1. const fs = require('fs');
  2. const { spawn } = require('child_process');
  4. /**
  5. * Searches for a pattern within a binary file, with a timeout.
  6. *
  7. * @param {string} filePath - The path to the binary file.
  8. * @param {string} searchPattern - The pattern to search for (hex or byte sequence).
  9. * @param {number} timeoutMs - The timeout in milliseconds.
  10. * @returns {Promise<number|null>} - The starting byte index of the first match, or null if no match found within the timeout.
  11. * @throws {Error} If the file does not exist.
  12. */
  13. async function searchBinaryFile(filePath, searchPattern, timeoutMs) {
  14. try {
  15. if (!fs.existsSync(filePath)) {
  16. throw new Error(`File not found: ${filePath}`);
  17. }
  19. return new Promise((resolve, reject) => {
  20. const startTime = Date.now();
  22. const search = (data, pattern, offset) => {
  23. for (let i = 0; i <= data.length - pattern.length; i++) {
  24. let match = true;
  25. for (let j = 0; j < pattern.length; j++) {
  26. if (data[i + j] !== pattern[j]) {
  27. match = false;
  28. break;
  29. }
  30. }
  31. if (match) {
  32. resolve(offset + i);
  33. return;
  34. }
  35. }
  36. resolve(null);
  37. };
  40. const stream = fs.createReadStream(filePath, { highWaterMark: 64 * 1024 }); // 64KB chunks
  41. let buffer = '';
  42. let bytesRead = 0;
  44. stream.on('data', (chunk) => {
  45. buffer += chunk;
  46. bytesRead += chunk.length;
  48. if (Date.now() - startTime > timeoutMs) {
  49. stream.destroy(); // Stop reading if timeout
  50. resolve(null);
  51. return;
  52. }
  54. const hexPattern = pattern.startsWith('0x') ? pattern.substring(2).split('').map(Number) : pattern.split('').map(Number);
  55. if(bytesRead >= hexPattern.length) {
  56. search(buffer, hexPattern, 0);
  57. }
  58. });
  60. stream.on('end', () => {
  61. if (Date.now() - startTime > timeoutMs) {
  62. resolve(null);
  63. } else {
  64. search(buffer, hexPattern, 0);
  65. }
  66. });
  68. stream.on('error', (err) => {
  69. stream.destroy();
  70. reject(err);
  71. });
  72. });
  74. } catch (error) {
  75. throw error;
  76. }
  77. }
  79. module.exports = searchBinaryFile;

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