ide: Compare with file, SVN History

git-svn-id: svn://ultimatepp.org/upp/trunk@935 f0d560ea-af0d-0410-9eb7-867de7ffcac7

uppsrc/TextDiffCtrl/TextDiff.cpp

@@ -0,0 +1,213 @@
+#include "TextDiffCtrl.h"
+
+namespace Upp {
+
+template <class I>
+static int CompareGetCount(I a, I b, int max_count)
+{
+	if(max_count <= 0 || *a != *b)
+		return 0;
+	int left;
+	for(left = max_count; --left > 0;)
+		if(*++a != *++b)
+			return max_count - left;
+	return max_count;
+}
+
+Vector<String> GetLineMap(Stream& stream)
+{
+	Vector<String> out;
+	int emp = 0;
+	if(stream.IsOpen())
+		while(!stream.IsEof()) {
+			String s = stream.GetLine();
+			const char *p = s, *e = s.End(), *f = e;
+			while(e > p && (byte)e[-1] <= ' ')
+				e--;
+			if(e == p)
+				emp++;
+			else
+			{
+				while(emp-- > 0)
+					out.Add(Null);
+				if(e != f)
+					s.Trim(e - p);
+				out.Add(s);
+				emp = 0;
+			}
+		}
+	return out;
+}
+
+Vector<String> GetFileLineMap(const String& path)
+{
+	FileIn fi(path);
+	return GetLineMap(fi);
+}
+
+Vector<String> GetStringLineMap(const String& s)
+{
+	StringStream ss(s);
+	return GetLineMap(ss);
+}
+
+class TextComparator
+{
+public:
+	TextComparator(const Vector<String>& f1, const Vector<String>& f2);
+
+	Array<TextSection>    GetSections() const;
+
+private:
+	bool                  Find(int start1, int end1, int start2, int end2, int& best_match, int& best_count) const;
+	void                  Split(Array<TextSection>& dest, int start1, int end1, int start2, int end2) const;
+
+private:
+	Vector<HashBase>      hash1;
+	Vector<HashBase>      hash2;
+	const Vector<String>& file1;
+	const Vector<String>& file2;
+};
+
+Array<TextSection> CompareLineMaps(const Vector<String>& s1, const Vector<String>& s2)
+{
+	return TextComparator(s1, s2).GetSections();
+}
+
+static void CalcHash(Vector<HashBase>& hash, const Vector<String>& file, int limit)
+{
+	{ // 1st row
+		HashBase& first = hash.Add();
+		for(int i = 0; i < file.GetCount(); i++)
+			first.Add(GetHashValue(file[i]));
+	}
+	static const int prime[] =
+	{
+		3,  5,  7,   11,  13,  17,  19,  21,
+		23, 29, 31,  37,  41,  43,  47,  51,
+		53, 61, 67,  71,  73,  79,  83,  87,
+		89, 97, 101, 103, 107, 109, 113, 117,
+	};
+	const int *pp = prime;
+	for(int l = 1; l < limit; l <<= 1) {
+		HashBase& nhash = hash.Add();
+		const HashBase& ohash = hash[hash.GetCount() - 2];
+		int pri = *pp++;
+		int t;
+		for(t = l; t < ohash.GetCount(); t++)
+			nhash.Add(ohash[t - l] + pri * ohash[t]);
+		for(t -= l; t < ohash.GetCount(); t++)
+			nhash.Add(ohash[t]);
+	}
+}
+
+TextComparator::TextComparator(const Vector<String>& f1, const Vector<String>& f2)
+: file1(f1), file2(f2)
+{
+	int limit = min(f1.GetCount(), f2.GetCount());
+	CalcHash(hash1, f1, limit);
+	CalcHash(hash2, f2, limit);
+}
+
+static bool CompareSection(const TextSection& ta, const TextSection& tb)
+{
+	return ta.start1 < tb.start1 || ta.start1 == tb.start1 && ta.start2 < tb.start2;
+}
+
+Array<TextSection> TextComparator::GetSections() const
+{
+	Array<TextSection> output;
+	Split(output, 0, file1.GetCount(), 0, file2.GetCount());
+	Sort(output, &CompareSection);
+	return output;
+}
+
+static int GetHashLevel(int min_count, int hash_count)
+{
+	int l = 0;
+	hash_count--;
+	while(min_count > 1 && l < hash_count)
+	{
+		min_count >>= 1;
+		l++;
+	}
+	return l;
+}
+
+bool TextComparator::Find(int start1, int end1, int start2, int end2, int& best_match, int& best_count) const
+{
+	ASSERT(end1 > start1 && end2 > start2);
+	bool done = false;
+	const String *f1 = file1.Begin() + start1;
+	int len1 = end1 - start1;
+	int lvl = GetHashLevel(best_count + 1, hash1.GetCount());
+	int chunk = 1 << lvl;
+	int last = max(best_count - chunk + 1, 0);
+	const HashBase *hp1 = &hash1[lvl];
+	const HashBase *hp2 = &hash2[lvl];
+	const unsigned *h1 = hp1->Begin() + start1;
+
+	int i = hp2->Find(*h1);
+	while(i >= 0)
+		if(i + best_count >= end2)
+			return done;
+		else {
+			if(i >= start2 && h1[last] == (*hp2)[i + last]) {
+				int top = min(len1, end2 - i);
+				int hc = CompareGetCount(h1, hp2->Begin() + i, top) + chunk - 1;
+				int cnt = CompareGetCount(f1, file2.Begin() + i, min(hc, top));
+				if(cnt > best_count) {
+					best_count = cnt;
+					best_match = i;
+					done = true;
+					last = best_count - chunk + 1;
+					if(best_count + 1 >= 2 * chunk)
+					{
+						lvl = GetHashLevel(best_count + 1, hash1.GetCount());
+						chunk = 1 << lvl;
+						last = best_count - chunk + 1;
+						hp1 = &hash1[lvl];
+						hp2 = &hash2[lvl];
+						h1 = hp1->Begin() + start1;
+						int oi = i;
+						for(i = hp2->Find(*h1); i >= 0 && i <= oi; i = hp2->FindNext(i))
+							;
+						continue;
+					}
+				}
+			}
+			i = hp2->FindNext(i);
+		}
+	return done;
+}
+
+void TextComparator::Split(Array<TextSection>& dest, int start1, int end1, int start2, int end2) const
+{
+	ASSERT(start1 <= end1 && start2 <= end2);
+	while(start1 < end1 && start2 < end2) {
+		int new1 = -1, new2 = -1, count = 0;
+		for(int i = start1; i + count < end1; i++)
+			if(Find(i, end1, start2, end2, new2, count))
+				new1 = i;
+		if(count == 0)
+			break; // no match at all
+		ASSERT(new1 >= start1 && new1 + count <= end1);
+		ASSERT(new2 >= start2 && new2 + count <= end2);
+		dest.Add(TextSection(new1, count, new2, count, true));
+		if(new1 - start1 >= end1 - new1 - count) { // head is longer - recurse for tail
+			Split(dest, new1 + count, end1, new2 + count, end2);
+			end1 = new1;
+			end2 = new2;
+		}
+		else { // tail is longer - recurse for head
+			Split(dest, start1, new1, start2, new2);
+			start1 = new1 + count;
+			start2 = new2 + count;
+		}
+		ASSERT(start1 <= end1 && start2 <= end2);
+	}
+	if(start1 < end1 || start2 < end2)
+		dest.Add(TextSection(start1, end1 - start1, start2, end2 - start2, false));
+}
+
+};