labscript-suite · zakv · Aug 20, 2021 · Oct 3, 2020 · Oct 3, 2020 · Oct 4, 2020
diff --git a/labscript/labscript.py b/labscript/labscript.py
@@ -16,6 +16,7 @@
 import sys
 import subprocess
 import keyword
+import threading
 from inspect import getcallargs
 from functools import wraps
 
@@ -31,6 +32,8 @@
 
 import labscript_utils.h5_lock, h5py
 import labscript_utils.properties
+from labscript_utils.labconfig import LabConfig
+from labscript_utils.filewatcher import FileWatcher
 
 # This imports the default Qt library that other labscript suite code will
 # import as well, since it all uses qtutils. By having a Qt library already
@@ -69,7 +72,10 @@
     startupinfo.dwFlags |= 1 #subprocess.STARTF_USESHOWWINDOW # This variable isn't defined, but apparently it's equal to one.
 else:
     startupinfo = None
-
+
+# Extract settings from labconfig
+_SAVE_HG_INFO = LabConfig().getboolean('labscript', 'save_hg_info', fallback=True)
+_SAVE_GIT_INFO = LabConfig().getboolean('labscript', 'save_git_info', fallback=False)
 
 class config(object):
     suppress_mild_warnings = True
@@ -2173,8 +2179,90 @@ def generate_connection_table(hdf5_file):
     else:
         master_pseudoclock_name = compiler.master_pseudoclock.name
     dataset.attrs['master_pseudoclock'] = master_pseudoclock_name
-
-
+
+# Create a dictionary for caching results from vcs commands. The keys will be
+# the paths to files that are saved during save_labscripts(). The values will be
+# a list of tuples of the form (command, info, err); see the "Returns" section
+# of the _run_vcs_commands() docstring for more info. Also create a FileWatcher
+# instance for tracking when vcs results need updating. The callback will
+# replace the outdated cache entry with a new list of updated vcs commands and
+# outputs.
+_vcs_cache = {}
+_vcs_cache_rlock = threading.RLock()
+def _file_watcher_callback(name, info, event):
+    with _vcs_cache_rlock:
+        _vcs_cache[name] = _run_vcs_commands(name)
+
+_file_watcher = FileWatcher(_file_watcher_callback)
+
+def _run_vcs_commands(path):
+    """Run some VCS commands on a file and return their output.
+
+    The function is used to gather up version control system information so that
+    it can be stored in the hdf5 files of shots. This is for convenience and
+    compliments the full copy of the file already included in the shot file.
+
+    Whether hg and git commands are run is controlled by the `save_hg_info`
+    and `save_git_info` options in the `[labscript]` section of the labconfig.
+
+    Args:
+        path (str): The path with file name and extension of the file on which
+            the commands will be run. The working directory will be set to the
+            directory containing the specified file.
+
+    Returns:
+        results (list of (tuple, str, str)): A list of tuples, each
+            containing information related to one vcs command of the form
+            (command, info, err). The first entry in that tuple is itself a
+            tuple of strings which was passed to subprocess.Popen() in order to
+            run the command. Then info is a string that contains the text
+            printed to stdout by that command, and err contains the text printed
+            to stderr by the command.
+    """
+    # Gather together a list of commands to run.
+    module_directory, module_filename = os.path.split(path)
+    vcs_commands = []
+    if compiler.save_hg_info:
+        hg_commands = [
+            ['log', '--limit', '1'],
+            ['status'],
+            ['diff'],
+        ]
+        for command in hg_commands:
+            command = tuple(['hg'] + command + [module_filename])
+            vcs_commands.append((command, module_directory))
+    if compiler.save_git_info:
+        git_commands = [
+            ['branch', '--show-current'],
+            ['describe', '--tags', '--always', 'HEAD'],
+            ['rev-parse', 'HEAD'],
+            ['diff', 'HEAD', module_filename],
+        ]
+        for command in git_commands:
+            command = tuple(['git'] + command)
+            vcs_commands.append((command, module_directory))
+
+    # Now go through and start running the commands.
+    process_list = []
+    for command, module_directory in vcs_commands:
+        process = subprocess.Popen(
+            command,
+            cwd=module_directory,
+            stdout=subprocess.PIPE,
+            stderr=subprocess.PIPE,
+            startupinfo=startupinfo,
+        )
+        process_list.append((command, process))
+
+    # Gather up results from the commands issued.
+    results = []
+    for command, process in process_list:
+        info, err = process.communicate()
+        info = info.decode('utf-8')
+        err = err.decode('utf-8')
+        results.append((command, info, err))
+    return results
+
 def save_labscripts(hdf5_file):
     if compiler.labscript_file is not None:
         script_text = open(compiler.labscript_file).read()
@@ -2198,18 +2286,19 @@ def save_labscripts(hdf5_file):
                         # Doesn't seem to want to double count files if you just import the contents of a file within a module
                         continue
                     hdf5_file.create_dataset(save_path, data=open(path).read())
-                    if compiler.save_hg_info:
-                        hg_commands = [['log', '--limit', '1'], ['status'], ['diff']]
-                        for command in hg_commands:
-                            process = subprocess.Popen(['hg'] + command + [os.path.split(path)[1]], cwd=os.path.split(path)[0],
-                                                       stdout=subprocess.PIPE, stderr=subprocess.PIPE, startupinfo=startupinfo)
-                            info, err = process.communicate()
-                            if info or err:
-                                hdf5_file[save_path].attrs['hg ' + str(command[0])] = info.decode('utf-8') + '\n' + err.decode('utf-8')
+                    with _vcs_cache_rlock:
+                        if path not in _vcs_cache:
+                            # Add file to watch list and create its entry in the cache.
+                            _file_watcher.add_file(path)
+                            _file_watcher_callback(path, None, None)
+                        # Save the cached vcs output to the file.
+                        for command, info, err in _vcs_cache[path]:
+                            attribute_str = command[0] + ' ' + command[1]
+                            hdf5_file[save_path].attrs[attribute_str] = (info + '\n' + err)
     except ImportError:
         pass
     except WindowsError if os.name == 'nt' else None:
-        sys.stderr.write('Warning: Cannot save Mercurial data for imported scripts. Check that the hg command can be run from the command line.\n')
+        sys.stderr.write('Warning: Cannot save version control data for imported scripts. Check that the hg and/or git command can be run from the command line.\n')
 
 
 def write_device_properties(hdf5_file):
@@ -2539,7 +2628,8 @@ def labscript_cleanup():
     compiler.wait_delay = 0
     compiler.time_markers = {}
     compiler._PrimaryBLACS = None
-    compiler.save_hg_info = True
+    compiler.save_hg_info = _SAVE_HG_INFO
+    compiler.save_git_info = _SAVE_GIT_INFO
     compiler.shot_properties = {}
 
 class compiler(object):
@@ -2559,7 +2649,8 @@ class compiler(object):
     wait_delay = 0
     time_markers = {}
     _PrimaryBLACS = None
-    save_hg_info = True
+    save_hg_info = _SAVE_HG_INFO
+    save_git_info = _SAVE_GIT_INFO
     shot_properties = {}
 
     # safety measure in case cleanup is called before init