go-car (go!)

A library to interact with merkledags stored as a single file

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

Note that 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 v0, in the root directory, just supports reading and writing CARv1 files.

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

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.

Install

To install the latest version of go-car/v2 module, run:

go get github.com/ipld/go-car/v2

Alternatively, to install the v0 module, run:

go get github.com/ipld/go-car

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

• Daniel Martí
• Masih Derkani

Contribute

PRs are welcome!

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

License

Apache-2.0/MIT © Protocol Labs