Function GetFastFileHash

src/OpenColorIO/PathUtils.cpp:64–115

}

std::string GetFastFileHash(const std::string & filename, const Context & context)
{
    FileHashResultPtr fileHashResultPtr;
    {
        AutoMutex lock(g_fastFileHashCache_mutex);
        FileCacheMap::iterator iter = g_fastFileHashCache.find(filename);
        if(iter != g_fastFileHashCache.end())
        {
            fileHashResultPtr = iter->second;
        }
        else
        {
            fileHashResultPtr = std::make_shared<FileHashResult>();
            g_fastFileHashCache[filename] = fileHashResultPtr;
        }
    }

    std::string hash;
    {
        AutoMutex lock(fileHashResultPtr->mutex);
        if(!fileHashResultPtr->ready)
        {
            // NB: OCIO does not attempt to detect if files have changed and caused the cache to
            // become stale.
            fileHashResultPtr->ready = true;

            std::string h = "";
            if (context.getConfigIOProxy())
            {
                // Case for when ConfigIOProxy is used (callbacks mechanism).
                h = context.getConfigIOProxy()->getFastLutFileHash(filename.c_str());

                // For absolute paths, if the proxy does not provide a hash, try the file system.
                if (h.empty() && pystring::os::path::isabs(filename)) 
                {
                    h = g_hashFunction(filename);
                }
            }
            else
            {
                // Default case
                h = g_hashFunction(filename);
            }

            fileHashResultPtr->hash = h;
        }

        hash = fileHashResultPtr->hash;
    }

    return hash;
}

bool FileExists(const std::string & filename, const Context & context)
{