Scripts to download files from google storage based on sha1 sums

third_party/gsutil/boto/gs/key.py

+# Copyright 2010 Google Inc.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the
+# "Software"), to deal in the Software without restriction, including
+# without limitation the rights to use, copy, modify, merge, publish, dis-
+# tribute, sublicense, and/or sell copies of the Software, and to permit
+# persons to whom the Software is furnished to do so, subject to the fol-
+# lowing conditions:
+#
+# The above copyright notice and this permission notice shall be included
+# in all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
+# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
+# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+# IN THE SOFTWARE.
+
+import os
+import StringIO
+from boto.exception import BotoClientError
+from boto.s3.key import Key as S3Key
+
+class Key(S3Key):
+    generation = None
+    meta_generation = None
+
+    def endElement(self, name, value, connection):
+        if name == 'Key':
+            self.name = value
+        elif name == 'ETag':
+            self.etag = value
+        elif name == 'IsLatest':
+            if value == 'true':
+                self.is_latest = True
+            else:
+                self.is_latest = False
+        elif name == 'LastModified':
+            self.last_modified = value
+        elif name == 'Size':
+            self.size = int(value)
+        elif name == 'StorageClass':
+            self.storage_class = value
+        elif name == 'Owner':
+            pass
+        elif name == 'VersionId':
+            self.version_id = value
+        elif name == 'Generation':
+            self.generation = value
+        elif name == 'MetaGeneration':
+            self.meta_generation = value
+        else:
+            setattr(self, name, value)
+
+    def get_file(self, fp, headers=None, cb=None, num_cb=10,
+                 torrent=False, version_id=None, override_num_retries=None,
+                 response_headers=None):
+        query_args = None
+        if self.generation:
+            query_args = ['generation=%s' % self.generation]
+        self._get_file_internal(fp, headers=headers, cb=cb, num_cb=num_cb,
+                                override_num_retries=override_num_retries,
+                                response_headers=response_headers,
+                                query_args=query_args)
+
+    def delete(self):
+        return self.bucket.delete_key(self.name, version_id=self.version_id,
+                                      generation=self.generation)
+
+    def add_email_grant(self, permission, email_address):
+        """
+        Convenience method that provides a quick way to add an email grant to a
+        key. This method retrieves the current ACL, creates a new grant based on
+        the parameters passed in, adds that grant to the ACL and then PUT's the
+        new ACL back to GS.
+
+        :type permission: string
+        :param permission: The permission being granted. Should be one of:
+            READ|FULL_CONTROL
+            See http://code.google.com/apis/storage/docs/developer-guide.html#authorization
+            for more details on permissions.
+
+        :type email_address: string
+        :param email_address: The email address associated with the Google
+                              account to which you are granting the permission.
+        """
+        acl = self.get_acl()
+        acl.add_email_grant(permission, email_address)
+        self.set_acl(acl)
+
+    def add_user_grant(self, permission, user_id):
+        """
+        Convenience method that provides a quick way to add a canonical user
+        grant to a key. This method retrieves the current ACL, creates a new
+        grant based on the parameters passed in, adds that grant to the ACL and
+        then PUT's the new ACL back to GS.
+
+        :type permission: string
+        :param permission: The permission being granted. Should be one of:
+            READ|FULL_CONTROL
+            See http://code.google.com/apis/storage/docs/developer-guide.html#authorization
+            for more details on permissions.
+
+        :type user_id: string
+        :param user_id: The canonical user id associated with the GS account to
+             which you are granting the permission.
+        """
+        acl = self.get_acl()
+        acl.add_user_grant(permission, user_id)
+        self.set_acl(acl)
+
+    def add_group_email_grant(self, permission, email_address, headers=None):
+        """
+        Convenience method that provides a quick way to add an email group
+        grant to a key. This method retrieves the current ACL, creates a new
+        grant based on the parameters passed in, adds that grant to the ACL and
+        then PUT's the new ACL back to GS.
+
+        :type permission: string
+        :param permission: The permission being granted. Should be one of:
+            READ|FULL_CONTROL
+            See http://code.google.com/apis/storage/docs/developer-guide.html#authorization
+            for more details on permissions.
+
+        :type email_address: string
+        :param email_address: The email address associated with the Google
+            Group to which you are granting the permission.
+        """
+        acl = self.get_acl(headers=headers)
+        acl.add_group_email_grant(permission, email_address)
+        self.set_acl(acl, headers=headers)
+
+    def add_group_grant(self, permission, group_id):
+        """
+        Convenience method that provides a quick way to add a canonical group
+        grant to a key. This method retrieves the current ACL, creates a new
+        grant based on the parameters passed in, adds that grant to the ACL and
+        then PUT's the new ACL back to GS.
