/**
* Index the region between <code>[ptr, end)</code> to find line starts.
* <para />
* The returned list is 1 indexed. Index 0 contains
* {@link Integer#MIN_VALUE} to pad the list out.
* <para />
* Using a 1 indexed list means that line numbers can be directly accessed
* from the list, so <code>list.get(1)</code> (aka get line 1) returns
* <code>ptr</code>.
* <para />
* The last element (index <code>map.size()-1</code>) always contains
* <code>end</code>.
*
* @param buf
* buffer to scan.
* @param ptr
* position within the buffer corresponding to the first byte of
* line 1.
* @param end
* 1 past the end of the content within <code>buf</code>.
* @return a line map indexing the start position of each line.
*/
internal static IntList lineMap(byte[] buf, int ptr, int end)
{
// Experimentally derived from multiple source repositories
// the average number of bytes/line is 36. Its a rough guess
// to initially size our map close to the target.
//
IntList map = new IntList((end - ptr) / 36);
map.fillTo(1, int.MinValue);
for (; ptr < end; ptr = nextLF(buf, ptr))
map.add(ptr);
map.add(end);
return map;
}
private IntList computeHashes()
{
var r = new IntList(lines.size());
r.add(0);
for (int lno = 1; lno < lines.size() - 1; lno++)
{
int ptr = lines.get(lno);
int end = lines.get(lno + 1);
r.add(HashLine(content, ptr, end));
}
r.add(0);
return r;
}