urbackup_backend/urbackupserver/treediff/TreeDiff.cpp
2021-03-31 19:42:58 +02:00

341 lines
8.3 KiB
C++

/*************************************************************************
* UrBackup - Client/Server backup system
* Copyright (C) 2011-2016 Martin Raiber
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
**************************************************************************/
#include "TreeDiff.h"
#include "TreeReader.h"
#include <algorithm>
#include <memory.h>
#include <memory>
#include "../../Interface/Server.h"
#include "../../Interface/File.h"
std::vector<size_t> TreeDiff::diffTrees(const std::string& t1, const std::string& t2, bool& error,
std::vector<size_t>* deleted_ids, std::vector<size_t>* large_unchanged_subtrees,
std::vector<size_t>* modified_inplace_ids, std::vector<size_t>& dir_diffs,
std::vector<size_t>* deleted_inplace_ids, bool has_symbit, bool is_windows)
{
std::unique_ptr<IFile> tf1(Server->openFile(t1, MODE_READ));
if (tf1.get() == nullptr)
{
error = true;
return std::vector<size_t>();
}
std::unique_ptr<IFile> tf2(Server->openFile(t2, MODE_READ));
if (tf2.get() == nullptr)
{
error = true;
return std::vector<size_t>();
}
return diffTrees(tf1.get(), tf2.get(), error, deleted_ids, large_unchanged_subtrees,
modified_inplace_ids, dir_diffs, deleted_inplace_ids, has_symbit,
is_windows);
}
std::vector<size_t> TreeDiff::diffTrees(IFile* t1, IFile* t2, bool& error,
std::vector<size_t>* deleted_ids, std::vector<size_t>* large_unchanged_subtrees,
std::vector<size_t>* modified_inplace_ids, std::vector<size_t>& dir_diffs,
std::vector<size_t>* deleted_inplace_ids, bool has_symbit, bool is_windows)
{
std::vector<size_t> ret;
TreeReader r1;
if(!r1.readTree(t1))
{
error=true;
return ret;
}
TreeReader r2;
if(!r2.readTree(t2))
{
error=true;
return ret;
}
gatherDiffs(&(*r1.getNodes())[0], &(*r2.getNodes())[0], 0, ret, modified_inplace_ids,
dir_diffs, deleted_inplace_ids, has_symbit, is_windows);
if(deleted_ids!=NULL)
{
gatherDeletes(&(*r1.getNodes())[0], *deleted_ids);
std::sort(deleted_ids->begin(), deleted_ids->end());
}
if(large_unchanged_subtrees!=NULL)
{
gatherLargeUnchangedSubtrees(&(*r2.getNodes())[0], *large_unchanged_subtrees);
std::sort(large_unchanged_subtrees->begin(), large_unchanged_subtrees->end());
}
std::sort(ret.begin(), ret.end());
std::sort(dir_diffs.begin(), dir_diffs.end());
if(modified_inplace_ids!=NULL)
{
std::sort(modified_inplace_ids->begin(), modified_inplace_ids->end());
}
if (deleted_inplace_ids != NULL)
{
std::sort(deleted_inplace_ids->begin(), deleted_inplace_ids->end());
}
return ret;
}
void TreeDiff::gatherDiffs(TreeNode *t1, TreeNode *t2, size_t depth, std::vector<size_t> &diffs,
std::vector<size_t> *modified_inplace_ids, std::vector<size_t> &dir_diffs,
std::vector<size_t> *deleted_inplace_ids, bool has_symbit, bool is_windows)
{
size_t nc_2=t2->getNumChildren();
size_t nc_1=t1->getNumChildren();
TreeNode *c2=t2->getFirstChild();
TreeNode *c1=t1->getFirstChild();
bool did_subtree_change=false;
while(c2!=NULL)
{
int cmp = 1;
if(c1!=NULL)
{
if (c1->getType() == 'f'
&& c2->getType() == 'd')
{
cmp = -1;
}
else if (c1->getType() == 'd'
&& c2->getType() == 'f')
{
cmp = 1;
}
else
{
cmp = c1->nameCompare(*c2);
}
}
//root may be unsorted
if (cmp != 0
&& depth == 0)
{
TreeNode* sn = t1->getFirstChild();
while (sn != NULL)
{
if (c2->getType() == sn->getType()
&& c2->nameEquals(*sn)
&& sn->getMappedNode()==NULL)
{
cmp = 0;
c1 = sn;
break;
}
sn = sn->getNextSibling();
}
}
if(cmp==0)
{
bool equal_dir = (c1->getType()=='d' && c2->getType()=='d');
bool data_equals = c1->dataEquals(*c2);
if(equal_dir && !data_equals)
{
dir_diffs.push_back(c2->getId());
subtreeChanged(c2);
}
if( equal_dir
|| data_equals )
{
gatherDiffs(c1, c2, depth+1, diffs, modified_inplace_ids,
dir_diffs, deleted_inplace_ids, has_symbit, is_windows);
c2->setMappedNode(c1);
c1->setMappedNode(c2);
}
else
{
if( modified_inplace_ids!=NULL
&& c1->getType() == c2->getType() )
{
modified_inplace_ids->push_back(c2->getId());
}
if (deleted_inplace_ids != NULL
&& c1->getType() == c2->getType()
&& isSymlink(c1, has_symbit, is_windows) == isSymlink(c2, has_symbit, is_windows) )
{
deleted_inplace_ids->push_back(c1->getId());
}
diffs.push_back(c2->getId());
subtreeChanged(c2);
}
#ifndef _WIN32
/**
* Stop it from moving directories above symlinks to the directory link
* pool on Linux/FreeBSD, as then symbolic links within that directory
* would not be able to point to the current backup (symbolic links
* are relative to the symbolic link location)
* On Windows this works. Could be because it uses junctions for the
* symlinks to the directory pool.
