mkm3u: Maintain a cache of durations because they take ages to look up.

[epls] / mkm3u

diff --git a/mkm3u b/mkm3u
index 5464ac7ec37d76e700a40e01a61d2204d05e2358..9053c5fe1879e61ecbf745e4b8fd5b22f01e4d94 100755 (executable)
--- a/mkm3u
+++ b/mkm3u
@@ -2,9 +2,11 @@
 ### -*- mode: python; coding: utf-8 -*-
 
 from contextlib import contextmanager
+import errno as E
 import optparse as OP
 import os as OS
 import re as RX
+import sqlite3 as SQL
 import subprocess as SP
 import sys as SYS
 
@@ -97,6 +99,34 @@ class FileLocation (BaseLocation):
 
 LOC = DummyLocation()
 
+ROOT = "/mnt/dvd/archive/"
+DB = None
+
+def init_db(fn):
+  global DB
+  DB = SQL.connect(fn)
+  DB.cursor().execute("PRAGMA journal_mode = WAL")
+
+def setup_db(fn):
+  try: OS.unlink(fn)
+  except OSError as e:
+    if e.errno == E.ENOENT: pass
+    else: raise
+  init_db(fn)
+  DB.cursor().execute("""
+          CREATE TABLE duration
+                  (path TEXT NOT NULL,
+                   title INTEGER NOT NULL,
+                   start_chapter INTEGER NOT NULL,
+                   end_chapter INTEGER NOT NULL,
+                   inode INTEGER NOT NULL,
+                   device INTEGER NOT NULL,
+                   size INTEGER NOT NULL,
+                   mtime REAL NOT NULL,
+                   duration REAL NOT NULL,
+                   PRIMARY KEY (path, title, start_chapter, end_chapter));
+  """)
+
 class Source (object):
   PREFIX = ""
   TITLEP = CHAPTERP = False
@@ -128,7 +158,48 @@ class Source (object):
     else:
       suffix = "#%d:%d-%d:%d" % (title, start_chapter, title, end_chapter - 1)
 
-    duration = me._duration(title, start_chapter, end_chapter)
+    duration = None
+    if DB is None:
+      duration = me._duration(title, start_chapter, end_chapter)
+    else:
+      st = OS.stat(OS.path.join(ROOT, me.fn))
+      duration = None
+      c = DB.cursor()
+      c.execute("""
+              SELECT device, inode, size, mtime,  duration FROM duration
+              WHERE path = ? AND title = ? AND
+                    start_chapter = ? AND end_chapter = ?
+      """, [me.fn, title, start_chapter is None and -1 or start_chapter,
+            end_chapter is None and -1 or end_chapter])
+      row = c.fetchone()
+      foundp = False
+      if row is None:
+        duration = me._duration(title, start_chapter, end_chapter)
+        c.execute("""
+                INSERT OR REPLACE INTO duration
+                        (path, title, start_chapter, end_chapter,
+                         device, inode, size, mtime,  duration)
+                VALUES (?, ?, ?, ?,  ?, ?, ?, ?,  ?)
+        """, [me.fn, title, start_chapter is None and -1 or start_chapter,
+              end_chapter is None and -1 or end_chapter,
+              st.st_dev, st.st_ino, st.st_size, st.st_mtime,
+              duration])
+      else:
+        dev, ino, sz, mt,  d = row
+        if (dev, ino, sz, mt) == \
+           (st.st_dev, st.st_ino, st.st_size, st.st_mtime):
+          duration = d
+        else:
+          duration = me._duration(title, start_chapter, end_chapter)
+          c.execute("""
+                  UPDATE duration
+                  SET device = ?, inode = ?, size = ?, mtime = ?, duration = ?
+                  WHERE path = ? AND title = ? AND
+                        start_chapter = ? AND end_chapter = ?
+        """, [st.st_dev, st.st_dev, st.st_size, st.st_mtime,  duration,
+              me.fn, title, start_chapter is None and -1 or start_chapter,
+              end_chapter is None and -1 or end_chapter])
+      DB.commit()
 
     if end_chapter is not None:
       keys = [(title, ch) for ch in range(start_chapter, end_chapter)]
@@ -737,29 +808,41 @@ class EpisodeListParser (object):
                             (d.fn, d.neps, d.nuses))
     return me._pl
 
-ROOT = "/mnt/dvd/archive/"
-
 op = OP.OptionParser \
-  (usage = "%prog [-c] [-s SERIES] EPLS",
+  (usage = "%prog [-c] [-d CACHE] [-s SERIES] EPLS\n"
+           "%prog -i -d CACHE",
    description = "Generate M3U playlists from an episode list.")
 op.add_option("-c", "--chapters",
               dest = "chaptersp", action = "store_true", default = False,
               help = "Output individual chapter names")
+op.add_option("-i", "--init-db",
+              dest = "initdbp", action = "store_true", default = False,
+              help = "Initialize the database")
+op.add_option("-d", "--database",
+              dest = "database", type = "str", default = None,
+              help = "Set filename for cache database")
 op.add_option("-s", "--series",
               dest = "series", type = "str", default = None,
               help = "Output only the listed SERIES (comma-separated)")
-opts, argv = op.parse_args()
-if len(argv) != 1: op.print_usage(file = SYS.stderr); SYS.exit(2)
-if opts.series is None:
-  series_wanted = None
-else:
-  series_wanted = set()
-  for name in opts.series.split(","): series_wanted.add(name)
 try:
-  ep = EpisodeListParser(series_wanted, opts.chaptersp)
-  ep.parse_file(argv[0])
-  pl = ep.done()
-  pl.write(SYS.stdout)
+  opts, argv = op.parse_args()
+  if opts.initdbp:
+    if opts.chaptersp or opts.series is not None or \
+       opts.database is None or len(argv):
+      op.print_usage(file = SYS.stderr); SYS.exit(2)
+    setup_db(opts.database)
+  else:
+    if len(argv) != 1: op.print_usage(file = SYS.stderr); SYS.exit(2)
+    if opts.database is not None: init_db(opts.database)
+    if opts.series is None:
+      series_wanted = None
+    else:
+      series_wanted = set()
+      for name in opts.series.split(","): series_wanted.add(name)
+    ep = EpisodeListParser(series_wanted, opts.chaptersp)
+    ep.parse_file(argv[0])
+    pl = ep.done()
+    pl.write(SYS.stdout)
 except (ExpectedError, IOError, OSError) as e:
   LOC.report(e)
   SYS.exit(2)