Chose "best" output and jobs

3 files changed, 56 insertions, 14 deletions

diff --git a/brutha/__main__.py b/brutha/__main__.py
index c69e92c..14ea60e 100644
--- a/brutha/__main__.py
+++ b/brutha/__main__.py
@@ -5,11 +5,14 @@ import sys
 from StringIO import StringIO
 
 from brutha.tree import Tree
-from brutha.util import uprint
+from brutha.util import uprint, detect_cores, default_output
 from brutha.output import PRINTERS, EXECUTORS
 
 
 def main():
+    cores = detect_cores()
+    output = default_output(cores)
+
     parser = argparse.ArgumentParser(
         description='Sync FLAC music files to Ogg Vorbis (or keep lossy as-is).')
     parser.add_argument('-q', '--quality', default=8, type=int,
@@ -18,8 +21,8 @@ def main():
                         help='Compute ReplayGain if missing')
     parser.add_argument('-d', '--delete', action='store_true',
                         help='Delete extraneous files in destination')
-    parser.add_argument('-o', '--output', default='sh', choices=PRINTERS.keys(),
-                        help='Command list type, default sh')
+    parser.add_argument('-o', '--output', default=output, choices=PRINTERS.keys(),
+                        help='Command list type, default %s' % output)
     parser.add_argument('-R', '--maxrate', type=int,
                         help='Maximum sample rate allowed (e.g. 44100)', metavar='RATE')
     parser.add_argument('-B', '--maxbits', type=int,
@@ -28,6 +31,8 @@ def main():
                         help='Show started commands')
     parser.add_argument('-x', '--execute', action='store_true',
                         help='Execute the script instead of printing it')
+    parser.add_argument('-j', '--jobs', type=int, default=cores,
+                        help='Number of concurrent jobs, default %s' % cores)
     parser.add_argument('src', help='Source directory', metavar='SOURCE')
     parser.add_argument('dest', help='Destination directory', metavar='DESTINATION')
     args = parser.parse_args()
@@ -41,11 +46,13 @@ def main():
     else:
         p = uprint(sys.stdout)
     outf = PRINTERS[args.output]
-    outf(p, tree.commands(), args.echo)
+    outf(p, tree.commands(), args.echo, args.jobs)
 
     if args.execute:
+        jobs = args.jobs if args.output in ('parallel', 'make') else 1
+        print >>sys.stderr, 'Synchronizing %s to %s, using %s concurrent jobs.' % (args.src, args.dest, jobs)
         exef = EXECUTORS[args.output]
-        sys.exit(exef(s))
+        sys.exit(exef(s, args.jobs))
 
 
 if __name__ == '__main__':
diff --git a/brutha/output.py b/brutha/output.py
index 02fe014..9368bba 100644
--- a/brutha/output.py
+++ b/brutha/output.py
@@ -3,7 +3,7 @@ from __future__ import division
 
 import subprocess
 
-from brutha.util import find_executable
+from brutha.util import require_executable
 
 
 def pbar(cur, total, color=True):
@@ -26,8 +26,8 @@ def pbar(cur, total, color=True):
 # PRINTERS
 
 
-def sh(p, commands, echo=False):
-    p('#!%s' % find_executable('sh', ['bash', 'zsh', 'dash', 'sh']))
+def sh(p, commands, echo=False, jobs=None):
+    p('#!%s' % require_executable('sh', ['bash', 'zsh', 'dash', 'sh']))
     p('set -eu')
     if echo:
         p('set -x')
@@ -40,13 +40,15 @@ def sh(p, commands, echo=False):
         p()
 
 
-def parallel(p, commands, echo=False):
-    p('#!%s --shebang%s --' % (find_executable('parallel'), (' --verbose' if echo else '')))
+def parallel(p, commands, echo=False, jobs=None):
+    verbose = ' --verbose' if echo else ''
+    jobs = ' --jobs %s' % jobs if jobs else ''
+    p('#!%s --shebang%s%s --' % (require_executable('parallel'), jobs, verbose))
     for i, subcommands in enumerate(commands):
         p(" && ".join(subcommands + [pbar(i+1, len(commands))]))
 
 
-def make(p, commands, echo=False):
+def make(p, commands, echo=False, jobs=None):
     prefix = '' if echo else '@'
     targets = ' '.join('d%s' % i for i in xrange(0, len(commands)))
     p('.PHONY: all %s' % targets)
@@ -65,7 +67,7 @@ PRINTERS = {'sh': sh, 'parallel': parallel, 'make': make}
 # EXECUTORS
 
 
-def shebang(stream):
+def shebang(stream, jobs=None):
     """
     Extracts the shebang (#!) line and runs it, with the script provided as stdin.
     This is known to work at least with bash and GNU parallel.
@@ -79,8 +81,13 @@ def shebang(stream):
     return p.returncode
 
 
-def emake(stream):
-    p = subprocess.Popen([find_executable('make', ['gmake', 'make']), '-f', '-'], shell=False, stdin=subprocess.PIPE)
+def emake(stream, jobs=None):
+    if jobs:
+        addon = ['-j', str(jobs)]
+    else:
+        addon = []
+    p = subprocess.Popen([require_executable('make', ['gmake', 'make']), '-f', '-'] + addon,
+                         shell=False, stdin=subprocess.PIPE)
     p.communicate(stream.getvalue())
     return p.returncode
 
diff --git a/brutha/util.py b/brutha/util.py
index ded3d90..723a374 100644
--- a/brutha/util.py
+++ b/brutha/util.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 
 import os
+import re
 
 
 def escape(x):
@@ -35,4 +36,31 @@ def find_executable(name, names=None):
                 fpath = os.path.join(path, name) + ext
                 if os.path.exists(fpath) and os.access(fpath, os.X_OK):
                     return fpath
+
+
+def require_executable(name, names=None):
+    e = find_executable(name, names)
+    if e:
+        return e
     raise Exception('Could not find executable: %s' % name)
+
+
+def detect_cores():
+    try:
+        import numpy.distutils.cpuinfo
+        return numpy.distutils.cpuinfo.cpuinfo()._getNCPUs()
+    except ImportError:
+        try:
+            with open('/proc/cpuinfo') as f:
+                return len(re.findall('^processor\s+:\s+(\d+)$', f.read(), re.MULTILINE))
+        except IOError:
+            pass
+
+
+def default_output(cores=None):
+    if cores and cores > 1:
+        if find_executable('make', ['gmake', 'make']):
+            return 'make'
+        if find_executable('parallel'):
+            return 'parallel'
+    return 'sh'