/// <summary>
/// Writes the sort key bytes for minLevel up to the iterator data's strength. Optionally writes
/// the case level. Stops writing levels when callback.NeedToWrite(level) returns false.
/// Separates levels with the <see cref="Collation.LevelSeparatorByte"/> but does not write a <see cref="Collation.TerminatorByte"/>.
/// </summary>
/// <param name="iter"></param>
/// <param name="compressibleBytes"></param>
/// <param name="settings"></param>
/// <param name="sink"></param>
/// <param name="minLevel"></param>
/// <param name="callback"></param>
/// <param name="preflight"></param>
public static void WriteSortKeyUpToQuaternary(CollationIterator iter, bool[] compressibleBytes,
CollationSettings settings, SortKeyByteSink sink, CollationSortKeyLevel minLevel, LevelCallback callback,
bool preflight)
{
int options = settings.Options;
// Set of levels to process and write.
int levels = levelMasks[(int)CollationSettings.GetStrength(options)];
if ((options & CollationSettings.CaseLevel) != 0)
{
levels |= Collation.CASE_LEVEL_FLAG;
}
// Minus the levels below minLevel.
levels &= ~((1 << (int)minLevel) - 1);
if (levels == 0)
{
return;
}
long variableTop;
if ((options & CollationSettings.AlternateMask) == 0)
{
variableTop = 0;
}
else
{
// +1 so that we can use "<" and primary ignorables test out early.
variableTop = settings.VariableTop + 1;
}
int tertiaryMask = CollationSettings.GetTertiaryMask(options);
byte[] p234 = new byte[3];
SortKeyLevel cases = GetSortKeyLevel(levels, Collation.CASE_LEVEL_FLAG);
SortKeyLevel secondaries = GetSortKeyLevel(levels, Collation.SECONDARY_LEVEL_FLAG);
SortKeyLevel tertiaries = GetSortKeyLevel(levels, Collation.TERTIARY_LEVEL_FLAG);
SortKeyLevel quaternaries = GetSortKeyLevel(levels, Collation.QUATERNARY_LEVEL_FLAG);
long prevReorderedPrimary = 0; // 0==no compression
int commonCases = 0;
int commonSecondaries = 0;
int commonTertiaries = 0;
int commonQuaternaries = 0;
int prevSecondary = 0;
int secSegmentStart = 0;
for (; ;)
{
// No need to keep all CEs in the buffer when we write a sort key.
iter.ClearCEsIfNoneRemaining();
long ce = iter.NextCE();
long p = ce.TripleShift(32);
if (p < variableTop && p > Collation.MergeSeparatorPrimary)
{
// Variable CE, shift it to quaternary level.
// Ignore all following primary ignorables, and shift further variable CEs.
if (commonQuaternaries != 0)
{
--commonQuaternaries;
while (commonQuaternaries >= QUAT_COMMON_MAX_COUNT)
{
quaternaries.AppendByte(QUAT_COMMON_MIDDLE);
commonQuaternaries -= QUAT_COMMON_MAX_COUNT;
}
// Shifted primary weights are lower than the common weight.
quaternaries.AppendByte(QUAT_COMMON_LOW + commonQuaternaries);
commonQuaternaries = 0;
}
do
{
if ((levels & Collation.QUATERNARY_LEVEL_FLAG) != 0)
{
if (settings.HasReordering)
{
p = settings.Reorder(p);
}
if (((int)p.TripleShift(24)) >= QUAT_SHIFTED_LIMIT_BYTE)
{
// Prevent shifted primary lead bytes from
// overlapping with the common compression range.
quaternaries.AppendByte(QUAT_SHIFTED_LIMIT_BYTE);
}
quaternaries.AppendWeight32(p);
}
do
{
ce = iter.NextCE();
p = ce.TripleShift(32);
} while (p == 0);
} while (p < variableTop && p > Collation.MergeSeparatorPrimary);
}
// ce could be primary ignorable, or NO_CE, or the merge separator,
// or a regular primary CE, but it is not variable.
