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Overview

The S3M class is the core JavaScript class that handles multipart file uploads to AWS S3. It manages chunking, concurrent uploads, retry logic, and progress tracking.

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Constructor

const uploader = new S3M(file, options);
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file
File
required
The File object to upload. This is a standard browser File object.
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options
Object
Configuration options for the upload. See the Options page for details.

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Class Constants

The S3M class defines several default constants that control upload behavior:
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DEFAULT_CHUNK_SIZE
number
default:"10485760"
Default chunk size in bytes (10MB). This is the size of each part in the multipart upload.
S3M.DEFAULT_CHUNK_SIZE // 10 * 1024 * 1024 = 10MB
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DEFAULT_MAX_CONCURRENT_UPLOADS
number
default:"5"
Maximum number of chunks that can be uploaded concurrently.
S3M.DEFAULT_MAX_CONCURRENT_UPLOADS // 5
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DEFAULT_MAX_CHUNK_RETRIES
number
default:"3"
Maximum number of retry attempts for a failed chunk upload.
S3M.DEFAULT_MAX_CHUNK_RETRIES // 3

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Instance Properties

After instantiation, the S3M instance has the following properties:
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file
File
The File object being uploaded.
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options
Object
The options object passed to the constructor.
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chunkSize
number
The chunk size for the upload. Defaults to DEFAULT_CHUNK_SIZE if not specified in options.
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maxConcurrentUploads
number
Maximum number of concurrent chunk uploads. Defaults to DEFAULT_MAX_CONCURRENT_UPLOADS if not specified.
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fileName
string
The name of the file being uploaded (from file.name).
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fileSize
number
The size of the file in bytes (from file.size).
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fileType
string
The MIME type of the file (from file.type).
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httpClient
Object
The HTTP client used for requests. Defaults to axios if not provided in options.
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chunkRetries
number
Maximum number of retries for failed chunks. Defaults to DEFAULT_MAX_CHUNK_RETRIES if not specified.

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Example Usage

import S3M from '@savannabits/s3m';

// Create an instance
const file = document.getElementById('file-input').files[0];
const uploader = new S3M(file, {
  chunk_size: 5 * 1024 * 1024, // 5MB chunks
  max_concurrent_uploads: 3,
  progress: (percent) => {
    console.log(`Upload progress: ${percent}%`);
  }
});

// Start the upload
const result = await uploader.upload();
console.log('Upload complete:', result);

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