From 10978a9e22ce8c606d157e16366430e1d97fa47d Mon Sep 17 00:00:00 2001
From: Jean-Paul Calderone <exarkun@twistedmatrix.com>
Date: Wed, 7 Jun 2023 11:07:49 -0400
Subject: [PATCH] the actual directory downloading function (used by
list-dircap example app)
---
src/Tahoe/Download.hs | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/src/Tahoe/Download.hs b/src/Tahoe/Download.hs
index dc62783..c5a64c4 100644
--- a/src/Tahoe/Download.hs
+++ b/src/Tahoe/Download.hs
@@ -229,3 +229,29 @@ downloadShare storageIndex (shareNum, s) = do
let massaged = first (ShareDownloadError . (displayException :: SomeException -> String)) shareBytes
print' "Downloaded it"
pure (shareNum, LB.fromStrict <$> massaged)
+
+{- | Download the data associated with a directory capability and interpret it
+ as a collection of entries.
+-}
+downloadDirectory ::
+ (MonadIO m, Readable readCap, Verifiable v, Verifier readCap ~ v) =>
+ -- | Information about the servers from which to consider downloading shares
+ -- representing the application data.
+ Map.Map StorageServerID StorageServerAnnouncement ->
+ -- | The read capability for the application data.
+ DirectoryCapability readCap ->
+ -- | Get functions for interacting with a server given its URL.
+ LookupServer m ->
+ -- | Either a description of how the recovery failed or the recovered
+ -- application data.
+ m (Either DirectoryDownloadError Directory)
+downloadDirectory anns (DirectoryCapability cap) lookupServer = do
+ bs <- download anns cap lookupServer
+ pure $ do
+ bs' <- first UnderlyingDownloadError bs
+ first (const DecodingError) $ Directory.parse (LB.toStrict bs')
+
+data DirectoryDownloadError
+ = UnderlyingDownloadError DownloadError
+ | DecodingError
+ deriving (Ord, Eq, Show)
--
GitLab