exchangev2: support fetching shallow files history
This commit teaches the exchangev2 client code to handle fetching shallow
files data.
Only shallow fetching of files data is supported: shallow fetching of
changeset and manifest data is explicitly not yet supported.
Previously, we would fetch file revisions for changesets that were received
by the current pull operation. In the new model, we calculate the set of
"relevant" changesets given the pull depth and only fetch files data for
those changesets.
We also teach the "filesdata" command invocation to vary parameters as needed.
The implementation here is far from complete or optimal. Subsequent pulls will
end up re-fetching a lot of files data. But the application of this data should
mostly be a no-op on the client, so it isn't a big deal.
Depending on the order file revisions are fetched in, revisions could get
inserted with the wrong revision number relationships. I think the best way
to deal with this is to remove revision numbers from storage and to either
dynamically derive them (by reconstructing a DAG from nodes/parents) or remove
revision numbers from the file storage interface completely.
A missing API that we'll likely want to write pretty soon is "ensure files
for revision(s) are present." We can kind of cajole exchangev2.pull() to do
this. But it isn't very efficient. For example, in simple cases like
widening the store to obtain data for a single revision, it is probably
more efficient to walk the manifest and find exactly which file revisions
are missing and to make explicit requests for just their data. In more
advanced cases, asking the server for all files data may be more efficient,
even though it requires sending data the client already has. There is tons
of room for future experimentation here. And TBH I'm not sure what the
final state will be.
Anyway, this commit gets us pretty close to being able to have shallow
and narrow checkouts with exchangev2/sqlite storage. Close enough that a
minimal extension should be able to provide fill in the gaps until the code
in core stabilizes and there is a user-facing way to trigger the
narrow/shallow bits from `hg clone` without also implying using of the
narrow extension...
Differential Revision: https://phab.mercurial-scm.org/D5169
;;; mq.el --- Emacs support for Mercurial Queues
;; Copyright (C) 2006 Bryan O'Sullivan
;; Author: Bryan O'Sullivan <bos@serpentine.com>
;; mq.el is free software; you can redistribute it and/or modify it
;; under the terms of the GNU General Public License version 2 or any
;; later version.
;; mq.el is distributed in the hope that it will be useful, but
;; WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
;; General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with mq.el, GNU Emacs, or XEmacs; see the file COPYING (`C-h
;; C-l'). If not, see <http://www.gnu.org/licenses/>.
(eval-when-compile (require 'cl))
(require 'mercurial)
(defcustom mq-mode-hook nil
"Hook run when a buffer enters mq-mode."
:type 'sexp
:group 'mercurial)
(defcustom mq-global-prefix "\C-cq"
"The global prefix for Mercurial Queues keymap bindings."
:type 'sexp
:group 'mercurial)
(defcustom mq-edit-mode-hook nil
"Hook run after a buffer is populated to edit a patch description."
:type 'sexp
:group 'mercurial)
(defcustom mq-edit-finish-hook nil
"Hook run before a patch description is finished up with."
:type 'sexp
:group 'mercurial)
(defcustom mq-signoff-address nil
"Address with which to sign off on a patch."
:type 'string
:group 'mercurial)
;;; Internal variables.
(defvar mq-mode nil
"Is this file managed by MQ?")
(make-variable-buffer-local 'mq-mode)
(put 'mq-mode 'permanent-local t)
(defvar mq-patch-history nil)
(defvar mq-top-patch '(nil))
(defvar mq-prev-buffer nil)
(make-variable-buffer-local 'mq-prev-buffer)
(put 'mq-prev-buffer 'permanent-local t)
(defvar mq-top nil)
(make-variable-buffer-local 'mq-top)
(put 'mq-top 'permanent-local t)
;;; Global keymap.
(defvar mq-global-map
(let ((map (make-sparse-keymap)))
(define-key map "." 'mq-push)
(define-key map ">" 'mq-push-all)
(define-key map "," 'mq-pop)
(define-key map "<" 'mq-pop-all)
(define-key map "=" 'mq-diff)
(define-key map "r" 'mq-refresh)
(define-key map "e" 'mq-refresh-edit)
(define-key map "i" 'mq-new)
(define-key map "n" 'mq-next)
(define-key map "o" 'mq-signoff)
(define-key map "p" 'mq-previous)
(define-key map "s" 'mq-edit-series)
(define-key map "t" 'mq-top)
map))
(global-set-key mq-global-prefix mq-global-map)
(add-minor-mode 'mq-mode 'mq-mode)
;;; Refresh edit mode keymap.
(defvar mq-edit-mode-map
(let ((map (make-sparse-keymap)))
(define-key map "\C-c\C-c" 'mq-edit-finish)
(define-key map "\C-c\C-k" 'mq-edit-kill)
(define-key map "\C-c\C-s" 'mq-signoff)
map))
;;; Helper functions.
(defun mq-read-patch-name (&optional source prompt force)
"Read a patch name to use with a command.
May return nil, meaning \"use the default\"."
(let ((patches (split-string
(hg-chomp (hg-run0 (or source "qseries"))) "\n")))
(when force
(completing-read (format "Patch%s: " (or prompt ""))
(mapcar (lambda (x) (cons x x)) patches)
nil
nil
nil
'mq-patch-history))))
(defun mq-refresh-buffers (root)
(save-excursion
(dolist (buf (hg-buffers-visiting-repo root))
(when (not (verify-visited-file-modtime buf))
(set-buffer buf)
(let ((ctx (hg-buffer-context)))
(message "Refreshing %s..." (buffer-name))
(revert-buffer t t t)
(hg-restore-context ctx)
(message "Refreshing %s...done" (buffer-name))))))
(hg-update-mode-lines root)
(mq-update-mode-lines root))
(defun mq-last-line ()
(goto-char (point-max))
(beginning-of-line)
(when (looking-at "^$")
(forward-line -1))
(let ((bol (point)))
(end-of-line)
(let ((line (buffer-substring bol (point))))
(when (> (length line) 0)
line))))
(defun mq-push (&optional patch)
"Push patches until PATCH is reached.
If PATCH is nil, push at most one patch."
(interactive (list (mq-read-patch-name "qunapplied" " to push"
current-prefix-arg)))
(let ((root (hg-root))
(prev-buf (current-buffer))
last-line ok)
(unless root
(error "Cannot push outside a repository!"))
(hg-sync-buffers root)
(let ((buf-name (format "MQ: Push %s" (or patch "next patch"))))
(kill-buffer (get-buffer-create buf-name))
(split-window-vertically)
(other-window 1)
(switch-to-buffer (get-buffer-create buf-name))
(cd root)
(message "Pushing...")
(setq ok (= 0 (apply 'call-process (hg-binary) nil t t "qpush"
(if patch (list patch))))
last-line (mq-last-line))
(let ((lines (count-lines (point-min) (point-max))))
(if (or (<= lines 1)
(and (equal lines 2) (string-match "Now at:" last-line)))
(progn
(kill-buffer (current-buffer))
(delete-window))
(hg-view-mode prev-buf))))
(mq-refresh-buffers root)
(sit-for 0)
(when last-line
(if ok
(message "Pushing... %s" last-line)
(error "Pushing... %s" last-line)))))
(defun mq-push-all ()
"Push patches until all are applied."
(interactive)
(mq-push "-a"))
(defun mq-pop (&optional patch)
"Pop patches until PATCH is reached.
If PATCH is nil, pop at most one patch."
(interactive (list (mq-read-patch-name "qapplied" " to pop to"
current-prefix-arg)))
(let ((root (hg-root))
last-line ok)
(unless root
(error "Cannot pop outside a repository!"))
(hg-sync-buffers root)
(set-buffer (generate-new-buffer "qpop"))
(cd root)
(message "Popping...")
(setq ok (= 0 (apply 'call-process (hg-binary) nil t t "qpop"
(if patch (list patch))))
last-line (mq-last-line))
(kill-buffer (current-buffer))
(mq-refresh-buffers root)
(sit-for 0)
(when last-line
(if ok
(message "Popping... %s" last-line)
(error "Popping... %s" last-line)))))
(defun mq-pop-all ()
"Push patches until none are applied."
(interactive)
(mq-pop "-a"))
(defun mq-refresh-internal (root &rest args)
(hg-sync-buffers root)
(let ((patch (mq-patch-info "qtop")))
(message "Refreshing %s..." patch)
(let ((ret (apply 'hg-run "qrefresh" args)))
(if (equal (car ret) 0)
(message "Refreshing %s... done." patch)
(error "Refreshing %s... %s" patch (hg-chomp (cdr ret)))))))
(defun mq-refresh (&optional git)
"Refresh the topmost applied patch.
With a prefix argument, generate a git-compatible patch."
(interactive "P")
(let ((root (hg-root)))
(unless root
(error "Cannot refresh outside of a repository!"))
(apply 'mq-refresh-internal root (if git '("--git")))))
(defun mq-patch-info (cmd &optional msg)
(let* ((ret (hg-run cmd))
(info (hg-chomp (cdr ret))))
(if (equal (car ret) 0)
(if msg
(message "%s patch: %s" msg info)
info)
(error "%s" info))))
(defun mq-top ()
"Print the name of the topmost applied patch."
(interactive)
(mq-patch-info "qtop" "Top"))
(defun mq-next ()
"Print the name of the next patch to be pushed."
(interactive)
(mq-patch-info "qnext" "Next"))
(defun mq-previous ()
"Print the name of the first patch below the topmost applied patch.
This would become the active patch if popped to."
(interactive)
(mq-patch-info "qprev" "Previous"))
(defun mq-edit-finish ()
"Finish editing the description of this patch, and refresh the patch."
(interactive)
(unless (equal (mq-patch-info "qtop") mq-top)
(error "Topmost patch has changed!"))
(hg-sync-buffers hg-root)
(run-hooks 'mq-edit-finish-hook)
(mq-refresh-internal hg-root "-m" (buffer-substring (point-min) (point-max)))
(let ((buf mq-prev-buffer))
(kill-buffer nil)
(switch-to-buffer buf)))
(defun mq-edit-kill ()
"Kill the edit currently being prepared."