**/
if (isSymlink(c2, has_symbit, is_windows))
{
subtreeChanged(c2);
}
#endif
c1=c1->getNextSibling();
c2=c2->getNextSibling();
}
else if(cmp<0)
{
c1=c1->getNextSibling();
subtreeChangedParent(t2);
}
else
{
diffs.push_back(c2->getId());
subtreeChanged(c2);
c2=c2->getNextSibling();
}
}
}
void TreeDiff::gatherDeletes(TreeNode *t1, std::vector<size_t> &deleted_ids)
{
TreeNode *c1=t1->getFirstChild();
while(c1!=NULL)
{
if(c1->getMappedNode()==NULL)
{
deleted_ids.push_back(c1->getId());
}
gatherDeletes(c1, deleted_ids);
c1=c1->getNextSibling();
}
}
void TreeDiff::subtreeChanged(TreeNode* t2)
{
TreeNode* p = t2->getParent();
if(p==NULL) return;
subtreeChangedParent(p);
}
void TreeDiff::subtreeChangedParent(TreeNode * p)
{
do
{
if (p->getSubtreeChanged())
{
return;
}
p->setSubtreeChanged(true);
p = p->getParent();
} while (p != NULL);
}
void TreeDiff::gatherLargeUnchangedSubtrees( TreeNode *t2, std::vector<size_t> &large_unchanged_subtrees )
{
TreeNode *c2=t2->getFirstChild();
while(c2!=NULL)
{
if(!c2->getSubtreeChanged()
&& c2->getMappedNode()!=NULL
&& getTreesize(c2,10)>10)
{
large_unchanged_subtrees.push_back(c2->getId());
}
else
{
gatherLargeUnchangedSubtrees(c2, large_unchanged_subtrees);
}
c2=c2->getNextSibling();
}
}
size_t TreeDiff::getTreesize( TreeNode* t, size_t limit )
{
size_t treesize=1;
TreeNode *c=t->getFirstChild();
while(c!=NULL)
{
treesize+=getTreesize(c, limit);
if(treesize>limit)
{
return treesize;
}
c=c->getNextSibling();
}
return treesize;
}
bool TreeDiff::isSymlink(TreeNode * n, bool has_symbit, bool is_windows)
{
uint64 change_indicator = 0;
if (n->getType() == 'd'
&& n->getDataSize() == sizeof(uint64))
{
memcpy(&change_indicator, n->getDataPtr(), sizeof(uint64));
}
else if (n->getType() == 'f'
&& n->getDataSize() == 2 * sizeof(uint64))
{
memcpy(&change_indicator, n->getDataPtr()+sizeof(uint64), sizeof(uint64));
}
if (has_symbit)
{
const uint64 symlink_bit = 0x4000000000000000ULL;
if (change_indicator & symlink_bit)
{
return true;
}
return false;
}
else
{
//Work-around for broken old versions
const uint64 neg_bit = 0x8000000000000000ULL;
const uint64 symlink_mask = 0x7000000000000000ULL;
if (is_windows)
{
if ((!(change_indicator & neg_bit) || n->getType() == 'd')
&& (change_indicator & symlink_mask) > 0)
{
return true;
}
}
else
{
if (change_indicator & neg_bit)
{
return true;
}
}
return false;
}
}