概述
Azure 存储提供三种类型的 Blob：块 Blob、页 Blob 和追加 Blob。其中，块 Blob 特别适用于存储短的文本或二进制文件，例如文档和媒体文件。
块 Blob 由块组成，每个块可以是不同的大小，最大为 100MB (对于 2016-05-31 之前 REST 版本的请求为 4MB )，块 Blob 最多可以包含 50,000 块。因此，块 Blob 的最大大小约为 4.75 TB (100MB X 50,000 块)。对于 2016-05-31 之前的 REST 版本，块 Blob 的最大大小约为 195 GB（4MB X 50,000 块），更多详细信息，请参阅块 Blob、追加 Blob 以及页 Blob 介绍。
在上传文件到 Azure Blob 存储时，Azure 支持两种方式，整体上传和分块上传。
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整块上传：当上传到块 Blob 的文件小于等于 SingleBlobUploadThresholdInBytes 属性（客户端可以通过设置该属性设置单个 Blob 上传的最大值，范围介于 1MB 和 256MB 之间）的值时，则可以采用整体上传的方式，调用 PutBlob 完整的上传 Blob ，更多详细信息，请参考 PutBlob 。
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分块上传：当上传的块 Blob 的文件大于 SingleBlobUploadThresholdInBytes 属性的值时，存储客户端会根据 StreamWriteSizeInBytes (客户端可以通过设置该属性设置单个分块 Blob 的大小，范围介于 16KB 和 100MB 之间) 的值将文件分解成块, 采用分块上传的方式上传文件，更多详细信息，请参考 PubBlobList 。
关于C#的示例目前官网已经给出，下面分别给出JAVA、Python和PHP语言的示例程序:
- JAVA Code Sample
import com.microsoft.azure.storage.CloudStorageAccount;
import com.microsoft.azure.storage.StorageException;
import com.microsoft.azure.storage.blob.BlockEntry;
import com.microsoft.azure.storage.blob.CloudBlobClient;
import com.microsoft.azure.storage.blob.CloudBlobContainer;
import com.microsoft.azure.storage.blob.CloudBlockBlob;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URISyntaxException;
import java.security.InvalidKeyException;
import java.util.ArrayList;
import java.util.Base64;
public class uploadFileBlocksAsBlockBlob {
public static void main(String[] args) throws IOException, StorageException, URISyntaxException, InvalidKeyException {
FileInputStream fileInputStream = null;
//存储连接字符串
String storageConnectionString = "<storage connection string>";
//上传容器的名称
String containerName= "aaa1";
// Parse the connection string and create a blob client to interact with Blob storage
CloudStorageAccount storageAccount = CloudStorageAccount.parse(storageConnectionString);
CloudBlobClient blobClient = storageAccount.createCloudBlobClient();
CloudBlobContainer container = blobClient.getContainerReference(containerName);
CloudBlockBlob blockBlob = container.getBlockBlobReference("testblockblob");//希望上传后文件的名称
//本地文件的位置
String filePath = "D:\test.zip";
try {
// Open the file
fileInputStream = new FileInputStream(filePath);
// Split the file into 32K blocks (block size deliberately kept small for the demo) and upload all the blocks
int blockNum = 0;
String blockId = null;
String blockIdEncoded = null;
ArrayList<BlockEntry> blockList = new ArrayList<BlockEntry>();
while (fileInputStream.available() > (32 * 1024)) {
blockId = String.format("%05d", blockNum);
blockIdEncoded = Base64.getEncoder().encodeToString(blockId.getBytes());
blockBlob.uploadBlock(blockIdEncoded, fileInputStream, (32 * 1024));
blockList.add(new BlockEntry(blockIdEncoded));
blockNum++;
}
blockId = String.format("%05d", blockNum);
blockIdEncoded = Base64.getEncoder().encodeToString(blockId.getBytes());
blockBlob.uploadBlock(blockIdEncoded, fileInputStream, fileInputStream.available());
blockList.add(new BlockEntry(blockIdEncoded));
// Commit the blocks
blockBlob.commitBlockList(blockList);
}
catch (Throwable t) {
throw t;
}
finally {
// Close the file output stream writer
if (fileInputStream != null) {
fileInputStream.close();
}
}
}
}
- Python Code Sample
from azure.storage.blob import BlockBlobService, PublicAccess
from azure.storage.blob.models import BlobBlock
from AzureStorageDemo.RandomData import RandomData
# Block Blob Operations
def block_blob_operations():
# Define the upload file
file_to_upload = "test.mp4"
# Define the block size
block_size = 1024*1024*4 #4MB
# Create blockblob_service object
blockblob_service = BlockBlobService(
connection_string='<storage connection string>')
# Define container name
container_name = 'blockblobcontainer' + RandomData().get_random_name(6)
print("Container name：" + container_name)
try:
# Create a new container
print('1. Create a container with name - ' + container_name)
blockblob_service.create_container(container_name)
blocks = []
# Read the file
print('2. Upload file to block blob')
with open(file_to_upload, "rb") as file:
file_bytes = file.read(block_size)
while len(file_bytes) > 0:
block_id = RandomData().get_random_name(32)
blockblob_service.put_block(container_name, file_to_upload, file_bytes, block_id)
blocks.append(BlobBlock(id=block_id))
file_bytes = file.read(block_size)
blockblob_service.put_block_list(container_name, file_to_upload, blocks)
print('3. Get the block list')
blockslist = blockblob_service.get_block_list(container_name, file_to_upload, None, 'all')
blocks = blockslist.committed_blocks
print('4. Enumerate blocks in block blob')
for block in blocks:
print('Block ' + block.id)
finally:
print('5. Delete container')
if blockblob_service.exists(container_name):
blockblob_service.delete_container(container_name)
# Main method.
if __name__ == '__main__':
block_blob_operations()
- PHP Code Sample
<?php
require_once 'vendorautoload.php';
use MicrosoftAzureStorageCommonServicesBuilder;
use MicrosoftAzureStorageCommonServiceException;
use MicrosoftAzureStorageBlobModelsBlockList;
// Create blob REST proxy.
$connectionString = 'BlobEndpoint=https://<storage account name>.blob.core.chinacloudapi.cn/;QueueEndpoint=https://<storage account name>.queue.core.chinacloudapi.cn/;TableEndpoint=https://<storage account name>.table.core.chinacloudapi.cn/;AccountName=<storage account name>;AccountKey=<storage account key>';
$blobRestProxy = ServicesBuilder::getInstance()->createBlobService($connectionString);
$container = "aaaa";
$file_name = 'bigfile';
$blob_name = basename($file_name);
$block_list = new BlockList();
define('CHUNK_SIZE', 4 * 1024 * 1024);#设置每个块的大小为4MB
try {
$fptr = fopen($file_name, "rb");
$index = 1;
while (!feof($fptr)) {
$block_id = base64_encode(str_pad($index, 6, "0", STR_PAD_LEFT));
$block_list->addUncommittedEntry($block_id);
$data = fread($fptr, CHUNK_SIZE);
$blobRestProxy->createBlobBlock($container, $blob_name, $block_id, $data);
++$index;
}
$blobRestProxy->commitBlobBlocks($container, $blob_name, $block_list);
} catch (ServiceException $e) {
$code = $e->getCode();
$error_message = $e->getMessage();
echo $code.": ".$error_message."<br />";
}
echo 'upload big file success'
?>