lexluthr / go-car

A content addressible archive utility

go-car (go!)

Work with car (Content addressed ARchive) files!

This is a Golang implementation of the CAR specifications, both CARv1 and CARv2.

As a format, there are two major module versions:

• go-car/v2 is geared towards reading and writing CARv2 files, and also supports consuming CARv1 files and using CAR files as an IPFS blockstore.
• go-car, in the root directory, only supports reading and writing CARv1 files.

Most users should use v2, especially for new software, since the v2 API transparently supports both CAR formats.

Usage / Installation

This repository provides a car binary that can be used for creating, extracting, and working with car files.

To install the latest version of car, run:

go install github.com/ipld/go-car/cmd/car@latest

More information about this binary is available in cmd/car

Features

CARv2 features:

• Generate index from an existing CARv1 file
• Wrap CARv1 files into a CARv2 with automatic index generation.
• Random-access to blocks in a CAR file given their CID via Read-Only blockstore API, with transparent support for both CARv1 and CARv2
• Write CARv2 files via Read-Write blockstore API, with support for appending blocks to an existing CARv2 file, and resumption from a partially written CARv2 files.
• Individual access to inner CARv1 data payload and index of a CARv2 file via the Reader API.

API Documentation

See docs on pkg.go.dev.

Examples

Here is a shortlist of other examples from the documentation

• Wrap an existing CARv1 file into an indexed CARv2 file
• Open read-only blockstore from a CAR file
• Open read-write blockstore from a CAR file
• Read the index from an existing CARv2 file
• Extract the index from a CARv2 file and store it as a separate file

Maintainers

• Masih Derkani
• Will Scott

Contribute

PRs are welcome!

When editing the Readme, please conform to the standard-readme specification.

License

Apache-2.0/MIT © Protocol Labs