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| 1 # Copyright 2012 Google Inc. All Rights Reserved. |
| 2 # |
| 3 # Permission is hereby granted, free of charge, to any person obtaining a |
| 4 # copy of this software and associated documentation files (the |
| 5 # "Software"), to deal in the Software without restriction, including |
| 6 # without limitation the rights to use, copy, modify, merge, publish, dis- |
| 7 # tribute, sublicense, and/or sell copies of the Software, and to permit |
| 8 # persons to whom the Software is furnished to do so, subject to the fol- |
| 9 # lowing conditions: |
| 10 # |
| 11 # The above copyright notice and this permission notice shall be included |
| 12 # in all copies or substantial portions of the Software. |
| 13 # |
| 14 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| 15 # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL- |
| 16 # ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT |
| 17 # SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| 18 # WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 19 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 20 # IN THE SOFTWARE. |
| 21 |
| 22 import time |
| 23 |
| 24 |
| 25 class BucketListingRef(object): |
| 26 """ |
| 27 Container that holds a reference to one result from a bucket listing, allowing |
| 28 polymorphic iteration over wildcard-iterated URIs, Keys, or Prefixes. At a |
| 29 minimum, every reference contains a StorageUri. If the reference came from a |
| 30 bucket listing (as opposed to a manually instantiated ref that might populate |
| 31 only the StorageUri), it will additionally contain either a Key or a Prefix, |
| 32 depending on whether it was a reference to an object or was just a prefix of a |
| 33 path (i.e., bucket subdirectory). The latter happens when the bucket was |
| 34 listed using delimiter='/'. |
| 35 |
| 36 Note that Keys are shallow-populated, based on the contents extracted from |
| 37 parsing a bucket listing. This includes name, length, and other fields |
| 38 (basically, the info listed by gsutil ls -l), but does not include information |
| 39 like ACL and location (which require separate server requests, which is why |
| 40 there's a separate gsutil ls -L option to get this more detailed info). |
| 41 """ |
| 42 |
| 43 def __init__(self, uri, key=None, prefix=None, headers=None): |
| 44 """Instantiate BucketListingRef from uri and (if available) key or prefix. |
| 45 |
| 46 Args: |
| 47 uri: StorageUri for the object (required). |
| 48 key: Key for the object, or None if not available. |
| 49 prefix: Prefix for the subdir, or None if not available. |
| 50 headers: Dictionary containing optional HTTP headers to pass to boto |
| 51 (which happens when GetKey() is called on an BucketListingRef which |
| 52 has no constructor-populated Key), or None if not available. |
| 53 |
| 54 At most one of key and prefix can be populated. |
| 55 """ |
| 56 assert key is None or prefix is None |
| 57 self.uri = uri |
| 58 self.key = key |
| 59 self.prefix = prefix |
| 60 self.headers = headers or {} |
| 61 |
| 62 def GetUri(self): |
| 63 """Get URI form of listed URI. |
| 64 |
| 65 Returns: |
| 66 StorageUri. |
| 67 """ |
| 68 return self.uri |
| 69 |
| 70 def GetUriString(self): |
| 71 """Get string URI form of listed URI. |
| 72 |
| 73 Returns: |
| 74 String. |
| 75 """ |
| 76 return self.uri.uri |
| 77 |
| 78 def NamesBucket(self): |
| 79 """Determines if this BucketListingRef names a bucket. |
| 80 |
| 81 Returns: |
| 82 bool indicator. |
| 83 """ |
| 84 return self.key is None and self.prefix is None and self.uri.names_bucket() |
| 85 |
| 86 def IsLatest(self): |
| 87 """Determines if this BucketListingRef names the latest version of an |
| 88 object. |
| 89 |
| 90 Returns: |
| 91 bool indicator. |
| 92 """ |
| 93 return hasattr(self.uri, 'is_latest') and self.uri.is_latest |
| 94 |
| 95 def GetRStrippedUriString(self): |
| 96 """Get string URI form of listed URI, stripped of any right trailing |
| 97 delims, and without version string. |
| 98 |
| 99 Returns: |
| 100 String. |
| 101 """ |
| 102 return self.uri.versionless_uri.rstrip('/') |
| 103 |
| 104 def HasKey(self): |
| 105 """Return bool indicator of whether this BucketListingRef has a Key.""" |
| 106 return bool(self.key) |
| 107 |
| 108 def HasPrefix(self): |
| 109 """Return bool indicator of whether this BucketListingRef has a Prefix.""" |
| 110 return bool(self.prefix) |
| 111 |
| 112 def GetKey(self): |
| 113 """Get Key form of listed URI. |
| 114 |
| 115 Returns: |
| 116 Subclass of boto.s3.key.Key. |
| 117 |
| 118 Raises: |
| 119 BucketListingRefException: for bucket-only uri. |
| 120 """ |
| 121 # For gsutil ls -l gs://bucket self.key will be populated from (boto) |
| 122 # parsing the bucket listing. But as noted and handled below there are |
| 123 # cases where self.key isn't populated. |
| 124 if not self.key: |
| 125 if not self.uri.names_object(): |
| 126 raise BucketListingRefException( |
| 127 'Attempt to call GetKey() on Key-less BucketListingRef (uri=%s) ' % |
| 128 self.uri) |
| 129 # This case happens when we do gsutil ls -l on a object name-ful |
| 130 # StorageUri with no object-name wildcard. Since the ls command |
| 131 # implementation only reads bucket info we need to read the object |
| 132 # for this case. |
| 133 self.key = self.uri.get_key(validate=False, headers=self.headers) |
| 134 # When we retrieve the object this way its last_modified timestamp |
| 135 # is formatted in RFC 1123 format, which is different from when we |
| 136 # retrieve from the bucket listing (which uses ISO 8601 format), so |
| 137 # convert so we consistently return ISO 8601 format. |
| 138 tuple_time = (time.strptime(self.key.last_modified, |
| 139 '%a, %d %b %Y %H:%M:%S %Z')) |
| 140 self.key.last_modified = time.strftime('%Y-%m-%dT%H:%M:%S', tuple_time) |
| 141 return self.key |
| 142 |
| 143 def GetPrefix(self): |
| 144 """Get Prefix form of listed URI. |
| 145 |
| 146 Returns: |
| 147 boto.s3.prefix.Prefix. |
| 148 |
| 149 Raises: |
| 150 BucketListingRefException: if this object has no Prefix. |
| 151 """ |
| 152 if not self.prefix: |
| 153 raise BucketListingRefException( |
| 154 'Attempt to call GetPrefix() on Prefix-less BucketListingRef ' |
| 155 '(uri=%s)' % self.uri) |
| 156 return self.prefix |
| 157 |
| 158 def __repr__(self): |
| 159 """Returns string representation of BucketListingRef.""" |
| 160 return 'BucketListingRef(%s, HasKey=%s, HasPrefix=%s)' % ( |
| 161 self.uri, self.HasKey(), self.HasPrefix()) |
| 162 |
| 163 |
| 164 class BucketListingRefException(StandardError): |
| 165 """Exception thrown for invalid BucketListingRef requests.""" |
| 166 |
| 167 def __init__(self, reason): |
| 168 StandardError.__init__(self) |
| 169 self.reason = reason |
| 170 |
| 171 def __repr__(self): |
| 172 return 'BucketListingRefException: %s' % self.reason |
| 173 |
| 174 def __str__(self): |
| 175 return 'BucketListingRefException: %s' % self.reason |
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