Revision c4399e62 snf-pithos-backend/pithos/backends/lib/hashfiler/context_file.py
| b/snf-pithos-backend/pithos/backends/lib/hashfiler/context_file.py | ||
|---|---|---|
| 31 | 31 |
# interpreted as representing official policies, either expressed |
| 32 | 32 |
# or implied, of GRNET S.A. |
| 33 | 33 |
|
| 34 |
from os import SEEK_CUR, SEEK_SET, fsync, makedirs |
|
| 34 |
from os import SEEK_CUR, SEEK_SET, fsync, makedirs, rename
|
|
| 35 | 35 |
from os.path import dirname |
| 36 |
from errno import ENOENT, EROFS
|
|
| 36 |
from errno import ENOENT, ESPIPE
|
|
| 37 | 37 |
|
| 38 | 38 |
|
| 39 | 39 |
_zeros = '' |
| 40 |
fsync # get used |
|
| 40 | 41 |
|
| 41 | 42 |
|
| 42 | 43 |
def zeros(nr): |
| ... | ... | |
| 65 | 66 |
|
| 66 | 67 |
try: |
| 67 | 68 |
seek(offset * chunksize) |
| 68 |
except IOError, e: |
|
| 69 |
except IOError as e: |
|
| 70 |
if e.errno != ESPIPE: |
|
| 71 |
raise |
|
| 72 |
|
|
| 73 |
# substitute seeking in a non-seekable file (e.g. pipe) |
|
| 69 | 74 |
seek = None |
| 70 | 75 |
for x in xrange(offset): |
| 71 | 76 |
fwrite(zeros(chunksize)) |
| ... | ... | |
| 106 | 111 |
seek = openfile.seek |
| 107 | 112 |
try: |
| 108 | 113 |
seek(remains) |
| 109 |
except IOError, e: |
|
| 114 |
except IOError as e: |
|
| 115 |
if e.errno != ESPIPE: |
|
| 116 |
raise |
|
| 117 |
|
|
| 118 |
# substitute seeking in a non-seekable file (e.g. pipe) |
|
| 110 | 119 |
seek = None |
| 111 | 120 |
while 1: |
| 112 | 121 |
s = fread(remains) |
| ... | ... | |
| 132 | 141 |
|
| 133 | 142 |
|
| 134 | 143 |
class ContextFile(object): |
| 135 |
__slots__ = ("name", "fdesc", "create")
|
|
| 136 | 144 |
|
| 137 |
def __init__(self, name, create=0):
|
|
| 145 |
def __init__(self, name, create=True, write=False, temp=''):
|
|
| 138 | 146 |
self.name = name |
| 139 | 147 |
self.fdesc = None |
| 140 |
self.create = create |
|
| 148 |
self._create = create |
|
| 149 |
self._write = write |
|
| 150 |
self._mode = 'rb+' if write else 'rb' |
|
| 151 |
self._temp = temp |
|
| 152 |
self._rename = False |
|
| 141 | 153 |
#self.dirty = 0 |
| 142 | 154 |
|
| 143 | 155 |
def __enter__(self): |
| 144 | 156 |
name = self.name |
| 145 | 157 |
try: |
| 146 |
fdesc = open(name, 'rb+')
|
|
| 158 |
fdesc = open(name, self._mode)
|
|
| 147 | 159 |
except IOError, e: |
| 148 |
if self.create and e.errno == ENOENT: |
|
| 149 |
try: |
|
| 150 |
fdesc = open(name, 'w+') |
|
| 151 |
except IOError as e: |
|
| 152 |
if e.errno != ENOENT: |
|
| 153 |
raise |
|
| 154 |
|
|
| 155 |
# ENOENT means parent dirs do not exist. |
|
| 156 |
# Create them. |
|
| 157 |
makedirs(dirname(name)) |
|
| 158 |
fdesc = open(name, 'w+') |
|
| 159 |
elif not self.create and e.errno == EROFS: |
|
| 160 |
fdesc = open(name, 'rb') |
|
| 161 |
else: |
|
| 160 |
if not (self._create and e.errno == ENOENT): |
|
| 162 | 161 |
raise |
| 163 | 162 |
|
| 163 |
# File does not exist. Create it, |
|
| 164 |
# optionally under a temporary filename. |
|
| 165 |
temp = self._temp |
|
| 166 |
self._rename = False |
|
| 167 |
if temp: |
|
| 168 |
name += '_' + temp |
|
| 169 |
self._rename = name |
|
| 170 |
|
|
| 171 |
try: |
|
| 172 |
fdesc = open(name, 'w+') |
|
| 173 |
except IOError as e: |
|
| 174 |
if e.errno != ENOENT: |
|
| 175 |
raise |
|
| 176 |
|
|
| 177 |
# ENOENT means parent dirs do not exist. |
|
| 178 |
# Create them. |
|
| 179 |
makedirs(dirname(name)) |
|
| 180 |
fdesc = open(name, 'w+') |
|
| 181 |
|
|
| 164 | 182 |
self.fdesc = fdesc |
| 165 | 183 |
return self |
| 166 | 184 |
|
| ... | ... | |
| 170 | 188 |
#if self.dirty: |
| 171 | 189 |
# fsync(fdesc.fileno()) |
| 172 | 190 |
fdesc.close() |
| 191 |
|
|
| 192 |
tempname = self._rename |
|
| 193 |
if tempname: |
|
| 194 |
# Temporary file needs to be moved into proper place |
|
| 195 |
# This is usually an atomic filesystem operation. |
|
| 196 |
rename(tempname, self.name) |
|
| 197 |
|
|
| 173 | 198 |
return False # propagate exceptions |
| 174 | 199 |
|
| 175 | 200 |
def seek(self, offset, whence=SEEK_SET): |
Also available in: Unified diff