zip-iterator
Version:
Extract contents from zip archive type using an iterator API using streams or paths. Use stream interface and pipe transforms to add decompression algorithms
81 lines (80 loc) • 2.51 kB
JavaScript
/**
* DeflateBufferHandler - Buffered DEFLATE decompression
*
* Used for entries with data descriptors where compressed size is unknown.
* Buffers all compressed data, then decompresses once the boundary is found.
*/ import { crc32, inflateRaw } from 'extract-base-iterator';
import * as C from '../constants.js';
export class DeflateBufferHandler {
write(chunk) {
this.chunks.push(chunk);
}
/**
* Decompress all buffered data and verify CRC
*/ finish(expectedCrc) {
if (this.chunks.length === 0) {
// No data to decompress
this.onComplete();
return {
continue: true
};
}
try {
// Concatenate all chunks
const compressedData = Buffer.concat(this.chunks);
this.chunks = [];
// Decompress using native zlib (Node 0.11.12+) or pako fallback
const decompressed = inflateRaw(compressedData);
// Verify CRC
if (this.verifyCrc) {
this.runningCrc = crc32(decompressed);
if (this.runningCrc !== expectedCrc) {
this.onError(C.createZipError(`CRC32 mismatch: expected ${expectedCrc.toString(16)}, got ${this.runningCrc.toString(16)}`, C.ZipErrorCode.CRC_MISMATCH));
return {
continue: false
};
}
}
// Write decompressed data
this.outputStream.write(decompressed);
this.onComplete();
return {
continue: true
};
} catch (err) {
this.onError(err);
return {
continue: false,
error: err
};
}
}
getRunningCrc() {
return this.runningCrc;
}
isWaiting() {
return false; // Buffered handler is always synchronous
}
/**
* Get accumulated compressed data without consuming it
*/ getBuffer() {
return Buffer.concat(this.chunks);
}
/**
* Clear the buffer
*/ clearBuffer() {
this.chunks = [];
}
destroy() {
this.chunks = [];
this.runningCrc = 0;
}
constructor(options){
this.chunks = [];
this.runningCrc = 0;
this.outputStream = options.outputStream;
this.onComplete = options.onComplete;
this.onError = options.onError;
this.verifyCrc = options.verifyCrc !== false;
}
}