module_cache.cpp

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#include "module_cache.h"
 
BYTE* pesieve::ModulesCache::loadCached(LPSTR szModName, size_t& module_size)
{
    BYTE *mapped_pe = getMappedCached(szModName, module_size);
    if (mapped_pe) {
        return mapped_pe; // retrieved from cache
    }
    size_t raw_size = 0;
    BYTE* raw_buf = peconv::load_file(szModName, raw_size);
    if (!raw_buf) {
        return nullptr; // failed to load the file
    }
 
    bool force_free_cache = false;
    // Add to cache if needed...
    {
        util::MutexLocker guard(cacheMutex);
        size_t currCntr = usageBeforeCounter[szModName]++;
        const size_t cachedModulesCntr = cachedModules.size();
        const bool is_cache_available = cachedModulesCntr < MaxCachedModules;
        if (currCntr >= MinUsageCntr && is_cache_available) {
            bool is_cached = false;
            CachedModule* mod_cache = new(std::nothrow) CachedModule(raw_buf, raw_size);
            if (mod_cache) {
                if (mod_cache->moduleData) {
                    cachedModules[szModName] = mod_cache;
                    is_cached = true;
#ifdef _DEBUG
                    std::cout << "Added to cache: " << szModName << " Total cached: " << cachedModulesCntr << "\n";
#endif
                }
            }
            if (!is_cached) {
                delete mod_cache;
                // possibly running out of memory, make sure to free some cache:
                force_free_cache = true;
            }
        }
    }
 
    // after adding file to the cache, wipe out the old ones:
    prepareCacheSpace(force_free_cache);
 
    // return the mapped module:
    mapped_pe = peconv::load_pe_module(raw_buf, raw_size, module_size, false, false);
    peconv::free_file(raw_buf);
    return mapped_pe;
}