index.js 7.3 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240
  1. "use strict";
  2. Object.defineProperty(exports, "__esModule", { value: true });
  3. exports.isBinaryFileSync = exports.isBinaryFile = void 0;
  4. const fs = require("fs");
  5. const util_1 = require("util");
  6. const statAsync = (0, util_1.promisify)(fs.stat);
  7. const openAsync = (0, util_1.promisify)(fs.open);
  8. const closeAsync = (0, util_1.promisify)(fs.close);
  9. const MAX_BYTES = 512;
  10. // A very basic non-exception raising reader. Read bytes and
  11. // at the end use hasError() to check whether this worked.
  12. class Reader {
  13. fileBuffer;
  14. size;
  15. offset;
  16. error;
  17. constructor(fileBuffer, size) {
  18. this.fileBuffer = fileBuffer;
  19. this.size = size;
  20. this.offset = 0;
  21. this.error = false;
  22. }
  23. hasError() {
  24. return this.error;
  25. }
  26. nextByte() {
  27. if (this.offset === this.size || this.hasError()) {
  28. this.error = true;
  29. return 0xff;
  30. }
  31. return this.fileBuffer[this.offset++];
  32. }
  33. next(len) {
  34. const n = new Array();
  35. for (let i = 0; i < len; i++) {
  36. n[i] = this.nextByte();
  37. }
  38. return n;
  39. }
  40. }
  41. // Read a Google Protobuf var(iable)int from the buffer.
  42. function readProtoVarInt(reader) {
  43. let idx = 0;
  44. let varInt = 0;
  45. while (!reader.hasError()) {
  46. const b = reader.nextByte();
  47. varInt = varInt | ((b & 0x7f) << (7 * idx));
  48. if ((b & 0x80) === 0) {
  49. break;
  50. }
  51. idx++;
  52. }
  53. return varInt;
  54. }
  55. // Attempt to taste a full Google Protobuf message.
  56. function readProtoMessage(reader) {
  57. const varInt = readProtoVarInt(reader);
  58. const wireType = varInt & 0x7;
  59. switch (wireType) {
  60. case 0:
  61. readProtoVarInt(reader);
  62. return true;
  63. case 1:
  64. reader.next(8);
  65. return true;
  66. case 2:
  67. const len = readProtoVarInt(reader);
  68. reader.next(len);
  69. return true;
  70. case 5:
  71. reader.next(4);
  72. return true;
  73. }
  74. return false;
  75. }
  76. // Check whether this seems to be a valid protobuf file.
  77. function isBinaryProto(fileBuffer, totalBytes) {
  78. const reader = new Reader(fileBuffer, totalBytes);
  79. let numMessages = 0;
  80. while (true) {
  81. // Definitely not a valid protobuf
  82. if (!readProtoMessage(reader) && !reader.hasError()) {
  83. return false;
  84. }
  85. // Short read?
  86. if (reader.hasError()) {
  87. break;
  88. }
  89. numMessages++;
  90. }
  91. return numMessages > 0;
  92. }
  93. async function isBinaryFile(file, size) {
  94. if (isString(file)) {
  95. const stat = await statAsync(file);
  96. isStatFile(stat);
  97. const fileDescriptor = await openAsync(file, 'r');
  98. const allocBuffer = Buffer.alloc(MAX_BYTES);
  99. // Read the file with no encoding for raw buffer access.
  100. // NB: something is severely wrong with promisify, had to construct my own Promise
  101. return new Promise((fulfill, reject) => {
  102. fs.read(fileDescriptor, allocBuffer, 0, MAX_BYTES, 0, (err, bytesRead, _) => {
  103. closeAsync(fileDescriptor);
  104. if (err) {
  105. reject(err);
  106. }
  107. else {
  108. fulfill(isBinaryCheck(allocBuffer, bytesRead));
  109. }
  110. });
  111. });
  112. }
  113. else {
  114. if (size === undefined) {
  115. size = file.length;
  116. }
  117. return isBinaryCheck(file, size);
  118. }
  119. }
  120. exports.isBinaryFile = isBinaryFile;
  121. function isBinaryFileSync(file, size) {
  122. if (isString(file)) {
  123. const stat = fs.statSync(file);
  124. isStatFile(stat);
  125. const fileDescriptor = fs.openSync(file, 'r');
  126. const allocBuffer = Buffer.alloc(MAX_BYTES);
  127. const bytesRead = fs.readSync(fileDescriptor, allocBuffer, 0, MAX_BYTES, 0);
  128. fs.closeSync(fileDescriptor);
  129. return isBinaryCheck(allocBuffer, bytesRead);
  130. }
  131. else {
  132. if (size === undefined) {
  133. size = file.length;
  134. }
  135. return isBinaryCheck(file, size);
  136. }
  137. }
  138. exports.isBinaryFileSync = isBinaryFileSync;
  139. function isBinaryCheck(fileBuffer, bytesRead) {
  140. // empty file. no clue what it is.
  141. if (bytesRead === 0) {
  142. return false;
  143. }
  144. let suspiciousBytes = 0;
  145. const totalBytes = Math.min(bytesRead, MAX_BYTES);
  146. // UTF-8 BOM
  147. if (bytesRead >= 3 && fileBuffer[0] === 0xef && fileBuffer[1] === 0xbb && fileBuffer[2] === 0xbf) {
  148. return false;
  149. }
  150. // UTF-32 BOM
  151. if (bytesRead >= 4 &&
  152. fileBuffer[0] === 0x00 &&
  153. fileBuffer[1] === 0x00 &&
  154. fileBuffer[2] === 0xfe &&
  155. fileBuffer[3] === 0xff) {
  156. return false;
  157. }
  158. // UTF-32 LE BOM
  159. if (bytesRead >= 4 &&
  160. fileBuffer[0] === 0xff &&
  161. fileBuffer[1] === 0xfe &&
  162. fileBuffer[2] === 0x00 &&
  163. fileBuffer[3] === 0x00) {
  164. return false;
  165. }
  166. // GB BOM
  167. if (bytesRead >= 4 &&
  168. fileBuffer[0] === 0x84 &&
  169. fileBuffer[1] === 0x31 &&
  170. fileBuffer[2] === 0x95 &&
  171. fileBuffer[3] === 0x33) {
  172. return false;
  173. }
  174. if (totalBytes >= 5 && fileBuffer.slice(0, 5).toString() === '%PDF-') {
  175. /* PDF. This is binary. */
  176. return true;
  177. }
  178. // UTF-16 BE BOM
  179. if (bytesRead >= 2 && fileBuffer[0] === 0xfe && fileBuffer[1] === 0xff) {
  180. return false;
  181. }
  182. // UTF-16 LE BOM
  183. if (bytesRead >= 2 && fileBuffer[0] === 0xff && fileBuffer[1] === 0xfe) {
  184. return false;
  185. }
  186. for (let i = 0; i < totalBytes; i++) {
  187. if (fileBuffer[i] === 0) {
  188. // NULL byte--it's binary!
  189. return true;
  190. }
  191. else if ((fileBuffer[i] < 7 || fileBuffer[i] > 14) && (fileBuffer[i] < 32 || fileBuffer[i] > 127)) {
  192. // UTF-8 detection
  193. if (fileBuffer[i] >= 0xc0 && fileBuffer[i] <= 0xdf && i + 1 < totalBytes) {
  194. i++;
  195. if (fileBuffer[i] >= 0x80 && fileBuffer[i] <= 0xbf) {
  196. continue;
  197. }
  198. }
  199. else if (fileBuffer[i] >= 0xe0 && fileBuffer[i] <= 0xef && i + 2 < totalBytes) {
  200. i++;
  201. if (fileBuffer[i] >= 0x80 && fileBuffer[i] <= 0xbf && fileBuffer[i + 1] >= 0x80 && fileBuffer[i + 1] <= 0xbf) {
  202. i++;
  203. continue;
  204. }
  205. }
  206. else if (fileBuffer[i] >= 0xf0 && fileBuffer[i] <= 0xf7 && i + 3 < totalBytes) {
  207. i++;
  208. if (fileBuffer[i] >= 0x80 &&
  209. fileBuffer[i] <= 0xbf &&
  210. fileBuffer[i + 1] >= 0x80 &&
  211. fileBuffer[i + 1] <= 0xbf &&
  212. fileBuffer[i + 2] >= 0x80 &&
  213. fileBuffer[i + 2] <= 0xbf) {
  214. i += 2;
  215. continue;
  216. }
  217. }
  218. suspiciousBytes++;
  219. // Read at least 32 fileBuffer before making a decision
  220. if (i >= 32 && (suspiciousBytes * 100) / totalBytes > 10) {
  221. return true;
  222. }
  223. }
  224. }
  225. if ((suspiciousBytes * 100) / totalBytes > 10) {
  226. return true;
  227. }
  228. if (suspiciousBytes > 1 && isBinaryProto(fileBuffer, totalBytes)) {
  229. return true;
  230. }
  231. return false;
  232. }
  233. function isString(x) {
  234. return typeof x === 'string';
  235. }
  236. function isStatFile(stat) {
  237. if (!stat.isFile()) {
  238. throw new Error(`Path provided was not a file!`);
  239. }
  240. }