blender/intern/cycles/util/util_cache.h
Sergey Sharybin 6212b7302c Cycles: Rebuild BVH from scratch if loading cache failed
Before this Cycles used to try using the cache even so it knew for the
fact that reading it from the disk failed. This change doesn't make it
more stable if someone will try to trick Cycles and give malformed data
but it solves general cases when Blender crashed during the cache write
and will preserve rendering from crashing when trying to use that partial
cache.
2014-09-01 18:05:10 +06:00

183 lines
4.1 KiB
C++

/*
* Copyright 2011-2013 Blender Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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
*/
#ifndef __UTIL_CACHE_H__
#define __UTIL_CACHE_H__
/* Disk Cache based on Hashing
*
* To be used to cache expensive computations. The hash key is created from an
* arbitrary number of bytes, by hashing the bytes using MD5, which then gives
* the file name containing the data. This data then is read from the file
* again into the appropriate data structures.
*
* This way we do not need to accurately track changes, compare dates and
* invalidate cache entries, at the cost of extra computation. If everything
* is stored in a global cache, computations can perhaps even be shared between
* different scenes where it may be hard to detect duplicate work.
*/
#include "util_set.h"
#include "util_string.h"
#include "util_vector.h"
CCL_NAMESPACE_BEGIN
class CacheBuffer {
public:
const void *data;
size_t size;
CacheBuffer(const void *data_, size_t size_)
{ data = data_; size = size_; }
};
class CacheData {
public:
vector<CacheBuffer> buffers;
string name;
string filename;
bool have_filename;
FILE *f;
CacheData(const string& name = "");
~CacheData();
const string& get_filename();
template<typename T> void add(const vector<T>& data)
{
CacheBuffer buffer(data.size()? &data[0]: NULL, data.size()*sizeof(T));
buffers.push_back(buffer);
}
template<typename T> void add(const array<T>& data)
{
CacheBuffer buffer(data.size()? &data[0]: NULL, data.size()*sizeof(T));
buffers.push_back(buffer);
}
void add(const void *data, size_t size)
{
if(size) {
CacheBuffer buffer(data, size);
buffers.push_back(buffer);
}
}
void add(const int& data)
{
CacheBuffer buffer(&data, sizeof(int));
buffers.push_back(buffer);
}
void add(const float& data)
{
CacheBuffer buffer(&data, sizeof(float));
buffers.push_back(buffer);
}
void add(const size_t& data)
{
CacheBuffer buffer(&data, sizeof(size_t));
buffers.push_back(buffer);
}
template<typename T> bool read(array<T>& data)
{
size_t size;
if(!fread(&size, sizeof(size), 1, f)) {
fprintf(stderr, "Failed to read vector size from cache.\n");
return false;
}
if(!size)
return false;
data.resize(size/sizeof(T));
if(!fread(&data[0], size, 1, f)) {
fprintf(stderr, "Failed to read vector data from cache (%lu).\n", (unsigned long)size);
return false;
}
return true;
}
bool read(int& data)
{
size_t size;
if(!fread(&size, sizeof(size), 1, f)) {
fprintf(stderr, "Failed to read int size from cache.\n");
return false;
}
if(!fread(&data, sizeof(data), 1, f)) {
fprintf(stderr, "Failed to read int from cache.\n");
return false;
}
return true;
}
bool read(float& data)
{
size_t size;
if(!fread(&size, sizeof(size), 1, f)) {
fprintf(stderr, "Failed to read float size from cache.\n");
return false;
}
if(!fread(&data, sizeof(data), 1, f)) {
fprintf(stderr, "Failed to read float from cache.\n");
return false;
}
return true;
}
bool read(size_t& data)
{
size_t size;
if(!fread(&size, sizeof(size), 1, f)) {
fprintf(stderr, "Failed to read size_t size from cache.\n");
return false;
}
if(!fread(&data, sizeof(data), 1, f)) {
fprintf(stderr, "Failed to read size_t from cache.\n");
return false;
}
return true;
}
};
class Cache {
public:
static Cache global;
void insert(CacheData& key, CacheData& value);
bool lookup(CacheData& key, CacheData& value);
void clear_except(const string& name, const set<string>& except);
protected:
string data_filename(CacheData& key);
};
CCL_NAMESPACE_END
#endif /* __UTIL_CACHE_H__ */