def generate_shelf(klass, file, items):
"""(File, [(str, str)])
This returns a generator that writes a new Shelf into file,
iterating once through the given items.
The use of an iterator makes it possible to build a new Shelf
incrementally.
"""
file.seek_end()
if not file.tell() == 0:
raise ValueError("Expected %s to be empty." % file)
write(file, klass.prefix)
if not items:
# Just write an empty transaction.
write_int8(file, 0)
# Write an empty index array.
offset_map = OffsetMap(file)
else:
# Write a transaction here with the given items.
transaction_start = file.tell()
# Write a placeholder for the length.
write_int8(file, 0)
# Loop over the items, writing their records.
# Keep track of max_key and max_offset.
max_key = 0
max_offset = 0
n = 0
for name, value in items:
max_key = max(max_key, str_to_int8(name))
max_offset = max(max_offset, file.tell())
write_int8(file, len(name) + len(value))
write(file, name)
write(file, value)
n += 1
yield n
transaction_end = file.tell()
# Write the correct transaction length.
file.seek(transaction_start)
write_int8(file, transaction_end - transaction_start - 8)
# Write the empty array with the calculated dimensions.
file.seek(transaction_end)
for step in OffsetMap.generate(file, max_key, max_offset):
yield step
offset_map = OffsetMap(file)
# Now read through the records and record the offsets in the array.
file.seek(transaction_start + 8)
while file.tell() < transaction_end:
position = file.tell()
record_length = read_int8(file)
name = read(file, 8)
k = str_to_int8(name)
offset_map[k] = position
file.seek(position + 8 + record_length)
n -= 1
yield n
for index in offset_map.gen_stitch():
yield index
def generate_shelf(klass, file, items):
"""(File, [(str, str)])
This returns a generator that writes a new Shelf into file,
iterating once through the given items.
The use of an iterator makes it possible to build a new Shelf
incrementally.
"""
file.seek_end()
if not file.tell() == 0:
raise ValueError("Expected %s to be empty." % file)
write(file, klass.prefix)
if not items:
# Just write an empty transaction.
write_int8(file, 0)
# Write an empty index array.
offset_map = OffsetMap(file)
else:
# Write a transaction here with the given items.
transaction_start = file.tell()
# Write a placeholder for the length.
write_int8(file, 0)
# Loop over the items, writing their records.
# Keep track of max_key and max_offset.
max_key = 0
max_offset = 0
n = 0
for name, value in items:
max_key = max(max_key, str_to_int8(name))
max_offset = max(max_offset, file.tell())
write_int8(file, len(name) + len(value))
write(file, name)
write(file, value)
n += 1
yield n
transaction_end = file.tell()
# Write the correct transaction length.
file.seek(transaction_start)
write_int8(file, transaction_end - transaction_start - 8)
# Write the empty array with the calculated dimensions.
file.seek(transaction_end)
for step in OffsetMap.generate(file, max_key, max_offset):
yield step
offset_map = OffsetMap(file)
# Now read through the records and record the offsets in the array.
file.seek(transaction_start + 8)
while file.tell() < transaction_end:
position = file.tell()
record_length = read_int8(file)
name = read(file, 8)
k = str_to_int8(name)
offset_map[k] = position
file.seek(position + 8 + record_length)
n -= 1
yield n
for index in offset_map.gen_stitch():
yield index
def gen_items(records):
for record in records:
oid, data, refdata = unpack_record(record)
yield str_to_int8(oid), as_bytes(data), as_bytes(refdata)
if self.pack_extra is not None:
# ensure object and refs are marked alive and not removed
self.pack_extra.append(oid)
def __init__(self, file=None, readonly=False, repair=False):
"""(file:str=None, readonly:bool=False, repair:bool=False)
If file is empty (or None), a temporary file will be used.
"""
self.oid = -1
if file is None:
file = File()
assert not readonly
assert not repair
elif not hasattr(file, 'seek'):
file = File(file, readonly=readonly)
if not readonly:
file.obtain_lock()
self.fp = file
self.pending_records = {}
self.pack_extra = None
self.fp.seek(0, 2)
if self.fp.tell() != 0:
assert self.has_format(self.fp)
else:
# Write header for new file.
self.fp.seek(len(self.MAGIC))
self._write_header(self.fp)
self._write_index(self.fp, {})
self.index = {}
self._build_index(repair)
max_oid = -1
for oid in self.index:
max_oid = max(max_oid, str_to_int8(oid))
self.oid = max_oid
self.invalid = set()
def packer():
yield "started %s" % datetime.now()
seen = IntSet()
items = self.gen_oid_record(start_oid=int8_to_str(0), seen=seen)
for step in Shelf.generate_shelf(file, items):
yield step
file.flush()
file.fsync()
shelf = Shelf(file)
yield "base written %s" % datetime.now()
# Invalidate oids that have been removed.
for hole in shelf.get_offset_map().gen_holes():
yield hole
oid = int8_to_str(hole)
if self.shelf.get_position(oid) is not None:
assert shelf.get_position(oid) is None
self.invalid.add(oid)
yield "invalidations identified %s" % datetime.now()
for oid in self.pack_extra:
seen.discard(str_to_int8(oid))
for oid in self.pack_extra:
shelf.store(self.gen_oid_record(start_oid=oid, seen=seen))
file.flush()
file.fsync()
if not self.shelf.get_file().is_temporary():
self.shelf.get_file().rename(file_path + '.prepack')
self.shelf.get_file().close()
shelf.get_file().rename(file_path)
self.shelf = shelf
self.pack_extra = None
yield "finished %s" % datetime.now()
def _get_refs(self, oid):
c = self._conn.cursor()
c.execute('SELECT refs FROM objects WHERE id = ?',
(str_to_int8(oid),))
v = c.fetchone()
if v is None:
raise KeyError(oid)
return split_oids(v[0])
def gen_oid_record(self, start_oid=None, **other):
if start_oid is None:
for item in iteritems(self.shelf):
yield item
else:
todo = [start_oid]
seen = IntSet() # This eventually contains them all.
while todo:
oid = todo.pop()
if str_to_int8(oid) in seen:
continue
seen.add(str_to_int8(oid))
record = self.load(oid)
record_oid, data, refdata = unpack_record(record)
assert oid == record_oid
todo.extend(split_oids(refdata))
yield oid, record
def gen_oid_record(self, start_oid=None, **other):
if start_oid is None:
for item in iteritems(self.shelf):
yield item
else:
todo = [start_oid]
seen = IntSet() # This eventually contains them all.
while todo:
oid = todo.pop()
if str_to_int8(oid) in seen:
continue
seen.add(str_to_int8(oid))
record = self.load(oid)
record_oid, data, refdata = unpack_record(record)
assert oid == record_oid
todo.extend(split_oids(refdata))
yield oid, record
def b(self):
n = 1000
s = BytesIO()
word_array = WordArray(file=s, bytes_per_word=8, number_of_words=n)
for x in xrange(n):
word_array[x] = int8_to_str(x)
assert word_array[-1] == int8_to_str(n - 1)
for x in xrange(n):
assert x == str_to_int8(word_array[x])
word_array[x] = int8_to_str(2*x)
assert x == str_to_int8(word_array[x]) / 2
assert len(word_array) == n
assert raises(IndexError, word_array.__getitem__, n + 1)
s.seek(0)
word_array2 = WordArray(file=s)
word_array2[-1] = as_bytes('mmmmmmmm')
assert word_array2[-1] == as_bytes('mmmmmmmm')
def __str__(self):
if self.oids is None:
return "conflicting oids not available"
else:
if len(self.oids) > 1:
s = "oids=[%s ...]"
else:
s = "oids=[%s]"
first_oid = self.oids[0]
return s % (first_oid and str_to_int8(first_oid))
def __str__(self):
if self.oids is None:
return "conflicting oids not available"
else:
if len(self.oids) > 1:
s = "oids=[%s ...]"
else:
s = "oids=[%s]"
first_oid = self.oids[0]
return s % (first_oid and str_to_int8(first_oid))
def gen_oid_record(self, start_oid=None, seen=None, **other):
if start_oid is None:
for item in iteritems(self.shelf):
yield item
else:
todo = [start_oid]
if seen is None:
seen = IntSet() # This eventually contains them all.
while todo:
oid = heapq.heappop(todo)
if str_to_int8(oid) in seen:
continue
seen.add(str_to_int8(oid))
record = self.load(oid)
record_oid, data, refdata = unpack_record(record)
assert oid == record_oid
for ref_oid in split_oids(refdata):
heapq.heappush(todo, ref_oid)
yield oid, record
def handle_commit(self, client, db_name):
# C
log(20, 'Commit %s' % db_name)
storage = self.storages[db_name]
self._sync_storage(db_name, storage)
invalid = client.invalid[db_name]
yield client.write(int4_to_str(len(invalid)))
yield client.write(join_bytes(invalid))
yield client.flush()
invalid.clear()
tdata_len = str_to_int4((yield client.read(4)))
if tdata_len == 0:
# Client decided not to commit (e.g. conflict)
return
tdata = yield client.read(tdata_len)
logging_debug = is_logging(10)
logging_debug and log(10, 'Committing %s bytes', tdata_len)
storage.begin()
i = 0
oids = []
while i < tdata_len:
rlen = str_to_int4(tdata[i:i+4])
i += 4
oid = tdata[i:i+8]
record = tdata[i+8:i+rlen]
i += rlen
if logging_debug:
class_name = extract_class_name(record)
log(10, ' oid=%-6s rlen=%-6s %s',
str_to_int8(oid), rlen, class_name)
storage.store(oid, record)
oids.append(oid)
assert i == tdata_len
oid_set = set(oids)
for c in self.clients:
if c is not client:
if oid_set.intersection(c.unused_oids[db_name]):
raise ClientError('invalid oid: %r' % oid)
try:
handle_invalidations = (
lambda oids: self._handle_invalidations(db_name, oids))
storage.end(handle_invalidations=handle_invalidations)
except ConflictError:
log(20, 'Conflict during commit')
yield client.write(STATUS_INVALID)
else:
self._report_load_record(storage)
log(20, 'Committed %3s objects %s bytes at %s',
len(oids), tdata_len, datetime.now())
yield client.write(STATUS_OKAY)
client.unused_oids[db_name] -= oid_set
for c in self.clients:
if c is not client:
c.invalid[db_name].update(oids)
storage.d_bytes_since_pack += tdata_len + 8
def load(self, oid):
"""(str) -> str
Return object record identified by 'oid'.
"""
c = self._conn.cursor()
c.execute('SELECT id, data, refs FROM objects WHERE id = ?',
(str_to_int8(oid),))
v = c.fetchone()
if v is None:
raise KeyError(oid)
return pack_record(int8_to_str(v[0]), v[1], v[2])
def _send_load_response(self, s, oid):
if oid in self._find_client(s).invalid:
write(s, STATUS_INVALID)
else:
try:
record = self.storage.load(oid)
except KeyError:
log(10, 'KeyError %s', str_to_int8(oid))
write(s, STATUS_KEYERROR)
except ReadConflictError:
log(10, 'ReadConflictError %s', str_to_int8(oid))
write(s, STATUS_INVALID)
else:
if is_logging(5):
class_name = extract_class_name(record)
if class_name in self.load_record:
self.load_record[class_name] += 1
else:
self.load_record[class_name] = 1
log(4, 'Load %-7s %s', str_to_int8(oid), class_name)
write(s, STATUS_OKAY)
write_int4_str(s, record)
def _send_load_response(self, s, oid):
if oid in self._find_client(s).invalid:
write(s, STATUS_INVALID)
else:
try:
record = self.storage.load(oid)
except KeyError:
log(10, 'KeyError %s', str_to_int8(oid))
write(s, STATUS_KEYERROR)
except ReadConflictError:
log(10, 'ReadConflictError %s', str_to_int8(oid))
write(s, STATUS_INVALID)
else:
if is_logging(5):
class_name = extract_class_name(record)
if class_name in self.load_record:
self.load_record[class_name] += 1
else:
self.load_record[class_name] = 1
log(4, 'Load %-7s %s', str_to_int8(oid), class_name)
write(s, STATUS_OKAY)
write_int4_str(s, record)
def _send_load_response(self, client, db_name, storage, oid):
if oid in client.invalid[db_name]:
yield client.write(STATUS_INVALID)
else:
try:
record = storage.load(oid)
except KeyError:
log(10, 'KeyError %s', str_to_int8(oid))
yield client.write(STATUS_KEYERROR)
except ReadConflictError:
log(10, 'ReadConflictError %s', str_to_int8(oid))
yield client.write(STATUS_INVALID)
else:
if is_logging(5):
class_name = extract_class_name(record)
if class_name in storage.d_load_record:
storage.d_load_record[class_name] += 1
else:
storage.d_load_record[class_name] = 1
log(4, 'Load %-7s %s', str_to_int8(oid), class_name)
yield client.write(STATUS_OKAY)
yield client.write(int4_to_str(len(record)))
