2 from __future__ import absolute_import
5 from bup import _helpers, compat, helpers
6 from bup.compat import buffer, join_bytes
7 from bup.helpers import sc_page_size
10 _fmincore = getattr(helpers, 'fmincore', None)
12 BLOB_MAX = 8192*4 # 8192 is the "typical" blob size for bupsplit
13 BLOB_READ_SIZE = 1024*1024
15 progress_callback = None
18 GIT_MODE_FILE = 0o100644
19 GIT_MODE_TREE = 0o40000
20 GIT_MODE_SYMLINK = 0o120000
22 # The purpose of this type of buffer is to avoid copying on peek(), get(),
23 # and eat(). We do copy the buffer contents on put(), but that should
24 # be ok if we always only put() large amounts of data at a time.
32 self.data = join_bytes(buffer(self.data, self.start), s)
35 def peek(self, count):
36 return buffer(self.data, self.start, count)
43 v = self.data[self.start : self.start + count]
45 v = buffer(self.data, self.start, count)
50 return len(self.data) - self.start
53 def _fadvise_pages_done(fd, first_page, count):
54 assert(first_page >= 0)
57 _helpers.fadvise_done(fd,
58 first_page * sc_page_size,
62 def _nonresident_page_regions(status_bytes, incore_mask, max_region_len=None):
63 """Return (start_page, count) pairs in ascending start_page order for
64 each contiguous region of nonresident pages indicated by the
65 mincore() status_bytes. Limit the number of pages in each region
67 assert(max_region_len is None or max_region_len > 0)
69 for i, x in enumerate(status_bytes):
70 in_core = x & incore_mask
79 elif max_region_len and count >= max_region_len:
83 yield (start, len(status_bytes) - start)
86 def _uncache_ours_upto(fd, offset, first_region, remaining_regions):
87 """Uncache the pages of fd indicated by first_region and
88 remaining_regions that are before offset, where each region is a
89 (start_page, count) pair. The final region must have a start_page
91 rstart, rlen = first_region
92 while rstart is not None and (rstart + rlen) * sc_page_size <= offset:
93 _fadvise_pages_done(fd, rstart, rlen)
94 rstart, rlen = next(remaining_regions, (None, None))
98 def readfile_iter(files, progress=None):
99 for filenum,f in enumerate(files):
102 fd = rpr = rstart = rlen = None
103 if _fmincore and hasattr(f, 'fileno'):
106 except io.UnsupportedOperation:
109 mcore = _fmincore(fd)
111 max_chunk = max(1, (8 * 1024 * 1024) / sc_page_size)
112 rpr = _nonresident_page_regions(mcore, helpers.MINCORE_INCORE,
114 rstart, rlen = next(rpr, (None, None))
117 progress(filenum, len(b))
118 b = f.read(BLOB_READ_SIZE)
121 rstart, rlen = _uncache_ours_upto(fd, ofs, (rstart, rlen), rpr)
126 rstart, rlen = _uncache_ours_upto(fd, ofs, (rstart, rlen), rpr)
129 def _splitbuf(buf, basebits, fanbits):
131 b = buf.peek(buf.used())
132 (ofs, bits) = _helpers.splitbuf(b)
138 level = (bits-basebits)//fanbits # integer division
140 yield buffer(b, 0, ofs), level
143 while buf.used() >= BLOB_MAX:
144 # limit max blob size
145 yield buf.get(BLOB_MAX), 0
148 def _hashsplit_iter(files, progress):
149 assert(BLOB_READ_SIZE > BLOB_MAX)
150 basebits = _helpers.blobbits()
151 fanbits = int(math.log(fanout or 128, 2))
153 for inblock in readfile_iter(files, progress):
155 for buf_and_level in _splitbuf(buf, basebits, fanbits):
158 yield buf.get(buf.used()), 0
161 def _hashsplit_iter_keep_boundaries(files, progress):
162 for real_filenum,f in enumerate(files):
164 def prog(filenum, nbytes):
165 # the inner _hashsplit_iter doesn't know the real file count,
166 # so we'll replace it here.
167 return progress(real_filenum, nbytes)
170 for buf_and_level in _hashsplit_iter([f], progress=prog):
174 def hashsplit_iter(files, keep_boundaries, progress):
176 return _hashsplit_iter_keep_boundaries(files, progress)
178 return _hashsplit_iter(files, progress)
182 def split_to_blobs(makeblob, files, keep_boundaries, progress):
184 for (blob, level) in hashsplit_iter(files, keep_boundaries, progress):
186 total_split += len(blob)
187 if progress_callback:
188 progress_callback(len(blob))
189 yield (sha, len(blob), level)
192 def _make_shalist(l):
195 total = sum(size for mode,sha,size, in l)
196 vlen = len(b'%x' % total)
198 for (mode, sha, size) in l:
199 shalist.append((mode, b'%0*x' % (vlen,ofs), sha))
202 return (shalist, total)
205 def _squish(maketree, stacks, n):
207 while i < n or len(stacks[i]) >= MAX_PER_TREE:
208 while len(stacks) <= i+1:
210 if len(stacks[i]) == 1:
211 stacks[i+1] += stacks[i]
213 (shalist, size) = _make_shalist(stacks[i])
214 tree = maketree(shalist)
215 stacks[i+1].append((GIT_MODE_TREE, tree, size))
220 def split_to_shalist(makeblob, maketree, files,
221 keep_boundaries, progress=None):
222 sl = split_to_blobs(makeblob, files, keep_boundaries, progress)
226 for (sha,size,level) in sl:
227 shal.append((GIT_MODE_FILE, sha, size))
228 return _make_shalist(shal)[0]
231 for (sha,size,level) in sl:
232 stacks[0].append((GIT_MODE_FILE, sha, size))
233 _squish(maketree, stacks, level)
234 #log('stacks: %r\n' % [len(i) for i in stacks])
235 _squish(maketree, stacks, len(stacks)-1)
236 #log('stacks: %r\n' % [len(i) for i in stacks])
237 return _make_shalist(stacks[-1])[0]
240 def split_to_blob_or_tree(makeblob, maketree, files,
241 keep_boundaries, progress=None):
242 shalist = list(split_to_shalist(makeblob, maketree,
243 files, keep_boundaries, progress))
244 if len(shalist) == 1:
245 return (shalist[0][0], shalist[0][2])
246 elif len(shalist) == 0:
247 return (GIT_MODE_FILE, makeblob(b''))
249 return (GIT_MODE_TREE, maketree(shalist))
252 def open_noatime(name):
253 fd = _helpers.open_noatime(name)
255 return os.fdopen(fd, 'rb', 1024*1024)