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GridValidator.h
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// Copyright Contributors to the OpenVDB Project
// SPDX-License-Identifier: MPL-2.0
/*!
\file GridValidator.h
\author Ken Museth
\date August 30, 2020
\brief Checks the validity of an existing NanoVDB grid.
*/
#ifndef NANOVDB_GRIDVALIDATOR_H_HAS_BEEN_INCLUDED
#define NANOVDB_GRIDVALIDATOR_H_HAS_BEEN_INCLUDED
#include <nanovdb/NanoVDB.h>
#include "GridChecksum.h"
namespace nanovdb {
/// @brief Return true if the specified grid passes several validation tests.
///
/// @param grid Grid to validate
/// @param detailed If true the validation test is detailed and relatively slow.
/// @param verbose If true information about the first failed test is printed to std::cerr
template <typename ValueT>
bool isValid(const NanoGrid<ValueT> &grid, bool detailed = true, bool verbose = false);
/// @brief Allows for the construction of NanoVDB grids without any dependecy
template <typename ValueT>
class GridValidator
{
using GridT = NanoGrid<ValueT>;
inline static void checkTree( const GridT&, std::string&, bool);
inline static void checkRoot( const GridT&, std::string&, bool);
inline static void checkNodes(const GridT&, std::string&);
public:
/// @brief Returns an error message (an empty string means no error)
///
/// @param grid NanoVDB grid to be tested
/// @param detailed If true the checksum is computed and validated as well as all the node pointers
///
/// @note The validation is much slower if @c detailed == true!
static std::string check(const GridT &grid, bool detailed = true);
};// GridValidator
//================================================================================================
template <typename ValueT>
std::string GridValidator<ValueT>::check(const GridT &grid, bool detailed)
{
std::string errorStr;
// First check the Grid
auto *data = reinterpret_cast<const typename GridT::DataType*>(&grid);
std::stringstream ss;
if (!isValid(data)) {
errorStr.assign("Grid is not 32B aligned");
} else if (data->mMagic != NANOVDB_MAGIC_NUMBER && data->mMagic != NANOVDB_MAGIC_GRID) {
const uint64_t magic1 = NANOVDB_MAGIC_NUMBER, magic2 = NANOVDB_MAGIC_GRID;
const char *c0 = (const char*)&(data->mMagic), *c1=(const char*)&magic1, *c2=(const char*)&magic2;
ss << "Incorrect magic number: Expected \"";
for (int i=0; i<8; ++i) ss << c1[i];
ss << "\" or \"";
for (int i=0; i<8; ++i) ss << c2[i];
ss << "\", but found \"";
for (int i=0; i<8; ++i) ss << c0[i];
ss << "\"";
errorStr = ss.str();
} else if (!validateChecksum(grid, detailed ? ChecksumMode::Full : ChecksumMode::Partial)) {
errorStr.assign("Mis-matching checksum");
} else if (data->mVersion >= Version(29,0,0) && data->mVersion.getMajor() != NANOVDB_MAJOR_VERSION_NUMBER) {
ss << "Invalid major version number: Expected " << NANOVDB_MAJOR_VERSION_NUMBER << ", but read " << data->mVersion.c_str();
errorStr = ss.str();
} else if (data->mVersion < Version(29,0,0) && data->mVersion.id() != 28u) {
ss << "Invalid old major version number: Expected 28 or newer, but read " << data->mVersion.id();
errorStr = ss.str();
} else if (data->mGridClass >= GridClass::End) {
errorStr.assign("Invalid GridClass");
} else if (data->mGridType >= GridType::End) {
errorStr.assign("Invalid GridType");
} else if (data->mGridType != mapToGridType<ValueT>()) {
errorStr.assign("Invalid combination of ValueType and GridType");
} else if (!isValid(data->mGridType, data->mGridClass)) {
errorStr.assign("Invalid combination of GridType and GridClass");
} else if ( (const uint8_t*)(&(grid.tree())) != (const uint8_t*)(&grid+1) ) {
errorStr.assign("Invalid Tree pointer");
} else {
checkTree(grid, errorStr, detailed);
}
return errorStr;
}
//================================================================================================
template<typename ValueT>
void GridValidator<ValueT>::checkTree(const GridT &grid, std::string &errorStr, bool detailed)
{
if (!isValid(&grid.tree())) {
errorStr.assign("Tree is not 32B aligned");
} else if ( (const uint8_t*)(&grid.tree().root()) < (const uint8_t*)(&grid.tree()+1)) {
errorStr.assign("Invalid root pointer (should be located after the Grid and Tree)");
} else if ( (const uint8_t*)(&grid.tree().root()) > (const uint8_t*)(&grid) + grid.gridSize() - sizeof(grid.tree().root()) ) {
errorStr.assign("Invalid root pointer (appears to be located after the end of the buffer)");
} else {
checkRoot(grid, errorStr, detailed);
}
}// GridValidator::checkTree
//================================================================================================
template<typename ValueT>
