*1*.
--
+
-See the http://zstd.net[Zstandard documentation] for more information.
+See the https://facebook.github.io/zstd/[Zstandard documentation] for more information.
[#config_cpp_extension]
*cpp_extension* (*CCACHE_EXTENSION*)::
information that affects the compilation. When the same hash is encountered
again, ccache can supply all the correct compiler outputs from the cache.
-For hashing, ccache uses BLAKE3, a fast cryptographic hash algorithm. For data
-integrity, cached data is protected with XXH3 checksums to detect corruption.
+For hashing, ccache uses https://blake3.io[BLAKE3], a fast cryptographic hash
+algorithm. For data integrity, cached data is protected with
+https://xxhash.com[XXH3] checksums to detect corruption.
Ccache has two strategies for gathering the information used to create cache
lookup keys:
locality.
- Added compression of result and manifest files using the
- http://zstd.net[Zstandard] algorithm. Compression is enabled by default with
- compression level 1. This makes ccache able to store more data in the cache.
- Previously compression using Deflate (zlib) was available but disabled by
- default. Files can be recompressed with another compression level later with
- the `-X/--recompress` option described further below.
+ https://facebook.github.io/zstd/[Zstandard] algorithm. Compression is enabled
+ by default with compression level 1. This makes ccache able to store more data
+ in the cache. Previously compression using Deflate (zlib) was available but
+ disabled by default. Files can be recompressed with another compression level
+ later with the `-X/--recompress` option described further below.
- Changed from MD4 to https://blake3.io[BLAKE3] for hashing input. This
improves performance and reduces the risk of hash collisions.
- Added checksumming of result and manifest files using the
- http://xxhash.com[XXH3] algorithm to detect data corruption.
+ https://xxhash.com[XXH3] algorithm to detect data corruption.
- Ccache now follows the
https://specifications.freedesktop.org/basedir-spec/[XDG base directory
- Added support for long command-line options.
- A `CACHEDIR.TAG` file is now created in the cache directory. See
- <http://www.brynosaurus.com/cachedir/>.
+ <https://bford.info/cachedir>.
- Messages printed to the debug log (specified by `CCACHE_LOGFILE`) have been
improved.