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Add support for compressed chunks on download

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uses lzma compression (4mb chunks currently)
This commit is contained in:
Campbell Barton
2015-02-20 15:52:37 +11:00
parent 7169a3d713
commit 18b1ecff1e
2 changed files with 64 additions and 31 deletions
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39
bam/cli.py
View File

@@ -653,15 +653,21 @@ class bam_commands:
import struct
ID_MESSAGE = 1
ID_PAYLOAD = 2
ID_PAYLOAD_EMPTY = 3
ID_DONE = 4
ID_PAYLOAD_APPEND = 3
ID_PAYLOAD_EMPTY = 4
ID_DONE = 5
head = r.raw.read(4)
if head != b'BAM\0':
fatal("bad header from server")
file_index = 0
is_header_read = True
while True:
if is_header_read:
msg_type, msg_size = struct.unpack("<II", r.raw.read(8))
else:
is_header_read = True
if msg_type == ID_MESSAGE:
sys.stdout.write(r.raw.read(msg_size).decode('utf-8'))
sys.stdout.flush()
@@ -679,20 +685,45 @@ class bam_commands:
os.makedirs(os.path.dirname(f_abs), exist_ok=True)
with open(f_abs, "wb") as f:
while True:
tot_size = 0
# No need to worry about filling memory,
# total chunk size is capped by the server
chunks = []
# for chunk in r.iter_content(chunk_size=CHUNK_SIZE):
for chunk in iter_content_size(r, msg_size, chunk_size=CHUNK_SIZE):
if chunk: # filter out keep-alive new chunks
tot_size += len(chunk)
f.write(chunk)
f.flush()
# f.write(chunk)
# f.flush()
chunks.append(chunk)
sys.stdout.write("\rdownload: [%03d%%]" % ((100 * tot_size) // msg_size))
sys.stdout.flush()
assert(tot_size == msg_size)
# decompress all chunks
import lzma
f.write(lzma.decompress(b''.join(chunks)))
f.flush()
del chunks
# take care! - re-reading the next header to see if
# we're appending to this file or not
msg_type, msg_size = struct.unpack("<II", r.raw.read(8))
if msg_type == ID_PAYLOAD_APPEND:
continue
# otherwise continue the outer loop, without re-reading the header
# don't re-read the header next iteration
is_header_read = False
break
elif msg_type == ID_DONE:
break
elif msg_type == ID_PAYLOAD_APPEND:
# Should only handle in a read-loop above
raise Exception("Invalid state for message-type %d" % msg_type)
else:
raise Exception("Unknown message-type %d" % msg_type)
del struct

38
webservice/bam/application/modules/resources/__init__.py
View File

@@ -278,14 +278,17 @@ class FileAPI(Resource):
# return Response(f, direct_passthrough=True)
return Response(response_message_iter(), direct_passthrough=True)
elif command == 'checkout_download':
# 4mb chunks
CHUNK_COMPRESS = 4194304
# CHUNK_COMPRESS = 512 # for testing, we can ensure many chunks are supported
files = command_args['files']
def response_message_iter():
ID_MESSAGE = 1
ID_PAYLOAD = 2
ID_PAYLOAD_EMPTY = 3
ID_DONE = 4
# ID_PAYLOAD_APPEND = 3
ID_PAYLOAD_APPEND = 3
ID_PAYLOAD_EMPTY = 4
ID_DONE = 5
import struct
def report(txt):
@@ -295,15 +298,6 @@ class FileAPI(Resource):
yield b'BAM\0'
# pack the file!
import tempfile
# weak! (ignore original opened file)
'''
filepath_zip = tempfile.mkstemp(suffix=".zip")
os.close(filepath_zip[0])
filepath_zip = filepath_zip[1]
'''
for f_rel in files:
f_abs = os.path.join(project.repository_path, f_rel)
if os.path.exists(f_abs):
@@ -314,12 +308,20 @@ class FileAPI(Resource):
f_size = f.tell()
f.seek(0, os.SEEK_SET)
yield struct.pack('<II', ID_PAYLOAD, f_size)
while True:
data = f.read(1024)
if not data:
break
yield data
id_payload = ID_PAYLOAD
f_size_left = f_size
import lzma
while f_size_left:
data_raw = f.read(CHUNK_COMPRESS)
f_size_left -= len(data_raw)
data_lzma = lzma.compress(data_raw)
del data_raw
assert(f_size_left >= 0)
yield struct.pack('<II', id_payload, len(data_lzma))
yield data_lzma
id_payload = ID_PAYLOAD_APPEND
else:
yield report("%s: %r\n" % ("source missing", f_rel))
yield struct.pack('<II', ID_PAYLOAD_EMPTY, 0)