// If ce==NO_CE, then write nothing for the primary level but
// terminate compression on all levels and then exit the loop.
if (p > Collation.NO_CE_PRIMARY && (levels & Collation.PRIMARY_LEVEL_FLAG) != 0)
{
// Test the un-reordered primary for compressibility.
bool isCompressible = compressibleBytes[(int)p.TripleShift(24)];
if (settings.HasReordering)
{
p = settings.Reorder(p);
}
int p1 = (int)p.TripleShift(24);
if (!isCompressible || p1 != ((int)prevReorderedPrimary.TripleShift(24)))
{
if (prevReorderedPrimary != 0)
{
if (p < prevReorderedPrimary)
{
// No primary compression terminator
// at the end of the level or merged segment.
if (p1 > Collation.MergeSeparatorByte)
{
sink.Append(Collation.PrimaryCompressionLowByte);
}
}
else
{
sink.Append(Collation.PrimaryCompressionHighByte);
}
}
sink.Append(p1);
if (isCompressible)
{
prevReorderedPrimary = p;
}
else
{
prevReorderedPrimary = 0;
}
}
byte p2 = (byte)(p.TripleShift(16));
if (p2 != 0)
{
p234[0] = p2;
p234[1] = (byte)(p.TripleShift(8));
p234[2] = (byte)p;
sink.Append(p234, (p234[1] == 0) ? 1 : (p234[2] == 0) ? 2 : 3);
}
// Optimization for internalNextSortKeyPart():
// When the primary level overflows we can stop because we need not
// calculate (preflight) the whole sort key length.
if (!preflight && sink.Overflowed)
{
// not used in Java -- if (!sink.IsOk()) {
// Java porting note: U_MEMORY_ALLOCATION_ERROR is set here in
// C implementation. IsOk() in Java always returns true, so this
// is a dead code.
return;
}
}
int lower32 = (int)ce;
if (lower32 == 0)
{
continue;
} // completely ignorable, no secondary/case/tertiary/quaternary
if ((levels & Collation.SECONDARY_LEVEL_FLAG) != 0)
{
int s = lower32.TripleShift(16); // 16 bits
if (s == 0)
{
// secondary ignorable
}
else if (s == Collation.CommonWeight16 &&
((options & CollationSettings.BackwardSecondary) == 0 ||
p != Collation.MergeSeparatorPrimary))
{
// s is a common secondary weight, and
// backwards-secondary is off or the ce is not the merge separator.
++commonSecondaries;
}
else if ((options & CollationSettings.BackwardSecondary) == 0)
{
if (commonSecondaries != 0)
{
--commonSecondaries;
while (commonSecondaries >= SEC_COMMON_MAX_COUNT)
{
secondaries.AppendByte(SEC_COMMON_MIDDLE);
commonSecondaries -= SEC_COMMON_MAX_COUNT;
}
int b;
if (s < Collation.CommonWeight16)
{
b = SEC_COMMON_LOW + commonSecondaries;
}
else
{
b = SEC_COMMON_HIGH - commonSecondaries;
}
secondaries.AppendByte(b);
commonSecondaries = 0;
}
secondaries.AppendWeight16(s);
}
else
{
if (commonSecondaries != 0)
{
--commonSecondaries;
// Append reverse weights. The level will be re-reversed later.
int remainder = commonSecondaries % SEC_COMMON_MAX_COUNT;
int b;
if (prevSecondary < Collation.CommonWeight16)
{
b = SEC_COMMON_LOW + remainder;
}
else
{
b = SEC_COMMON_HIGH - remainder;
}
secondaries.AppendByte(b);
commonSecondaries -= remainder;
// commonSecondaries is now a multiple of SEC_COMMON_MAX_COUNT.
while (commonSecondaries > 0)
{ // same as >= SEC_COMMON_MAX_COUNT
secondaries.AppendByte(SEC_COMMON_MIDDLE);
commonSecondaries -= SEC_COMMON_MAX_COUNT;
}
// commonSecondaries == 0
}
if (0 < p && p <= Collation.MergeSeparatorPrimary)
{
// The backwards secondary level compares secondary weights backwards
// within segments separated by the merge separator (U+FFFE).
byte[] secs = secondaries.Data();
int last = secondaries.Length - 1;
while (secSegmentStart < last)
{
byte b = secs[secSegmentStart];
secs[secSegmentStart++] = secs[last];
secs[last--] = b;
}
secondaries.AppendByte(p == Collation.NO_CE_PRIMARY ?
