internal static BtreeResult insertByteArrayKey(StorageImpl db, Page pg, int r, BtreeKey ins, int height)
{
int nItems = getnItems(pg);
int size = getSize(pg);
int n = (height != 0)?nItems + 1:nItems;
// insert before e[r]
byte[] bval = (byte[])ins.key.oval;
int len = bval.Length;
if (size + len + (n + 1) * strKeySize <= keySpace)
{
memcpy(pg, r + 1, pg, r, n - r, strKeySize);
size += len;
setKeyStrOffs(pg, r, keySpace - size);
setKeyStrSize(pg, r, len);
setKeyStrOid(pg, r, ins.oid);
setKeyBytes(pg, keySpace - size, bval);
nItems += 1;
}
else
{
// page is full then divide page
int pageId = db.allocatePage();
Page b = db.putPage(pageId);
int moved = 0;
int inserted = len + strKeySize;
int prevDelta = (1 << 31) + 1;
for (int bn = 0, i = 0; ; bn += 1)
{
int addSize, subSize;
int j = nItems - i - 1;
int keyLen = getKeyStrSize(pg, i);
if (bn == r)
{
keyLen = len;
inserted = 0;
addSize = len;
if (height == 0)
{
subSize = 0;
j += 1;
}
else
{
subSize = getKeyStrSize(pg, i);
}
}
else
{
addSize = subSize = keyLen;
if (height != 0)
{
if (i + 1 != r)
{
subSize += getKeyStrSize(pg, i + 1);
j -= 1;
}
else
{
inserted = 0;
}
}
}
int delta = (moved + addSize + (bn + 1) * strKeySize) - (j * strKeySize + size - subSize + inserted);
if (delta >= - prevDelta)
{
if (height == 0)
{
ins.getByteArray(b, bn - 1);
}
else
{
Debug.Assert(moved + (bn + 1) * strKeySize <= keySpace, "String fits in the B-Tree page");
if (bn != r)
{
ins.getByteArray(pg, i);
setKeyStrOid(b, bn, getKeyStrOid(pg, i));
size -= keyLen;
i += 1;
}
else
{
setKeyStrOid(b, bn, ins.oid);
}
}
nItems = compactifyByteArrays(pg, i);
if (bn < r || (bn == r && height == 0))
{
memcpy(pg, r - i + 1, pg, r - i, n - r, strKeySize);
size += len;
nItems += 1;
Debug.Assert(size + (n - i + 1) * strKeySize <= keySpace, "String fits in the B-Tree page");
setKeyStrOffs(pg, r - i, keySpace - size);
setKeyStrSize(pg, r - i, len);
setKeyStrOid(pg, r - i, ins.oid);
setKeyBytes(pg, keySpace - size, bval);
}
setnItems(b, bn);
setSize(b, moved);
setSize(pg, size);
setnItems(pg, nItems);
ins.oid = pageId;
db.pool.unfix(b);
return BtreeResult.Overflow;
}
moved += keyLen;
prevDelta = delta;
Debug.Assert(moved + (bn + 1) * strKeySize <= keySpace, "String fits in the B-Tree page");
setKeyStrSize(b, bn, keyLen);
setKeyStrOffs(b, bn, keySpace - moved);
if (bn == r)
{
setKeyStrOid(b, bn, ins.oid);
setKeyBytes(b, keySpace - moved, bval);
}
else
{
setKeyStrOid(b, bn, getKeyStrOid(pg, i));
memcpy(b, keySpace - moved, pg, getKeyStrOffs(pg, i), keyLen, 1);
size -= keyLen;
i += 1;
}
}
}
setnItems(pg, nItems);
setSize(pg, size);
return size + strKeySize * (nItems + 1) < keySpace / 3 ? BtreeResult.Underflow : BtreeResult.Done;
}
internal static BtreeResult insert(StorageImpl db, int pageId, Btree tree, BtreeKey ins, int height, bool unique, bool overwrite)
{
Page pg = db.getPage(pageId);
BtreeResult result;
int l = 0, n = getnItems(pg), r = n;
int ahead = unique ? 1 : 0;
try
{
if (tree.FieldType == ClassDescriptor.FieldType.tpString)
{
while (l < r)
{
int i = (l + r) >> 1;
if (compareStr(ins.key, pg, i) >= ahead)
{
l = i + 1;
}
else
{
r = i;
}
}
Debug.Assert(l == r);
if (--height != 0)
{
