/**
* Check if a file has already been cached.
* @param cache_key Cache key.
* @return Filename in the cache, or empty string if not found.
*/
string CacheManager::findInCache(const string &cache_key)
{
// Get the cache key filename.
string cache_filename = getCacheFilename(cache_key);
if (cache_filename.empty()) {
// Error obtaining the cache key filename.
return string();
}
// Return the filename if the file exists.
return (!access(cache_filename, R_OK) ? cache_filename : string());
}
/**
* Download a file.
*
* @param url URL.
* @param cache_key Cache key.
*
* If the file is present in the cache, the cached version
* will be retrieved. Otherwise, the file will be downloaded.
*
* If the file was not found on the server, or it was not found
* the last time it was requested, an empty string will be
* returned, and a zero-byte file will be stored in the cache.
*
* @return Absolute path to the cached file.
*/
string CacheManager::download(
const string &url,
const string &cache_key)
{
// Check the main cache key.
string cache_filename = getCacheFilename(cache_key);
if (cache_filename.empty()) {
// Error obtaining the cache key filename.
return string();
}
// Lock the semaphore to make sure we don't
// download too many files at once.
SemaphoreLocker locker(m_dlsem);
// Check if the file already exists.
if (!access(cache_filename, R_OK)) {
// File exists.
// Is it larger than 0 bytes?
int64_t sz = filesize(cache_filename);
if (sz == 0) {
// File is 0 bytes, which indicates it didn't exist
// on the server. If the file is older than a week,
// try to redownload it.
// TODO: Configurable time.
// TODO: How should we handle errors?
time_t filetime;
if (get_mtime(cache_filename, &filetime) != 0)
return string();
struct timeval systime;
if (gettimeofday(&systime, nullptr) != 0)
return string();
if ((systime.tv_sec - filetime) < (86400*7)) {
// Less than a week old.
return string();
}
// More than a week old.
// Delete the cache file and redownload it.
if (delete_file(cache_filename) != 0)
return string();
} else if (sz > 0) {
// File is larger than 0 bytes, which indicates
// it was cached successfully.
return cache_filename;
}
}
// Check if the URL is blank.
// This is allowed for some databases that are only available offline.
if (url.empty()) {
// Blank URL. Don't try to download anything.
// Don't mark the file as unavailable by creating a
// 0-byte dummy file, either.
return string();
}
// Make sure the subdirectories exist.
// NOTE: The filename portion MUST be kept in cache_filename,
// since the last component is ignored by rmkdir().
if (rmkdir(cache_filename) != 0) {
// Error creating subdirectories.
return string();
}
// TODO: Keep-alive cURL connections (one per server)?
m_downloader->setUrl(url);
m_downloader->setProxyUrl(m_proxyUrl);
int ret = m_downloader->download();
// Write the file to the cache.
unique_ptr<IRpFile> file(new RpFile(cache_filename, RpFile::FM_CREATE_WRITE));
if (ret != 0 || !file || !file->isOpen()) {
// Error downloading the file, or error opening
// the file in the local cache.
// TODO: Only keep a negative cache if it's a 404.
// Keep the cached file as a 0-byte file to indicate
// a "negative" hit, but return an empty filename.
return string();
}
// Write the file.
file->write((void*)m_downloader->data(), m_downloader->dataSize());
file->close();
// Set the file's mtime if it was obtained by the downloader.
// TODO: IRpFile::set_mtime()?
time_t mtime = m_downloader->mtime();
if (mtime >= 0) {
set_mtime(cache_filename, mtime);
}
// Return the cache filename.
return cache_filename;
}
Readable*
ModuleMap::getMapLoadingReadable(uint32 mapID,
uint32 loadMapRequestType,
const char* handshake,
byte zoomlevel,
MapSafeVector* loadedMaps )
{
FileUtils::FilePtr file;
MC2String cacheFileName = getCacheFilename(mapID,
loadMapRequestType,
zoomlevel);
mc2dbg << "[ModuleMap]: Filename would be \""
<< cacheFileName << '"' << endl ;
bool useCache = cacheFileName.length();
if ( useCache ) {
// If the cache filename exists we should try the cache.
file.reset( fopen( cacheFileName.c_str(), "r" ) );
}
TCPSocket* tcpsock = NULL;
uint32 mapVersion = MAX_UINT32;
uint32 generatorVersion = MAX_UINT32;
if ( file.get() != NULL ) {
mc2dbg << "[ModuleMap]: Cached map found" << endl;
// Check versions of map in file.
ScopedArray<byte> headerBuf( new byte[CACHED_MAP_HEADER_SIZE] );
uint32 fileMapVersion = MAX_UINT32;
uint32 fileGeneratorVersion = MAX_UINT32;
uint32 fileMapID = MAX_UINT32;
if ( fread( headerBuf.get(), CACHED_MAP_HEADER_SIZE, 1, file.get() ) == 1 ) {
DataBuffer dataBuf(headerBuf.get(), CACHED_MAP_HEADER_SIZE);
uint32 first = dataBuf.readNextLong();
first = first;
fileMapID = dataBuf.readNextLong();
fileMapVersion = dataBuf.readNextLong();
fileGeneratorVersion = dataBuf.readNextLong();
if ( fileMapID == mapID ) {
mapVersion = fileMapVersion;
generatorVersion = fileGeneratorVersion;
} else {
mc2dbg << "[ModuleMap]: Wrong mapid in file - was "
<< fileMapID << " should be " << mapID
<< endl;
}
}
headerBuf.reset( NULL );
mc2dbg << "[ModuleMap]: Version from file 0x"
<< hex << fileMapVersion << ":" << dec << fileGeneratorVersion
<< endl;
tcpsock = getMapLoadingSocket(mapID,
loadMapRequestType,
handshake,
zoomlevel,
loadedMaps,
&mapVersion,
&generatorVersion);
mc2dbg << "[ModuleMap]: Version from getMapLoadingSocket "
<< hex << "0x" << mapVersion << dec << ":" << generatorVersion
<< endl;
if ( (tcpsock == NULL ) &&
( mapVersion == fileMapVersion ) &&
( generatorVersion == fileGeneratorVersion ) ) {
mc2dbg << "[ModuleMap]: Cached file OK" << endl;
return new FileReadable(file.release());
} else {
if ( tcpsock != NULL ) {
mc2dbg << "[ModuleMap]: Versions differ (file/MM)." << endl;
} else {
mc2dbg << "[ModuleMap]: Wrong version or no socket." << endl;
}
}
} else {
mc2dbg << "[ModuleMap]: No cache file" << endl;
// Just get the socket and load.
tcpsock = getMapLoadingSocket(mapID,
loadMapRequestType,
handshake,
zoomlevel,
loadedMaps,
&mapVersion,
&generatorVersion);
}
if ( tcpsock != NULL && useCache ) {
mc2dbg << "[ModuleMap]: Will write to cache" << endl;
// We do not have the map cached or it may have been the wrong
// version.
int headerSize = 0;
ScopedArray<byte> header( makeHeader( headerSize,
mapID, mapVersion,
generatorVersion) );
TCPSocketReadable* tsockRead = new TCPSocketReadable( tcpsock );
return new AutoWritingReadable( tsockRead,
cacheFileName.c_str(),
header.get(),
headerSize );
} else if ( tcpsock ) {
mc2dbg << "[ModuleMap]: Will not write to cache" << endl;
return new TCPSocketReadable(tcpsock);
} else {
mc2dbg << "[ModuleMap]: No socket" << endl;
// Loading failed
return NULL;
}
}