feature(cache): add dune cache size command

Signed-off-by: Ali Caglayan <alizter@gmail.com>
ocaml · Dec 30, 2022 · 81786a7 · 81786a7
1 parent fa3aa28
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diff --git a/CHANGES.md b/CHANGES.md
@@ -85,6 +85,9 @@ Unreleased
 - Validate the command line arguments for `$ dune ocaml top-module`. This
   command requires one positional argument (#6796, fixes #6793, @rgrinberg)
 
+- Add a `dune cache size` command for displaying the size of the cache (#6638,
+  @Alizter)
+
 3.6.1 (2022-11-24)
 ------------------
 

diff --git a/bin/cache.ml b/bin/cache.ml
@@ -52,17 +52,43 @@ let trim =
          (User_message.make
             [ Pp.textf "Freed %s" (Bytes_unit.pp trimmed_bytes) ])
 
+let size =
+  let info =
+    let doc = "Query the size of the Dune cache" in
+    let man =
+      [ `P
+          "Compute the total size of files in the Dune cache which are not \
+           hardlinked from any build directory and output it in a \
+           human-readable form."
+      ]
+    in
+    Cmd.info "size" ~doc ~man
+  in
+  Cmd.v info
+  @@ let+ machine_readble =
+       Arg.(
+         value & flag
+         & info [ "machine-readable" ]
+             ~doc:"Outputs size as a plain number of bytes.")
+     in
+     let size = Dune_cache.Trimmer.overhead_size () in
+     if machine_readble then
+       User_message.print (User_message.make [ Pp.textf "%Ld" size ])
+     else
+       User_message.print
+         (User_message.make [ Pp.textf "%s" (Bytes_unit.pp size) ])
+
 let command =
   let info =
     let doc = "Manage the shared cache of build artifacts" in
     let man =
       [ `S "DESCRIPTION"
       ; `P
-          "Dune can share build artifacts between workspaces. Currently, the \
-           only action supported by this command is `trim`, but we plan to \
-           provide more functionality soon."
+          "Dune can share build artifacts between workspaces. We currently \
+           only support a few subcommands; however, we plan to provide more \
+           functionality soon."
       ]
     in
     Cmd.info "cache" ~doc ~man
   in
-  Cmd.group info [ trim ]
+  Cmd.group info [ trim; size ]
diff --git a/test/blackbox-tests/test-cases/dune-cache/cache-man.t b/test/blackbox-tests/test-cases/dune-cache/cache-man.t
@@ -8,53 +8,14 @@ Here we observe the documentation for the dune cache commands.
          dune cache COMMAND …
 
   DESCRIPTION
-         Dune can share build artifacts between workspaces. Currently, the only
-         action supported by this command is `trim`, but we plan to provide
-         more functionality soon.
+         Dune can share build artifacts between workspaces. We currently only
+         support a few subcommands; however, we plan to provide more
+         functionality soon.
 
   COMMANDS
-         trim [--size=BYTES] [--trimmed-size=BYTES] [OPTION]…
-             Trim the Dune cache
-
-  COMMON OPTIONS
-         --help[=FMT] (default=auto)
-             Show this help in format FMT. The value FMT must be one of auto,
-             pager, groff or plain. With auto, the format is pager or plain
-             whenever the TERM env var is dumb or undefined.
-
-         --version
-             Show version information.
+         size [--machine-readable] [OPTION]…
+             Query the size of the Dune cache
 
-  EXIT STATUS
-         cache exits with the following status:
-
-         0   on success.
-
-         123 on indiscriminate errors reported on standard error.
-
-         124 on command line parsing errors.
-
-         125 on unexpected internal errors (bugs).
-
-  SEE ALSO
-         dune(1)
-
-
-Man pages of the deprecated start and stop commands.
-
-  $ dune cache start --help=plain
-  NAME
-         dune-cache - Manage the shared cache of build artifacts
-
-  SYNOPSIS
-         dune cache COMMAND …
-
-  DESCRIPTION
-         Dune can share build artifacts between workspaces. Currently, the only
-         action supported by this command is `trim`, but we plan to provide
-         more functionality soon.
-
-  COMMANDS
          trim [--size=BYTES] [--trimmed-size=BYTES] [OPTION]…
              Trim the Dune cache
 
