/// <summary>
/// Prefetch the lsruns up to the point of the specified line length and map
/// the specified length to the corresponding LSCP length.
/// </summary>
/// <remarks>
/// See comment in the remark section of FullTextState.GetBreakpointInternalCp.
/// </remarks>
private int PrefetchLSRuns(
TextStore store,
int cpFirst,
int lineLength
)
{
Debug.Assert(lineLength > 0);
LSRun lsrun;
int prefetchLength = 0;
int lscpLineLength = 0;
int lastSpanLength = 0;
int lastRunLength = 0;
do
{
Plsrun plsrun;
int lsrunOffset;
int lsrunLength;
lsrun = store.FetchLSRun(
cpFirst + lscpLineLength,
_textFormattingMode,
false,
out plsrun,
out lsrunOffset,
out lsrunLength
);
if (lineLength == prefetchLength && lsrun.Type == Plsrun.Reverse)
{
break;
}
lastSpanLength = lsrunLength;
lastRunLength = lsrun.Length;
lscpLineLength += lastSpanLength;
prefetchLength += lastRunLength;
} while ( !TextStore.IsNewline(lsrun.Type)
&& lineLength >= prefetchLength
);
// calibrate the LSCP length to the LSCP equivalence of the last CP of the line
if (prefetchLength == lineLength || lastSpanLength == lastRunLength)
return lscpLineLength - prefetchLength + lineLength;
Invariant.Assert(prefetchLength - lineLength == lastRunLength);
return lscpLineLength - lastSpanLength;
}
