Info command that prints snapshot changes

Summary:
This diff makes `hg snapshot info` an equivalent to `hg show`, which shows info about the snapshot and its changes.

To do that, it creates a `memctx` for the snapshot, which is kind of a commit in memory, which is useful because we can then reuse base hg stuff to show the diff :)

Reviewed By: mitrandir77

Differential Revision: D31802201

fbshipit-source-id: 1bcea87e9a1b3ee665e04822fe78ff03e3ad393e

eden/scm/edenscm/hgext/snapshot/commands.py

@@ -6,7 +6,7 @@
 from edenscm.mercurial import error, registrar
 from edenscm.mercurial.i18n import _
 
-from . import createremote, restore, info
+from . import createremote, update, show
 
 cmdtable = {}
 command = registrar.command(cmdtable)
@@ -23,8 +23,8 @@ def snapshot(ui, repo, **opts):
 
 subcmd = snapshot.subcommand(
     categories=[
-        ("Manage snapshots", ["createremote", "restore"]),
-        ("Query snapshots", ["info"]),
+        ("Manage snapshots", ["create", "update"]),
+        ("Query snapshots", ["show"]),
     ]
 )
 
@@ -36,7 +36,7 @@ def createremotecmd(*args, **kwargs):
 
 
 @subcmd(
-    "restore",
+    "update|restore|checkout|co|up",
     [
         (
             "C",
@@ -47,12 +47,12 @@ def createremotecmd(*args, **kwargs):
     ],
     _("ID"),
 )
-def restorecmd(*args, **kwargs):
+def updatecmd(*args, **kwargs):
     """download a previously created snapshot and update working copy to its state"""
-    restore.restore(*args, **kwargs)
+    update.update(*args, **kwargs)
 
 
-@subcmd("info", [], _("ID"))
-def infocmd(*args, **kwargs):
+@subcmd("show|info", [], _("ID"))
+def showcmd(*args, **kwargs):
     """gather information about the snapshot"""
-    info.info(*args, **kwargs)
+    show.show(*args, **kwargs)

eden/scm/edenscm/hgext/snapshot/info.py

@@ -1,24 +0,0 @@
-# Copyright (c) Facebook, Inc. and its affiliates.
-#
-# This software may be used and distributed according to the terms of the
-# GNU General Public License version 2.
-
-from edenscm.mercurial import error
-from edenscm.mercurial.edenapi_upload import (
-    getreponame,
-)
-from edenscm.mercurial.i18n import _
-
-
-def info(ui, repo, csid, **opts):
-    try:
-        repo.edenapi.fetchsnapshot(
-            getreponame(repo),
-            {
-                "cs_id": bytes.fromhex(csid),
-            },
-        )
-    except Exception:
-        raise error.Abort(_("snapshot doesn't exist"))
-    else:
-        ui.status(_("snapshot exists\n"))

eden/scm/edenscm/hgext/snapshot/show.py

@@ -0,0 +1,88 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2.
+
+from edenscm.mercurial import error, scmutil
+from edenscm.mercurial.cmdutil import changeset_printer
+from edenscm.mercurial.context import memctx, memfilectx
+from edenscm.mercurial.edenapi_upload import (
+    getreponame,
+)
+from edenscm.mercurial.i18n import _
+from edenscm.mercurial.node import nullid
+from edenscm.mercurial.util import pickle
+
+
+def _snapshot2ctx(repo, snapshot):
+    """Build a memctx for this snapshot.
+
+    This is not precisely correct as it doesn't differentiate untracked/added
+    but it's good enough for diffing.
+    """
+
+    parent = snapshot["hg_parents"]
+    # Once merges/conflicted states are supported, we'll need to support more
+    # than one parent
+    assert isinstance(parent, bytes)
+
+    parents = (parent, nullid)
+    path2filechange = {f[0]: f[1] for f in snapshot["file_changes"]}
+
+    def token2cacheable(token):
+        data = token["data"]
+        return pickle.dumps((data["id"], data["bubble_id"]))
+
+    cache = {}
+
+    def getfile(repo, memctx, path):
+        change = path2filechange.get(path)
+        if change is None:
+            return repo[parent][path]
+        if change == "Deletion" or change == "UntrackedDeletion":
+            return None
+        elif "Change" in change or "UntrackedChange" in change:
+            change = change.get("Change") or change["UntrackedChange"]
+            token = change["upload_token"]
+            key = token2cacheable(token)
+            if key not in cache:
+                # Possible future optimisation: Download files in parallel
+                cache[key] = repo.edenapi.downloadfiletomemory(getreponame(repo), token)
+            islink = change["file_type"] == "Symlink"
+            isexec = change["file_type"] == "Executable"
+            return memfilectx(
+                repo, None, path, data=cache[key], islink=islink, isexec=isexec
+            )
+        else:
+            raise error.Abort(_("Unknown file change {}").format(change))
+
+    ctx = memctx(
+        repo,
+        parents,
+        text="",
+        files=list(path2filechange.keys()),
+        filectxfn=getfile,
+        user=None,
+        date=None,
+    )
+    return ctx
+
+
+def show(ui, repo, csid, **opts):
+    try:
+        snapshot = repo.edenapi.fetchsnapshot(
+            getreponame(repo),
+            {
+                "cs_id": bytes.fromhex(csid),
+            },
+        )
+    except Exception:
+        raise error.Abort(_("snapshot doesn't exist"))
+    else:
+        ui.status(_("snapshot: {}\n").format(csid))
+        ctx = _snapshot2ctx(repo, snapshot)
+        displayer = changeset_printer(
+            ui, repo, scmutil.matchall(repo), {"patch": True}, False
+        )
+        displayer.show(ctx)
+        displayer.close()