@@ -81,22 +42,22 @@ Man pages of the deprecated start and stop commands.
   SEE ALSO
          dune(1)
 
+Testing the output of `dune cache size --machine-readable`
 
-  $ dune cache stop --help=plain
+  $ dune cache size --help=plain
   NAME
-         dune-cache - Manage the shared cache of build artifacts
+         dune-cache-size - Query the size of the Dune cache
 
   SYNOPSIS
-         dune cache COMMAND …
+         dune cache size [--machine-readable] [OPTION]…
 
-  DESCRIPTION
-         Dune can share build artifacts between workspaces. Currently, the only
-         action supported by this command is `trim`, but we plan to provide
-         more functionality soon.
+         Compute the total size of files in the Dune cache which are not
+         hardlinked from any build directory and output it in a human-readable
+         form.
 
-  COMMANDS
-         trim [--size=BYTES] [--trimmed-size=BYTES] [OPTION]…
-             Trim the Dune cache
+  OPTIONS
+         --machine-readable
+             Outputs size as a plain number of bytes.
 
   COMMON OPTIONS
          --help[=FMT] (default=auto)
@@ -108,7 +69,7 @@ Man pages of the deprecated start and stop commands.
              Show version information.
 
   EXIT STATUS
-         cache exits with the following status:
+         size exits with the following status:
 
          0   on success.
 
@@ -121,7 +82,6 @@ Man pages of the deprecated start and stop commands.
   SEE ALSO
          dune(1)
 
-
 Testing the output of dune cache trim.
 
   $ dune cache trim --help=plain

diff --git a/test/blackbox-tests/test-cases/dune-cache/size.t/run.t b/test/blackbox-tests/test-cases/dune-cache/size.t/run.t
@@ -0,0 +1,45 @@
+This test checks that the `dune cache size` command returns the correct size of
+the cache.
+
+  $ export DUNE_CACHE=enabled
+  $ export DUNE_CACHE_ROOT=$PWD/.cache
+
+  $ cat > config << EOF
+  > (lang dune 3.7)
+  > (cache enabled)
+  > (cache-storage-mode copy)
+  > EOF
+
+  $ cat > dune-project << EOF
+  > (lang dune 3.7)
+  > EOF
+
+  $ cat > dune << EOF
+  > (rule
+  > (targets target_a)
+  > (action
+  >  (with-outputs-to
+  >   target_a
+  >   (echo Hello World!))))
+  > EOF
+
+We build a simple file with the contents of "Hello World!".
+
+  $ dune build target_a --display=short
+
+Now we remove it so that we are checking the size of the file rather than the
+link Dune created.
+
+  $ rm _build/default/target_a
+
+The size command reports the size of the cache in bytes in human-readable form.
+It correctly reports 12 bytes.
+
+  $ dune cache size
+  12B
+
+We also have a machine-readable version of the command which reports the size of
+the cache in bytes directly without any units.
+
+  $ dune cache size --machine-readable
+  12
diff --git a/test/blackbox-tests/test-cases/dune-cache/trim.t b/test/blackbox-tests/test-cases/dune-cache/trim.t
@@ -192,5 +192,3 @@ are part of the same rule.
 
 TODO: Test trimming priority in the [copy] mode. In PR #4497 we added a test but
 it turned out to be flaky so we subsequently deleted it in #4511.
-
-
Original file line number	Diff line number	Diff line change
Expand Up		@@ -192,5 +192,3 @@ are part of the same rule.

		TODO: Test trimming priority in the [copy] mode. In PR #4497 we added a test but
		it turned out to be flaky so we subsequently deleted it in #4511.