Collation.LevelSeparatorByte : Collation.MergeSeparatorByte);
prevSecondary = 0;
secSegmentStart = secondaries.Length;
}
else
{
secondaries.AppendReverseWeight16(s);
prevSecondary = s;
}
}
}
if ((levels & Collation.CASE_LEVEL_FLAG) != 0)
{
if ((CollationSettings.GetStrength(options) == (int)CollationStrength.Primary) ? p == 0
: (lower32.TripleShift(16)) == 0)
{
// Primary+caseLevel: Ignore case level weights of primary ignorables.
// Otherwise: Ignore case level weights of secondary ignorables.
// For details see the comments in the CollationCompare class.
}
else
{
int c = (lower32.TripleShift(8)) & 0xff; // case bits & tertiary lead byte
Debug.Assert((c & 0xc0) != 0xc0);
if ((c & 0xc0) == 0 && c > Collation.LevelSeparatorByte)
{
++commonCases;
}
else
{
if ((options & CollationSettings.UpperFirst) == 0)
{
// lowerFirst: Compress common weights to nibbles 1..7..13, mixed=14,
// upper=15.
// If there are only common (=lowest) weights in the whole level,
// then we need not write anything.
// Level length differences are handled already on the next-higher level.
if (commonCases != 0 &&
(c > Collation.LevelSeparatorByte || !cases.IsEmpty))
{
--commonCases;
while (commonCases >= CASE_LOWER_FIRST_COMMON_MAX_COUNT)
{
cases.AppendByte(CASE_LOWER_FIRST_COMMON_MIDDLE << 4);
commonCases -= CASE_LOWER_FIRST_COMMON_MAX_COUNT;
}
int b;
if (c <= Collation.LevelSeparatorByte)
{
b = CASE_LOWER_FIRST_COMMON_LOW + commonCases;
}
else
{
b = CASE_LOWER_FIRST_COMMON_HIGH - commonCases;
}
cases.AppendByte(b << 4);
commonCases = 0;
}
if (c > Collation.LevelSeparatorByte)
{
c = (CASE_LOWER_FIRST_COMMON_HIGH + (c.TripleShift(6))) << 4; // 14 or 15
}
}
else
{
// upperFirst: Compress common weights to nibbles 3..15, mixed=2,
// upper=1.
// The compressed common case weights only go up from the "low" value
// because with upperFirst the common weight is the highest one.
if (commonCases != 0)
{
--commonCases;
while (commonCases >= CASE_UPPER_FIRST_COMMON_MAX_COUNT)
{
cases.AppendByte(CASE_UPPER_FIRST_COMMON_LOW << 4);
commonCases -= CASE_UPPER_FIRST_COMMON_MAX_COUNT;
}
cases.AppendByte((CASE_UPPER_FIRST_COMMON_LOW + commonCases) << 4);
commonCases = 0;
}
if (c > Collation.LevelSeparatorByte)
{
c = (CASE_UPPER_FIRST_COMMON_LOW - (c.TripleShift(6))) << 4; // 2 or 1
}
}
// c is a separator byte 01,
// or a left-shifted nibble 0x10, 0x20, ... 0xf0.
cases.AppendByte(c);
}
}
}
if ((levels & Collation.TERTIARY_LEVEL_FLAG) != 0)
{
int t = lower32 & tertiaryMask;
Debug.Assert((lower32 & 0xc000) != 0xc000);
if (t == Collation.CommonWeight16)
{
++commonTertiaries;
}
else if ((tertiaryMask & 0x8000) == 0)
{
// Tertiary weights without case bits.
