Add Noop store

Cargo.toml

@@ -63,6 +63,7 @@ members = [
   "gencargo/mock_running_actions_manager",
   "gencargo/mock_scheduler",
   "gencargo/mock_worker_api_client",
+  "gencargo/noop_store",
   "gencargo/platform_property_manager",
   "gencargo/property_modifier_scheduler",
   "gencargo/property_modifier_scheduler_test",
@@ -212,6 +213,7 @@ metrics_utils = { path = "gencargo/metrics_utils" }
 mock_running_actions_manager = { path = "gencargo/mock_running_actions_manager" }
 mock_scheduler = { path = "gencargo/mock_scheduler" }
 mock_worker_api_client = { path = "gencargo/mock_worker_api_client" }
+noop_store = { path = "gencargo/noop_store" }
 platform_property_manager = { path = "gencargo/platform_property_manager" }
 property_modifier_scheduler = { path = "gencargo/property_modifier_scheduler" }
 property_modifier_scheduler_test = { path = "gencargo/property_modifier_scheduler_test" }

cas/store/BUILD

@@ -28,6 +28,7 @@ rust_library(
         ":filesystem_store",
         ":grpc_store",
         ":memory_store",
+        ":noop_store",
         ":ref_store",
         ":s3_store",
         ":shard_store",
@@ -126,6 +127,22 @@ rust_library(
     ],
 )
 
+rust_library(
+    name = "noop_store",
+    srcs = ["noop_store.rs"],
+    proc_macro_deps = ["@crate_index//:async-trait"],
+    visibility = [
+        "//cas:__pkg__",
+        "//cas:__subpackages__",
+    ],
+    deps = [
+        ":traits",
+        "//util:buf_channel",
+        "//util:common",
+        "//util:error",
+    ],
+)
+
 rust_library(
     name = "verify_store",
     srcs = ["verify_store.rs"],

cas/store/default_store_factory.rs

@@ -28,6 +28,7 @@ use filesystem_store::FilesystemStore;
 use grpc_store::GrpcStore;
 use memory_store::MemoryStore;
 use metrics_utils::Registry;
+use noop_store::NoopStore;
 use ref_store::RefStore;
 use s3_store::S3Store;
 use shard_store::ShardStore;
@@ -75,6 +76,7 @@ pub fn store_factory<'a>(
                 store_factory(&config.upper_store, store_manager, None).await?,
             )),
             StoreConfig::grpc(config) => Arc::new(GrpcStore::new(config).await?),
+            StoreConfig::noop => Arc::new(NoopStore::new()),
             StoreConfig::shard(config) => {
                 let stores = config
                     .stores

cas/store/noop_store.rs

@@ -0,0 +1,74 @@
+// Copyright 2023 The Native Link Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use std::pin::Pin;
+use std::sync::Arc;
+
+use async_trait::async_trait;
+
+use buf_channel::{DropCloserReadHalf, DropCloserWriteHalf};
+use common::DigestInfo;
+use error::{make_err, Code, Error, ResultExt};
+use traits::{StoreTrait, UploadSizeInfo};
+
+#[derive(Default)]
+pub struct NoopStore;
+
+impl NoopStore {
+    pub fn new() -> Self {
+        NoopStore {}
+    }
+}
+
+#[async_trait]
+impl StoreTrait for NoopStore {
+    async fn has_with_results(
+        self: Pin<&Self>,
+        _digests: &[DigestInfo],
+        results: &mut [Option<usize>],
+    ) -> Result<(), Error> {
+        results.iter_mut().for_each(|r| *r = None);
+        Ok(())
+    }
+
+    async fn update(
+        self: Pin<&Self>,
+        _digest: DigestInfo,
+        mut reader: DropCloserReadHalf,
+        _size_info: UploadSizeInfo,
+    ) -> Result<(), Error> {
+        // We need to drain the reader to avoid the writer complaining that we dropped
+        // the connection prematurely.
+        loop {
+            if reader.recv().await.err_tip(|| "In NoopStore::update")?.is_empty() {
+                break; // EOF.
+            }
+        }
+        Ok(())
+    }
+
+    async fn get_part_ref(
+        self: Pin<&Self>,
+        _digest: DigestInfo,
+        _writer: &mut DropCloserWriteHalf,
+        _offset: usize,
+        _length: Option<usize>,
+    ) -> Result<(), Error> {
+        Err(make_err!(Code::NotFound, "Not found in noop store"))
+    }
+
+    fn as_any(self: Arc<Self>) -> Box<dyn std::any::Any + Send> {
+        Box::new(self)
+    }
+}

