
return true; // this call will have no effect, just ignore it
}
_base.SetItem(row_, col_, buf_);
if (keyMod)
{
// TODO adjust index
}
return true;
}
bool c4_IndexedViewer::InsertRows(int, c4_Cursor value_, int count_)
{
d4_assert(count_ > 0);
if (_unique)
count_ = 1;
int n;
int i = Lookup(value_, n);
// XXX if the lookup does not work, then insert as first element (!?)
d4_assert(i >= 0);
if (i < 0)
i = 0;
if (n == 0)
_base.InsertAt(i, *value_);
else
{
d4_assert(i < _base.GetSize());
_base.SetAt(i, *value_); // replace existing
}
return true;
}
bool c4_IndexedViewer::RemoveRows(int pos_, int count_)
{
_base.RemoveAt(pos_, count_);
int n = _map.GetSize();
while (--n >= 0)
{
int v = _mapProp (_map[n]);
if (v >= pos_)
if (v < pos_ + count_)
_map.RemoveAt(n);
else
_mapProp (_map[n]) = v - count_;
}
return true;
}
/////////////////////////////////////////////////////////////////////////////
c4_CustomViewer* f4_CreateReadOnly(c4_Sequence& seq_)
{
return d4_new c4_ReadOnlyViewer (seq_);
}
c4_CustomViewer* f4_CreateHash(c4_Sequence& seq_, int nk_, c4_Sequence* map_)
{
return d4_new c4_HashViewer (seq_, nk_, map_);
}
c4_CustomViewer* f4_CreateBlocked(c4_Sequence& seq_)
{
return d4_new c4_BlockedViewer (seq_);
}
c4_CustomViewer* f4_CreateOrdered(c4_Sequence& seq_, int nk_)
{
return d4_new c4_OrderedViewer (seq_, nk_);
}
c4_CustomViewer* f4_CreateIndexed(c4_Sequence& seq_, c4_Sequence& map_,
const c4_View& props_, bool unique_)
{
return d4_new c4_IndexedViewer (seq_, map_, props_, unique_);
}
/////////////////////////////////////////////////////////////////////////////