diff options
Diffstat (limited to 'pyeclib/ec_iface.py')
| -rw-r--r-- | pyeclib/ec_iface.py | 60 |
1 files changed, 33 insertions, 27 deletions
diff --git a/pyeclib/ec_iface.py b/pyeclib/ec_iface.py index 4cc9eb6..27c92f7 100644 --- a/pyeclib/ec_iface.py +++ b/pyeclib/ec_iface.py @@ -123,18 +123,18 @@ class ECDriver(object): if key == "k": try: self.k = positive_int_value(value) - except ValueError as e: + except ValueError: raise ECDriverError( "Invalid number of data fragments (k)") elif key == "m": try: self.m = positive_int_value(value) - except ValueError as e: + except ValueError: raise ECDriverError( "Invalid number of data fragments (m)") elif key == "ec_type": if value in ["flat_xor_hd_3", "flat_xor_hd_4"]: - value = "flat_xor_hd" + value = "flat_xor_hd" if PyECLib_EC_Types.has_enum(value): self.ec_type = \ PyECLib_EC_Types.get_by_name(value) @@ -198,7 +198,8 @@ class ECDriver(object): """ return self.ec_lib_reference.encode(data_bytes) - def decode(self, fragment_payloads, ranges=None, force_metadata_checks=False): + def decode(self, fragment_payloads, ranges=None, + force_metadata_checks=False): """ Decode a set of fragments into a buffer that represents the original buffer passed into encode(). @@ -213,7 +214,7 @@ class ECDriver(object): :raises: ECDriverError if there is an error during decoding """ return self.ec_lib_reference.decode(fragment_payloads, ranges, - force_metadata_checks) + force_metadata_checks) def reconstruct(self, available_fragment_payloads, missing_fragment_indexes): @@ -236,7 +237,8 @@ class ECDriver(object): return self.ec_lib_reference.reconstruct( available_fragment_payloads, missing_fragment_indexes) - def fragments_needed(self, reconstruction_indexes, exclude_indexes = []): + def fragments_needed(self, reconstruction_indexes, + exclude_indexes=[]): """ Determine which fragments are needed to reconstruct some subset of missing fragments. @@ -247,18 +249,19 @@ class ECDriver(object): :param exclude_indexes: a list of integers representing the indexes of the fragments to be excluded from the reconstruction - equations. - :returns: a list containing fragment indexes that can be used to + equations. + :returns: a list containing fragment indexes that can be used to reconstruct the missing fragments. :raises: ECDriverError if there is an error during decoding or there are not sufficient fragments to decode """ - return self.ec_lib_reference.fragments_needed(reconstruction_indexes, exclude_indexes) + return self.ec_lib_reference.fragments_needed(reconstruction_indexes, + exclude_indexes) def min_parity_fragments_needed(self): return self.ec_lib_reference.min_parity_fragments_needed() - def get_metadata(self, fragment, formatted = 0): + def get_metadata(self, fragment, formatted=0): """ Get opaque metadata for a fragment. The metadata is opaque to the client, but meaningful to the underlying library. It is used to verify @@ -321,37 +324,38 @@ class ECDriver(object): Get segmentation info for a byterange request, given a data length and segment size. - This will return a map-of-maps that represents a recipe describing + This will return a map-of-maps that represents a recipe describing the segments and ranges within each segment needed to satisfy a range request. Assume a range request is given for an object with segment size 3K and a 1 MB file: - Ranges = (0, 1), (1, 12), (10, 1000), (0, segment_size-1), + Ranges = (0, 1), (1, 12), (10, 1000), (0, segment_size-1), (1, segment_size+1), (segment_size-1, 2*segment_size) This will return a map keyed on the ranges, where there is a recipe given for each range: { - (0, 1): {0: (0, 1)}, - (10, 1000): {0: (10, 1000)}, - (1, 12): {0: (1, 12)}, - (0, 3071): {0: (0, 3071)}, - (3071, 6144): {0: (3071, 3071), 1: (0, 3071), 2: (0, 0)}, + (0, 1): {0: (0, 1)}, + (10, 1000): {0: (10, 1000)}, + (1, 12): {0: (1, 12)}, + (0, 3071): {0: (0, 3071)}, + (3071, 6144): {0: (3071, 3071), 1: (0, 3071), 2: (0, 0)}, (1, 3073): {0: (1, 3071), 1: (0,0)} } """ - segment_info = self.ec_lib_reference.get_segment_info(data_len, segment_size) + segment_info = self.ec_lib_reference.get_segment_info( + data_len, segment_size) segment_size = segment_info['segment_size'] - last_segment_size = segment_info['last_segment_size'] - fragment_size = segment_info['fragment_size'] - last_fragment_size = segment_info['last_fragment_size'] - num_segments = segment_info['num_segments'] + # last_segment_size = segment_info['last_segment_size'] + # fragment_size = segment_info['fragment_size'] + # last_fragment_size = segment_info['last_fragment_size'] + # num_segments = segment_info['num_segments'] sorted_ranges = ranges[:] sorted_ranges.sort(key=lambda obj: obj[0]) @@ -368,15 +372,17 @@ class ECDriver(object): if begin_segment == end_segment: begin_relative_off = begin_off % segment_size end_relative_off = end_off % segment_size - segment_map[begin_segment] = (begin_relative_off, end_relative_off) + segment_map[begin_segment] = (begin_relative_off, + end_relative_off) else: begin_relative_off = begin_off % segment_size end_relative_off = end_off % segment_size - segment_map[begin_segment] = (begin_relative_off, segment_size-1) + segment_map[begin_segment] = (begin_relative_off, + segment_size - 1) - for middle_segment in range(begin_segment+1, end_segment): - segment_map[middle_segment] = (0, segment_size-1) + for middle_segment in range(begin_segment + 1, end_segment): + segment_map[middle_segment] = (0, segment_size - 1) segment_map[end_segment] = (0, end_relative_off) @@ -400,7 +406,7 @@ class ECDriverError(Exception): return self.error_str -## More specific exceptions, mapped to liberasurecode error codes +# More specific exceptions, mapped to liberasurecode error codes # Specified EC backend is not supported by PyECLib/liberasurecode class ECBackendNotSupported(ECDriverError): |