+
+        :type permission: string
+        :param permission: The permission being granted. Should be one of:
+            READ|FULL_CONTROL
+            See http://code.google.com/apis/storage/docs/developer-guide.html#authorization
+            for more details on permissions.
+
+        :type group_id: string
+        :param group_id: The canonical group id associated with the Google
+            Groups account you are granting the permission to.
+        """
+        acl = self.get_acl()
+        acl.add_group_grant(permission, group_id)
+        self.set_acl(acl)
+
+    def set_contents_from_file(self, fp, headers=None, replace=True,
+                               cb=None, num_cb=10, policy=None, md5=None,
+                               res_upload_handler=None, size=None, rewind=False):
+        """
+        Store an object in GS using the name of the Key object as the
+        key in GS and the contents of the file pointed to by 'fp' as the
+        contents.
+
+        :type fp: file
+        :param fp: the file whose contents are to be uploaded
+
+        :type headers: dict
+        :param headers: additional HTTP headers to be sent with the PUT request.
+
+        :type replace: bool
+        :param replace: If this parameter is False, the method will first check
+            to see if an object exists in the bucket with the same key. If it
+            does, it won't overwrite it. The default value is True which will
+            overwrite the object.
+
+        :type cb: function
+        :param cb: a callback function that will be called to report
+            progress on the upload. The callback should accept two integer
+            parameters, the first representing the number of bytes that have
+            been successfully transmitted to GS and the second representing the
+            total number of bytes that need to be transmitted.
+
+        :type num_cb: int
+        :param num_cb: (optional) If a callback is specified with the cb
+            parameter, this parameter determines the granularity of the callback
+            by defining the maximum number of times the callback will be called
+            during the file transfer.
+
+        :type policy: :class:`boto.gs.acl.CannedACLStrings`
+        :param policy: A canned ACL policy that will be applied to the new key
+            in GS.
+
+        :type md5: A tuple containing the hexdigest version of the MD5 checksum
+            of the file as the first element and the Base64-encoded version of
+            the plain checksum as the second element. This is the same format
+            returned by the compute_md5 method.
+        :param md5: If you need to compute the MD5 for any reason prior to
+            upload, it's silly to have to do it twice so this param, if present,
+            will be used as the MD5 values of the file. Otherwise, the checksum
+            will be computed.
+
+        :type res_upload_handler: ResumableUploadHandler
+        :param res_upload_handler: If provided, this handler will perform the
+            upload.
+
+        :type size: int
+        :param size: (optional) The Maximum number of bytes to read from
+            the file pointer (fp). This is useful when uploading
+            a file in multiple parts where you are splitting the
+            file up into different ranges to be uploaded. If not
+            specified, the default behaviour is to read all bytes
+            from the file pointer. Less bytes may be available.
+            Notes:
+
+                1. The "size" parameter currently cannot be used when
+                   a resumable upload handler is given but is still
+                   useful for uploading part of a file as implemented
+                   by the parent class.
+                2. At present Google Cloud Storage does not support
+                   multipart uploads.
+
+        :type rewind: bool
+        :param rewind: (optional) If True, the file pointer (fp) will be 
+                       rewound to the start before any bytes are read from
+                       it. The default behaviour is False which reads from
+                       the current position of the file pointer (fp).
+
+        :rtype: int
+        :return: The number of bytes written to the key.
+
+        TODO: At some point we should refactor the Bucket and Key classes,
+        to move functionality common to all providers into a parent class,
+        and provider-specific functionality into subclasses (rather than
+        just overriding/sharing code the way it currently works).
+        """
+        provider = self.bucket.connection.provider
+        if res_upload_handler and size:
+            # could use size instead of file_length if provided but...
+            raise BotoClientError('"size" param not supported for resumable uploads.')
+        headers = headers or {}
+        if policy:
+            headers[provider.acl_header] = policy
+
+        if rewind:
+            # caller requests reading from beginning of fp.
+            fp.seek(0, os.SEEK_SET)
+        else:
+            spos = fp.tell()
+            fp.seek(0, os.SEEK_END)
+            if fp.tell() == spos:
+                fp.seek(0, os.SEEK_SET)
+                if fp.tell() != spos:
+                    # Raise an exception as this is likely a programming error
+                    # whereby there is data before the fp but nothing after it.
+                    fp.seek(spos)
+                    raise AttributeError(
+                     'fp is at EOF. Use rewind option or seek() to data start.')
+            # seek back to the correct position.