config/examples/basic_cas.json

@@ -1,13 +1,5 @@
 {
   "stores": {
-    "CAS_MAIN_STORE": {
-      "memory": {
-        "eviction_policy": {
-          // 1gb.
-          "max_bytes": 1000000000,
-        }
-      }
-    },
     "AC_MAIN_STORE": {
       "memory": {
         "eviction_policy": {
@@ -31,9 +23,12 @@
           }
         },
         "slow": {
-          "ref_store": {
-            "name": "CAS_MAIN_STORE",
-          }
+          /// Discard data.
+          /// This example usage has the CAS and the Worker live in the same place,
+          /// so they share the same underlying CAS. Since workers require a fast_slow
+          /// store, we use the fast store as our primary data store, and the slow store
+          /// is just a noop, since there's no shared storage in this config.
+          "noop": {}
         }
       }
     }
@@ -56,7 +51,9 @@
           "cpu_arch": "Exact",
           "cpu_model": "Exact",
           "kernel_version": "Exact",
-          "docker_image": "Priority",
+          // Example of how to set which docker images are available and set
+          // them in the platform properties.
+          // "docker_image": "Priority",
         }
       }
     }
@@ -84,9 +81,11 @@
         "cpu_arch": {
           "values": ["x86_64"],
         },
-        "docker_image": {
-          "query_cmd": "docker images --format {{.Repository}}:{{.Tag}}",
-        }
+        // Example of how to set which docker images are available and set
+        // them in the platform properties.
+        // "docker_image": {
+        //   "query_cmd": "docker images --format {{.Repository}}:{{.Tag}}",
+        // }
       }
     }
   }],

config/stores.rs

@@ -140,6 +140,12 @@ pub enum StoreConfig {
     /// this store directly without being a child of any store there are no
     /// side effects and is the most efficient way to use it.
     grpc(GrpcStore),
+
+    /// Noop store is a store that sends streams into the void and all data
+    /// retrieval will return 404 (NotFound). This can be useful for cases
+    /// where you may need to partition your data and part of your data needs
+    /// to be discarded.
+    noop,
 }
 
 /// Configuration for an individual shard of the store.

gencargo/default_store_factory/Cargo.toml

@@ -29,6 +29,7 @@ fast_slow_store = { workspace = true }
 filesystem_store = { workspace = true }
 grpc_store = { workspace = true }
 memory_store = { workspace = true }
+noop_store = { workspace = true }
 ref_store = { workspace = true }
 s3_store = { workspace = true }
 shard_store = { workspace = true }

gencargo/noop_store/Cargo.toml

@@ -0,0 +1,28 @@
+# This file is automatically generated from `tools/build_cargo_manifest.py`.
+# If you want to add a dependency add it to `tools/cargo_shared.bzl`
+# then run `python tools/build_cargo_manifest.py`.
+# Do not edit this file directly.
+
+[package]
+name = "noop_store"
+version = "0.0.0"
+edition = "2021"
+autobins = false
+autoexamples = false
+autotests = false
+autobenches = false
+
+[lib]
+name = "noop_store"
+path = "../../cas/store/noop_store.rs"
+# TODO(allada) We should support doctests.
+doctest = false
+
+[dependencies]
+async-trait = { workspace = true }
+
+# Local libraries.
+traits = { workspace = true }
+buf_channel = { workspace = true }
+common = { workspace = true }
+error = { workspace = true }