lix/src/libstore/datatransfer.hh
2020-04-08 22:26:57 +02:00

114 lines
3.2 KiB
C++

#pragma once
#include "types.hh"
#include "hash.hh"
#include "config.hh"
#include <string>
#include <future>
namespace nix {
struct DataTransferSettings : Config
{
Setting<bool> enableHttp2{this, true, "http2",
"Whether to enable HTTP/2 support."};
Setting<std::string> userAgentSuffix{this, "", "user-agent-suffix",
"String appended to the user agent in HTTP requests."};
Setting<size_t> httpConnections{this, 25, "http-connections",
"Number of parallel HTTP connections.",
{"binary-caches-parallel-connections"}};
Setting<unsigned long> connectTimeout{this, 0, "connect-timeout",
"Timeout for connecting to servers during downloads. 0 means use curl's builtin default."};
Setting<unsigned long> stalledDownloadTimeout{this, 300, "stalled-download-timeout",
"Timeout (in seconds) for receiving data from servers during download. Nix cancels idle downloads after this timeout's duration."};
Setting<unsigned int> tries{this, 5, "download-attempts",
"How often Nix will attempt to download a file before giving up."};
};
extern DataTransferSettings dataTransferSettings;
struct DataTransferRequest
{
std::string uri;
std::string expectedETag;
bool verifyTLS = true;
bool head = false;
size_t tries = dataTransferSettings.tries;
unsigned int baseRetryTimeMs = 250;
ActivityId parentAct;
bool decompress = true;
std::shared_ptr<std::string> data;
std::string mimeType;
std::function<void(char *, size_t)> dataCallback;
DataTransferRequest(const std::string & uri)
: uri(uri), parentAct(getCurActivity()) { }
std::string verb()
{
return data ? "upload" : "download";
}
};
struct DataTransferResult
{
bool cached = false;
std::string etag;
std::string effectiveUri;
std::shared_ptr<std::string> data;
uint64_t bodySize = 0;
};
class Store;
struct Downloader
{
virtual ~Downloader() { }
/* Enqueue a download request, returning a future to the result of
the download. The future may throw a DownloadError
exception. */
virtual void enqueueDownload(const DataTransferRequest & request,
Callback<DataTransferResult> callback) = 0;
std::future<DataTransferResult> enqueueDownload(const DataTransferRequest & request);
/* Synchronously download a file. */
DataTransferResult download(const DataTransferRequest & request);
/* Download a file, writing its data to a sink. The sink will be
invoked on the thread of the caller. */
void download(DataTransferRequest && request, Sink & sink);
enum Error { NotFound, Forbidden, Misc, Transient, Interrupted };
};
/* Return a shared Downloader object. Using this object is preferred
because it enables connection reuse and HTTP/2 multiplexing. */
ref<Downloader> getDownloader();
/* Return a new Downloader object. */
ref<Downloader> makeDownloader();
class DownloadError : public Error
{
public:
Downloader::Error error;
DownloadError(Downloader::Error error, const FormatOrString & fs)
: Error(fs), error(error)
{ }
};
bool isUri(const string & s);
/* Resolve deprecated 'channel:<foo>' URLs. */
std::string resolveUri(const std::string & uri);
}