[file_utils] dirpacker: refactoring (class Bin)

file_utils/dirpacker.py

@@ -36,6 +36,29 @@ from collections import defaultdict
 import math
 
 
+class Bin:
+    """ Represents a bin (a volume) containing files and directories.
+    """
+    def __init__(self, bin_id, total_size, files):
+        """bin_id is the bin's identifier, total_size the sum of the sizes of
+        all the files it contains, and files is a dictionary with file names
+        as the keys and sizes as values.
+        """
+        self.id = bin_id
+        self.size = total_size
+        self.files = files
+
+    def print(self):
+        """Displays the contents of the bin.
+        """
+        print("\n### Bin #{} ###\n# List of files:".format(self.id))
+        for filename, size in sorted(self.files.items()):
+            print("{} # {:.2f} MiB".format(filename, size))
+        print("# This bin's size: {:.2f} MiB".format(self.size))
+        sizefree = options.maxbinsize - self.size
+        print("# Free space: {:.2f} MiB".format(sizefree))
+
+
 def du(basepath):
     """ Returns the size of the file of directory `basepath`, in MiB.
     """
@@ -51,10 +74,10 @@ def du(basepath):
 
 def create_bin(binnumber):
     """Creates a bin numbered `binnumber` from the global list of files and
-    sizes.
+    sizes, and returns it.
     """
-    print("\n### Bin #{} ###\n# List of files:".format(binnumber))
     binsize = 0
+    files = {}
     for size in reversed(sorted(sizes.keys())):
         newbinsize = binsize + size
         # Try the next, smaller file if we would exceed the bin's maximum size
@@ -62,8 +85,7 @@ def create_bin(binnumber):
         if newbinsize > options.maxbinsize:
             continue
 
-        filename = sizes[size].pop()
-        print("{} # {:.2f} MiB".format(filename, size))
+        files[sizes[size].pop()] = size
         # Delete the size from the dictionary if its last file name was just
         # popped:
         if not len(sizes[size]):
@@ -71,22 +93,23 @@ def create_bin(binnumber):
 
         binsize = newbinsize
 
-    print("# This bin's size: {:.2f} MiB".format(binsize))
-    sizefree = options.maxbinsize - binsize
-    print("# Free space: {:.2f} MiB".format(sizefree))
+    return Bin(binnumber, binsize, files)
 
 
 ### Parse command-line arguments ###
 
 arg_parser = argparse.ArgumentParser(
     description="Packs files and directories into fixed-size volumes",
-    epilog="For more information about this program, see the README file \
-provided with the distribution.")
+    epilog="For more information about this program, see the README file"
+    "provided with the distribution.")
 arg_parser.add_argument("-s", "--size", action="store", dest="maxbinsize",
                         type=float, default=703,
                         help="maximal size of each volume (bin), in MiB; the "
-                        +"default is 703 MiB, i.e. the size of a 80-minute "
-                        +"CD-ROM")
+                        "default is 703 MiB, i.e. the size of a 80-minute "
+                        "CD-ROM")
+arg_parser.add_argument("-a", "--action", action="store", default="list",
+                        help='action to be taken; can be "list" (default)'
+                        ' or "move" (move input to per-volume directories)')
 arg_parser.add_argument("filenames", metavar="file", nargs="+",
                         help="files or directories to pack")
 options = arg_parser.parse_args()
@@ -115,14 +138,16 @@ print("# Total size of the input files: {:.2f} MiB".format(totalsize))
 minbins = math.ceil(totalsize / options.maxbinsize)
 print("# Minimal (optimal) number of bins required: ", minbins)
 sizefree = minbins * options.maxbinsize - totalsize
-print("# Total unused space with {} bins: {:.2f} MiB".format(minbins, sizefree))
+print("# Theoretical unused space with {} bins: {:.2f} MiB"
+      .format(minbins, sizefree))
 
 
 ### Assemble the bins ###
 
+bins = []
 binnumber = 1
 while len(sizes):
-    create_bin(binnumber)
+    bins.append(create_bin(binnumber))
     binnumber += 1
 binscreated = binnumber - 1
 
@@ -130,8 +155,26 @@ binscreated = binnumber - 1
 ### Final statistics ###
 
 sizefree = binscreated * options.maxbinsize - totalsize
-print("\n# Total unused space over the {} bins created: {:.2f} MiB"
-      .format(binscreated, sizefree))
+print("""\
+# {} bins created.
+# Actual unused space over the {} bins created: {:.2f} MiB"""
+      .format(binscreated, binscreated, sizefree))
+
+
+### Execute the requested action ###
+
+if options.action == "list":
+    for b in bins:
+        b.print()
+elif options.action == "move":
+    print('Action "move" is not implemented yet.')
+    exit(0)
+else:
+    print('ERROR! Action "{}" is unknown.'.format(options.action))
+    exit(1)
+
+
+### Wrapping-up ###
 
 if (ignored_files):
     print("\n# WARNING! There were ignored files, see at the top of this log.")