result = insert(db, getKeyStrOid(pg, r), tree, ins, height, unique, overwrite);
Debug.Assert(result != BtreeResult.NotFound);
if (result != BtreeResult.Overflow)
{
return result;
}
}
else if (r < n && compareStr(ins.key, pg, r) == 0)
{
if (overwrite)
{
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
setKeyStrOid(pg, r, ins.oid);
return BtreeResult.Overwrite;
}
else if (unique)
{
return BtreeResult.Duplicate;
}
}
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return insertStrKey(db, pg, r, ins, height);
}
else if (tree.FieldType == ClassDescriptor.FieldType.tpArrayOfByte)
{
while (l < r)
{
int i = (l + r) >> 1;
if (tree.compareByteArrays(ins.key, pg, i) >= ahead)
{
l = i + 1;
}
else
{
r = i;
}
}
Debug.Assert(l == r);
if (--height != 0)
{
result = insert(db, getKeyStrOid(pg, r), tree, ins, height, unique, overwrite);
Debug.Assert(result != BtreeResult.NotFound);
if (result != BtreeResult.Overflow)
{
return result;
}
}
else if (r < n && tree.compareByteArrays(ins.key, pg, r) == 0)
{
if (overwrite)
{
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
setKeyStrOid(pg, r, ins.oid);
return BtreeResult.Overwrite;
}
else if (unique)
{
return BtreeResult.Duplicate;
}
}
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return insertByteArrayKey(db, pg, r, ins, height);
}
else
{
while (l < r)
{
int i = (l + r) >> 1;
if (compare(ins.key, pg, i) >= ahead)
l = i + 1;
else
r = i;
}
Debug.Assert(l == r);
/* insert before e[r] */
if (--height != 0)
{
result = insert(db, getReference(pg, maxItems - r - 1), tree, ins, height, unique, overwrite);
Debug.Assert(result != BtreeResult.NotFound);
if (result != BtreeResult.Overflow)
{
return result;
}
n += 1;
}
else if (r < n && compare(ins.key, pg, r) == 0)
{
if (overwrite)
{
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
setReference(pg, maxItems - r - 1, ins.oid);
return BtreeResult.Overwrite;
}
else if (unique)
{
return BtreeResult.Duplicate;
}
}
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
int itemSize = ClassDescriptor.Sizeof[(int)tree.FieldType];
int max = keySpace / (4 + itemSize);
if (n < max)
{
memcpy(pg, r + 1, pg, r, n - r, itemSize);
memcpy(pg, maxItems - n - 1, pg, maxItems - n, n - r, 4);
ins.pack(pg, r);
setnItems(pg, getnItems(pg) + 1);
return BtreeResult.Done;
}
else
{
/* page is full then divide page */
pageId = db.allocatePage();
Page b = db.putPage(pageId);
Debug.Assert(n == max);
int m = (max + 1) / 2;
if (r < m)
{
memcpy(b, 0, pg, 0, r, itemSize);
memcpy(b, r + 1, pg, r, m - r - 1, itemSize);
memcpy(pg, 0, pg, m - 1, max - m + 1, itemSize);
memcpy(b, maxItems - r, pg, maxItems - r, r, 4);
ins.pack(b, r);
memcpy(b, maxItems - m, pg, maxItems - m + 1, m - r - 1, 4);
memcpy(pg, maxItems - max + m - 1, pg, maxItems - max, max - m + 1, 4);
}
else
{
memcpy(b, 0, pg, 0, m, itemSize);
memcpy(pg, 0, pg, m, r - m, itemSize);
memcpy(pg, r - m + 1, pg, r, max - r, itemSize);
memcpy(b, maxItems - m, pg, maxItems - m, m, 4);
memcpy(pg, maxItems - r + m, pg, maxItems - r, r - m, 4);
ins.pack(pg, r - m);
memcpy(pg, maxItems - max + m - 1, pg, maxItems - max, max - r, 4);
}
ins.oid = pageId;
ins.extract(b, firstKeyOffs + (m - 1) * itemSize, tree.FieldType);
