From cc01059d405e982e3a7de78e318374c3dbace48b Mon Sep 17 00:00:00 2001 From: Kane York Date: Tue, 4 Aug 2020 15:21:11 -0700 Subject: docs(sparse): Add RFC design for depot worktree tool This is meant to be a high-velocity alternative to writing an entire FUSE filesystem to facilitate smaller checkouts of the depot. The script mostly works today, except that remote dependency detection is not set up. Change-Id: Idf9048df4f7ee39eaaedcdafcd9621f3d7479947 Reviewed-on: https://cl.tvl.fyi/c/depot/+/1644 Tested-by: BuildkiteCI Reviewed-by: edef Reviewed-by: tazjin --- docs/designs/SPARSE_CHECKOUTS.md | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 docs/designs/SPARSE_CHECKOUTS.md (limited to 'docs') diff --git a/docs/designs/SPARSE_CHECKOUTS.md b/docs/designs/SPARSE_CHECKOUTS.md new file mode 100644 index 000000000000..fe3a4c0104e5 --- /dev/null +++ b/docs/designs/SPARSE_CHECKOUTS.md @@ -0,0 +1,37 @@ +Below is a prototype for a script to create Git sparse checkouts of the depot. +The script below works today with relatively recent versions of git. + +Open items: + + - Read-increment-write the checkout ID from a file in .git. + - `NICE_CHECKOUT_ROOT` should be a git configuration value. + - `tvl-get-depends` will be a script that contacts the build farm and asks for + the closure of a given source directory, using [depot-scan]. + +```bash +DEPOT_ROOT="${depot.depotPath}" +XDG_DATA_HOME="${XDG_DATA_HOME:-$HOME/.local/share}" +CLIENT_ROOT="$XDG_DATA_HOME/tvlc/clients" +NICE_CHECKOUT_ROOT="$HOME/tvlc" +CHECKOUT_ID=1 +CHECKOUT_NAME=myclient # command line variables + +assertAbsolutePath "$CLIENT_ROOT" + +mkdir "$CLIENT_ROOT"/"$CHECKOUT_ID" +ln -s "$CLIENT_ROOT"/"$CHECKOUT_ID" "$NICE_CHECKOUT_ROOT"/"$CHECKOUT_NAME" + +cd "$DEPOT_ROOT" +git worktree add --no-checkout -b "tvlc-$CHECKOUT_ID" "$CLIENT_ROOT/$CHECKOUT_ID/" canon +# BUG: git not creating the /info/ subdir +mkdir "$DEPOT_ROOT"/.git/worktrees/"$CHECKOUT_ID"/info + +cd "$CLIENT_ROOT/$CHECKOUT_ID" +git sparse-checkout init --cone +git sparse-checkout set "$TARGET_DIR" nix/readTree overrides +tvl-get-depends "$TARGET_DIR" | xargs git sparse-checkout add + +cd "$NICE_CHECKOUT_ROOT"/"$CHECKOUT_NAME" +``` + +[depot-scan]: ../users/edef/depot-scan.nix -- cgit 1.4.1