[Buildroot] [PATCH 09/19] support: add parser in python for packages-file-list files

[Yann E. MORIN]

Currently, each script that want to parse the package-files lists has to
invent its own parsing. So far, this was acceptable, as the format of
those files was relatively easy (line-based records, comma-separated
fields).

However, that format is not very resilient against weird filenames (e.g.
filenames with commas in the, or even with \n chars in them.

Furthermore, that format is not easily extensible.

So, introduce a parser, in python, that abstracts the format of these
files, and returns a dictionaries. Using dictionaries makes it easy for
callers to just ignore the fields they are not interested in, or even
are not aware of. Consequently, it will make it easy for us to introduce
new fields in the future.

Convert the two existing python scripts that parse those files.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998 at free.fr>

---
Note: a shell-script also parses those files, it will be handled in a
subsequent change.
---
 support/scripts/brpkgutil.py     | 16 ++++++++++++++++
 support/scripts/check-uniq-files |  7 +++----
 support/scripts/size-stats       | 14 +++++++-------
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/support/scripts/brpkgutil.py b/support/scripts/brpkgutil.py
index e70d525353..d15b18845b 100644
--- a/support/scripts/brpkgutil.py
+++ b/support/scripts/brpkgutil.py
@@ -5,6 +5,22 @@ import sys
 import subprocess
 
 
+# Iterate on all records of the packages-file-list file passed as filename
+# Returns an iterator over a list of dictionaries. Each dictionary contains
+# these keys (others maybe added in the future):
+# 'file': the path of the file,
+# 'pkg':  the last package that installed that file
+def parse_pkg_file_list(path):
+    with open(path, 'rb') as f:
+        for rec in f.readlines():
+            l = rec.split(',0')
+            d = {
+                  'file': l[0],
+                  'pkg':  l[1],
+                }
+            yield d
+
+
 # Execute the "make <pkg>-show-version" command to get the version of a given
 # list of packages, and return the version formatted as a Python dictionary.
 def get_version(pkgs):
diff --git a/support/scripts/check-uniq-files b/support/scripts/check-uniq-files
index e95a134168..7020462981 100755
--- a/support/scripts/check-uniq-files
+++ b/support/scripts/check-uniq-files
@@ -3,6 +3,7 @@
 import sys
 import argparse
 from collections import defaultdict
+from brpkgutil import parse_pkg_file_list as parse_pkg_file_list
 
 warn = 'Warning: {0} file "{1}" is touched by more than one package: {2}\n'
 
@@ -35,10 +36,8 @@ def main():
         return False
 
     file_to_pkg = defaultdict(set)
-    with open(args.packages_file_list[0], 'rb') as pkg_file_list:
-        for line in pkg_file_list.readlines():
-            pkg, _, file = line.rstrip(b'\n').partition(b',')
-            file_to_pkg[file].add(pkg)
+    for record in parse_pkg_file_list(args.packages_file_list[0]):
+        file_to_pkg[record['file']].add(record['pkg'])
 
     for file in file_to_pkg:
         if len(file_to_pkg[file]) > 1:
diff --git a/support/scripts/size-stats b/support/scripts/size-stats
index deea92e278..48cd834ab4 100755
--- a/support/scripts/size-stats
+++ b/support/scripts/size-stats
@@ -22,6 +22,7 @@ import os.path
 import argparse
 import csv
 import collections
+from brpkgutil import parse_pkg_file_list as parse_pkg_file_list
 
 try:
     import matplotlib
@@ -66,13 +67,12 @@ def add_file(filesdict, relpath, abspath, pkg):
 #
 def build_package_dict(builddir):
     filesdict = {}
-    with open(os.path.join(builddir, "build", "packages-file-list.txt")) as filelistf:
-        for l in filelistf.readlines():
-            pkg, fpath = l.split(",", 1)
-            # remove the initial './' in each file path
-            fpath = fpath.strip()[2:]
-            fullpath = os.path.join(builddir, "target", fpath)
-            add_file(filesdict, fpath, fullpath, pkg)
+    fname = os.path.join(builddir, "build", "packages-file-list.txt")
+    for record in parse_pkg_file_list(fname):
+        # remove the initial './' in each file path
+        fpath = record['file'].strip()[2:]
+        fullpath = os.path.join(builddir, "target", fpath)
+        add_file(filesdict, fpath, fullpath, record['pkg'])
     return filesdict
 
 
-- 
2.14.1