history pull (xonsh#5047)

Co-authored-by: a <[email protected]>
Closes xonsh#5044

docs/tutorial_hist.rst

@@ -255,6 +255,13 @@ may be useful to share entries between shell sessions. In such a case, one can u
 the ``flush`` action to immediately save the session history to disk and make it
 accessible from other shell sessions.
 
+``pull`` action
+================
+Tries to pull the history from parallel sessions and add to the current session.
+
+For example if there are two parallel terminal windows the run of ``history pull``
+command from the second terminal window will get the commands from the first terminal.
+
 ``clear`` action
 ================
 Deletes the history from the current session up until this point. Later commands

news/history_pull.rst

@@ -0,0 +1,23 @@
+**Added:**
+
+* Added ``history pull`` command to SQLite history backend to pull the history from parallel sessions and add to the current session.
+
+**Changed:**
+
+* <news item>
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>

xonsh/history/base.py

@@ -130,6 +130,10 @@ def append(self, cmd):
  """
  pass
 
+ def pull(self, **kwargs):
+ """Pull history from other parallel sessions."""
+ raise NotImplementedError
+
  def flush(self, **kwargs):
  """Flush the history items to disk from a buffer."""
  pass

xonsh/history/main.py

@@ -281,6 +281,31 @@ def id_cmd(_stdout):
  return
  print(str(hist.sessionid), file=_stdout)
 
+ @staticmethod
+ def pull(show_commands=False, _stdout=None):
+ """Pull history from other parallel sessions.
+
+ Parameters
+ ----------
+ show_commands: -c, --show-commands
+ show pulled commands
+ """
+
+ hist = XSH.history
+
+ if hist.pull.__module__ == "xonsh.history.base":
+ backend = XSH.env.get("XONSH_HISTORY_BACKEND", "unknown")
+ print(
+ f"Pull method is not supported in {backend} history backend.",
+ file=_stdout,
+ )
+
+ lines_added = hist.pull(show_commands)
+ if lines_added:
+ print(f"Added {lines_added} records!", file=_stdout)
+ else:
+ print(f"No records found!", file=_stdout)
+
  @staticmethod
  def flush(_stdout):
  """Flush the current history to disk"""
@@ -428,14 +453,15 @@ def transfer(
 
  dest.flush()
 
- self.out("done.")
+ self.out("Done")
 
  def build(self):
  parser = self.create_parser(prog="history")
  parser.add_command(self.show, prefix_chars="-+")
  parser.add_command(self.id_cmd, prog="id")
  parser.add_command(self.file)
  parser.add_command(self.info)
+ parser.add_command(self.pull)
  parser.add_command(self.flush)
  parser.add_command(self.off)
  parser.add_command(self.on)

xonsh/history/sqlite.py

@@ -204,6 +204,15 @@ def xh_sqlite_delete_items(size_to_keep, filename=None):
  return _xh_sqlite_delete_records(c, size_to_keep)
 
 
+def xh_sqlite_pull(filename, last_pull_time, current_sessionid):
+ sql = f"SELECT inp FROM xonsh_history WHERE tsb > ? AND sessionid != ? ORDER BY tsb"
+ params = [last_pull_time, current_sessionid]
+ with _xh_sqlite_get_conn(filename=filename) as conn:
+ c = conn.cursor()
+ c.execute(sql, tuple(params))
+ return c.fetchall()
+
+
 def xh_sqlite_wipe_session(sessionid=None, filename=None):
  """Wipe the current session's entries from the database."""
  sql = "DELETE FROM xonsh_history WHERE sessionid = ?"
@@ -256,6 +265,7 @@ def __init__(self, gc=True, filename=None, save_cwd=None, **kwargs):
  if filename is None:
  filename = _xh_sqlite_get_file_name()
  self.filename = filename
+ self.last_pull_time = time.time()
  self.gc = SqliteHistoryGC() if gc else None
  self._last_hist_inp = None
  self.inps = []
@@ -345,6 +355,22 @@ def info(self):
  data["gc options"] = envs.get("XONSH_HISTORY_SIZE")
  return data
 
+ def pull(self, show_commands=False):
+ if not hasattr(XSH.shell.shell, "prompter"):
+ print(f"Shell type {XSH.shell.shell} is not supported.")
+ return 0
+
+ cnt = 0
+ for r in xh_sqlite_pull(
+ self.filename, self.last_pull_time, str(self.sessionid)
+ ):
+ if show_commands:
+ print(r[0])
+ XSH.shell.shell.prompter.history.append_string(r[0])
+ cnt += 1
+ self.last_pull_time = time.time()
+ return cnt
+
  def run_gc(self, size=None, blocking=True):
  self.gc = SqliteHistoryGC(wait_for_shell=False, size=size)
  if blocking: