public ArrayList DifferenceReport() { ArrayList retval = new ArrayList(); int dcount = _destination.Count(); int scount = _source.Count(); // Deal with the special case of empty files if (dcount == 0) { if (scount > 0) { retval.Add(DifferenceResultSpan.CreateDeleteSource(0, scount)); } return(retval); } else { if (scount == 0) { retval.Add(DifferenceResultSpan.CreateAddDestination(0, dcount)); return(retval); } } _matchList.Sort(); int curDest = 0; int curSource = 0; DifferenceResultSpan last = null; // Process each match record foreach (DifferenceResultSpan drs in _matchList) { if ((!AddChanges(retval, curDest, drs.DestIndex, curSource, drs.SourceIndex)) && (last != null)) { last.AddLength(drs.Length); } else { retval.Add(drs); } curDest = drs.DestIndex + drs.Length; curSource = drs.SourceIndex + drs.Length; last = drs; } // Process any tail end data AddChanges(retval, curDest, dcount, curSource, scount); return(retval); }
private bool AddChanges(ArrayList report, int curDest, int nextDest, int curSource, int nextSource) { bool retval = false; int diffDest = nextDest - curDest; int diffSource = nextSource - curSource; if (diffDest > 0) { if (diffSource > 0) { int minDiff = Math.Min(diffDest, diffSource); report.Add(DifferenceResultSpan.CreateReplace(curDest, curSource, minDiff)); if (diffDest > diffSource) { curDest += minDiff; report.Add(DifferenceResultSpan.CreateAddDestination(curDest, diffDest - diffSource)); } else { if (diffSource > diffDest) { curSource += minDiff; report.Add(DifferenceResultSpan.CreateDeleteSource(curSource, diffSource - diffDest)); } } } else { report.Add(DifferenceResultSpan.CreateAddDestination(curDest, diffDest)); } retval = true; } else { if (diffSource > 0) { report.Add(DifferenceResultSpan.CreateDeleteSource(curSource, diffSource)); retval = true; } } return(retval); }
private void ProcessRange(int destStart, int destEnd, int sourceStart, int sourceEnd) { int curBestIndex = -1; int curBestLength = -1; DifferenceState curItem; DifferenceState bestItem = null; for (int destIndex = destStart; destIndex <= destEnd; destIndex++) { int maxPossibleDestLength = (destEnd - destIndex) + 1; if (maxPossibleDestLength <= curBestLength) { // we won't find a longer one even if we looked break; } curItem = _stateList.GetByIndex(destIndex); if (!curItem.HasValidLength(sourceStart, sourceEnd, maxPossibleDestLength)) { // recalc new best length since it isn't valid or has never been done. GetLongestSourceMatch(curItem, destIndex, destEnd, sourceStart, sourceEnd); } if (curItem.Status == DifferenceStatus.Matched) { switch (_level) { case DifferenceEngineLevel.FastImperfect: if (curItem.Length > curBestLength) { // this is longest match so far curBestIndex = destIndex; curBestLength = curItem.Length; bestItem = curItem; } // Jump over the match destIndex += curItem.Length - 1; break; case DifferenceEngineLevel.Medium: if (curItem.Length > curBestLength) { // this is longest match so far curBestIndex = destIndex; curBestLength = curItem.Length; bestItem = curItem; // Jump over the match destIndex += curItem.Length - 1; } break; default: if (curItem.Length > curBestLength) { // this is longest match so far curBestIndex = destIndex; curBestLength = curItem.Length; bestItem = curItem; } break; } } } if (curBestIndex < 0) { // we are done - there are no matches in this span } else { if (bestItem != null) { int sourceIndex = bestItem.StartIndex; _matchList.Add(DifferenceResultSpan.CreateNoChange(curBestIndex, sourceIndex, curBestLength)); if (destStart < curBestIndex) { // Still have more lower destination data if (sourceStart < sourceIndex) { // Still have more lower source data // Recursive call to process lower indexes ProcessRange(destStart, curBestIndex - 1, sourceStart, sourceIndex - 1); } } int upperDestStart = curBestIndex + curBestLength; int upperSourceStart = sourceIndex + curBestLength; if (destEnd > upperDestStart) { // we still have more upper dest data if (sourceEnd > upperSourceStart) { // set still have more upper source data // Recursive call to process upper indexes ProcessRange(upperDestStart, destEnd, upperSourceStart, sourceEnd); } } } } }