void GridValidator<ValueT>::checkRoot(const GridT &grid, std::string &errorStr, bool detailed)
{
auto &root = grid.tree().root();
auto *data = root.data();
if (!isValid(data)) {
errorStr.assign("Root is not 32B aligned");
}
const uint8_t *minPtr = (const uint8_t*)(&root + 1);
const uint8_t *maxPtr = (const uint8_t*)(&root) + root.memUsage();
for (uint32_t i = 0; errorStr.empty() && i<data->mTableSize; ++i) {
const auto *tile = data->tile(i);
if ( (const uint8_t *) tile < minPtr ) {
errorStr.assign("Invalid root tile pointer (below lower bound");
} else if ( (const uint8_t *) tile > maxPtr - sizeof(*tile) ) {
errorStr.assign("Invalid root tile pointer (above higher bound");
}
}
if (detailed && errorStr.empty()) {
checkNodes(grid, errorStr);
}
}// GridValidator::processRoot
//================================================================================================
template<typename ValueT>
void GridValidator<ValueT>::checkNodes(const GridT &grid, std::string &errorStr)
{
auto &root = grid.tree().root();// note, the root node was already checked
const uint8_t *minPtr = (const uint8_t*)(&root) + root.memUsage();
const uint8_t *maxPtr = (const uint8_t*)(&grid) + grid.gridSize();
auto check = [&](const void * ptr, size_t ptrSize) -> bool {
if (!isValid(ptr)) {
errorStr.assign("Invalid node pointer: not 32B aligned");
} else if ( (const uint8_t *) ptr < minPtr ) {
errorStr.assign("Invalid node pointer: below lower bound");
} else if ( (const uint8_t *) ptr > maxPtr - ptrSize ) {
errorStr.assign("Invalid node pointer: above higher bound");
}
return errorStr.empty();
};
for (auto it2 = grid.tree().root().cbeginChild(); it2; ++it2) {
auto &node2 = *it2;
if (!check(&node2, sizeof(node2))) return;
for (auto it1 = node2.cbeginChild(); it1; ++it1) {
auto &node1 = *it1;
if (!check(&node1, sizeof(node1))) return;
for (auto it0 = node1.cbeginChild(); it0; ++it0) {
auto &node0 = *it0;
if (!check(&node2, sizeof(node2))) return;
}// loop over child nodes of the lower internal node
}// loop over child nodes of the upper internal node
}// loop over child nodes of the root node
} // GridValidator::processNodes
//================================================================================================
template <typename ValueT>
bool isValid(const NanoGrid<ValueT> &grid, bool detailed, bool verbose)
{
const std::string str = GridValidator<ValueT>::check( grid, detailed );
if (verbose && !str.empty()) std::cerr << "Validation failed: " << str << std::endl;
return str.empty();
}
} // namespace nanovdb
#endif // NANOVDB_GRIDVALIDATOR_H_HAS_BEEN_INCLUDED
GridChecksum.h
Computes a pair of 32bit checksums, of a Grid, by means of Cyclic Redundancy Check (CRC)
NanoVDB.h
Implements a light-weight self-contained VDB data-structure in a single file! In other words,...
NANOVDB_MAGIC_GRID
#define NANOVDB_MAGIC_GRID
Definition NanoVDB.h:127
NANOVDB_MAJOR_VERSION_NUMBER
#define NANOVDB_MAJOR_VERSION_NUMBER
Definition NanoVDB.h:133
NANOVDB_MAGIC_NUMBER
#define NANOVDB_MAGIC_NUMBER
Definition NanoVDB.h:126
nanovdb::Grid< NanoTree< BuildT > >::DataType
GridData DataType
Definition NanoVDB.h:3707
nanovdb::Grid::tree
const TreeT & tree() const
Return a const reference to the tree.
Definition NanoVDB.h:3753
nanovdb::GridValidator
Allows for the construction of NanoVDB grids without any dependecy.
Definition GridValidator.h:33
nanovdb::GridValidator::check
static std::string check(const GridT &grid, bool detailed=true)
Returns an error message (an empty string means no error)
Definition GridValidator.h:53
nanovdb::Version
Bit-compacted representation of all three version numbers.
Definition NanoVDB.h:948
nanovdb::Version::getMajor
uint32_t getMajor() const
Definition NanoVDB.h:971
nanovdb::Version::id
uint32_t id() const
Definition NanoVDB.h:970
nanovdb
Definition NanoVDB.h:247
nanovdb::NanoGrid
Grid< NanoTree< BuildT > > NanoGrid
Definition NanoVDB.h:6449
nanovdb::GridClass::End
@ End
Definition NanoVDB.h:372
nanovdb::GridType::End
@ End
Definition NanoVDB.h:343
nanovdb::validateChecksum
bool validateChecksum(const NanoGrid< BuildT > &grid, ChecksumMode mode=ChecksumMode::Default)
Return true if the checksum of the grid matches the expected value already encoded into the grid's me...
nanovdb::mapToGridType
GridType mapToGridType()
Maps from a templated build type to a GridType enum.
Definition NanoVDB.h:2050
nanovdb::ChecksumMode::Partial
@ Partial
Definition GridChecksum.h:39
nanovdb::ChecksumMode::Full
@ Full
Definition GridChecksum.h:40
nanovdb::isValid
static bool isValid(const void *p)
return true if the specified pointer is aligned and not NULL
Definition NanoVDB.h:743