package/license000644 0000002127 3560116604 010627 0ustar00000000 000000 The MIT License (MIT) Copyright (c) Ben Drucker (bendrucker.me) Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. package/decode-test.js000644 0000000633 3560116604 012020 0ustar00000000 000000 'use strict' const test = require('tape') const decode = require('./') test('decode', (t) => { t.test('pg <9 escape format', (t) => { const buffer = Buffer.from([102, 111, 111, 0, 128, 92, 255]) t.ok(buffer.equals(decode('foo\\000\\200\\\\\\377'))) t.end() }) t.test('pg >=9 hex format', (t) => { t.ok(decode('\\x1234').equals(Buffer.from([0x12, 0x34]))) t.end() }) t.end() }) package/decode.js000644 0000001717 3560116604 011047 0ustar00000000 000000 'use strict' module.exports = byteaToBinary function byteaToBinary (input) { if (/^\\x/.test(input)) { return byteaHexFormatToBinary(input) } return byteaEscapeFormatToBinary(input) } function byteaHexFormatToBinary (input) { return Buffer.from(input.substr(2), 'hex') } function byteaEscapeFormatToBinary (input) { let output = '' let i = 0 while (i < input.length) { if (input[i] !== '\\') { output += input[i] ++i } else { if (/[0-7]{3}/.test(input.substr(i + 1, 3))) { output += String.fromCharCode(parseInt(input.substr(i + 1, 3), 8)) i += 4 } else { let backslashes = 1 while (i + backslashes < input.length && input[i + backslashes] === '\\') { backslashes++ } for (let k = 0; k < Math.floor(backslashes / 2); ++k) { output += '\\' } i += Math.floor(backslashes / 2) * 2 } } } return Buffer.from(output, 'binary') } package/decoder-test.js000644 0000001462 3560116604 012203 0ustar00000000 000000 'use strict' const test = require('tape-promise').default(require('tape')) const { Readable } = require('stream') const streamToPromise = require('stream-to-promise') const Decoder = require('./decoder') test('decoder', (t) => { t.test('input cuts at chunk boundary', async (t) => { const input = [...Buffer.from('\\\\x616263').values()] for (let i = 1; i < input.length; i++) { const result = await streamToPromise(Readable.from([input.slice(0, i), input.slice(i)].map(Buffer.from)).pipe(new Decoder())) t.equal(result.toString(), 'abc', `i=${i}`) } }) t.test('fails if not prefixed with \\\\x', async (t) => { const dest = new Decoder() const promise = streamToPromise(dest) dest.write(Buffer.from('616263')) await t.rejects(promise, /prefix/) }) t.end() }) package/decoder.js000644 0000003032 3560116604 011221 0ustar00000000 000000 'use strict' const BufferList = require('obuf') const { Transform } = require('stream') const State = { READ_PREFIX: 1, READ_DATA: 2 } class ByteaDecoder extends Transform { constructor () { super() this._incomingChunks = new BufferList() this._state = State.READ_PREFIX } _transform (chunk, encoding, callback) { this._incomingChunks.push(chunk) while (true) { if (this._state === State.READ_PREFIX) { if (this._incomingChunks.has(3)) { const prefix = this._incomingChunks.take(3) const prefixString = prefix.toString() if (prefixString !== '\\\\x') { return this.emit('error', new Error(`Expected double-escaped postgres bytea hex format prefix, received: '${prefixString}'`)) } this._state = State.READ_DATA continue } else { break } } if (this._state === State.READ_DATA) { if (this._incomingChunks.size >= 2) { // two hex characters are needed to parse a byte. read even number of chars, and let remainder roll over let evenChunk const isEvenLength = this._incomingChunks.size % 2 === 0 if (isEvenLength) { evenChunk = this._incomingChunks.take(this._incomingChunks.size) } else { evenChunk = this._incomingChunks.take(this._incomingChunks.size - 1) } this.push(Buffer.from(evenChunk.toString(), 'hex')) } break } } callback() } } module.exports = ByteaDecoder package/encoder-test.js000644 0000001406 3560116604 012213 0ustar00000000 000000 'use strict' const test = require('tape-promise').default(require('tape')) const { Readable } = require('stream') const streamToPromise = require('stream-to-promise') const Encoder = require('./encoder') test('encoder', (t) => { t.test('empty input gives empty result', async (t) => { const result = await streamToPromise(Readable.from([]).pipe(new