Durham Goode <durham@fb.com> [Mon, 24 Mar 2014 15:42:13 -0700] rev 20883
fncache: move fncache writing to be in a transaction
Previously the fncache was written at lock.release time. This meant it was not
tracked by a transaction, and if an error occurred during the fncache write it
would fail to update the fncache, but would not rollback the transaction,
resulting in an fncache that was not in sync with the files on disk (which
causes verify to fail, and causes streaming clones to not copy all the revlogs).
This uses the new transaction backup mechanism to make the fncache transacted.
It also moves the fncache from being written at lock.release time, to being
written at transaction.close time.
Durham Goode <durham@fb.com> [Mon, 24 Mar 2014 15:21:51 -0700] rev 20882
transaction: add support for non-append files
This adds support for normal, non-append-only files in transactions. For
example, .hg/store/fncache and .hg/store/phaseroots should be written as part of
the transaction, but are not append only files.
This adds a journal.backupfiles along side the normal journal. This tracks which
files have been backed up as part of the transaction. transaction.addbackup()
creates a backup of the file (using a hardlink), which is later used to recover
in the event of the transaction failing.
Using a seperate journal allows the repository to still be used by older
versions of Mercurial. A future patch will use this functionality and add tests
for it.
Durham Goode <durham@fb.com> [Mon, 24 Mar 2014 15:57:47 -0700] rev 20881
transaction: add onclose/onabort hook for pre-close logic
Adds an optional onclose parameter to transactions that gets called just before
the transaction is committed. This allows things that build up data over the
course of the transaction (like the fncache) to commit their data.
Also adds onabort. It's not used, but will allow extensions to hook into onclose
and onabort to provide transaction support.
Durham Goode <durham@fb.com> [Mon, 24 Mar 2014 15:38:20 -0700] rev 20880
clone: put streaming clones in a transaction
Streaming clones were writing to files outside of a transaction. Soon the
fncache will be written at transaction close time, so we need streaming clones
to be in a transaction.