_logger = logging.getLogger('arvados.ranges')
+# Log level below 'debug' !
+RANGES_SPAM = 9
+
class Range(object):
def __init__(self, locator, range_start, range_size, segment_offset=0):
self.locator = locator
self.range_size == other.range_size and
self.segment_offset == other.segment_offset)
-def first_block(data_locators, range_start, range_size):
+def first_block(data_locators, range_start):
block_start = 0L
# range_start/block_start is the inclusive lower bound
def __repr__(self):
return "LocatorAndRange(%r, %r, %r, %r)" % (self.locator, self.block_size, self.segment_offset, self.segment_size)
-def locators_and_ranges(data_locators, range_start, range_size):
+def locators_and_ranges(data_locators, range_start, range_size, limit=None):
"""Get blocks that are covered by a range.
Returns a list of LocatorAndRange objects.
:range_size:
size of range
+ :limit:
+ Maximum segments to return, default None (unlimited). Will truncate the
+ result if there are more segments needed to cover the range than the
+ limit.
+
"""
if range_size == 0:
return []
resp = []
range_end = range_start + range_size
- i = first_block(data_locators, range_start, range_size)
+ i = first_block(data_locators, range_start)
if i is None:
return []
# We should always start at the first segment due to the binary
# search.
- while i < len(data_locators):
+ while i < len(data_locators) and len(resp) != limit:
dl = data_locators[i]
block_start = dl.range_start
block_size = dl.range_size
block_end = block_start + block_size
- _logger.debug(dl.locator, "range_start", range_start, "block_start", block_start, "range_end", range_end, "block_end", block_end)
+ _logger.log(RANGES_SPAM,
+ "%s range_start %s block_start %s range_end %s block_end %s",
+ dl.locator, range_start, block_start, range_end, block_end)
if range_end <= block_start:
# range ends before this block starts, so don't look at any more locators
break
data_locators.append(Range(new_locator, new_range_start, new_range_size, new_segment_offset))
return
- i = first_block(data_locators, new_range_start, new_range_size)
+ i = first_block(data_locators, new_range_start)
if i is None:
return
dl = data_locators[i]
old_segment_start = dl.range_start
old_segment_end = old_segment_start + dl.range_size
- _logger.debug(dl, "range_start", new_range_start, "segment_start", old_segment_start, "range_end", new_range_end, "segment_end", old_segment_end)
+ _logger.log(RANGES_SPAM,
+ "%s range_start %s segment_start %s range_end %s segment_end %s",
+ dl, new_range_start, old_segment_start, new_range_end,
+ old_segment_end)
if new_range_end <= old_segment_start:
# range ends before this segment starts, so don't look at any more locators
break