thoughts
This commit is contained in:
Joey Hess
parent
fe49747fc8
commit
cd20dc4158
1 changed files with 165 additions and 0 deletions
|
|
@ -22,6 +22,171 @@ process.
|
|||
around with a hack that escapes FilePaths that contain unusual
|
||||
characters. It would be much better to use a BLOB.
|
||||
|
||||
Also, when LANG=C is sometimes used, the hack can result in duplicates with
|
||||
different representations of the same filename, like this:
|
||||
|
||||
INSERT INTO associated VALUES(4,'SHA256E-s30--7d51d2454391a40e952bea478e45d64cf0d606e1e8c0652bb815a22e0e23419a,'foo.ü');
|
||||
INSERT INTO associated VALUES(5,'SHA256E-s30--7d51d2454391a40e952bea478e45d64cf0d606e1e8c0652bb815a22e0e23419a','"foo.\56515\56508"');
|
||||
|
||||
* IKey could fail to round-trip as well, when a Key contains something
|
||||
(eg, a filename extension) that is not valid in the current locale,
|
||||
for similar reasons to SFilePath. Using BLOB would be better.
|
||||
|
||||
See [[!commit cf260d9a159050e2a7e70394fdd8db289c805ec3]] for how the
|
||||
encoding problem was fixed for SFilePath. I reproduced a similar problem
|
||||
by making a file `foo.ü` and running `git add` on it in a unicode
|
||||
locale. Then with LANG=C, `git annex drop --force foo.ü` thinks
|
||||
it drops the content, but in fact the work tree file is left containing
|
||||
the dropped content. The database then contained:
|
||||
|
||||
INSERT INTO associated VALUES(8,'SHA256E-s30--59594eea8d6f64156b3ce6530cc3a661739abf2a0b72443de8683c34b0b19344.ü','foo.ü');
|
||||
INSERT INTO associated VALUES(9,'SHA256E-s30--59594eea8d6f64156b3ce6530cc3a661739abf2a0b72443de8683c34b0b19344.<2E><>','"foo.\56515\56508"');
|
||||
|
||||
> Investigated this in more detail, and I can't find a way to
|
||||
> solve the encoding problem other than changing the encoding
|
||||
> SKey, IKey, and SFilePath in a non-backwards-compatible way.
|
||||
>
|
||||
> (Unless the encoding problem is related to persistent's use of Text
|
||||
> internally, and could then perhaps be avoided by avoiding that?)
|
||||
>
|
||||
> The simplest and best final result would be use a ByteString
|
||||
> for all of them, and store a blob in sqlite. Attached patch
|
||||
> shows how to do that, but old git-annex won't be able to read
|
||||
> the updated databases, and won't know that it can't read them!
|
||||
>
|
||||
> This seems to call for a flag day, throwing out the old database
|
||||
> contents and regenerating them from other data:
|
||||
>
|
||||
> * Fsck (SKey)
|
||||
> can't rebuild? Just drop and let incremental fscks re-do work
|
||||
> * ContentIdentifier (IKey)
|
||||
> rebuild with updateFromLog, would need to diff from empty tree to
|
||||
> current git-annex branch, may be expensive to do!
|
||||
> * Export (IKey, SFilePath)
|
||||
> difficult to rebuild, what if in the middle of an interrupted
|
||||
> export?
|
||||
>
|
||||
> updateExportTreeFromLog only updates two tables, not others
|
||||
>
|
||||
> Conceptually, this is the same as the repo being lost and another
|
||||
> clone being used to update the export. The clone can only learn
|
||||
> export state from the log. It's supposed to recover from such
|
||||
> situations, the next time an export is run, so should be ok.
|
||||
> But it might result in already exported files being re-uploaded,
|
||||
> or other unncessary work.
|
||||
> Keys (IKey, SFilePath)
|
||||
> rebuild with scanUnlockedFiles
|
||||
>
|
||||
> does that update the Content table with the InodeCache?
|
||||
>
|
||||
> But after such a transition, how to communicate to the old git-annex
|
||||
> that it can't use the databases any longer? Moving the databases
|
||||
> out of the way won't do; old git-annex will just recreate them and
|
||||
> start with missing data!
|
||||
>
|
||||
> And, what about users who really need to continue using an old git-annex
|
||||
> and get bitten by the flag day?
|
||||
>
|
||||
> Should this instead be a annex.version bump from v7 to v8?
|
||||
> But v5 is also affected for ContentIdentifier and Export and Fsck.
|
||||
> Don't want v5.1.
|
||||
|
||||
----
|
||||
|
||||
[[!format patch """
|
||||
diff --git a/Database/Types.hs b/Database/Types.hs
|
||||
index f08cf4e9d..3e9c9e267 100644
|
||||
--- a/Database/Types.hs
|
||||
+++ b/Database/Types.hs
|
||||
@@ -14,11 +14,12 @@ import Database.Persist.TH
|
||||
import Database.Persist.Class hiding (Key)
|
||||
import Database.Persist.Sql hiding (Key)
|
||||
import Data.Maybe
|
||||
-import Data.Char
|
||||
import qualified Data.ByteString as S
|
||||
+import qualified Data.ByteString.Lazy as L
|
||||
import qualified Data.Text as T
|
||||
|
||||
import Utility.PartialPrelude
|
||||
+import Utility.FileSystemEncoding
|
||||
import Key
|
||||
import Utility.InodeCache
|
||||
import Git.Types (Ref(..))
|
||||
@@ -37,23 +38,18 @@ fromSKey (SKey s) = fromMaybe (error $ "bad serialized Key " ++ s) (deserializeK
|
||||
|
||||
derivePersistField "SKey"
|
||||
|
||||
--- A Key index. More efficient than SKey, but its Read instance does not
|
||||
--- work when it's used in any kind of complex data structure.
|
||||
-newtype IKey = IKey String
|
||||
-
|
||||
-instance Read IKey where
|
||||
- readsPrec _ s = [(IKey s, "")]
|
||||
-
|
||||
-instance Show IKey where
|
||||
- show (IKey s) = s
|
||||
+-- A Key index. More efficient than SKey.
|
||||
+newtype IKey = IKey S.ByteString
|
||||
+ deriving (Eq, Show, PersistField, PersistFieldSql)
|
||||
|
||||
+-- FIXME: toStrict copies, not efficient
|
||||
toIKey :: Key -> IKey
|
||||
-toIKey = IKey . serializeKey
|
||||
+toIKey = IKey . L.toStrict . serializeKey'
|
||||
|
||||
fromIKey :: IKey -> Key
|
||||
-fromIKey (IKey s) = fromMaybe (error $ "bad serialized Key " ++ s) (deserializeKey s)
|
||||
-
|
||||
-derivePersistField "IKey"
|
||||
+fromIKey (IKey b) = fromMaybe
|
||||
+ (error $ "bad serialized Key " ++ show b)
|
||||
+ (deserializeKey' b)
|
||||
|
||||
-- A serialized InodeCache
|
||||
newtype SInodeCache = I String
|
||||
@@ -67,39 +63,15 @@ fromSInodeCache (I s) = fromMaybe (error $ "bad serialized InodeCache " ++ s) (r
|
||||
|
||||
derivePersistField "SInodeCache"
|
||||
|
||||
--- A serialized FilePath.
|
||||
---
|
||||
--- Not all unicode characters round-trip through sqlite. In particular,
|
||||
--- surrigate code points do not. So, escape the FilePath. But, only when
|
||||
--- it contains such characters.
|
||||
-newtype SFilePath = SFilePath String
|
||||
-
|
||||
--- Note that Read instance does not work when used in any kind of complex
|
||||
--- data structure.
|
||||
-instance Read SFilePath where
|
||||
- readsPrec _ s = [(SFilePath s, "")]
|
||||
-
|
||||
-instance Show SFilePath where
|
||||
- show (SFilePath s) = s
|
||||
+-- A serialized FilePath. Stored as a ByteString to avoid encoding problems.
|
||||
+newtype SFilePath = SFilePath S.ByteString
|
||||
+ deriving (Eq, Show, PersistField, PersistFieldSql)
|
||||
|
||||
toSFilePath :: FilePath -> SFilePath
|
||||
-toSFilePath s@('"':_) = SFilePath (show s)
|
||||
-toSFilePath s
|
||||
- | any needsescape s = SFilePath (show s)
|
||||
- | otherwise = SFilePath s
|
||||
- where
|
||||
- needsescape c = case generalCategory c of
|
||||
- Surrogate -> True
|
||||
- PrivateUse -> True
|
||||
- NotAssigned -> True
|
||||
- _ -> False
|
||||
+toSFilePath = SFilePath . encodeBS
|
||||
|
||||
fromSFilePath :: SFilePath -> FilePath
|
||||
-fromSFilePath (SFilePath s@('"':_)) =
|
||||
- fromMaybe (error "bad serialized SFilePath " ++ s) (readish s)
|
||||
-fromSFilePath (SFilePath s) = s
|
||||
-
|
||||
-derivePersistField "SFilePath"
|
||||
+fromSFilePath (SFilePath b) = decodeBS b
|
||||
|
||||
-- A serialized Ref
|
||||
newtype SRef = SRef Ref
|
||||
"""]]
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue