/*
* Tencent is pleased to support the open source community by making Tinker available.
*
* Copyright (C) 2016 THL A29 Limited, a Tencent company. All rights reserved.
*
* Licensed under the BSD 3-Clause License (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
*
* https://opensource.org/licenses/BSD-3-Clause
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is
* distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.taobao.common.dexpatcher.algorithms.diff;
import com.taobao.common.dexpatcher.struct.PatchOperation;
import com.taobao.dex.Dex;
import com.taobao.dex.SizeOf;
import com.taobao.dex.TableOfContents;
import com.taobao.dex.io.DexDataBuffer;
import com.taobao.dex.util.CompareUtils;
import com.taobao.dx.util.IndexMap;
import java.util.*;
/**
* Created by tangyinsheng on 2016/6/29.
*/
public abstract class DexSectionDiffAlgorithm<T extends Comparable<T>> {
private static final AbstractMap.SimpleEntry[] EMPTY_ENTRY_ARRAY = new AbstractMap.SimpleEntry[0];
protected final Dex oldDex;
protected final Dex newDex;
/**
* IndexMap for mapping items between old dex and new dex.
* e.g. item.oldIndex => item.newIndex
*/
private final IndexMap oldToNewIndexMap;
/**
* IndexMap for mapping items between old dex and patched dex.
* e.g. item.oldIndex => item.patchedIndex
*/
private final IndexMap oldToPatchedIndexMap;
/**
* IndexMap for mapping items between new dex and patched dex.
* e.g. item.newIndex => item.newIndexInPatchedDex
*/
private final IndexMap newToPatchedIndexMap;
/**
* IndexMap for mapping items in new dex when skip items.
*/
private final IndexMap selfIndexMapForSkip;
private final List<PatchOperation<T>> patchOperationList;
private final Map<Integer, PatchOperation<T>> indexToDelOperationMap = new HashMap<Integer, PatchOperation<T>>();
private final Map<Integer, PatchOperation<T>> indexToAddOperationMap = new HashMap<Integer, PatchOperation<T>>();
private final Map<Integer, PatchOperation<T>> indexToReplaceOperationMap = new HashMap<Integer, PatchOperation<T>>();
private final Map<Integer, Integer> oldIndexToNewIndexMap = new HashMap<Integer, Integer>();
private final Map<Integer, Integer> oldOffsetToNewOffsetMap = new HashMap<Integer, Integer>();
private int patchedSectionSize;
private Comparator<AbstractMap.SimpleEntry<Integer, T>> comparatorForItemDiff = new Comparator<AbstractMap.SimpleEntry<Integer, T>>() {
@Override
public int compare(AbstractMap.SimpleEntry<Integer, T> o1, AbstractMap.SimpleEntry<Integer, T> o2) {
return o1.getValue().compareTo(o2.getValue());
}
};
private Comparator<PatchOperation<T>> comparatorForPatchOperationOpt = new Comparator<PatchOperation<T>>() {
@Override
public int compare(PatchOperation<T> o1, PatchOperation<T> o2) {
if (o1.index != o2.index) {
return CompareUtils.sCompare(o1.index, o2.index);
}
int o1OrderId;
switch (o1.op) {
case PatchOperation.OP_DEL:
o1OrderId = 0;
break;
case PatchOperation.OP_ADD:
o1OrderId = 1;
break;
case PatchOperation.OP_REPLACE:
o1OrderId = 2;
break;
default:
throw new IllegalStateException("unexpected patch operation code: " + o1.op);
}
int o2OrderId;
switch (o2.op) {
case PatchOperation.OP_DEL:
o2OrderId = 0;
break;
case PatchOperation.OP_ADD:
o2OrderId = 1;
break;
case PatchOperation.OP_REPLACE:
o2OrderId = 2;
break;
default:
throw new IllegalStateException("unexpected patch operation code: " + o2.op);
}
return CompareUtils.sCompare(o1OrderId, o2OrderId);
}
};
private AbstractMap.SimpleEntry<Integer, T>[] adjustedOldIndexedItemsWithOrigOrder = null;
private int oldItemCount = 0;
private int newItemCount = 0;
public DexSectionDiffAlgorithm(
Dex oldDex,
Dex newDex,
IndexMap oldToNewIndexMap,
IndexMap oldToPatchedIndexMap,
IndexMap newToPatchedIndexMap,
IndexMap selfIndexMapForSkip
) {
this.oldDex = oldDex;
this.newDex = newDex;
this.oldToNewIndexMap = oldToNewIndexMap;
this.oldToPatchedIndexMap = oldToPatchedIndexMap;
this.newToPatchedIndexMap = newToPatchedIndexMap;
this.selfIndexMapForSkip = selfIndexMapForSkip;
this.patchOperationList = new ArrayList<PatchOperation<T>>();
this.patchedSectionSize = 0;
}
public List<PatchOperation<T>> getPatchOperationList() {
return this.patchOperationList;
}
public int getPatchedSectionSize() {
return this.patchedSectionSize;
}
/**
* Get {@code Section} in {@code TableOfContents}.
