Revert "refactor: reduce execution requirements for copy" (#594)

* Revert "refactor: reduce execution requirements for copy"

This reverts commit 40c2ddc.

* Update ci.bazelrc

lib/private/copy_common.bzl

@@ -1,11 +1,61 @@
 "Helpers for copy rules"
 
-# Hints for Bazel spawn strategy, copied from
-# https://github.com/bazelbuild/bazel-skylib/blob/0171c69e5cc691e2d0cd9f3f3e4c3bf112370ca2/rules/private/copy_common.bzl
-# See extensive comments there for reasoning on this execution-requirements selection.
+# Hints for Bazel spawn strategy
 COPY_EXECUTION_REQUIREMENTS = {
+ # ----------------+-----------------------------------------------------------------------------
+ # no-remote | Prevents the action or test from being executed remotely or cached remotely.
+ # | This is equivalent to using both `no-remote-cache` and `no-remote-exec`.
+ # ----------------+-----------------------------------------------------------------------------
+ # no-remote-cache | Results in the action or test never being cached remotely (but it may
+ # | be cached locally; it may also be executed remotely). Note: for the purposes
+ # | of this tag, the disk-cache is considered a local cache, whereas the http
+ # | and gRPC caches are considered remote. If a combined cache is specified
+ # | (i.e. a cache with local and remote components), it's treated as a remote
+ # | cache and disabled entirely unless --incompatible_remote_results_ignore_disk
+ # | is set in which case the local components will be used.
+ # ----------------+-----------------------------------------------------------------------------
+ # no-remote-exec | Results in the action or test never being executed remotely (but it may be
+ # | cached remotely).
+ # ----------------+-----------------------------------------------------------------------------
+ # no-cache | Results in the action or test never being cached (remotely or locally)
+ # ----------------+-----------------------------------------------------------------------------
+ # no-sandbox | Results in the action or test never being sandboxed; it can still be cached
+ # | or run remotely - use no-cache or no-remote to prevent either or both of
+ # | those.
+ # ----------------+-----------------------------------------------------------------------------
+ # local | Precludes the action or test from being remotely cached, remotely executed,
+ # | or run inside the sandbox. For genrules and tests, marking the rule with the
+ # | local = True attribute has the same effect.
+ # ----------------+-----------------------------------------------------------------------------
+ # See https://bazel.google.cn/reference/be/common-definitions?hl=en&authuser=0#common-attributes
+ #
+ # Copying file & directories is entirely IO-bound and there is no point doing this work
+ # remotely.
+ #
+ # Also, remote-execution does not allow source directory inputs, see
+ # https://github.com/bazelbuild/bazel/commit/c64421bc35214f0414e4f4226cc953e8c55fa0d2 So we must
+ # not attempt to execute remotely in that case.
+ #
+ # There is also no point pulling the output file or directory from the remote cache since the
+ # bytes to copy are already available locally. Conversely, no point in writing to the cache if
+ # no one has any reason to check it for this action.
+ #
+ # Read and writing to disk cache is disabled as well primarily to reduce disk usage on the local
+ # machine. A disk cache hit of a directory copy could be slghtly faster than a copy since the
+ # disk cache stores the directory artifact as a single entry, but the slight performance bump
+ # comes at the cost of heavy disk cache usage, which is an unmanaged directory that grow beyond
+ # the bounds of the physical disk.
+ # TODO: run benchmarks to measure the impact on copy_directory
+ #
+ # Sandboxing for this action is wasteful as well since there is a 1:1 mapping of input
+ # file/directory to output file/directory and no room for non-hermetic inputs to sneak in to the
+ # input.
  "no-remote": "1",
+ "no-remote-cache": "1",
+ "no-remote-exec": "1",
  "no-cache": "1",
+ "no-sandbox": "1",
+ "local": "1",
 }
 
 def progress_path(f):