//该方法将不同行细分为：修改、删除、新增类型；
private bool AddChanges(
ArrayList report,
int curDest,
int nextDest,
int curSource,
int nextSource)
{
bool retval = false;
int diffDest = nextDest - curDest;//下一个区域的索引减去当前区域索引（区域总共多少行？）
int diffSource = nextSource - curSource;
int minDiff = 0;
if (diffDest > 0)
{
if (diffSource > 0)
{
minDiff = Math.Min(diffDest, diffSource);
//curDest---新版本文件中区域块第一行的索引
//curSource --- 老版本文件中区域块第一行索引
//minDiff ---区域块中行数目
report.Add(DiffResultSpan.CreateReplace(curDest, curSource, minDiff));
//比如老版本10行，新版本5行；合并后10行不同，前5行是修改状态，后5行是新增状态
//minDiff = 5；
if (diffDest > diffSource)
{
curDest += minDiff;
report.Add(DiffResultSpan.CreateAddDestination(curDest, diffDest - diffSource));
}
else//比如老版本3行，新版本5行；合并后5行不同，前3行是修改状态，后2行是删除状态
//minDiff = 3;
{
if (diffSource > diffDest)
{
curSource += minDiff;
report.Add(DiffResultSpan.CreateDeleteSource(curSource, diffSource - diffDest));
}
}
}
else //diffSource == 0表示老版本没有行，新版本有，表示新增行
{
report.Add(DiffResultSpan.CreateAddDestination(curDest, diffDest));
}
retval = true;
}
else
{
if (diffSource > 0)
{
report.Add(DiffResultSpan.CreateDeleteSource(curSource, diffSource));
retval = true;
}
}
return(retval);
}
public ArrayList DiffReport()
{
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(DiffResultSpan.CreateDeleteSource(0, scount));
}
return(retval);
}
else
{
if (scount == 0)
{
retval.Add(DiffResultSpan.CreateAddDestination(0, dcount));
return(retval);
}
}
_matchList.Sort();
int curDest = 0;
int curSource = 0;
DiffResultSpan last = null;
//Process each match record
foreach (DiffResultSpan 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);
}
public DiffResultSpanCollection DiffReport()
{
DiffResultSpanCollection returnResultSpanCollection = new DiffResultSpanCollection();
int dcount = _dest.Count();
int scount = _source.Count();
//Deal with the special case of empty files
if (dcount == 0)
{
if (scount > 0)
{
returnResultSpanCollection.Add(DiffResultSpan.CreateDeleteSource(0, scount));
}
return(returnResultSpanCollection);
}
else
{
if (scount == 0)
{
returnResultSpanCollection.Add(DiffResultSpan.CreateAddDestination(0, dcount));
return(returnResultSpanCollection);
}
}
_matchList.Sort();
int curDest = 0;
int curSource = 0;
DiffResultSpan lastResultSpan = null;
//Process each match record
foreach (DiffResultSpan resultSpan in _matchList)
{
if ((!AddChanges(returnResultSpanCollection, curDest, resultSpan.DestIndex, curSource, resultSpan.SourceIndex)) &&
(lastResultSpan != null))
{
lastResultSpan.AddLength(resultSpan.Length);
}
else
{
returnResultSpanCollection.Add(resultSpan);
}
curDest = resultSpan.DestIndex + resultSpan.Length;
curSource = resultSpan.SourceIndex + resultSpan.Length;
lastResultSpan = resultSpan;
}
//Process any tail end data
AddChanges(returnResultSpanCollection, curDest, dcount, curSource, scount);
return(returnResultSpanCollection);
}
//添加不同行的区域块，从第一行到最后一行，相邻的行状态相同为一个区域块
//DiffReport返回参数解释：
//int DestIndex ---区域块第一行在新版本文件中的原来的索引
//SourceIndex ---区域块第一行在老版本文件中的原来的索引
//int Length ---当前区域块中的行的个数
//Status ---改区域块中所有行共同的状态（Add/Delete/Modify）
public ArrayList DiffReport()
{
ArrayList resultList = new ArrayList();//返回值
int dcount = _dest.Count();
int scount = _source.Count();
//处理空文件
if (dcount == 0)
{
if (scount > 0)
{
resultList.Add(DiffResultSpan.CreateDeleteSource(0, scount));
}
return(resultList);
}
else
{
if (scount == 0)
{
resultList.Add(DiffResultSpan.CreateAddDestination(0, dcount));
return(resultList);
}
}
//_matchList添加了相同行和不同行区域块，但是不同行又分为：新增、删除、修改三个状态没有区分
_matchList.Sort();
int curNewIndex = 0;
int curOldIndex = 0;
DiffResultSpan last = null;
//Process each match record
foreach (DiffResultSpan drs in _matchList)
{
if ((!AddChanges(resultList, curNewIndex, drs.DestIndex, curOldIndex, drs.SourceIndex)) &&
