ChenYFan/R2Worker.js

## R2Worker.js
addEventListener("fetch", event => {
    event.respondWith(handleRequest(event.request))
})

async function handleRequest(request) {
    const url = new URL(request.url)
    const objectName = url.pathname.slice(1)

    console.log(`${request.method} object ${objectName}: ${request.url}`)

    if (request.method === 'GET' || request.method === 'HEAD') {
        if (objectName === '') {
            if (request.method == 'HEAD') {
                return new Response(undefined, { status: 400 })
            }

            const options = {
                prefix: url.searchParams.get('prefix') ?? undefined,
                delimiter: url.searchParams.get('delimiter') ?? undefined,
                cursor: url.searchParams.get('cursor') ?? undefined,
                include: ['customMetadata', 'httpMetadata'],
            }
            console.log(JSON.stringify(options))

            const listing = await R2.list(options)
            return new Response(JSON.stringify(listing), {
                headers: {
                    'content-type': 'application/json; charset=UTF-8',
                }
            })
        }

        if (request.method === 'GET') {
            const range = parseRange(request.headers.get('range'))
            const object = await R2.get(objectName, {
                range,
                onlyIf: request.headers,
            })

            if (object === null) {
                return objectNotFound(objectName)
            }

            const headers = new Headers()
            //object.writeHttpMetadata(headers)
            headers.set('etag', object.httpEtag)
            const status = object.body ? (range ? 206 : 200) : 304
            return new Response(object.body, {
                headers,
                status
            })
        }

        const object = await R2.head(objectName, {
            onlyIf: request.headers,
        })

        if (object === null) {
            return objectNotFound(objectName)
        }

        const headers = new Headers()
        //object.writeHttpMetadata(headers)
        headers.set('etag', object.httpEtag)
        return new Response(null, {
            headers,
        })
    }
    if (request.method === 'PUT' || request.method == 'POST') {
        const object = await R2.put(objectName, request.body, {
            httpMetadata: request.headers,
        })
        return new Response(null, {
            headers: {
                'etag': object.httpEtag,
            }
        })
    }
    if (request.method === 'DELETE') {
        await R2.delete(url.pathname.slice(1))
        return new Response()
    }

    return new Response(`Unsupported method`, {
        status: 400
    })
}

function parseRange(encoded) {
    if (encoded === null) {
        return
    }

    const parts = encoded.split("bytes=")[1]?.split("-") ?? []
    if (parts.length !== 2) {
        throw new Error('Not supported to skip specifying the beginning/ending byte at this time')
    }

    return {
        offset: Number(parts[0]),
        length: Number(parts[1]) + 1 - Number(parts[0]),
    }
}

function objectNotFound(objectName) {
    return new Response(`<html><body>R2 object "<b>${objectName}</b>" not found</body></html>`, {
        status: 404,
        headers: {
            'content-type': 'text/html; charset=UTF-8'
        }
    })
}
	addEventListener("fetch", event => {
	event.respondWith(handleRequest(event.request))
	})

	async function handleRequest(request) {
	const url = new URL(request.url)
	const objectName = url.pathname.slice(1)

	console.log(`${request.method} object ${objectName}: ${request.url}`)

	if (request.method === 'GET' \|\| request.method === 'HEAD') {
	if (objectName === '') {
	if (request.method == 'HEAD') {
	return new Response(undefined, { status: 400 })
	}

	const options = {
	prefix: url.searchParams.get('prefix') ?? undefined,
	delimiter: url.searchParams.get('delimiter') ?? undefined,
	cursor: url.searchParams.get('cursor') ?? undefined,
	include: ['customMetadata', 'httpMetadata'],
	}
	console.log(JSON.stringify(options))

	const listing = await R2.list(options)
	return new Response(JSON.stringify(listing), {
	headers: {
	'content-type': 'application/json; charset=UTF-8',
	}
	})
	}

	if (request.method === 'GET') {
	const range = parseRange(request.headers.get('range'))
	const object = await R2.get(objectName, {
	range,
	onlyIf: request.headers,
	})

	if (object === null) {
	return objectNotFound(objectName)
	}

	const headers = new Headers()
	//object.writeHttpMetadata(headers)
	headers.set('etag', object.httpEtag)
	const status = object.body ? (range ? 206 : 200) : 304
	return new Response(object.body, {
	headers,
	status
	})
	}

	const object = await R2.head(objectName, {
	onlyIf: request.headers,
	})

	if (object === null) {
	return objectNotFound(objectName)
	}

	const headers = new Headers()
	//object.writeHttpMetadata(headers)
	headers.set('etag', object.httpEtag)
	return new Response(null, {
	headers,
	})
	}
	if (request.method === 'PUT' \|\| request.method == 'POST') {
	const object = await R2.put(objectName, request.body, {
	httpMetadata: request.headers,
	})
	return new Response(null, {
	headers: {
	'etag': object.httpEtag,
	}
	})
	}
	if (request.method === 'DELETE') {
	await R2.delete(url.pathname.slice(1))
	return new Response()
	}

	return new Response(`Unsupported method`, {
	status: 400
	})
	}

	function parseRange(encoded) {
	if (encoded === null) {
	return
	}

	const parts = encoded.split("bytes=")[1]?.split("-") ?? []
	if (parts.length !== 2) {
	throw new Error('Not supported to skip specifying the beginning/ending byte at this time')
	}

	return {
	offset: Number(parts[0]),
	length: Number(parts[1]) + 1 - Number(parts[0]),
	}
	}

	function objectNotFound(objectName) {
	return new Response(`<html><body>R2 object "<b>${objectName}</b>" not found</body></html>`, {
	status: 404,
	headers: {
	'content-type': 'text/html; charset=UTF-8'
	}
	})
	}