multipart.py

# Copyright (c) 2006-2010 Mitch Garnaat http://garnaat.org/
# Copyright (c) 2010, Eucalyptus Systems, 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 boto.s3.user
import boto.s3.key
from boto import handler
import xml.sax

class CompleteMultiPartUpload(object):
    """
    Represents a completed MultiPart Upload.  Contains the
    following useful attributes:

     * location - The URI of the completed upload
     * bucket_name - The name of the bucket in which the upload
                     is contained
     * key_name - The name of the new, completed key
     * etag - The MD5 hash of the completed, combined upload
    """

    def __init__(self, bucket=None):
        self.bucket = None
        self.location = None
        self.bucket_name = None
        self.key_name = None
        self.etag = None

    def __repr__(self):
        return '<CompleteMultiPartUpload: %s.%s>' % (self.bucket_name,
                                                     self.key_name)
        
    def startElement(self, name, attrs, connection):
        return None

    def endElement(self, name, value, connection):
        if name == 'Location':
            self.location = value
        elif name == 'Bucket':
            self.bucket_name = value
        elif name == 'Key':
            self.key_name = value
        elif name == 'ETag':
            self.etag = value
        else:
            setattr(self, name, value)
        
class Part(object):
    """
    Represents a single part in a MultiPart upload.
    Attributes include:

     * part_number - The integer part number
     * last_modified - The last modified date of this part
     * etag - The MD5 hash of this part
     * size - The size, in bytes, of this part
    """

    def __init__(self, bucket=None):
        self.bucket = bucket
        self.part_number = None
        self.last_modified = None
        self.etag = None
        self.size = None

    def __repr__(self):
        if isinstance(self.part_number, int):
            return '<Part %d>' % self.part_number
        else:
            return '<Part %s>' % None
        
    def startElement(self, name, attrs, connection):
        return None

    def endElement(self, name, value, connection):
        if name == 'PartNumber':
            self.part_number = int(value)
        elif name == 'LastModified':
            self.last_modified = value
        elif name == 'ETag':
            self.etag = value
        elif name == 'Size':
            self.size = int(value)
        else:
            setattr(self, name, value)
        
def part_lister(mpupload, part_number_marker=''):
    """
    A generator function for listing parts of a multipart upload.
    """
    more_results = True
    part = None
    while more_results:
        parts = mpupload.get_all_parts(None, part_number_marker)
        for part in parts:
            yield part
        part_number_marker = mpupload.next_part_number_marker
        more_results= mpupload.is_truncated
        
class MultiPartUpload(object):
    """
    Represents a MultiPart Upload operation.
    """
    
    def __init__(self, bucket=None):
        self.bucket = bucket
        self.bucket_name = None
        self.key_name = None
        self.id = id
        self.initiator = None
        self.owner = None
        self.storage_class = None
        self.initiated = None
        self.part_number_marker = None
        self.next_part_number_marker = None
        self.max_parts = None
        self.is_truncated = False
        self._parts = None

    def __repr__(self):
        return '<MultiPartUpload %s>' % self.key_name

    def __iter__(self):
        return part_lister(self, part_number_marker=self.part_number_marker)

    def to_xml(self):
        self.get_all_parts()
        s = '<CompleteMultipartUpload>\n'
        for part in self:
            s += '  <Part>\n'
            s += '    <PartNumber>%d</PartNumber>\n' % part.part_number
            s += '    <ETag>%s</ETag>\n' % part.etag
            s += '  </Part>\n'
        s += '</CompleteMultipartUpload>'
        return s

    def startElement(self, name, attrs, connection):
        if name == 'Initiator':
            self.initiator = user.User(self)
            return self.initiator
        elif name == 'Owner':
            self.owner = user.User(self)
            return self.owner
        elif name == 'Part':
            part = Part(self.bucket)
            self._parts.append(part)
            return part
        return None

    def endElement(self, name, value, connection):
        if name == 'Bucket':
            self.bucket_name = value
        elif name == 'Key':
            self.key_name = value
        elif name == 'UploadId':
            self.id = value
        elif name == 'StorageClass':
            self.storage_class = value
        elif name == 'PartNumberMarker':
            self.part_number_marker = value
        elif name == 'NextPartNumberMarker':
            self.next_part_number_marker = value
        elif name == 'MaxParts':
            self.max_parts = int(value)
        elif name == 'IsTruncated':
            if value == 'true':
                self.is_truncated = True
            else:
                self.is_truncated = False
        else:
            setattr(self, name, value)

    def get_all_parts(self, max_parts=None, part_number_marker=None):
        """
        Return the uploaded parts of this MultiPart Upload.  This is
        a lower-level method that requires you to manually page through
        results.  To simplify this process, you can just use the
        object itself as an iterator and it will automatically handle
        all of the paging with S3.
        """
        self._parts = []
        query_args = 'uploadId=%s' % self.id
        if max_parts:
            query_args += '&max_parts=%d' % max_parts
        if part_number_marker:
            query_args += '&part-number-marker=%s' % part_number_marker
        response = self.bucket.connection.make_request('GET', self.bucket.name,
                                                       self.key_name,
                                                       query_args=query_args)
        body = response.read()
        if response.status == 200:
            h = handler.XmlHandler(self, self)
            xml.sax.parseString(body, h)
            return self._parts

    def upload_part_from_file(self, fp, part_num, headers=None, replace=True,
                               cb=None, num_cb=10, policy=None, md5=None):
        """
        Upload another part of this MultiPart Upload.
        
        :type fp: file
        :param fp: The file object you want to upload.
        
        :type part_num: int
        :param part_num: The number of this part.

        The other parameters are exactly as defined for the
        :class:`boto.s3.key.Key` set_contents_from_file method.
        """
        if part_num < 1:
            raise ValueError('Part numbers must be greater than zero')
        query_args = 'uploadId=%s&partNumber=%d' % (self.id, part_num)
        key = self.bucket.new_key(self.key_name)
        key.set_contents_from_file(fp, headers, replace, cb, num_cb, policy,
                                   md5, reduced_redundancy=False, query_args=query_args)

    def complete_upload(self):
        """
        Complete the MultiPart Upload operation.  This method should
        be called when all parts of the file have been successfully
        uploaded to S3.

        :rtype: :class:`boto.s3.multipart.CompletedMultiPartUpload`
        :returns: An object representing the completed upload.
        """
        xml = self.to_xml()
        self.bucket.complete_multipart_upload(self.key_name,
                                              self.id, xml)

    def cancel_upload(self):
        """
        Cancels a MultiPart Upload operation.  The storage consumed by
        any previously uploaded parts will be freed. However, if any
        part uploads are currently in progress, those part uploads
        might or might not succeed. As a result, it might be necessary
        to abort a given multipart upload multiple times in order to
        completely free all storage consumed by all parts.
        """
        self.bucket.cancel_multipart_upload(self.key_name, self.id)