def __init__(self, input_files, do_sort, mem_sort_limit):
self.inputs = []
part = PART_SUFFIX % this_partition()
for input in input_files:
if input.startswith("dir://"):
try:
self.inputs += parse_dir(input,
part_id = this_partition())
except:
data_err("Couldn't resolve address %s"\
% input, input)
else:
self.inputs.append(input)
self.line_count = 0
if do_sort:
total_size = 0
for input in self.inputs:
sze, fd = connect_input(input)
total_size += sze
msg("Reduce[%d] input is %.2fMB" %\
(this_partition(), total_size / 1024.0**2))
if total_size > mem_sort_limit:
self.iterator = self.download_and_sort()
else:
msg("Sorting in memory")
m = list(self.multi_file_iterator(self.inputs, False))
m.sort(num_cmp)
self.iterator = self.list_iterator(m)
else:
self.iterator = self.multi_file_iterator(self.inputs)
def re_reader(item_re_str, fd, content_len, fname, output_tail = False, read_buffer_size=8192):
item_re = re.compile(item_re_str)
buf = ""
tot = 0
while True:
if content_len:
r = fd.read(min(read_buffer_size, content_len - tot))
else:
r = fd.read(read_buffer_size)
tot += len(r)
buf += r
m = item_re.match(buf)
while m:
yield m.groups()
buf = buf[m.end():]
m = item_re.match(buf)
if not len(r) or tot >= content_len:
if content_len != None and tot < content_len:
data_err("Truncated input (%s). "\
"Expected %d bytes, got %d" %\
(fname, content_len, tot), fname)
if len(buf):
if output_tail:
yield [buf]
else:
msg("Couldn't match the last %d "\
"bytes in %s. Some bytes may be "\
"missing from input." %\
(len(buf), fname))
break
def get(key, job = None):
try:
job = job or this_name()
return load_oob("http://" + this_master(), job, key)
except comm.CommException, x:
data_err("OOB key (%s) not found at %s: HTTP status '%s'" %\
(key, url, x.http_code), key)
def open_local(input, fname):
try:
f = file(fname)
sze = os.stat(fname).st_size
return sze, f
except:
data_err("Can't access a local input file (%s): %s"\
% (input, fname), input)
def open_remote(input, ext_host, ext_file, is_chunk):
try:
# We can't open a new HTTP connection for each intermediate
# result -- this would result to M * R TCP connections where
# M is the number of maps and R the number of reduces. Instead,
# we pool connections and reuse them whenever possible. HTTP
# 1.1 defaults to keep-alive anyway.
if ext_host in http_pool:
http = http_pool[ext_host]
if http._HTTPConnection__response:
http._HTTPConnection__response.read()
else:
http = httplib.HTTPConnection(ext_host)
http_pool[ext_host] = http
if is_chunk:
pos = this_partition() * 8
rge = "bytes=%d-%d" % (pos, pos + 15)
#msg("Reading offsets at %s" % rge)
http.request("GET", ext_file, None, {"Range": rge})
fd = http.getresponse()
if fd.status != 206:
raise "HTTP error %d" % fd.status
start, end = struct.unpack("QQ", fd.read())
if start == end:
return 0, cStringIO.StringIO()
else:
rge = "bytes=%d-%d" % (start, end - 1)
#msg("Reading data at %s" % rge)
http.request("GET", ext_file, None, {"Range": rge})
fd = http.getresponse()
if fd.status != 206:
raise "HTTP error %d" % fd.status
else:
http.request("GET", ext_file, "")
fd = http.getresponse()
if fd.status != 200:
raise "HTTP error %d" % fd.status
sze = fd.getheader("content-length")
if sze:
sze = int(sze)
return sze, fd
except httplib.BadStatusLine:
