Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

The idea is to save the whole untouched clone (with no checkout) in the cache.

If already present, the pull is done directly in the cache, and is
faster (except on very small repos) because only new changeset are
transfered.

If the ref is a changeset id (not a tag, branch, topic or bookmark), and
the changeset is already known in the cached clone, no pull is done
which avoid any network exchange.

Then we copy the cached entry and do the checkout.

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

The repo URL must be in the cache id.
The ref is purposely not included in it because we want to reuse the cached repository
when the ref moves.
And finally, we use a sha256 hash to mask any authentication data because we don't
want them to be readable in the cache folder name.

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Use only the repository URL as a cacheID

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

The 'hg' type is strictly an internal tool of the 'hg' fetcher.
The only meaningful public API of this package is the 'Sync' type.

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>

Signed-off-by: Christophe de Vienne <christophe.devienne@orus.io>