(interactive)
(when (or (not (buffer-modified-p)) (y-or-n-p "Really kill this edit? "))
(let ((buf mq-prev-buffer))
(kill-buffer nil)
(switch-to-buffer buf))))
(defun mq-get-top (root)
(let ((entry (assoc root mq-top-patch)))
(if entry
(cdr entry))))
(defun mq-set-top (root patch)
(let ((entry (assoc root mq-top-patch)))
(if entry
(if patch
(setcdr entry patch)
(setq mq-top-patch (delq entry mq-top-patch)))
(setq mq-top-patch (cons (cons root patch) mq-top-patch)))))
(defun mq-update-mode-lines (root)
(let ((cwd default-directory))
(cd root)
(condition-case nil
(mq-set-top root (mq-patch-info "qtop"))
(error (mq-set-top root nil)))
(cd cwd))
(let ((patch (mq-get-top root)))
(save-excursion
(dolist (buf (hg-buffers-visiting-repo root))
(set-buffer buf)
(if mq-mode
(setq mq-mode (or (and patch (concat " MQ:" patch)) " MQ")))))))
(defun mq-mode (&optional arg)
"Minor mode for Mercurial repositories with an MQ patch queue"
(interactive "i")
(cond ((hg-root)
(setq mq-mode (if (null arg) (not mq-mode)
arg))
(mq-update-mode-lines (hg-root))))
(run-hooks 'mq-mode-hook))
(defun mq-edit-mode ()
"Mode for editing the description of a patch.
Key bindings
------------
\\[mq-edit-finish] use this description
\\[mq-edit-kill] abandon this description"
(interactive)
(use-local-map mq-edit-mode-map)
(set-syntax-table text-mode-syntax-table)
(setq local-abbrev-table text-mode-abbrev-table
major-mode 'mq-edit-mode
mode-name "MQ-Edit")
(set-buffer-modified-p nil)
(setq buffer-undo-list nil)
(run-hooks 'text-mode-hook 'mq-edit-mode-hook))
(defun mq-refresh-edit ()
"Refresh the topmost applied patch, editing the patch description."
(interactive)
(while mq-prev-buffer
(set-buffer mq-prev-buffer))
(let ((root (hg-root))
(prev-buffer (current-buffer))
(patch (mq-patch-info "qtop")))
(hg-sync-buffers root)
(let ((buf-name (format "*MQ: Edit description of %s*" patch)))
(switch-to-buffer (get-buffer-create buf-name))
(when (= (point-min) (point-max))
(set (make-local-variable 'hg-root) root)
(set (make-local-variable 'mq-top) patch)
(setq mq-prev-buffer prev-buffer)
(insert (hg-run0 "qheader"))
(goto-char (point-min)))
(mq-edit-mode)
(cd root)))
(message "Type `C-c C-c' to finish editing and refresh the patch."))
(defun mq-new (name)
"Create a new empty patch named NAME.
The patch is applied on top of the current topmost patch.
With a prefix argument, forcibly create the patch even if the working
directory is modified."
(interactive (list (mq-read-patch-name "qseries" " to create" t)))
(message "Creating patch...")
(let ((ret (if current-prefix-arg
(hg-run "qnew" "-f" name)
(hg-run "qnew" name))))
(if (equal (car ret) 0)
(progn
(hg-update-mode-lines (buffer-file-name))
(message "Creating patch... done."))
(error "Creating patch... %s" (hg-chomp (cdr ret))))))
(defun mq-edit-series ()
"Edit the MQ series file directly."
(interactive)
(let ((root (hg-root)))
(unless root
(error "Not in an MQ repository!"))
(find-file (concat root ".hg/patches/series"))))
(defun mq-diff (&optional git)
"Display a diff of the topmost applied patch.
With a prefix argument, display a git-compatible diff."
(interactive "P")
(hg-view-output ((format "MQ: Diff of %s" (mq-patch-info "qtop")))
(if git
(call-process (hg-binary) nil t nil "qdiff" "--git")
(call-process (hg-binary) nil t nil "qdiff"))
(diff-mode)
(font-lock-fontify-buffer)))
(defun mq-signoff ()
"Sign off on the current patch, in the style used by the Linux kernel.
If the variable mq-signoff-address is non-nil, it will be used, otherwise
the value of the ui.username item from your hgrc will be used."
(interactive)
(let ((was-editing (eq major-mode 'mq-edit-mode))
signed)
(unless was-editing
(mq-refresh-edit))
(save-excursion
(let* ((user (or mq-signoff-address
(hg-run0 "debugconfig" "ui.username")))
(signoff (concat "Signed-off-by: " user)))
(if (search-forward signoff nil t)
(message "You have already signed off on this patch.")
(goto-char (point-max))
(let ((case-fold-search t))
(if (re-search-backward "^Signed-off-by: " nil t)
(forward-line 1)
(insert "\n")))
(insert signoff)
(message "%s" signoff)
(setq signed t))))
(unless was-editing
(if signed
(mq-edit-finish)
(mq-edit-kill)))))
(provide 'mq)
;;; Local Variables:
;;; prompt-to-byte-compile: nil
;;; end: