writableSegment method
Implementation
@internal
Segment writableSegment(int minimumCapacity) {
checkArgument(minimumCapacity >= 1 && minimumCapacity <= kBlockSize,
'unexpected capacity');
if (head == null) {
return head = Segment();
}
var tail = head!.prev;
if (tail.limit + minimumCapacity > kBlockSize || !tail.owner) {
// Append a new empty segment to fill up.
tail = tail.push(Segment());
}
return tail;
}