Caricare un oggetto tramite streaming

Utilizza lo streaming per caricare un oggetto in un bucket Cloud Storage.

Per saperne di più

Per la documentazione dettagliata che include questo esempio di codice, consulta quanto segue:

Esempio di codice

C++

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage C++.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 

namespace gcs = ::google::cloud::storage;
using ::google::cloud::StatusOr;
[](gcs::Client client, std::string const& bucket_name,
   std::string const& object_name, int desired_line_count) {
  std::string const text = "Lorem ipsum dolor sit amet";
  gcs::ObjectWriteStream stream =
      client.WriteObject(bucket_name, object_name);

  for (int lineno = 0; lineno != desired_line_count; ++lineno) {
    // Add 1 to the counter, because it is conventional to number lines
    // starting at 1.
    stream << (lineno + 1) << ": " << text << "\n";
  }

  stream.Close();

  StatusOr<gcs::ObjectMetadata> metadata = std::move(stream).metadata();
  if (!metadata) throw std::move(metadata).status();
  std::cout << "Successfully wrote to object " << metadata->name()
            << " its size is: " << metadata->size()
            << "\nFull metadata: " << *metadata << "\n";
}

C#

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage C#.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 


using Google.Cloud.Storage.V1;
using System;
using System.IO;

public class UploadFileSample
{
    public void UploadFile(
        string bucketName = "your-unique-bucket-name",
        string localPath = "my-local-path/my-file-name",
        string objectName = "my-file-name")
    {
        var storage = StorageClient.Create();
        using var fileStream = File.OpenRead(localPath);
        storage.UploadObject(bucketName, objectName, null, fileStream);
        Console.WriteLine($"Uploaded {objectName}.");
    }
}

Go

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage Go.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 

import (
	"bytes"
	"context"
	"fmt"
	"io"
	"time"

	"cloud.google.com/go/storage"
)

// streamFileUpload uploads an object via a stream.
func streamFileUpload(w io.Writer, bucket, object string) error {
	// bucket := "bucket-name"
	// object := "object-name"
	ctx := context.Background()
	client, err := storage.NewClient(ctx)
	if err != nil {
		return fmt.Errorf("storage.NewClient: %w", err)
	}
	defer client.Close()

	b := []byte("Hello world.")
	buf := bytes.NewBuffer(b)

	ctx, cancel := context.WithTimeout(ctx, time.Second*50)
	defer cancel()

	// Upload an object with storage.Writer.
	wc := client.Bucket(bucket).Object(object).NewWriter(ctx)
	wc.ChunkSize = 0 // note retries are not supported for chunk size 0.

	if _, err = io.Copy(wc, buf); err != nil {
		return fmt.Errorf("io.Copy: %w", err)
	}
	// Data can continue to be added to the file until the writer is closed.
	if err := wc.Close(); err != nil {
		return fmt.Errorf("Writer.Close: %w", err)
	}
	fmt.Fprintf(w, "%v uploaded to %v.\n", object, bucket)

	return nil
}

Java

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage Java.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 


import com.google.cloud.WriteChannel;
import com.google.cloud.storage.BlobId;
import com.google.cloud.storage.BlobInfo;
import com.google.cloud.storage.Storage;
import com.google.cloud.storage.StorageOptions;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;

public class StreamObjectUpload {

  public static void streamObjectUpload(
      String projectId, String bucketName, String objectName, String contents) throws IOException {
    // The ID of your GCP project
    // String projectId = "your-project-id";

    // The ID of your GCS bucket
    // String bucketName = "your-unique-bucket-name";

    // The ID of your GCS object
    // String objectName = "your-object-name";

    // The string of contents you wish to upload
    // String contents = "Hello world!";

    Storage storage = StorageOptions.newBuilder().setProjectId(projectId).build().getService();
    BlobId blobId = BlobId.of(bucketName, objectName);
    BlobInfo blobInfo = BlobInfo.newBuilder(blobId).build();
    byte[] content = contents.getBytes(StandardCharsets.UTF_8);
    try (WriteChannel writer = storage.writer(blobInfo)) {
      writer.write(ByteBuffer.wrap(content));
      System.out.println(
          "Wrote to " + objectName + " in bucket " + bucketName + " using a WriteChannel.");
    }
  }
}

