49 lines
1.8 KiB
C++
49 lines
1.8 KiB
C++
//===--- DeltaTree.h - B-Tree for Rewrite Delta tracking --------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file defines the DeltaTree class.
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//
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//===----------------------------------------------------------------------===//
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#ifndef CLANG_REWRITE_DELTATREE_H
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#define CLANG_REWRITE_DELTATREE_H
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namespace clang {
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/// DeltaTree - a multiway search tree (BTree) structure with some fancy
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/// features. B-Trees are generally more memory and cache efficient than
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/// binary trees, because they store multiple keys/values in each node. This
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/// implements a key/value mapping from index to delta, and allows fast lookup
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/// on index. However, an added (important) bonus is that it can also
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/// efficiently tell us the full accumulated delta for a specific file offset
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/// as well, without traversing the whole tree.
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class DeltaTree {
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void *Root; // "DeltaTreeNode *"
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void operator=(const DeltaTree&); // DO NOT IMPLEMENT
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public:
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DeltaTree();
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// Note: Currently we only support copying when the RHS is empty.
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DeltaTree(const DeltaTree &RHS);
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~DeltaTree();
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/// getDeltaAt - Return the accumulated delta at the specified file offset.
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/// This includes all insertions or delections that occurred *before* the
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/// specified file index.
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int getDeltaAt(unsigned FileIndex) const;
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/// AddDelta - When a change is made that shifts around the text buffer,
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/// this method is used to record that info. It inserts a delta of 'Delta'
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/// into the current DeltaTree at offset FileIndex.
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void AddDelta(unsigned FileIndex, int Delta);
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};
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} // end namespace clang
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#endif
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