/// <returns>the offset for the nth member from an Array or Object type</returns>
private int getNthOffset(int index)
{
int offset;
byte head = head();
if (head == unchecked ((int)0x13) || head == unchecked ((int)0x14))
{
// compact Array or Object
offset = this.getNthOffsetFromCompact(index);
}
else
{
if (head == unchecked ((int)0x01) || head == unchecked ((int)0x0a))
{
// special case: empty Array or empty Object
throw new System.IndexOutOfRangeException();
}
else
{
long n;
int offsetsize = ObjectArrayUtil.getOffsetSize
(head);
long end = NumberUtil.toLong(this.vpack, this.start
+ 1, offsetsize);
int dataOffset = this.findDataOffset();
if ((sbyte)head <= unchecked ((int)0x05))
{
// array with no offset table or length
VPackSlice first = new VPackSlice
(this.vpack, this.start + dataOffset);
n = (end - dataOffset) / first.getByteSize();
}
else
{
if (offsetsize < 8)
{
n = NumberUtil.toLong(this.vpack, this.start + 1 + offsetsize
, offsetsize);
}
else
{
n = NumberUtil.toLong(this.vpack, (int)(this.start +
end - offsetsize), offsetsize);
}
}
if (index >= n)
{
throw new System.IndexOutOfRangeException();
}
if ((sbyte)head <= unchecked ((int)0x05) || n == 1)
{
// no index table, but all array items have the same length
// or only one item is in the array
// now fetch first item and determine its length
if (dataOffset == 0)
{
dataOffset = this.findDataOffset();
}
offset = dataOffset + index * new VPackSlice(this.vpack, this.start
+ dataOffset).getByteSize();
}
else
{
long ieBase = end - n * offsetsize + index * offsetsize - (offsetsize == 8 ? 8 :
0);
offset = (int)NumberUtil.toLong(this.vpack, (int
)(this.start + ieBase), offsetsize);
}
}
}
return(offset);
}
/// <exception cref="VPackException"/>
public virtual VPackSlice get(string attribute)
{
if (!this.isObject())
{
throw new VPackValueTypeException(ValueType
.OBJECT);
}
byte head = head();
VPackSlice result = new VPackSlice
();
if (head == unchecked ((int)0x0a))
{
// special case, empty object
result = new VPackSlice();
}
else
{
if (head == unchecked ((int)0x14))
{
// compact Object
result = this.getFromCompactObject(attribute);
}
else
{
int offsetsize = ObjectArrayUtil.getOffsetSize
(head);
long end = NumberUtil.toLong(this.vpack, this.start
+ 1, offsetsize);
long n;
if (offsetsize < 8)
{
n = NumberUtil.toLong(this.vpack, this.start + 1 + offsetsize
, offsetsize);
}
else
{
n = NumberUtil.toLong(this.vpack, (int)(this.start +
end - offsetsize), offsetsize);
}
if (n == 1)
{
// Just one attribute, there is no index table!
VPackSlice key = new VPackSlice(this.vpack
, this.start + this.findDataOffset());
if (key.isString())
{
if (key.isEqualString(attribute))
{
result = new VPackSlice(this.vpack, key.start + key.getByteSize
());
}
else
{
// no match
result = new VPackSlice();
}
}
else
{
if (key.isInteger())
{
// translate key
if (VPackSlice.attributeTranslator == null)
{
throw new VPackNeedAttributeTranslatorException
();
}
if (key.translateUnchecked().isEqualString(attribute))
{
result = new VPackSlice(this.vpack, key.start + key.getByteSize
());
}
else
{
// no match
result = new VPackSlice();
}
}
else
{
// no match
result = new VPackSlice();
}
}
}
else
{
long ieBase = end - n * offsetsize - (offsetsize == 8 ? 8 : 0);
// only use binary search for attributes if we have at least
// this many entries
// otherwise we'll always use the linear search
long sortedSearchEntriesThreshold = 4;
bool sorted = head >= unchecked ((int)0x0b) && (sbyte)head <= unchecked ((int)0x0e);
if (sorted && n >= sortedSearchEntriesThreshold)
{
// This means, we have to handle the special case n == 1
// only in the linear search!
result = this.searchObjectKeyBinary(attribute, ieBase, offsetsize, n);
}
else
{
result = this.searchObjectKeyLinear(attribute, ieBase, offsetsize, n);
}
}
}
}
return(result);
}
/// <exception cref="com.arangodb.velocypack.exception.VPackValueTypeException"/>
/// <exception cref="com.arangodb.velocypack.exception.VPackNeedAttributeTranslatorException
/// "/>
private VPackSlice searchObjectKeyBinary(string attribute
, long ieBase, int offsetsize, long n)
{
bool useTranslator = VPackSlice.attributeTranslator != null;
VPackSlice result;
long l = 0;
long r = n - 1;
for (;;)
{
// midpoint
long index = l + (r - l) / 2;
long offset = ieBase + index * offsetsize;
long keyIndex = NumberUtil.toLong(this.vpack, (
int)(this.start + offset), offsetsize);
VPackSlice key = new VPackSlice(this.vpack
, (int)(this.start + keyIndex));
int res = 0;
if (key.isString())
{
res = key.compareString(attribute);
}
else
{
if (key.isInteger())
{
// translate key
if (!useTranslator)
{
// no attribute translator
throw new VPackNeedAttributeTranslatorException
();
}
res = key.translateUnchecked().compareString(attribute);
}
else
{
// invalid key
result = new VPackSlice();
break;
}
}
if (res == 0)
{
// found
result = new VPackSlice(this.vpack, key.start + key.getByteSize
());
break;
}
if (res > 0)
{
if (index == 0)
{
result = new VPackSlice();
break;
}
r = index - 1;
}
else
{
l = index + 1;
}
if (r < l)
{
result = new VPackSlice();
break;
}
}
return(result);
}
/// <returns>the number of members for an Array, Object or String</returns>
public virtual int getLength()
{
long length;
if (this.isString())
{
length = this.getStringLength();
}
else
{
if (!this.isArray() && !this.isObject())
{
throw new VPackValueTypeException(ValueType
.ARRAY, ValueType.OBJECT, ValueType
.STRING);
}
else
{
byte head = head();
if (head == unchecked ((int)0x01) || head == unchecked ((int)0x0a))
{
// empty
length = 0;
}
else
{
if (head == unchecked ((int)0x13) || head == unchecked ((int)0x14))
{
// compact array or object
long end = NumberUtil.readVariableValueLength
(this.vpack, this.start + 1, false);
length = NumberUtil.readVariableValueLength
(this.vpack, (int)(this.start + end - 1), true);
}
else
{
int offsetsize = ObjectArrayUtil.getOffsetSize
(head);
long end = NumberUtil.toLong(this.vpack, this.start
+ 1, offsetsize);
if ((sbyte)head <= unchecked ((int)0x05))
{
// array with no offset table or length
int dataOffset = this.findDataOffset();
VPackSlice first = new VPackSlice
(this.vpack, this.start + dataOffset);
length = (end - dataOffset) / first.getByteSize();
}
else
{
if (offsetsize < 8)
{
length = NumberUtil.toLong(this.vpack, this.start +
1 + offsetsize, offsetsize);
}
else
{
length = NumberUtil.toLong(this.vpack, (int)(this.start
+ end - offsetsize), offsetsize);
}
}
}
}
}
}
return((int)length);
}