Node.js

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage Node.js.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 

/**
 * TODO(developer): Uncomment the following lines before running the sample
 */
// The ID of your GCS bucket
// const bucketName = 'your-unique-bucket-name';

// The new ID for your GCS file
// const destFileName = 'your-new-file-name';

// The content to be uploaded in the GCS file
// const contents = 'your file content';

// Imports the Google Cloud client library
const {Storage} = require('@google-cloud/storage');

// Import Node.js stream
const stream = require('stream');

// Creates a client
const storage = new Storage();

// Get a reference to the bucket
const myBucket = storage.bucket(bucketName);

// Create a reference to a file object
const file = myBucket.file(destFileName);

// Create a pass through stream from a string
const passthroughStream = new stream.PassThrough();
passthroughStream.write(contents);
passthroughStream.end();

async function streamFileUpload() {
  passthroughStream.pipe(file.createWriteStream()).on('finish', () => {
    // The file upload is complete
  });

  console.log(`${destFileName} uploaded to ${bucketName}`);
}

streamFileUpload().catch(console.error);

PHP

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage PHP.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 

use Google\Cloud\Storage\StorageClient;
use Google\Cloud\Storage\WriteStream;

/**
 * Upload a chunked file stream.
 *
 * @param string $bucketName The name of your Cloud Storage bucket.
 *        (e.g. 'my-bucket')
 * @param string $objectName The name of your Cloud Storage object.
 *        (e.g. 'my-object')
 * @param string $contents The contents to upload via stream chunks.
 *        (e.g. 'these are my contents')
 */
function upload_object_stream(string $bucketName, string $objectName, string $contents): void
{
    $storage = new StorageClient();
    $bucket = $storage->bucket($bucketName);
    $writeStream = new WriteStream(null, [
        'chunkSize' => 1024 * 256, // 256KB
    ]);
    $uploader = $bucket->getStreamableUploader($writeStream, [
        'name' => $objectName,
    ]);
    $writeStream->setUploader($uploader);
    $stream = fopen('data://text/plain,' . $contents, 'r');
    while (($line = stream_get_line($stream, 1024 * 256)) !== false) {
        $writeStream->write($line);
    }
    $writeStream->close();

    printf('Uploaded %s to gs://%s/%s' . PHP_EOL, $contents, $bucketName, $objectName);
}

Python

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage Python.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 

from google.cloud import storage


def upload_blob_from_stream(bucket_name, file_obj, destination_blob_name):
    """Uploads bytes from a stream or other file-like object to a blob."""
    # The ID of your GCS bucket
    # bucket_name = "your-bucket-name"

    # The stream or file (file-like object) from which to read
    # import io
    # file_obj = io.BytesIO()
    # file_obj.write(b"This is test data.")

    # The desired name of the uploaded GCS object (blob)
    # destination_blob_name = "storage-object-name"

    # Construct a client-side representation of the blob.
    storage_client = storage.Client()
    bucket = storage_client.bucket(bucket_name)
    blob = bucket.blob(destination_blob_name)

    # Rewind the stream to the beginning. This step can be omitted if the input
    # stream will always be at a correct position.
    file_obj.seek(0)

    # Upload data from the stream to your bucket.
    blob.upload_from_file(file_obj)

    print(
        f"Stream data uploaded to {destination_blob_name} in bucket {bucket_name}."
    )

Ruby

Per ulteriori informazioni, consulta la documentazione di riferimento dell'API Cloud Storage Ruby.

Per autenticarti a Cloud Storage, configura le Credenziali predefinite dell'applicazione. Per saperne di più, consulta Configurare l'autenticazione per le librerie client. 


# The ID of your GCS bucket
# bucket_name = "your-unique-bucket-name"

# The stream or file (file-like object) from which to read
# local_file_obj = StringIO.new "This is test data."

# Name of a file in the Storage bucket
# file_name   = "some_file.txt"

require "google/cloud/storage"

storage = Google::Cloud::Storage.new
bucket  = storage.bucket bucket_name

local_file_obj.rewind
bucket.create_file local_file_obj, file_name

puts "Stream data uploaded to #{file_name} in bucket #{bucket_name}"

Passaggi successivi

Per cercare e filtrare i sample di codice per altri Google Cloud prodotti, consulta il Google Cloud browser di sample.