def snapshot(self, data):
chunksize = len(data)
offset = self._grow(chunksize=chunksize)
os.lseek(self.fd, offset, 0)
os.write(self.fd, data)
cp = str(
carvpath._Entity(
lpmap=self.context.longpathmap,
maxfstoken=self.context.maxfstoken,
fragments=[carvpath.Fragment(offset=offset, size=chunksize)]))
return cp
def newmutable(self, chunksize):
# Grow the underlying archive by chunksize
chunkoffset = self._grow(chunksize=chunksize)
# Get the (currently still secret) carvpath of the unfrozen allocated
# chunk.
cp = str(carvpath._Entity(lpmap=self.context.longpathmap,
maxfstoken=self.context.maxfstoken,
fragments=[
carvpath.Fragment(offset=chunkoffset,
size=chunksize)]))
return cp
def newmutable(self, chunksize):
# Grow the underlying archive by chunksize
chunkoffset = self._grow(chunksize=chunksize)
# Get the (currently still secret) carvpath of the unfrozen allocated
# chunk.
cp = str(
carvpath._Entity(lpmap=self.context.longpathmap,
maxfstoken=self.context.maxfstoken,
fragments=[
carvpath.Fragment(offset=chunkoffset,
size=chunksize)
]))
return cp
def read(self, offset, size):
# Create an entity object for the thing we need to read.
readent = self.entity.subentity(childent=carvpath._Entity(
lpmap=self.entity.longpathmap,
maxfstoken=self.entity.maxfstoken,
fragments=[carvpath.Fragment(offset=offset, size=size)]),
truncate=True)
# Start with empty result.
result = b''
for chunk in readent: # One entity chunk at a time.
datachunk = self.pread(chunk=chunk) # Read chunk from offset
result += datachunk # Add chunk to result.
if not chunk.issparse():
self.ohashcollection.lowlevel_read_data(
offset=chunk.offset,
data=datachunk) # Do opportunistic hasing
# if possible.
return result
def read(self, offset, size):
# Create an entity object for the thing we need to read.
readent = self.entity.subentity(
childent=carvpath._Entity(lpmap=self.entity.longpathmap,
maxfstoken=self.entity.maxfstoken,
fragments=[carvpath.Fragment(
offset=offset,
size=size)]),
truncate=True)
# Start with empty result.
result = b''
for chunk in readent: # One entity chunk at a time.
datachunk = self.pread(chunk=chunk) # Read chunk from offset
result += datachunk # Add chunk to result.
if not chunk.issparse():
self.ohashcollection.lowlevel_read_data(
offset=chunk.offset,
data=datachunk) # Do opportunistic hasing
# if possible.
return result
def write(self, offset, data):
size = len(data)
# Create an entity object for the thing we need to write.
writeent = self.entity.subentity(childent=carvpath._Entity(
lpmap=self.entity.longpathmap,
maxfstoken=self.entity.maxfstoken,
fragments=[carvpath.Fragment(offset=offset, size=size)]),
truncate=True)
# Start of at a zero data index wigin our writale entity.
dataindex = 0
for chunk in writeent: # One fragment at a time.
# Get the part of our writable data we need for this fragment.
chunkdata = data[dataindex:dataindex + chunk.size]
dataindex += chunk.size # Update dataindex for next fragment.
# Write data fragment to propper offset
self.pwrite(chunk=chunk, chunkdata=chunkdata)
# Update opportunistic hasing if possible.
self.ohashcollection.lowlevel_written_data(offset=chunk.offset,
data=chunkdata)
return size
def write(self, offset, data):
size = len(data)
# Create an entity object for the thing we need to write.
writeent = self.entity.subentity(
childent=carvpath._Entity(lpmap=self.entity.longpathmap,
maxfstoken=self.entity.maxfstoken,
fragments=[carvpath.Fragment(
offset=offset,
size=size)]),
truncate=True)
# Start of at a zero data index wigin our writale entity.
dataindex = 0
for chunk in writeent: # One fragment at a time.
# Get the part of our writable data we need for this fragment.
chunkdata = data[dataindex:dataindex+chunk.size]
dataindex += chunk.size # Update dataindex for next fragment.
# Write data fragment to propper offset
self.pwrite(chunk=chunk, chunkdata=chunkdata)
# Update opportunistic hasing if possible.
self.ohashcollection.lowlevel_written_data(offset=chunk.offset,
data=chunkdata)
return size