if (height == 0)
{
setnItems(pg, max - m + 1);
setnItems(b, m);
}
else
{
setnItems(pg, max - m);
setnItems(b, m - 1);
}
db.pool.unfix(b);
return BtreeResult.Overflow;
}
}
}
finally
{
if (pg != null)
{
db.pool.unfix(pg);
}
}
}
internal static int allocate(StorageImpl db, int root, ClassDescriptor.FieldType type, BtreeKey ins)
{
int pageId = db.allocatePage();
Page pg = db.putPage(pageId);
setnItems(pg, 1);
if (type == ClassDescriptor.FieldType.tpString)
{
char[] sval = (char[])ins.key.oval;
int len = sval.Length;
setSize(pg, len * 2);
setKeyStrOffs(pg, 0, keySpace - len * 2);
setKeyStrSize(pg, 0, len);
setKeyStrOid(pg, 0, ins.oid);
setKeyStrOid(pg, 1, root);
setKeyStrChars(pg, keySpace - len * 2, sval);
}
else if (type == ClassDescriptor.FieldType.tpArrayOfByte)
{
byte[] bval = (byte[])ins.key.oval;
int len = bval.Length;
setSize(pg, len);
setKeyStrOffs(pg, 0, keySpace - len);
setKeyStrSize(pg, 0, len);
setKeyStrOid(pg, 0, ins.oid);
setKeyStrOid(pg, 1, root);
setKeyBytes(pg, keySpace - len, bval);
}
else
{
ins.pack(pg, 0);
setReference(pg, maxItems - 2, root);
}
db.pool.unfix(pg);
return pageId;
}
internal static BtreeResult remove(StorageImpl db, int pageId, Btree tree, BtreeKey rem, int height)
{
Page pg = db.getPage(pageId);
try
{
int i, n = getnItems(pg), l = 0, r = n;
if (tree.FieldType == ClassDescriptor.FieldType.tpString)
{
while (l < r)
{
i = (l + r) >> 1;
if (compareStr(rem.key, pg, i) > 0)
{
l = i + 1;
}
else
{
r = i;
}
}
if (--height != 0)
{
do
{
switch (remove(db, getKeyStrOid(pg, r), tree, rem, height))
{
case BtreeResult.Underflow:
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return handlePageUnderflow(db, pg, r, tree.FieldType, rem, height);
case BtreeResult.Done:
return BtreeResult.Done;
case BtreeResult.Overflow:
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return insertStrKey(db, pg, r, rem, height);
}
}
while (++r <= n);
}
else
{
while (r < n)
{
if (compareStr(rem.key, pg, r) == 0)
{
int oid = getKeyStrOid(pg, r);
if (oid == rem.oid || rem.oid == 0)
{
rem.oldOid = oid;
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return removeStrKey(pg, r);
}
}
else
{
break;
}
r += 1;
}
}
}
else if (tree.FieldType == ClassDescriptor.FieldType.tpArrayOfByte)
{
while (l < r)
{
i = (l + r) >> 1;
if (tree.compareByteArrays(rem.key, pg, i) > 0)
{
l = i + 1;
}
else
{
r = i;
}
}
if (--height != 0)
{
do
{
switch (remove(db, getKeyStrOid(pg, r), tree, rem, height))
{
case BtreeResult.Underflow:
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return handlePageUnderflow(db, pg, r, tree.FieldType, rem, height);
case BtreeResult.Done:
return BtreeResult.Done;
case BtreeResult.Overflow:
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return insertByteArrayKey(db, pg, r, rem, height);
}
}
while (++r <= n);
}
else
{
while (r < n)
{
if (tree.compareByteArrays(rem.key, pg, r) == 0)
{
int oid = getKeyStrOid(pg, r);
if (oid == rem.oid || rem.oid == 0)
{
rem.oldOid = oid;
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
return removeByteArrayKey(pg, r);
}
}
else
{
break;
}
r += 1;
}
}
}
else // scalars
{
int itemSize = ClassDescriptor.Sizeof[(int)tree.FieldType];
while (l < r)
{
