Block-sorting compression using Burrows-Wheeler Transform, Move-to-Front coding, Run-Length Encoding, and Huffman coding. Both compression and decompression are implemented and interoperate with the real bzip2 CLI in both directions (verified against bzip2 1.0.8: it decodes our compressed output, and our decoder reads real bzip2 -9 output, including block and stream CRC verification). The encoder always uses the minimum legal number of Huffman tables (2, both identical) rather than bzip2’s multi-table selector optimization, so output is larger than the reference encoder’s but fully standard-compliant.
| Property | Value |
|---|---|
| Category | Compression Algorithms |
| Sub-category | Block Sorting |
| Security status | 🎓 Educational Only |
| Complexity | Advanced |
| Inventor | Julian Seward |
| Year | 1996 |
| Origin | 🇬🇧 United Kingdom |
| Source | algorithms/compression/bzip2.js |
Status: 🎓 Educational Only
No vulnerabilities are recorded for this implementation.
6 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Hello World - Go stdlib test vector
| Field | Value |
|---|---|
inverse |
Yes |
input |
425a68393141592653594eece8360000 0251800010400006449080200031064c 4101a7a9a580bb9431f8bb9229c28482 776741b0 |
expected |
68656c6c6f20776f726c640a |
Vector 2 — 32 Zero Bytes - Go stdlib test vector
| Field | Value |
|---|---|
inverse |
Yes |
input |
425a6839314159265359b5aa50980000 00600040000004200021008283177245 385090b5aa5098 |
expected |
0000000000000000000000000000000000000000000000000000000000000000 |
Vector 3 — 1MiB Zeros - Go stdlib test vector
| Field | Value |
|---|---|
inverse |
Yes |
input |
425a683931415926535938571ce50008 084000c0040008200030cc0529a60806 c4201e2ee48a70a12070ae39ca |
expected |
00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 00000000000000000000000000000000 … (1048576 bytes; the full value is in the source) |
Vector 4 — Round-trip - short text (compression + decompression)
| Field | Value |
|---|---|
inverse |
No |
input |
68656c6c6f20776f726c64 |
expected |
(empty) |
Vector 5 — Round-trip - repeated pattern (compression + decompression)
| Field | Value |
|---|---|
inverse |
No |
input |
74686520717569636b2062726f776e20 666f78206a756d7073206f7665722074 6865206c617a7920646f672e20746865 20717569636b2062726f776e20666f78 … (900 bytes; the full value is in the source) |
expected |
(empty) |
Vector 6 — Round-trip - all 256 byte values (compression + decompression)
| Field | Value |
|---|---|
inverse |
No |
input |
000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f 404142434445464748494a4b4c4d4e4f 505152535455565758595a5b5c5d5e5f 606162636465666768696a6b6c6d6e6f 707172737475767778797a7b7c7d7e7f 808182838485868788898a8b8c8d8e8f 909192939495969798999a9b9c9d9e9f a0a1a2a3a4a5a6a7a8a9aaabacadaeaf b0b1b2b3b4b5b6b7b8b9babbbcbdbebf c0c1c2c3c4c5c6c7c8c9cacbcccdcecf d0d1d2d3d4d5d6d7d8d9dadbdcdddedf e0e1e2e3e4e5e6e7e8e9eaebecedeeef f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff |
expected |
(empty) |