yield client.write(record)
def handle_C(self, s):
# commit
self._sync_storage()
client = self._find_client(s)
write_all(s, int4_to_str(len(client.invalid)),
join_bytes(client.invalid))
client.invalid.clear()
tdata = read_int4_str(s)
if len(tdata) == 0:
return # client decided not to commit (e.g. conflict)
logging_debug = is_logging(10)
logging_debug and log(10, 'Committing %s bytes', len(tdata))
self.storage.begin()
i = 0
oids = []
while i < len(tdata):
rlen = str_to_int4(tdata[i:i + 4])
i += 4
oid = tdata[i:i + 8]
record = tdata[i + 8:i + rlen]
i += rlen
if logging_debug:
class_name = extract_class_name(record)
log(10, ' oid=%-6s rlen=%-6s %s', str_to_int8(oid), rlen,
class_name)
self.storage.store(oid, record)
oids.append(oid)
assert i == len(tdata)
oid_set = set(oids)
for other_client in self.clients:
if other_client is not client:
if oid_set.intersection(other_client.unused_oids):
raise ClientError("invalid oid: %r" % oid)
try:
self.storage.end(handle_invalidations=self._handle_invalidations)
except ConflictError:
log(20, 'Conflict during commit')
write(s, STATUS_INVALID)
else:
self._report_load_record()
log(20, 'Committed %3s objects %s bytes at %s', len(oids),
len(tdata), datetime.now())
write(s, STATUS_OKAY)
client.unused_oids -= oid_set
for c in self.clients:
if c is not client:
c.invalid.update(oids)
self.bytes_since_pack += len(tdata) + 8
def handle_C(self, s):
# commit
self._sync_storage()
client = self._find_client(s)
write_all(s,
int4_to_str(len(client.invalid)), join_bytes(client.invalid))
client.invalid.clear()
tdata = read_int4_str(s)
if len(tdata) == 0:
return # client decided not to commit (e.g. conflict)
logging_debug = is_logging(10)
logging_debug and log(10, 'Committing %s bytes', len(tdata))
self.storage.begin()
i = 0
oids = []
while i < len(tdata):
rlen = str_to_int4(tdata[i:i+4])
i += 4
oid = tdata[i:i+8]
record = tdata[i+8:i+rlen]
i += rlen
if logging_debug:
class_name = extract_class_name(record)
log(10, ' oid=%-6s rlen=%-6s %s',
str_to_int8(oid), rlen, class_name)
self.storage.store(oid, record)
oids.append(oid)
assert i == len(tdata)
oid_set = set(oids)
for other_client in self.clients:
if other_client is not client:
if oid_set.intersection(other_client.unused_oids):
raise ClientError("invalid oid: %r" % oid)
try:
self.storage.end(handle_invalidations=self._handle_invalidations)
except ConflictError:
log(20, 'Conflict during commit')
write(s, STATUS_INVALID)
else:
self._report_load_record()
log(20, 'Committed %3s objects %s bytes at %s',
len(oids), len(tdata), datetime.now())
write(s, STATUS_OKAY)
client.unused_oids -= oid_set
for c in self.clients:
if c is not client:
c.invalid.update(oids)
self.bytes_since_pack += len(tdata) + 8
def get_position(self, name):
"""(str) -> int
Return the position of the most recent value with this name.
"""
if len(name) != 8:
raise ValueError("Expected a string with 8 bytes.")
p = self.memory_index.get(name, None)
if p is not None:
return p
current = self.file.tell()
result = self.offset_map.get(str_to_int8(name), None)
self.file.seek(current)
if result is None or result >= self.offset_map.get_start():
return None
else:
return result
def get_position(self, name):
"""(str) -> int
Return the position of the most recent value with this name.
"""
if len(name) != 8:
raise ValueError("Expected a string with 8 bytes.")
p = self.memory_index.get(name, None)
if p is not None:
return p
current = self.file.tell()
result = self.offset_map.get(str_to_int8(name), None)
self.file.seek(current)
if result is None or result >= self.offset_map.get_start():
return None
else:
return result
def __str__(self):
first_oid = self.oids[0]
return str(first_oid and str_to_int8(first_oid))
def _p_format_oid(self):
oid = self._p_oid
return str(oid and str_to_int8(as_bytes(oid)))
def __str__(self):
first_oid = self.oids[0]
return str(first_oid and str_to_int8(first_oid))
def check_int8_to_str_str_to_int8(self):
for x in range(3):
assert len(int8_to_str(x)) == 8
assert str_to_int8(int8_to_str(x)) == x
def gen_ids():
for oid in oids:
yield (str_to_int8(oid),)