*/
protected abstract TableOfContents.Section getTocSection(Dex dex);
/**
* Get next item in {@code section}.
*/
protected abstract T nextItem(DexDataBuffer section);
/**
* Get item size.
*/
protected abstract int getItemSize(T item);
/**
* Adjust {@code item} using specific {@code indexMap}
*/
protected T adjustItem(IndexMap indexMap, T item) {
return item;
}
/**
* Indicate if {@code item} should be skipped in new dex.
*/
protected boolean shouldSkipInNewDex(T newItem) {
return false;
}
/**
* Update index or offset mapping in {@code indexMap}.
*/
protected void updateIndexOrOffset(IndexMap indexMap, int oldIndex, int oldOffset, int newIndex, int newOffset) {
// Should override by subclass if needed.
}
/**
* Mark deleted index or offset in {@code indexMap}.
*
* Here we mark deleted item for such a case like this:
* Item in DebugInfo section reference a string in StringData section
* by index X, while in patched dex, the referenced string is removed.
*
* The {@code indexMap} must be aware of this case and return -1
* instead of the original value X.
*
* Further more, the special value -1 is not chosen by our inspiration but
* the definition of NO_INDEX in document of dex file format.
*/
protected void markDeletedIndexOrOffset(IndexMap indexMap, int deletedIndex, int deletedOffset) {
// Should override by subclass if needed.
}
/**
* Adapter method for item's offset fetching, if an item is not
* inherited from {@code Item} (which means it is a simple item in dex section
* that doesn't need multiple members to describe), this method
* return {@code index} instead.
*/
private int getItemOffsetOrIndex(int index, T item) {
if (item instanceof TableOfContents.Section.Item) {
return ((TableOfContents.Section.Item<?>) item).off;
} else {
return index;
}
}
@SuppressWarnings("unchecked,NewApi")
private AbstractMap.SimpleEntry<Integer, T>[] collectSectionItems(Dex dex, boolean isOldDex) {
TableOfContents.Section tocSec = getTocSection(dex);
if (!tocSec.exists()) {
return EMPTY_ENTRY_ARRAY;
}
Dex.Section dexSec = dex.openSection(tocSec);
int itemCount = tocSec.size;
List<AbstractMap.SimpleEntry<Integer, T>> result = new ArrayList<AbstractMap.SimpleEntry<Integer, T>>(itemCount);
if (isOldDex) {
for (int i = 0; i < itemCount; ++i) {
T nextItem = nextItem(dexSec);
T adjustedItem = adjustItem(oldToPatchedIndexMap, nextItem);
result.add(new AbstractMap.SimpleEntry<Integer, T>(i, adjustedItem));
}
} else {
int i = 0;
while (i < itemCount) {
T nextItem = nextItem(dexSec);
int indexBeforeSkip = i;
int offsetBeforeSkip = getItemOffsetOrIndex(indexBeforeSkip, nextItem);
int indexAfterSkip = indexBeforeSkip;
while (indexAfterSkip < itemCount && shouldSkipInNewDex(nextItem)) {
if (indexAfterSkip + 1 >= itemCount) {
// after skipping last item, nextItem will be null.