(last != null))
{
last.AddLength(drs.Length);
}
else
{
resultList.Add(drs);
}
curNewIndex = drs.DestIndex + drs.Length;//新版本当前区域块第一行的索引。
curOldIndex = drs.SourceIndex + drs.Length;
last = drs;
}
//Process any tail end data
AddChanges(resultList, curNewIndex, dcount, curOldIndex, scount);
return(resultList);
}
private bool AddChanges(
List <DiffResultSpan> report,
int curDest,
int nextDest,
int curSource,
int nextSource)
{
bool retval = false;
int diffDest = nextDest - curDest;
int diffSource = nextSource - curSource;
int minDiff = 0;
if (diffDest > 0)
{
if (diffSource > 0)
{
minDiff = Math.Min(diffDest, diffSource);
report.Add(DiffResultSpan.CreateReplace(curDest, curSource, minDiff));
if (diffDest > diffSource)
{
curDest += minDiff;
report.Add(DiffResultSpan.CreateAddDestination(curDest, diffDest - diffSource));
}
else
{
if (diffSource > diffDest)
{
curSource += minDiff;
report.Add(DiffResultSpan.CreateDeleteSource(curSource, diffSource - diffDest));
}
}
}
else
{
report.Add(DiffResultSpan.CreateAddDestination(curDest, diffDest));
}
retval = true;
}
else
{
if (diffSource > 0)
{
report.Add(DiffResultSpan.CreateDeleteSource(curSource, diffSource));
retval = true;
}
}
return(retval);
}
private void ProcessRange(int destStart, int destEnd, int sourceStart, int sourceEnd)
{
int curBestIndex = -1;
int curBestLength = -1;
int maxPossibleDestLength = 0;
DiffState curItem = null;
DiffState bestItem = null;
for (int destIndex = destStart; destIndex <= destEnd; destIndex++)
{
maxPossibleDestLength = (destEnd - destIndex) + 1;
if (maxPossibleDestLength <= curBestLength)
{
//we won't find a longer one even if we looked
break;
}
curItem = _diffStateList.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 == DiffStatus.Matched)
{
switch (_level)
{
case DiffEngineLevel.Fast:
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 DiffEngineLevel.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)
{
// there are no matches in this span
}
else
{
int sourceIndex = bestItem.StartIndex;
_matchList.Add(DiffResultSpan.CreateNoChange(curBestIndex, sourceIndex, curBestLength));
if (destStart < curBestIndex && sourceStart < sourceIndex)
{
// Recursive call to process lower indexes
ProcessRange(destStart, curBestIndex - 1, sourceStart, sourceIndex - 1);
}
int upperDestStart = curBestIndex + curBestLength;
int upperSourceStart = sourceIndex + curBestLength;
if (destEnd > upperDestStart && sourceEnd > upperSourceStart)
{
// Recursive call to process upper indexes
ProcessRange(upperDestStart, destEnd, upperSourceStart, sourceEnd);
}
}
}
private void ProcessRange(int destStart, int destEnd, int sourceStart, int sourceEnd)
{
int curBestIndex = -1; //当前匹配项
int curBestLength = -1; //当前匹配状态（匹配、不匹配）
int maxPossibleDestLength = 0; //最大行数
DiffState curItem = null;
DiffState bestItem = null;
//循环新版本所有行
for (int destIndex = destStart; destIndex <= destEnd; destIndex++)
{
maxPossibleDestLength = (destEnd - destIndex) + 1;
if (maxPossibleDestLength <= curBestLength)
{
break;
}
//循环新文件的当前行状态对象：
curItem = _stateList.GetByIndex(destIndex);
if (!curItem.HasValidLength(sourceStart, sourceEnd, maxPossibleDestLength))
{
//如果装填不知道，返回true
//设置当前行的状态
//recalc new best length since it isn't valid or has never been done.
GetLongestSourceMatch(curItem, destIndex, destEnd, sourceStart, sourceEnd);
}
//如果新文件当前行和老文件匹配（相同）
if (curItem.Status == DiffStatus.Matched)
{
switch (_level)
{
case DiffEngineLevel.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; //当前第9行不相同，从第9行开始往下比较下一个不匹配项
break;
}
}
}
if (curBestIndex < 0)
{
//we are done - there are no matches in this span
}
else //如果新文件当前行和老文件匹配（相同）
{
int sourceIndex = bestItem.StartIndex;
_matchList.Add(DiffResultSpan.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);
}
}
}
}