// Move lead bytes 06..3F to C6..FF for a large common-weight range.
if (commonTertiaries != 0)
{
--commonTertiaries;
while (commonTertiaries >= TER_ONLY_COMMON_MAX_COUNT)
{
tertiaries.AppendByte(TER_ONLY_COMMON_MIDDLE);
commonTertiaries -= TER_ONLY_COMMON_MAX_COUNT;
}
int b;
if (t < Collation.CommonWeight16)
{
b = TER_ONLY_COMMON_LOW + commonTertiaries;
}
else
{
b = TER_ONLY_COMMON_HIGH - commonTertiaries;
}
tertiaries.AppendByte(b);
commonTertiaries = 0;
}
if (t > Collation.CommonWeight16)
{
t += 0xc000;
}
tertiaries.AppendWeight16(t);
}
else if ((options & CollationSettings.UpperFirst) == 0)
{
// Tertiary weights with caseFirst=lowerFirst.
// Move lead bytes 06..BF to 46..FF for the common-weight range.
if (commonTertiaries != 0)
{
--commonTertiaries;
while (commonTertiaries >= TER_LOWER_FIRST_COMMON_MAX_COUNT)
{
tertiaries.AppendByte(TER_LOWER_FIRST_COMMON_MIDDLE);
commonTertiaries -= TER_LOWER_FIRST_COMMON_MAX_COUNT;
}
int b;
if (t < Collation.CommonWeight16)
{
b = TER_LOWER_FIRST_COMMON_LOW + commonTertiaries;
}
else
{
b = TER_LOWER_FIRST_COMMON_HIGH - commonTertiaries;
}
tertiaries.AppendByte(b);
commonTertiaries = 0;
}
if (t > Collation.CommonWeight16)
{
t += 0x4000;
}
tertiaries.AppendWeight16(t);
}
else
{
// Tertiary weights with caseFirst=upperFirst.
// Do not change the artificial uppercase weight of a tertiary CE (0.0.ut),
// to keep tertiary CEs well-formed.
// Their case+tertiary weights must be greater than those of
// primary and secondary CEs.
//
// Separator 01 -> 01 (unchanged)
// Lowercase 02..04 -> 82..84 (includes uncased)
// Common weight 05 -> 85..C5 (common-weight compression range)
// Lowercase 06..3F -> C6..FF
// Mixed case 42..7F -> 42..7F
// Uppercase 82..BF -> 02..3F
// Tertiary CE 86..BF -> C6..FF
if (t <= Collation.NO_CE_WEIGHT16)
{
// Keep separators unchanged.
}
else if ((lower32.TripleShift(16)) != 0)
{
// Invert case bits of primary & secondary CEs.
t ^= 0xc000;
if (t < (TER_UPPER_FIRST_COMMON_HIGH << 8))
{
t -= 0x4000;
}
}
else
{
// Keep uppercase bits of tertiary CEs.
Debug.Assert(0x8600 <= t && t <= 0xbfff);
t += 0x4000;
}
if (commonTertiaries != 0)
{
--commonTertiaries;
while (commonTertiaries >= TER_UPPER_FIRST_COMMON_MAX_COUNT)
{
tertiaries.AppendByte(TER_UPPER_FIRST_COMMON_MIDDLE);
commonTertiaries -= TER_UPPER_FIRST_COMMON_MAX_COUNT;
}
int b;
if (t < (TER_UPPER_FIRST_COMMON_LOW << 8))
{
b = TER_UPPER_FIRST_COMMON_LOW + commonTertiaries;
}
else
{
b = TER_UPPER_FIRST_COMMON_HIGH - commonTertiaries;
}
tertiaries.AppendByte(b);
commonTertiaries = 0;
}
tertiaries.AppendWeight16(t);
}
}
if ((levels & Collation.QUATERNARY_LEVEL_FLAG) != 0)
{
int q = lower32 & 0xffff;
if ((q & 0xc0) == 0 && q > Collation.NO_CE_WEIGHT16)
{
++commonQuaternaries;
}
else if (q == Collation.NO_CE_WEIGHT16 &&
(options & CollationSettings.AlternateMask) == 0 &&
quaternaries.IsEmpty)
{
// If alternate=non-ignorable and there are only common quaternary weights,
// then we need not write anything.
