ZArchive is yet another file archive format. Think of zip, tar, 7z, etc. but with the requirement of allowing random-access reads and supporting compression.
- Supports random-access reads within stored files
- Uses zstd compression (64KiB blocks)
- Scales reasonably well up to multiple terabytes with millions of files
- The theoretical size limit per-file is 2^48-1 (256 Terabyte)
- The encoding for paths within the archive is Windows-1252 (case-insensitive)
- Contains a SHA256 hash of the whole archive for integrity checks
- Endian-independent. The format always uses big-endian internally
- Stateless file and directory iterator handles which don't require memory allocation
#include "zarchive/zarchivereader.h"
int main()
{
ZArchiveReader* reader = ZArchiveReader::OpenFromFile("archive.zar");
if (!reader)
return -1;
ZArchiveNodeHandle fileHandle = reader->LookUp("myfolder/example.bin");
if (reader->IsFile(fileHandle))
{
uint8_t buffer[1000];
uint64_t n = reader->ReadFromFile(fileHandle, 0, 1000, buffer);
// buffer now contains the first n (up to 1000) bytes of example.bin
}
delete reader;
return 0;
}For a more detailed example see main.cpp
- Not designed for adding, removing or modifying files after the archive has been created
When creating new archives only byte append operations are used. No file seeking is necessary. This makes it possible to create archives on storage which is write-once. It also simplifies streaming ZArchive creation over network.
UTF8 for file and folder paths is theoretically supported as paths are just binary blobs. But the case-insensitive comparison only applies to latin letters (a-z).
Originally this format was created to store Wii U games dumps. These use the file extension .wua (Wii U Archive) but are otherwise regular ZArchive files. To allow multiple Wii U titles to be stored inside a single archive, each title must be placed in a subfolder following the naming scheme: 16-digit titleId followed by _v and then the version as decimal. For example: 0005000e10102000_v32
The ZArchive library is licensed under MIT No Attribution, with the exception of sha_256.c and sha_256.h which are public domain, see: https://github.com/amosnier/sha-2.