nextItem = null;
} else {
nextItem = nextItem(dexSec);
}
++indexAfterSkip;
}
if (nextItem != null) {
int offsetAfterSkip = getItemOffsetOrIndex(indexAfterSkip, nextItem);
T adjustedItem = adjustItem(newToPatchedIndexMap, adjustItem(selfIndexMapForSkip, nextItem));
int currentOutIndex = result.size();
result.add(new AbstractMap.SimpleEntry<Integer, T>(currentOutIndex, adjustedItem));
updateIndexOrOffset(selfIndexMapForSkip, indexBeforeSkip, offsetBeforeSkip, indexAfterSkip, offsetAfterSkip);
}
i = indexAfterSkip;
++i;
}
}
return result.toArray(new AbstractMap.SimpleEntry[0]);
}
public void execute() {
this.patchOperationList.clear();
this.adjustedOldIndexedItemsWithOrigOrder = collectSectionItems(this.oldDex, true);
this.oldItemCount = this.adjustedOldIndexedItemsWithOrigOrder.length;
AbstractMap.SimpleEntry<Integer, T>[] adjustedOldIndexedItems = new AbstractMap.SimpleEntry[this.oldItemCount];
System.arraycopy(this.adjustedOldIndexedItemsWithOrigOrder, 0, adjustedOldIndexedItems, 0, this.oldItemCount);
Arrays.sort(adjustedOldIndexedItems, this.comparatorForItemDiff);
AbstractMap.SimpleEntry<Integer, T>[] adjustedNewIndexedItems = collectSectionItems(this.newDex, false);
this.newItemCount = adjustedNewIndexedItems.length;
Arrays.sort(adjustedNewIndexedItems, this.comparatorForItemDiff);
int oldCursor = 0;
int newCursor = 0;
while (oldCursor < this.oldItemCount || newCursor < this.newItemCount) {
if (oldCursor >= this.oldItemCount) {
// rest item are all newItem.
while (newCursor < this.newItemCount) {
AbstractMap.SimpleEntry<Integer, T> newIndexedItem = adjustedNewIndexedItems[newCursor++];
this.patchOperationList.add(new PatchOperation<T>(PatchOperation.OP_ADD, newIndexedItem.getKey(), newIndexedItem.getValue()));
}
} else
if (newCursor >= newItemCount) {
// rest item are all oldItem.
while (oldCursor < oldItemCount) {
AbstractMap.SimpleEntry<Integer, T> oldIndexedItem = adjustedOldIndexedItems[oldCursor++];
int deletedIndex = oldIndexedItem.getKey();
int deletedOffset = getItemOffsetOrIndex(deletedIndex, oldIndexedItem.getValue());
this.patchOperationList.add(new PatchOperation<T>(PatchOperation.OP_DEL, deletedIndex));
markDeletedIndexOrOffset(this.oldToPatchedIndexMap, deletedIndex, deletedOffset);
}
} else {
AbstractMap.SimpleEntry<Integer, T> oldIndexedItem = adjustedOldIndexedItems[oldCursor];
AbstractMap.SimpleEntry<Integer, T> newIndexedItem = adjustedNewIndexedItems[newCursor];
int cmpRes = oldIndexedItem.getValue().compareTo(newIndexedItem.getValue());
if (cmpRes < 0) {
int deletedIndex = oldIndexedItem.getKey();
int deletedOffset = getItemOffsetOrIndex(deletedIndex, oldIndexedItem.getValue());
this.patchOperationList.add(new PatchOperation<T>(PatchOperation.OP_DEL, deletedIndex));
markDeletedIndexOrOffset(this.oldToPatchedIndexMap, deletedIndex, deletedOffset);
++oldCursor;
} else
if (cmpRes > 0) {
this.patchOperationList.add(new PatchOperation<T>(PatchOperation.OP_ADD, newIndexedItem.getKey(), newIndexedItem.getValue()));
++newCursor;
} else {
int oldIndex = oldIndexedItem.getKey();
int newIndex = newIndexedItem.getKey();
int oldOffset = getItemOffsetOrIndex(oldIndexedItem.getKey(), oldIndexedItem.getValue());
int newOffset = getItemOffsetOrIndex(newIndexedItem.getKey(), newIndexedItem.getValue());
if (oldIndex != newIndex) {
this.oldIndexToNewIndexMap.put(oldIndex, newIndex);
}
if (oldOffset != newOffset) {
this.oldOffsetToNewOffsetMap.put(oldOffset, newOffset);
}
++oldCursor;
++newCursor;
}
}
}
// So far all diff works are done. Then we perform some optimize works.