eden/scm/edenscm/hgext/snapshot/update.py

@@ -38,7 +38,7 @@ def _fullclean(ui, repo):
     )
 
 
-def restore(ui, repo, csid, clean=False):
+def update(ui, repo, csid, clean=False):
     ui.status(_("Will restore snapshot {}\n").format(csid), component="snapshot")
 
     snapshot = repo.edenapi.fetchsnapshot(

eden/scm/edenscm/mercurial/cmdutil.py

@@ -1954,10 +1954,11 @@ class changeset_printer(object):
             return
 
         columns = self._columns
-        self.ui.write(
-            columns["changeset"] % scmutil.formatchangeid(ctx),
-            label=_changesetlabels(ctx),
-        )
+        if changenode:
+            self.ui.write(
+                columns["changeset"] % scmutil.formatchangeid(ctx),
+                label=_changesetlabels(ctx),
+            )
 
         # branches are shown first before any other names due to backwards
         # compatibility

eden/scm/edenscmnative/bindings/modules/pyedenapi/src/client.rs

@@ -392,6 +392,15 @@ py_class!(pub class client |py| {
         self.inner(py).clone().downloadfiles_py(py, repo, root, files)
     }
 
+    /// Download file from given upload token to memory
+    def downloadfiletomemory(
+        &self,
+        repo: String,
+        token: Serde<UploadToken>
+    ) -> PyResult<PyBytes> {
+        self.inner(py).clone().downloadfiletomemory_py(py, repo, token)
+    }
+
     def ephemeralprepare(&self, repo: String)
         -> PyResult<TStream<anyhow::Result<Serde<EphemeralPrepareResponse>>>>
     {

eden/scm/edenscmnative/bindings/modules/pyedenapi/src/pyext.rs

@@ -741,6 +741,18 @@ pub trait EdenApiPyExt: EdenApi {
             .map_pyerr(py)
             .map(|_| true)
     }
+
+    fn downloadfiletomemory_py(
+        &self,
+        py: Python,
+        repo: String,
+        token: Serde<UploadToken>,
+    ) -> PyResult<PyBytes> {
+        py.allow_threads(|| block_unless_interrupted(self.download_file(repo.clone(), token.0)))
+            .map_pyerr(py)?
+            .map_pyerr(py)
+            .map(|data| PyBytes::new(py, &data))
+    }
 }
 
 impl<T: EdenApi + ?Sized> EdenApiPyExt for T {}

eden/scm/tests/test-log-t.py

@@ -1627,13 +1627,11 @@ sh % "hg log -r 'null:null'" == r"""
 # clean:
 
 sh % "hg log -r 'wdir()' --debug" == r"""
-    commit:      ffffffffffffffffffffffffffffffffffffffff
     phase:       draft
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     extra:       branch=default"""
 sh % "hg log -r 'wdir()' -p --stat" == r"""
-    commit:      ffffffffffff
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000"""
 
@@ -1649,13 +1647,11 @@ sh % "hg status" == r"""
     R .d6/f1"""
 
 sh % "hg log -r 'wdir()'" == r"""
-    commit:      ffffffffffff
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000"""
 sh % "hg log -r 'wdir()' -q" == "ffffffffffff"
 
 sh % "hg log -r 'wdir()' --debug" == r"""
-    commit:      ffffffffffffffffffffffffffffffffffffffff
     phase:       draft
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
@@ -1664,7 +1660,6 @@ sh % "hg log -r 'wdir()' --debug" == r"""
     files-:      .d6/f1
     extra:       branch=default"""
 sh % "hg log -r 'wdir()' -p --stat --git" == r"""
-    commit:      ffffffffffff
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000