i = (l + r) >> 1;
if (compare(rem.key, pg, i) > 0)
{
l = i + 1;
}
else
{
r = i;
}
}
if (--height == 0)
{
int oid = rem.oid;
while (r < n)
{
if (compare(rem.key, pg, r) == 0)
{
if (getReference(pg, maxItems - r - 1) == oid || oid == 0)
{
rem.oldOid = getReference(pg, maxItems - r - 1);
db.pool.unfix(pg);
pg = null;
pg = db.putPage(pageId);
memcpy(pg, r, pg, r + 1, n - r - 1, itemSize);
memcpy(pg, maxItems - n + 1, pg, maxItems - n, n - r - 1, 4);
setnItems(pg, --n);
return n * (itemSize + 4) < keySpace / 3 ? BtreeResult.Underflow : BtreeResult.Done;
}
}
else
{
break;
}
r += 1;
}
return BtreeResult.NotFound;
}
do
{
switch (remove(db, getReference(pg, maxItems - r - 1), tree, rem, height))
{
case BtreeResult.Underflow:
db.pool.unfix(pg);
pg = db.putPage(pageId);
return handlePageUnderflow(db, pg, r, tree.FieldType, rem, height);
case BtreeResult.Done:
return BtreeResult.Done;
}
}
while (++r <= n);
}
return BtreeResult.NotFound;
}
finally
{
if (pg != null)
{
db.pool.unfix(pg);
}
}
}
internal static BtreeResult handlePageUnderflow(StorageImpl db, Page pg, int r, ClassDescriptor.FieldType type, BtreeKey rem, int height)
{
int nItems = getnItems(pg);
if (type == ClassDescriptor.FieldType.tpString)
{
Page a = db.putPage(getKeyStrOid(pg, r));
int an = getnItems(a);
if (r < nItems)
{
// exists greater page
Page b = db.getPage(getKeyStrOid(pg, r + 1));
int bn = getnItems(b);
int merged_size = (an + bn) * strKeySize + getSize(a) + getSize(b);
if (height != 1)
{
merged_size += getKeyStrSize(pg, r) * 2 + strKeySize * 2;
}
if (merged_size > keySpace)
{
// reallocation of nodes between pages a and b
int i, j, k;
db.pool.unfix(b);
b = db.putPage(getKeyStrOid(pg, r + 1));
int size_a = getSize(a);
int size_b = getSize(b);
int addSize, subSize;
if (height != 1)
{
addSize = getKeyStrSize(pg, r);
subSize = getKeyStrSize(b, 0);
}
else
{
addSize = subSize = getKeyStrSize(b, 0);
}
i = 0;
int prevDelta = (an * strKeySize + size_a) - (bn * strKeySize + size_b);
while (true)
{
i += 1;
int delta = ((an + i) * strKeySize + size_a + addSize * 2) - ((bn - i) * strKeySize + size_b - subSize * 2);
if (delta >= 0)
{
if (delta >= - prevDelta)
{
i -= 1;
}
break;
}
size_a += addSize * 2;
size_b -= subSize * 2;
prevDelta = delta;
if (height != 1)
{
addSize = subSize;
subSize = getKeyStrSize(b, i);
}
else
{
addSize = subSize = getKeyStrSize(b, i);
}
}
BtreeResult result = BtreeResult.Done;
if (i > 0)
{
k = i;
if (height != 1)
{
int len = getKeyStrSize(pg, r);
setSize(a, getSize(a) + len * 2);
setKeyStrOffs(a, an, keySpace - getSize(a));
setKeyStrSize(a, an, len);
memcpy(a, getKeyStrOffs(a, an), pg, getKeyStrOffs(pg, r), len * 2, 1);
k -= 1;
an += 1;
setKeyStrOid(a, an + k, getKeyStrOid(b, k));
setSize(b, getSize(b) - getKeyStrSize(b, k) * 2);
}
for (j = 0; j < k; j++)
{
int len = getKeyStrSize(b, j);
setSize(a, getSize(a) + len * 2);
setSize(b, getSize(b) - len * 2);
setKeyStrOffs(a, an, keySpace - getSize(a));
setKeyStrSize(a, an, len);
setKeyStrOid(a, an, getKeyStrOid(b, j));
memcpy(a, getKeyStrOffs(a, an), b, getKeyStrOffs(b, j), len * 2, 1);
an += 1;
}
rem.getStr(b, i - 1);
result = replaceStrKey(db, pg, r, rem, height);
setnItems(a, an);
setnItems(b, compactifyStrings(b, i));
}
db.pool.unfix(a);
db.pool.unfix(b);
return result;
}
else
{
// merge page b to a
if (height != 1)
{
int r_len = getKeyStrSize(pg, r);
setKeyStrSize(a, an, r_len);
setSize(a, getSize(a) + r_len * 2);
setKeyStrOffs(a, an, keySpace - getSize(a));
memcpy(a, getKeyStrOffs(a, an), pg, getKeyStrOffs(pg, r), r_len * 2, 1);
an += 1;
setKeyStrOid(a, an + bn, getKeyStrOid(b, bn));
}
for (int i = 0; i < bn; i++, an++)
{
setKeyStrSize(a, an, getKeyStrSize(b, i));
setKeyStrOffs(a, an, getKeyStrOffs(b, i) - getSize(a));
setKeyStrOid(a, an, getKeyStrOid(b, i));
}
setSize(a, getSize(a) + getSize(b));
setnItems(a, an);
memcpy(a, keySpace - getSize(a), b, keySpace - getSize(b), getSize(b), 1);
db.pool.unfix(a);
db.pool.unfix(b);
db.freePage(getKeyStrOid(pg, r + 1));
setKeyStrOid(pg, r + 1, getKeyStrOid(pg, r));
return removeStrKey(pg, r);
}
}
else
{
// page b is before a
Page b = db.getPage(getKeyStrOid(pg, r - 1));
int bn = getnItems(b);
int merged_size = (an + bn) * strKeySize + getSize(a) + getSize(b);
if (height != 1)
{
merged_size += getKeyStrSize(pg, r - 1) * 2 + strKeySize * 2;
}
if (merged_size > keySpace)
{
// reallocation of nodes between pages a and b
int i, j, k, len;
db.pool.unfix(b);
b = db.putPage(getKeyStrOid(pg, r - 1));
int size_a = getSize(a);
int size_b = getSize(b);
int addSize, subSize;
if (height != 1)
{
addSize = getKeyStrSize(pg, r - 1);
subSize = getKeyStrSize(b, bn - 1);
}
else
{
addSize = subSize = getKeyStrSize(b, bn - 1);
}
i = 0;
int prevDelta = (an * strKeySize + size_a) - (bn * strKeySize + size_b);
while (true)
{
i += 1;
int delta = ((an + i) * strKeySize + size_a + addSize * 2) - ((bn - i) * strKeySize + size_b - subSize * 2);
if (delta >= 0)
{
if (delta >= - prevDelta)
{
i -= 1;
}
break;
}
prevDelta = delta;
size_a += addSize * 2;
size_b -= subSize * 2;
if (height != 1)
{
addSize = subSize;
subSize = getKeyStrSize(b, bn - i - 1);
}
else
{
addSize = subSize = getKeyStrSize(b, bn - i - 1);
}
}
BtreeResult result = BtreeResult.Done;
if (i > 0)
{
k = i;
Debug.Assert(i < bn);
if (height != 1)
{
setSize(b, getSize(b) - getKeyStrSize(b, bn - k) * 2);
memcpy(a, i, a, 0, an + 1, strKeySize);
k -= 1;
setKeyStrOid(a, k, getKeyStrOid(b, bn));
len = getKeyStrSize(pg, r - 1);
setKeyStrSize(a, k, len);
setSize(a, getSize(a) + len * 2);
setKeyStrOffs(a, k, keySpace - getSize(a));
memcpy(a, getKeyStrOffs(a, k), pg, getKeyStrOffs(pg, r - 1), len * 2, 1);
}
else
{
memcpy(a, i, a, 0, an, strKeySize);
}
for (j = 0; j < k; j++)
{
len = getKeyStrSize(b, bn - k + j);
setSize(a, getSize(a) + len * 2);
setSize(b, getSize(b) - len * 2);
setKeyStrOffs(a, j, keySpace - getSize(a));
setKeyStrSize(a, j, len);
setKeyStrOid(a, j, getKeyStrOid(b, bn - k + j));
memcpy(a, getKeyStrOffs(a, j), b, getKeyStrOffs(b, bn - k + j), len * 2, 1);
}
an += i;
setnItems(a, an);
rem.getStr(b, bn - k - 1);
result = replaceStrKey(db, pg, r - 1, rem, height);
setnItems(b, compactifyStrings(b, - i));
}
db.pool.unfix(a);
db.pool.unfix(b);
return result;
}
else
{
// merge page b to a
if (height != 1)
{
memcpy(a, bn + 1, a, 0, an + 1, strKeySize);
int len = getKeyStrSize(pg, r - 1);
setKeyStrSize(a, bn, len);
setSize(a, getSize(a) + len * 2);
setKeyStrOffs(a, bn, keySpace - getSize(a));
setKeyStrOid(a, bn, getKeyStrOid(b, bn));
memcpy(a, getKeyStrOffs(a, bn), pg, getKeyStrOffs(pg, r - 1), len * 2, 1);
an += 1;
}
else
{
memcpy(a, bn, a, 0, an, strKeySize);
}
for (int i = 0; i < bn; i++)
{
setKeyStrOid(a, i, getKeyStrOid(b, i));
setKeyStrSize(a, i, getKeyStrSize(b, i));
setKeyStrOffs(a, i, getKeyStrOffs(b, i) - getSize(a));
}
an += bn;
setnItems(a, an);
setSize(a, getSize(a) + getSize(b));
memcpy(a, keySpace - getSize(a), b, keySpace - getSize(b), getSize(b), 1);
db.pool.unfix(a);
db.pool.unfix(b);
db.freePage(getKeyStrOid(pg, r - 1));
return removeStrKey(pg, r - 1);
}
}
}
else if (type == ClassDescriptor.FieldType.tpArrayOfByte)
{
Page a = db.putPage(getKeyStrOid(pg, r));
int an = getnItems(a);
if (r < nItems)
{
// exists greater page
Page b = db.getPage(getKeyStrOid(pg, r + 1));
int bn = getnItems(b);
int merged_size = (an + bn) * strKeySize + getSize(a) + getSize(b);
if (height != 1)
{
merged_size += getKeyStrSize(pg, r) + strKeySize * 2;
}
if (merged_size > keySpace)
{
// reallocation of nodes between pages a and b
int i, j, k;
db.pool.unfix(b);
b = db.putPage(getKeyStrOid(pg, r + 1));
int size_a = getSize(a);
int size_b = getSize(b);
int addSize, subSize;
if (height != 1)
{
addSize = getKeyStrSize(pg, r);
subSize = getKeyStrSize(b, 0);
}
else
{
addSize = subSize = getKeyStrSize(b, 0);
}
i = 0;
int prevDelta = (an * strKeySize + size_a) - (bn * strKeySize + size_b);
while (true)
{
i += 1;
int delta = ((an + i) * strKeySize + size_a + addSize) - ((bn - i) * strKeySize + size_b - subSize);
if (delta >= 0)
{
if (delta >= - prevDelta)
{
i -= 1;
}
break;
}
size_a += addSize;
size_b -= subSize;
prevDelta = delta;
if (height != 1)
{
addSize = subSize;
subSize = getKeyStrSize(b, i);
}
else
{
addSize = subSize = getKeyStrSize(b, i);
}
}
BtreeResult result = BtreeResult.Done;
if (i > 0)
{
k = i;
if (height != 1)
{
int len = getKeyStrSize(pg, r);
setSize(a, getSize(a) + len);
setKeyStrOffs(a, an, keySpace - getSize(a));
setKeyStrSize(a, an, len);
memcpy(a, getKeyStrOffs(a, an), pg, getKeyStrOffs(pg, r), len, 1);
k -= 1;
an += 1;
setKeyStrOid(a, an + k, getKeyStrOid(b, k));
setSize(b, getSize(b) - getKeyStrSize(b, k));
}
for (j = 0; j < k; j++)
{
int len = getKeyStrSize(b, j);
setSize(a, getSize(a) + len);
setSize(b, getSize(b) - len);
setKeyStrOffs(a, an, keySpace - getSize(a));
setKeyStrSize(a, an, len);
setKeyStrOid(a, an, getKeyStrOid(b, j));
memcpy(a, getKeyStrOffs(a, an), b, getKeyStrOffs(b, j), len, 1);
an += 1;
}
rem.getByteArray(b, i - 1);
result = replaceByteArrayKey(db, pg, r, rem, height);
setnItems(a, an);
setnItems(b, compactifyByteArrays(b, i));
}
db.pool.unfix(a);
db.pool.unfix(b);
return result;
}
else
{
// merge page b to a
if (height != 1)
{
int r_len = getKeyStrSize(pg, r);
setKeyStrSize(a, an, r_len);
setSize(a, getSize(a) + r_len);
setKeyStrOffs(a, an, keySpace - getSize(a));
memcpy(a, getKeyStrOffs(a, an), pg, getKeyStrOffs(pg, r), r_len, 1);
an += 1;
setKeyStrOid(a, an + bn, getKeyStrOid(b, bn));
}
for (int i = 0; i < bn; i++, an++)
{
setKeyStrSize(a, an, getKeyStrSize(b, i));
setKeyStrOffs(a, an, getKeyStrOffs(b, i) - getSize(a));
setKeyStrOid(a, an, getKeyStrOid(b, i));
}
setSize(a, getSize(a) + getSize(b));
setnItems(a, an);
memcpy(a, keySpace - getSize(a), b, keySpace - getSize(b), getSize(b), 1);
db.pool.unfix(a);
db.pool.unfix(b);
db.freePage(getKeyStrOid(pg, r + 1));
setKeyStrOid(pg, r + 1, getKeyStrOid(pg, r));
return removeByteArrayKey(pg, r);
}
}
else
{
// page b is before a
Page b = db.getPage(getKeyStrOid(pg, r - 1));
int bn = getnItems(b);
int merged_size = (an + bn) * strKeySize + getSize(a) + getSize(b);
if (height != 1)
{
merged_size += getKeyStrSize(pg, r - 1) + strKeySize * 2;
}
if (merged_size > keySpace)
{
// reallocation of nodes between pages a and b
int i, j, k, len;
db.pool.unfix(b);
b = db.putPage(getKeyStrOid(pg, r - 1));
int size_a = getSize(a);
int size_b = getSize(b);
int addSize, subSize;
if (height != 1)
{
addSize = getKeyStrSize(pg, r - 1);
subSize = getKeyStrSize(b, bn - 1);
}
else
{
addSize = subSize = getKeyStrSize(b, bn - 1);
}
i = 0;
int prevDelta = (an * strKeySize + size_a) - (bn * strKeySize + size_b);
while (true)
{
i += 1;
int delta = ((an + i) * strKeySize + size_a + addSize) - ((bn - i) * strKeySize + size_b - subSize);
if (delta >= 0)
{
if (delta >= - prevDelta)
{
i -= 1;
}
break;
}
prevDelta = delta;
size_a += addSize;
size_b -= subSize;
if (height != 1)
{
addSize = subSize;
subSize = getKeyStrSize(b, bn - i - 1);
}
else
{
addSize = subSize = getKeyStrSize(b, bn - i - 1);
}
}
BtreeResult result = BtreeResult.Done;
if (i > 0)
{
k = i;
Debug.Assert(i < bn);
if (height != 1)
{
setSize(b, getSize(b) - getKeyStrSize(b, bn - k));
memcpy(a, i, a, 0, an + 1, strKeySize);
k -= 1;
setKeyStrOid(a, k, getKeyStrOid(b, bn));
len = getKeyStrSize(pg, r - 1);
setKeyStrSize(a, k, len);
setSize(a, getSize(a) + len);
setKeyStrOffs(a, k, keySpace - getSize(a));
memcpy(a, getKeyStrOffs(a, k), pg, getKeyStrOffs(pg, r - 1), len, 1);
}
else
{
memcpy(a, i, a, 0, an, strKeySize);
}
for (j = 0; j < k; j++)
{
len = getKeyStrSize(b, bn - k + j);
setSize(a, getSize(a) + len);
setSize(b, getSize(b) - len);
setKeyStrOffs(a, j, keySpace - getSize(a));
setKeyStrSize(a, j, len);
setKeyStrOid(a, j, getKeyStrOid(b, bn - k + j));
memcpy(a, getKeyStrOffs(a, j), b, getKeyStrOffs(b, bn - k + j), len, 1);
}
an += i;
setnItems(a, an);
rem.getByteArray(b, bn - k - 1);
result = replaceByteArrayKey(db, pg, r - 1, rem, height);
setnItems(b, compactifyByteArrays(b, - i));
}
db.pool.unfix(a);
db.pool.unfix(b);
return result;
}
else
{
// merge page b to a
if (height != 1)
{
memcpy(a, bn + 1, a, 0, an + 1, strKeySize);
int len = getKeyStrSize(pg, r - 1);
setKeyStrSize(a, bn, len);
setSize(a, getSize(a) + len);
setKeyStrOffs(a, bn, keySpace - getSize(a));
setKeyStrOid(a, bn, getKeyStrOid(b, bn));
memcpy(a, getKeyStrOffs(a, bn), pg, getKeyStrOffs(pg, r - 1), len, 1);
an += 1;
}
else
{
memcpy(a, bn, a, 0, an, strKeySize);
}
for (int i = 0; i < bn; i++)
{
setKeyStrOid(a, i, getKeyStrOid(b, i));
setKeyStrSize(a, i, getKeyStrSize(b, i));
setKeyStrOffs(a, i, getKeyStrOffs(b, i) - getSize(a));
}
an += bn;
setnItems(a, an);
setSize(a, getSize(a) + getSize(b));
memcpy(a, keySpace - getSize(a), b, keySpace - getSize(b), getSize(b), 1);
db.pool.unfix(a);
db.pool.unfix(b);
db.freePage(getKeyStrOid(pg, r - 1));
return removeByteArrayKey(pg, r - 1);
}
}
}
else
{
Page a = db.putPage(getReference(pg, maxItems - r - 1));
int an = getnItems(a);
int itemSize = ClassDescriptor.Sizeof[(int)type];
if (r < nItems)
{
// exists greater page
Page b = db.getPage(getReference(pg, maxItems - r - 2));
int bn = getnItems(b);
Debug.Assert(bn >= an);
if (height != 1)
{
memcpy(a, an, pg, r, 1, itemSize);
an += 1;
bn += 1;
}
int merged_size = (an + bn) * (4 + itemSize);
if (merged_size > keySpace)
{
// reallocation of nodes between pages a and b
int i = bn - ((an + bn) >> 1);
db.pool.unfix(b);
b = db.putPage(getReference(pg, maxItems - r - 2));
memcpy(a, an, b, 0, i, itemSize);
memcpy(b, 0, b, i, bn - i, itemSize);
memcpy(a, maxItems - an - i, b, maxItems - i, i, 4);
memcpy(b, maxItems - bn + i, b, maxItems - bn, bn - i, 4);
memcpy(pg, r, a, an + i - 1, 1, itemSize);
setnItems(b, getnItems(b) - i);
setnItems(a, getnItems(a) + i);
db.pool.unfix(a);
db.pool.unfix(b);
return BtreeResult.Done;
}
else
{
// merge page b to a
memcpy(a, an, b, 0, bn, itemSize);
memcpy(a, maxItems - an - bn, b, maxItems - bn, bn, 4);
db.freePage(getReference(pg, maxItems - r - 2));
memcpy(pg, maxItems - nItems, pg, maxItems - nItems - 1, nItems - r - 1, 4);
memcpy(pg, r, pg, r + 1, nItems - r - 1, itemSize);
setnItems(a, getnItems(a) + bn);
setnItems(pg, nItems - 1);
db.pool.unfix(a);
db.pool.unfix(b);
return nItems * (itemSize + 4) < keySpace / 3 ? BtreeResult.Underflow : BtreeResult.Done;
}
}
else
{
// page b is before a
Page b = db.getPage(getReference(pg, maxItems - r));
int bn = getnItems(b);
Debug.Assert(bn >= an);
if (height != 1)
{
an += 1;
bn += 1;
}
int merged_size = (an + bn) * (4 + itemSize);
if (merged_size > keySpace)
{
// reallocation of nodes between pages a and b
int i = bn - ((an + bn) >> 1);
db.pool.unfix(b);
b = db.putPage(getReference(pg, maxItems - r));
memcpy(a, i, a, 0, an, itemSize);
memcpy(a, 0, b, bn - i, i, itemSize);
memcpy(a, maxItems - an - i, a, maxItems - an, an, 4);
memcpy(a, maxItems - i, b, maxItems - bn, i, 4);
if (height != 1)
{
memcpy(a, i - 1, pg, r - 1, 1, itemSize);
}
memcpy(pg, r - 1, b, bn - i - 1, 1, itemSize);
setnItems(b, getnItems(b) - i);
setnItems(a, getnItems(a) + i);
db.pool.unfix(a);
db.pool.unfix(b);
return BtreeResult.Done;
}
else
{
// merge page b to a
memcpy(a, bn, a, 0, an, itemSize);
memcpy(a, 0, b, 0, bn, itemSize);
memcpy(a, maxItems - an - bn, a, maxItems - an, an, 4);
memcpy(a, maxItems - bn, b, maxItems - bn, bn, 4);
if (height != 1)
{
memcpy(a, bn - 1, pg, r - 1, 1, itemSize);
}
db.freePage(getReference(pg, maxItems - r));
setReference(pg, maxItems - r, getReference(pg, maxItems - r - 1));
setnItems(a, getnItems(a) + bn);
setnItems(pg, nItems - 1);
db.pool.unfix(a);
db.pool.unfix(b);
return nItems * (itemSize + 4) < keySpace / 3 ? BtreeResult.Underflow : BtreeResult.Done;
}
}
}
}
internal static BtreeResult replaceByteArrayKey(StorageImpl db, Page pg, int r, BtreeKey ins, int height)
{
ins.oid = getKeyStrOid(pg, r);
removeByteArrayKey(pg, r);
return insertByteArrayKey(db, pg, r, ins, height);
}