# BadStatusLine is caused by a closed connection. Re-open a new
# connection by deleting this connection from the pool and
# calling this function again. Note that this might result in
# endless recursion if something went seriously wrong.
http.close()
del http_pool[ext_host]
return open_remote(input, ext_host, ext_file, is_chunk)
except:
data_err("Can't access an external input file (%s/%s): %s"\
% (ext_host, ext_file, input), input)
def get(key, job = None):
if job:
c = urllib.urlopen(OOB_URL % (job, key))
else:
c = urllib.urlopen(OOB_URL % (job_name, key))
if "status" in c.headers and not c.headers["status"].startswith("200"):
data_err("OOB <%s> key (%s) not found" % (c.headers["status"], key), key)
else:
r = c.read()
c.close()
return r
def open_local(input, fname, is_chunk):
try:
f = file(fname)
if is_chunk:
f.seek(this_partition() * 8)
start, end = struct.unpack("QQ", f.read(16))
sze = end - start
f.seek(start)
else:
sze = os.stat(fname).st_size
return sze, f
except:
data_err("Can't access a local input file: %s"\
% input, input)
def read_netstr(idx, data, tot):
ldata = len(data)
i = 0
lenstr = ""
if ldata - idx < 11:
data = data[idx:] + fd.read(8192)
ldata = len(data)
idx = 0
i = data.find(" ", idx, idx + 11)
if i == -1:
err("Corrupted input (%s). Could not "\
"parse a value length at %d bytes."\
% (fname, tot))
else:
lenstr = data[idx:i + 1]
idx = i + 1
if ldata < i + 1:
data_err("Truncated input (%s). "\
"Expected %d bytes, got %d" %\
(fname, content_len, tot), fname)
try:
llen = int(lenstr)
except ValueError:
err("Corrupted input (%s). Could not "\
"parse a value length at %d bytes."\
% (fname, tot))
tot += len(lenstr)
if ldata - idx < llen + 1:
data = data[idx:] + fd.read(llen + 8193)
ldata = len(data)
idx = 0
msg = data[idx:idx + llen]
if idx + llen + 1 > ldata:
data_err("Truncated input (%s). "\
"Expected a value of %d bytes "\
"(offset %u bytes)" %\
(fname, llen + 1, tot), fname)
tot += llen + 1
idx += llen + 1
return idx, data, tot, msg
def merge_chunks(partitions):
mapout = CHUNK_OUTPUT % (job_name, this_partition())
f = file(mapout + ".partial", "w")
offset = (len(partitions) + 1) * 8
for p in partitions:
f.write(struct.pack("Q", offset))
offset += os.stat(p.fname).st_size
f.write(struct.pack("Q", offset))
f.close()
if subprocess.call("cat %s >> %s.partial" %
(" ".join([p.fname for p in partitions]),
mapout), shell = True):
data_err("Couldn't create a chunk", mapout)
os.rename(mapout + ".partial", mapout)
for p in partitions:
os.remove(p.fname)
def ensure_file(fname, data = None, timeout = 60, mode = 500):
while timeout > 0:
if os.path.exists(fname):
return False
try:
fd = os.open(fname + ".partial",
os.O_CREAT | os.O_EXCL | os.O_WRONLY, mode)
if callable(data):
data = data()
os.write(fd, data)
os.close(fd)
os.rename(fname + ".partial", fname)
return True
except OSError, x:
if x.errno == errno.EEXIST:
time.sleep(1)
timeout -= 1
else:
data_err("Writing external file %s failed"\
% fname, fname)
return
outstream.write(buf)
except Exception, x:
# output file is inconsistent state
# we must crash the job
err("Updating file %s failed: %s" %\
(outfile, x))
except IOError, x:
# Python doc guides us to check both the
# EWOULDBLOCK (11) and EACCES (13) errors
if x.errno == 11 or x.errno == 13:
time.sleep(1)
timeout -= 1
else:
raise
data_err("Timeout when updating file %s" % outfile, outfile)
def ensure_file(fname, data = None, timeout = 60, mode = 500):
while timeout > 0:
if os.path.exists(fname):
return False
try:
fd = os.open(fname + ".partial",
os.O_CREAT | os.O_EXCL | os.O_WRONLY, mode)
if type(data) == str:
os.write(fd, data)
else:
os.write(fd, data())
os.close(fd)
os.rename(fname + ".partial", fname)
def open_remote(input, ext_host, ext_file):
try:
return comm.open_remote("http://%s%s" % (ext_host, ext_file))
except Exception, x:
data_err("Can't access an external input file (%s%s): %s"\
% (ext_host, ext_file, x), x)
