1 files changed, 116 insertions, 0 deletions
diff --git a/src/libstore/filetransfer.hh b/src/libstore/filetransfer.hh
new file mode 100644
index 000000000..2347f363d
--- /dev/null
+++ b/src/libstore/filetransfer.hh
@@ -0,0 +1,116 @@
+#pragma once
+
+#include "types.hh"
+#include "hash.hh"
+#include "config.hh"
+
+#include <string>
+#include <future>
+
+namespace nix {
+
+struct FileTransferSettings : 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 FileTransferSettings fileTransferSettings;
+
+struct FileTransferRequest
+{
+    std::string uri;
+    std::string expectedETag;
+    bool verifyTLS = true;
+    bool head = false;
+    size_t tries = fileTransferSettings.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;
+
+    FileTransferRequest(const std::string & uri)
+        : uri(uri), parentAct(getCurActivity()) { }
+
+    std::string verb()
+    {
+        return data ? "upload" : "download";
+    }
+};
+
+struct FileTransferResult
+{
+    bool cached = false;
+    std::string etag;
+    std::string effectiveUri;
+    std::shared_ptr<std::string> data;
+    uint64_t bodySize = 0;
+};
+
+class Store;
+
+struct FileTransfer
+{
+    virtual ~FileTransfer() { }
+
+    /* Enqueue a data transfer request, returning a future to the result of
+       the download. The future may throw a FileTransferError
+       exception. */
+    virtual void enqueueFileTransfer(const FileTransferRequest & request,
+        Callback<FileTransferResult> callback) = 0;
+
+    std::future<FileTransferResult> enqueueFileTransfer(const FileTransferRequest & request);
+
+    /* Synchronously download a file. */
+    FileTransferResult download(const FileTransferRequest & request);
+
+    /* Synchronously upload a file. */
+    FileTransferResult upload(const FileTransferRequest & request);
+
+    /* Download a file, writing its data to a sink. The sink will be
+       invoked on the thread of the caller. */
+    void download(FileTransferRequest && request, Sink & sink);
+
+    enum Error { NotFound, Forbidden, Misc, Transient, Interrupted };
+};
+
+/* Return a shared FileTransfer object. Using this object is preferred
+   because it enables connection reuse and HTTP/2 multiplexing. */
+ref<FileTransfer> getFileTransfer();
+
+/* Return a new FileTransfer object. */
+ref<FileTransfer> makeFileTransfer();
+
+class FileTransferError : public Error
+{
+public:
+    FileTransfer::Error error;
+    FileTransferError(FileTransfer::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);
+
+}