From 81958f7958bd48c1ff1785fe1561a42b9a8cb172 Mon Sep 17 00:00:00 2001
From: Andrei Gherzan <andrei@gherzan.ro>
Date: Fri, 6 Mar 2020 16:55:09 +0000
Subject: [PATCH] bmaptool: Implement flag to interact with psplash progress

This flag is implemented as a best effort to avoid breaking the
writing functionality when psplash is not available. For example when
bmap is used during boot where psplash might or might not be available.

Signed-off-by: Andrei Gherzan <andrei@gherzan.ro>
---
 bmaptools/BmapCopy.py | 34 ++++++++++++++++++++++++++++++++++
 bmaptools/CLI.py      |  7 +++++++
 2 files changed, 41 insertions(+)

diff --git a/bmaptools/BmapCopy.py b/bmaptools/BmapCopy.py
index b0e251e..c6a2603 100644
--- a/bmaptools/BmapCopy.py
+++ b/bmaptools/BmapCopy.py
@@ -172,6 +172,7 @@ def __init__(self, image, dest, bmap=None, image_size=None):
         self._progress_file = None
         self._progress_format = None
         self.set_progress_indicator(None, None)
+        self._psplash_pipe = None
 
         self._f_image = image
         self._image_path = image.name
@@ -211,6 +212,28 @@ def __init__(self, image, dest, bmap=None, image_size=None):
 
         self._batch_blocks = self._batch_bytes // self.block_size
 
+    def set_psplash_pipe(self, path):
+        """
+        Set the psplash named pipe file path to be used when updating the
+        progress - best effort.
+
+        The 'path' argument is the named pipe used by the psplash process to get
+        progress bar commands. When the path argument doesn't exist or is not a
+        pipe, the function will ignore with a warning. This behavior is
+        considered as such because the progress is considered a decoration
+        functionality which might or might not be available even if requested.
+        When used as a boot service, the unavailability of the psplash service
+        (due to various reasons: no screen, racing issues etc.) should not
+        break the writting process. This is why this implementation is done as
+        a best effort.
+        """
+
+        if os.path.exists(pipe) and stat.S_ISFIFO(os.stat(pipe).st_mode):
+            self._psplash_pipe = pipe
+        else:
+            _log.warning("'%s' is not a pipe, so psplash progress will not be "
+                         "updated" % pipe)
+
     def set_progress_indicator(self, file_obj, format_string):
         """
         Setup the progress indicator which shows how much data has been copied
@@ -404,6 +427,17 @@ def _update_progress(self, blocks_written):
         self._progress_file.write(progress)
         self._progress_file.flush()
 
+        # Update psplash progress when configured. This is using a best effort
+        # strategy to not affect the writing process when psplash breaks, is
+        # not available early enough or screen is not available.
+        if self._psplash_pipe and self.mapped_cnt:
+            try:
+                mode = os.O_WRONLY | os.O_NONBLOCK
+                with os.fdopen(os.open(self._psplash_pipe, mode), 'w') as p_fo:
+                    p_fo.write("PROGRESS %d\n" % percent)
+            except:
+                pass
+
     def _get_block_ranges(self):
         """
         This is a helper generator that parses the bmap XML file and for each
diff --git a/bmaptools/CLI.py b/bmaptools/CLI.py
index 49a3d3f..4a39c04 100644
--- a/bmaptools/CLI.py
+++ b/bmaptools/CLI.py
@@ -482,6 +482,9 @@ def copy_command(args):
                  % (os.path.basename(args.image), dest_str,
                     os.path.basename(bmap_path)))
 
+    if args.psplash_pipe:
+        writer.set_psplash_pipe(args.psplash_pipe)
+
     try:
         try:
             writer.copy(False, not args.no_verify)
@@ -640,6 +643,10 @@ def parse_arguments():
     text = "do not verify the data checksum while writing"
     parser_copy.add_argument("--no-verify", action="store_true", help=text)
 
+    # The --psplash-pipe option
+    text = "write progress to a psplash pipe"
+    parser_copy.add_argument("--psplash-pipe", help=text)
+
     return parser.parse_args()