Object Storage Service:Upload retomável com o SDK do OSS para Python 1.0

Precauções

• Este tópico utiliza o endpoint público da região China (Hangzhou). Para acessar o OSS a partir de outros serviços da Alibaba Cloud na mesma região, use um endpoint interno. Para obter mais detalhes sobre as regiões e os endpoints compatíveis, consulte Regions and endpoints.

• Este exemplo obtém as credenciais de acesso de variáveis de ambiente. Para obter mais informações sobre como configurar credenciais de acesso, consulte Configure access credentials using OSS SDK for Python 1.0.

• Este tópico demonstra como criar uma instância OSSClient com um endpoint do OSS. Para configurações alternativas, como usar um domínio personalizado ou se autenticar com credenciais do Security Token Service (STS), consulte Initialization.

• O upload retomável requer as permissões oss:PutObject e oss:ListParts. Para obter mais informações, consulte Grant custom access policies to RAM users.

• O upload retomável é executado em várias threads. Não use threads externas ao chamar esta função. Caso contrário, os dados podem ser transmitidos repetidamente.

• Aumente o tamanho das partes em condições de rede favoráveis e reduza o tamanho em condições de rede desfavoráveis.

Código de exemplo

O código a seguir mostra um exemplo de upload retomável:

# -*- coding: utf-8 -*-
import oss2
from oss2.credentials import EnvironmentVariableCredentialsProvider
# Obtain access credentials from environment variables. Before you run the sample code, make sure that the OSS_ACCESS_KEY_ID and OSS_ACCESS_KEY_SECRET environment variables are configured.
auth = oss2.ProviderAuthV4(EnvironmentVariableCredentialsProvider())

# Specify the endpoint of the region where the bucket is located. For example, if the bucket is in the China (Hangzhou) region, set the endpoint to https://oss-cn-hangzhou.aliyuncs.com.
endpoint = "https://oss-cn-hangzhou.aliyuncs.com"

# Specify the region where the bucket is located, such as cn-hangzhou. Note that this parameter is required for V4 signatures.
region = "cn-hangzhou"

# Set yourBucketName to the name of the bucket.
bucket = oss2.Bucket(auth, endpoint, "yourBucketName", region=region)

# Set yourObjectName to the full path of the object. The full path cannot contain the bucket name. Example: exampledir/exampleobject.txt.
# Set yourLocalFile to the full path of the local file. Example: D:\\localpath\\examplefile.txt. If you do not specify a local path, the file is uploaded from the local path that corresponds to the project to which the sample program belongs.
oss2.resumable_upload(bucket, 'exampledir/exampleobject.txt', 'D:\\localpath\\examplefile.txt')
# If you do not use the store parameter to specify a directory, the .py-oss-upload directory is created in the HOME directory to save breakpoint information.

# Python SDK 2.1.0 and later support the following optional parameters for resumable upload.
# import sys
# # If the length of the data to be uploaded cannot be determined, the value of total_bytes is None.
# def percentage(consumed_bytes, total_bytes):
#     if total_bytes:
#         rate = int(100 * (float(consumed_bytes) / float(total_bytes)))
#         print('\r{0}% '.format(rate), end='')
#         sys.stdout.flush()
# # If you use the store parameter to specify a directory, breakpoint information is saved in the specified directory. If you use num_threads to set the number of concurrent upload threads, set oss2.defaults.connection_pool_size to a value that is greater than or equal to the number of concurrent upload threads. The default number of concurrent upload threads is 1.
# oss2.resumable_upload(bucket, '<yourObjectName>', '<yourLocalFile>',
#                       store=oss2.ResumableStore(root='/tmp'),
#                       # Specify that multipart upload is used when the file size is greater than or equal to the value of the optional parameter multipart_threshold. The default value is 10 MB.
#                       multipart_threshold=100*1024,
#                       # Set the part size in bytes. The value must be in the range of 100 KB to 5 GB. The default value is 100 KB.
#                       part_size=100*1024,
#                       # Set the upload progress callback function.
#                       progress_callback=percentage,
#                       # If you use num_threads to set the number of concurrent upload threads, set oss2.defaults.connection_pool_size to a value that is greater than or equal to the number of concurrent upload threads. The default number of concurrent upload threads is 1.
#                       num_threads=4)

Referências

Para acessar o código de exemplo completo para upload retomável, consulte o exemplo no GitHub.