// detail: {OP_DEL idx} followed by {OP_ADD the_same_idx newItem}
// will be replaced by {OP_REPLACE idx newItem}
Collections.sort(this.patchOperationList, comparatorForPatchOperationOpt);
Iterator<PatchOperation<T>> patchOperationIt = this.patchOperationList.iterator();
PatchOperation<T> prevPatchOperation = null;
while (patchOperationIt.hasNext()) {
PatchOperation<T> patchOperation = patchOperationIt.next();
if (prevPatchOperation != null
&& prevPatchOperation.op == PatchOperation.OP_DEL
&& patchOperation.op == PatchOperation.OP_ADD
) {
if (prevPatchOperation.index == patchOperation.index) {
prevPatchOperation.op = PatchOperation.OP_REPLACE;
prevPatchOperation.newItem = patchOperation.newItem;
patchOperationIt.remove();
prevPatchOperation = null;
} else {
prevPatchOperation = patchOperation;
}
} else {
prevPatchOperation = patchOperation;
}
}
// Finally we record some information for the final calculations.
patchOperationIt = this.patchOperationList.iterator();
while (patchOperationIt.hasNext()) {
PatchOperation<T> patchOperation = patchOperationIt.next();
switch (patchOperation.op) {
case PatchOperation.OP_DEL: {
indexToDelOperationMap.put(patchOperation.index, patchOperation);
break;
}
case PatchOperation.OP_ADD: {
indexToAddOperationMap.put(patchOperation.index, patchOperation);
break;
}
case PatchOperation.OP_REPLACE: {
indexToReplaceOperationMap.put(patchOperation.index, patchOperation);
break;
}
}
}
}
public void simulatePatchOperation(int baseOffset) {
boolean isNeedToMakeAlign = getTocSection(this.oldDex).isElementFourByteAligned;
int oldIndex = 0;
int patchedIndex = 0;
int patchedOffset = baseOffset;
while (oldIndex < this.oldItemCount || patchedIndex < this.newItemCount) {
if (this.indexToAddOperationMap.containsKey(patchedIndex)) {
PatchOperation<T> patchOperation = this.indexToAddOperationMap.get(patchedIndex);
if (isNeedToMakeAlign) {
patchedOffset = SizeOf.roundToTimesOfFour(patchedOffset);
}
T newItem = patchOperation.newItem;
int itemSize = getItemSize(newItem);
updateIndexOrOffset(
this.newToPatchedIndexMap,
0,
getItemOffsetOrIndex(patchOperation.index, newItem),
0,
patchedOffset
);
++patchedIndex;
patchedOffset += itemSize;
} else
if (this.indexToReplaceOperationMap.containsKey(patchedIndex)) {
PatchOperation<T> patchOperation = this.indexToReplaceOperationMap.get(patchedIndex);
if (isNeedToMakeAlign) {
patchedOffset = SizeOf.roundToTimesOfFour(patchedOffset);
}
T newItem = patchOperation.newItem;
int itemSize = getItemSize(newItem);
updateIndexOrOffset(
this.newToPatchedIndexMap,
0,
getItemOffsetOrIndex(patchOperation.index, newItem),
0,
patchedOffset
);
++patchedIndex;
patchedOffset += itemSize;
} else
if (this.indexToDelOperationMap.containsKey(oldIndex)) {
++oldIndex;
} else
if (this.indexToReplaceOperationMap.containsKey(oldIndex)) {
++oldIndex;
} else
if (oldIndex < this.oldItemCount) {
if (isNeedToMakeAlign) {
patchedOffset = SizeOf.roundToTimesOfFour(patchedOffset);
}
T oldItem = this.adjustedOldIndexedItemsWithOrigOrder[oldIndex].getValue();
int itemSize = getItemSize(oldItem);
int oldOffset = getItemOffsetOrIndex(oldIndex, oldItem);
updateIndexOrOffset(
this.oldToPatchedIndexMap,
oldIndex,
oldOffset,
patchedIndex,
patchedOffset
);
int newIndex = oldIndex;
if (this.oldIndexToNewIndexMap.containsKey(oldIndex)) {
newIndex = this.oldIndexToNewIndexMap.get(oldIndex);
}
int newOffset = oldOffset;
if (this.oldOffsetToNewOffsetMap.containsKey(oldOffset)) {
newOffset = this.oldOffsetToNewOffsetMap.get(oldOffset);
}
updateIndexOrOffset(
this.newToPatchedIndexMap,
newIndex,
newOffset,
patchedIndex,
patchedOffset
);
++oldIndex;
++patchedIndex;
patchedOffset += itemSize;
}
}
this.patchedSectionSize = SizeOf.roundToTimesOfFour(patchedOffset - baseOffset);
}
}