mirror of
https://github.com/overleaf/overleaf.git
synced 2024-12-25 18:34:52 +00:00
80 lines
2.1 KiB
JavaScript
80 lines
2.1 KiB
JavaScript
/** @module */
|
|
'use strict'
|
|
|
|
const BPromise = require('bluebird')
|
|
const fs = BPromise.promisifyAll(require('fs'))
|
|
const crypto = require('crypto')
|
|
const { pipeline } = require('stream')
|
|
const assert = require('./assert')
|
|
|
|
function getGitBlobHeader(byteLength) {
|
|
return 'blob ' + byteLength + '\x00'
|
|
}
|
|
|
|
function getBlobHash(byteLength) {
|
|
const hash = crypto.createHash('sha1')
|
|
hash.setEncoding('hex')
|
|
hash.update(getGitBlobHeader(byteLength))
|
|
return hash
|
|
}
|
|
|
|
/**
|
|
* Compute the git blob hash for a blob from a readable stream of its content.
|
|
*
|
|
* @function
|
|
* @param {number} byteLength
|
|
* @param {stream.Readable} stream
|
|
* @return {Promise.<string>} hexadecimal SHA-1 hash
|
|
*/
|
|
exports.fromStream = BPromise.method(
|
|
function blobHashFromStream(byteLength, stream) {
|
|
assert.integer(byteLength, 'blobHash: bad byteLength')
|
|
assert.object(stream, 'blobHash: bad stream')
|
|
|
|
const hash = getBlobHash(byteLength)
|
|
return new BPromise(function (resolve, reject) {
|
|
pipeline(stream, hash, function (err) {
|
|
if (err) {
|
|
reject(err)
|
|
} else {
|
|
hash.end()
|
|
resolve(hash.read())
|
|
}
|
|
})
|
|
})
|
|
}
|
|
)
|
|
|
|
/**
|
|
* Compute the git blob hash for a blob with the given string content.
|
|
*
|
|
* @param {string} string
|
|
* @return {string} hexadecimal SHA-1 hash
|
|
*/
|
|
exports.fromString = function blobHashFromString(string) {
|
|
assert.string(string, 'blobHash: bad string')
|
|
const hash = getBlobHash(Buffer.byteLength(string))
|
|
hash.update(string, 'utf8')
|
|
hash.end()
|
|
return hash.read()
|
|
}
|
|
|
|
/**
|
|
* Compute the git blob hash for the content of a file
|
|
*
|
|
* @param {string} filePath
|
|
* @return {string} hexadecimal SHA-1 hash
|
|
*/
|
|
exports.fromFile = function blobHashFromFile(pathname) {
|
|
assert.string(pathname, 'blobHash: bad pathname')
|
|
|
|
function getByteLengthOfFile() {
|
|
return fs.statAsync(pathname).then(stat => stat.size)
|
|
}
|
|
|
|
const fromStream = this.fromStream
|
|
return getByteLengthOfFile(pathname).then(function (byteLength) {
|
|
const stream = fs.createReadStream(pathname)
|
|
return fromStream(byteLength, stream)
|
|
})
|
|
}
|