Encoder())) t.equal(result.toString(), '\\\\x') }) t.test('input cuts at chunk boundary multiple ways', async (t) => { const input = [0x12, 0x34, 0x56] for (let i = 1; i < input.length; i++) { const result = await streamToPromise(Readable.from([input.slice(0, i), input.slice(i)].map(Buffer.from)).pipe(new Encoder())) t.equal(result.toString(), '\\\\x123456') } t.end() }) }) package/encoder.js000644 0000000435 3560116604 011237 0ustar00000000 000000 'use strict' const { Transform } = require('stream') class ByteaEncoder extends Transform { constructor () { super() this.push('\\\\x') } _transform (chunk, encoding, callback) { this.push(chunk.toString('hex')) callback() } } module.exports = ByteaEncoder package/index.js000644 0000000214 3560116604 010722 0ustar00000000 000000 'use strict' exports = module.exports = require('./decode') exports.Encoder = require('./encoder') exports.Decoder = require('./decoder') package/package.json000644 0000001304 3560116604 011544 0ustar00000000 000000 { "name": "postgres-bytea", "main": "index.js", "version": "3.0.0", "description": "Postgres bytea parser", "license": "MIT", "repository": "bendrucker/postgres-bytea", "author": { "name": "Ben Drucker", "email": "bvdrucker@gmail.com", "url": "bendrucker.me" }, "engines": { "node": ">= 6" }, "scripts": { "test": "standard && tape *.js" }, "keywords": [ "bytea", "postgres", "binary", "parser" ], "dependencies": { "obuf": "~1.1.2" }, "devDependencies": { "concat-stream": "2.0.0", "standard": "^14.0.0", "stream-to-promise": "^3.0.0", "tape": "^5.0.0", "tape-promise": "4.0.0" }, "files": [ "*.js" ] } package/readme.md000644 0000004756 3560116604 011053 0ustar00000000 000000 # postgres-bytea [![Build Status](https://travis-ci.org/bendrucker/postgres-bytea.svg?branch=master)](https://travis-ci.org/bendrucker/postgres-bytea) [![Greenkeeper badge](https://badges.greenkeeper.io/bendrucker/postgres-bytea.svg)](https://greenkeeper.io/) > Decode/encode Postgres bytea strings to Buffers ## Install ```sh npm install postgres-bytea ``` ## Usage ### Decoding To decode a bytea string into a buffer: ```js const bytea = require('postgres-bytea') // bytea hex format bytea.decode('\\x1234') // // bytea escape format bytea.decode('\\000\\100\\200') // ``` The `decode` function supports both the hex format used in Postgres 9+ and the escape format used in Postgres 8 and earlier. It automatically detects the format from the incoming data. For backward compatibility, `decode` is also the default export from the package. ### Decoding (Stream) To decode a bytea hex stream into binary: ```js const bytea = require('postgres-bytea') readable.pipe(new bytea.Decoder()) ``` `Decoder` expects a double-escaped `\\x` prefix to allow reading from a `COPY TO` statement. ### Encoding (Stream) ```js const bytea = require('postgres-bytea') readable.pipe(new bytea.Encoder()) ``` `Encoder` adds a double-escaped `\\x` prefix to allow writing to a `COPY FROM` statement. ## API #### `bytea.decode(input)` -> `buffer` ##### input *Required* Type: `string` A Postgres bytea binary string. #### `new bytea.Decoder()` -> `stream.Transform` Creates a bytea decoder stream that emits buffer chunks. #### `new bytea.Encoder()` -> `stream.Transform` Creates a bytea encoder stream that receives buffer chunks and emits them as bytea strings. ## Prefix Escaping > The “hex” format encodes binary data as 2 hexadecimal digits per byte, most significant nibble first. The entire string is preceded by the sequence \x (to distinguish it from the escape format). In some contexts, the initial backslash may need to be escaped by doubling it (see Section 4.1.2.1). > > https://www.postgresql.org/docs/12/datatype-binary.html#id-1.5.7.12.9 A `SELECT` statement returns bytea values using the single-escaped `\x` prefix. The `COPY TO` and `COPY FROM` commands expect and return bytea values with the double-escaped `\\x` prefix. `bytea.decode` expects the single-escaped prefix. The `Decoder` and `Encoder` streams expect the double-escaped prefix, since they are most useful in `COPY FROM` and `COPY TO` statements. ## License MIT © [Ben Drucker](http://bendrucker.me)