+            fp.seek(spos)
+
+        if hasattr(fp, 'name'):
+            self.path = fp.name
+        if self.bucket != None:
+            if size:
+                self.size = size
+            else:
+                # If md5 is provided, still need to size so
+                # calculate based on bytes to end of content
+                spos = fp.tell()
+                fp.seek(0, os.SEEK_END)
+                self.size = fp.tell() - spos
+                fp.seek(spos)
+                size = self.size
+
+            if self.name == None:
+                if md5 == None:
+                  md5 = self.compute_md5(fp, size)
+                  self.md5 = md5[0]
+                  self.base64md5 = md5[1]
+
+                self.name = self.md5
+            if not replace:
+                if self.bucket.lookup(self.name):
+                    return
+            if res_upload_handler:
+                res_upload_handler.send_file(self, fp, headers, cb, num_cb)
+            else:
+                # Not a resumable transfer so use basic send_file mechanism.
+                self.send_file(fp, headers, cb, num_cb, size=size)
+
+    def set_contents_from_filename(self, filename, headers=None, replace=True,
+                                   cb=None, num_cb=10, policy=None, md5=None,
+                                   reduced_redundancy=None,
+                                   res_upload_handler=None):
+        """
+        Store an object in GS using the name of the Key object as the
+        key in GS and the contents of the file named by 'filename'.
+        See set_contents_from_file method for details about the
+        parameters.
+
+        :type filename: string
+        :param filename: The name of the file that you want to put onto GS
+
+        :type headers: dict
+        :param headers: Additional headers to pass along with the request to GS.
+
+        :type replace: bool
+        :param replace: If True, replaces the contents of the file if it
+            already exists.
+
+        :type cb: function
+        :param cb: (optional) a callback function that will be called to report
+            progress on the download. The callback should accept two integer
+            parameters, the first representing the number of bytes that have
+            been successfully transmitted from GS and the second representing
+            the total number of bytes that need to be transmitted.
+
+        :type cb: int
+        :param num_cb: (optional) If a callback is specified with the cb
+            parameter this parameter determines the granularity of the callback
+            by defining the maximum number of times the callback will be called
+            during the file transfer.
+
+        :type policy: :class:`boto.gs.acl.CannedACLStrings`
+        :param policy: A canned ACL policy that will be applied to the new key
+            in GS.
+
+        :type md5: A tuple containing the hexdigest version of the MD5 checksum
+            of the file as the first element and the Base64-encoded version of
+            the plain checksum as the second element. This is the same format
+            returned by the compute_md5 method.
+        :param md5: If you need to compute the MD5 for any reason prior to
+            upload, it's silly to have to do it twice so this param, if present,
+            will be used as the MD5 values of the file. Otherwise, the checksum
+            will be computed.
+
+        :type res_upload_handler: ResumableUploadHandler
+        :param res_upload_handler: If provided, this handler will perform the
+            upload.
+        """
+        # Clear out any previously computed md5 hashes, since we are setting the content.
+        self.md5 = None
+        self.base64md5 = None
+
+        fp = open(filename, 'rb')
+        self.set_contents_from_file(fp, headers, replace, cb, num_cb,
+                                    policy, md5, res_upload_handler)
+        fp.close()
+
+    def set_contents_from_string(self, s, headers=None, replace=True,
+                                 cb=None, num_cb=10, policy=None, md5=None):
+        """
+        Store an object in S3 using the name of the Key object as the
+        key in S3 and the string 's' as the contents.
+        See set_contents_from_file method for details about the
+        parameters.
+
+        :type headers: dict
+        :param headers: Additional headers to pass along with the
+                        request to AWS.
+
+        :type replace: bool
+        :param replace: If True, replaces the contents of the file if
+                        it already exists.
+
+        :type cb: function
+        :param cb: a callback function that will be called to report
+                   progress on the upload.  The callback should accept
+                   two integer parameters, the first representing the
+                   number of bytes that have been successfully
+                   transmitted to S3 and the second representing the
+                   size of the to be transmitted object.
+
+        :type cb: int
+        :param num_cb: (optional) If a callback is specified with
+                       the cb parameter this parameter determines the
+                       granularity of the callback by defining
+                       the maximum number of times the callback will
+                       be called during the file transfer.
+
+        :type policy: :class:`boto.s3.acl.CannedACLStrings`
+        :param policy: A canned ACL policy that will be applied to the
+                       new key in S3.
+
+        :type md5: A tuple containing the hexdigest version of the MD5
+                   checksum of the file as the first element and the
+                   Base64-encoded version of the plain checksum as the
+                   second element.  This is the same format returned by
+                   the compute_md5 method.
+        :param md5: If you need to compute the MD5 for any reason prior
+                    to upload, it's silly to have to do it twice so this
+                    param, if present, will be used as the MD5 values
+                    of the file.  Otherwise, the checksum will be computed.
+        """
+
+        # Clear out any previously computed md5 hashes, since we are setting the content.
+        self.md5 = None
+        self.base64md5 = None
+
+        if isinstance(s, unicode):
+            s = s.encode("utf-8")
+        fp = StringIO.StringIO(s)
+        r = self.set_contents_from_file(fp, headers, replace, cb, num_cb,
+                                        policy, md5)
+        fp.close()
+        return r