// The only weights greater than the merge separator and less than the common
// weight
// are shifted primary weights, which are not generated for
// alternate=non-ignorable.
// There are also exactly as many quaternary weights as tertiary weights,
// so level length differences are handled already on tertiary level.
// Any above-common quaternary weight will compare greater regardless.
quaternaries.AppendByte(Collation.LevelSeparatorByte);
}
else
{
if (q == Collation.NO_CE_WEIGHT16)
{
q = Collation.LevelSeparatorByte;
}
else
{
q = 0xfc + ((q.TripleShift(6)) & 3);
}
if (commonQuaternaries != 0)
{
--commonQuaternaries;
while (commonQuaternaries >= QUAT_COMMON_MAX_COUNT)
{
quaternaries.AppendByte(QUAT_COMMON_MIDDLE);
commonQuaternaries -= QUAT_COMMON_MAX_COUNT;
}
int b;
if (q < QUAT_COMMON_LOW)
{
b = QUAT_COMMON_LOW + commonQuaternaries;
}
else
{
b = QUAT_COMMON_HIGH - commonQuaternaries;
}
quaternaries.AppendByte(b);
commonQuaternaries = 0;
}
quaternaries.AppendByte(q);
}
}
if ((lower32.TripleShift(24)) == Collation.LevelSeparatorByte)
{
break;
} // ce == NO_CE
}
// Append the beyond-primary levels.
// not used in Java -- boolean ok = true;
if ((levels & Collation.SECONDARY_LEVEL_FLAG) != 0)
{
if (!callback.NeedToWrite(CollationSortKeyLevel.Secondary))
{
return;
}
// not used in Java -- ok &= secondaries.isOk();
sink.Append(Collation.LevelSeparatorByte);
secondaries.AppendTo(sink);
}
if ((levels & Collation.CASE_LEVEL_FLAG) != 0)
{
if (!callback.NeedToWrite(CollationSortKeyLevel.Case))
{
return;
}
// not used in Java -- ok &= cases.isOk();
sink.Append(Collation.LevelSeparatorByte);
// Write pairs of nibbles as bytes, except separator bytes as themselves.
int length = cases.Length - 1; // Ignore the trailing NO_CE.
byte b = 0;
for (int i = 0; i < length; ++i)
{
byte c = cases.GetAt(i);
Debug.Assert((c & 0xf) == 0 && c != 0);
if (b == 0)
{
b = c;
}
else
{
sink.Append(b | ((c >> 4) & 0xf));
b = 0;
}
}
if (b != 0)
{
sink.Append(b);
}
}
if ((levels & Collation.TERTIARY_LEVEL_FLAG) != 0)
{
if (!callback.NeedToWrite(CollationSortKeyLevel.Tertiary))
{
return;
}
// not used in Java -- ok &= tertiaries.isOk();
sink.Append(Collation.LevelSeparatorByte);
tertiaries.AppendTo(sink);
}
if ((levels & Collation.QUATERNARY_LEVEL_FLAG) != 0)
{
if (!callback.NeedToWrite(CollationSortKeyLevel.Quaternary))
{
return;
}
// not used in Java -- ok &= quaternaries.isOk();
sink.Append(Collation.LevelSeparatorByte);
quaternaries.AppendTo(sink);
}
// not used in .NET -- if (!ok || !sink.IsOk()) {
// .NET porting note: U_MEMORY_ALLOCATION_ERROR is set here in
// C implementation. IsOk() in .NET always returns true, so this
// is a dead code.
}
/// <param name="level">The next level about to be written to the <see cref="SortKeyByteSink"/>.</param>
/// <returns>true if the level is to be written (the base class implementation always returns true).</returns>
internal bool NeedToWrite(CollationSortKeyLevel level)
{
return(true);
}
