Send the list of used and unused resources for precache

components/precache/core/proto/precache.proto

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 syntax = "proto2";
 
+import "timestamp.proto";
+
 package precache;
 
 // Chrome requires this.
 option optimize_for = LITE_RUNTIME;
 
 // Information about a cacheable resource to be precached.
 message PrecacheResource {
   // The URL of the resource. This field must always be present.
   optional string url = 1;
+
+  // The tophost this resource corresponds to.
+  optional string tophostname = 2;

[sclittle, 2016/08/11 22:52:36]

nit: maybe change to top_host_name?

[Raj, 2016/08/12 19:04:21]

Done.

 };
 
+message PrecacheManifestId {
+  // Time at the creation of this manifest.

[sclittle, 2016/08/11 22:52:36]

What determines this time? The server? If so, then timestamps aren't guaranteed
to be unique IDs, and this could cause weird bugs to happen.

[Raj, 2016/08/12 19:04:22]

The manifest_id(timestamp) is just an opaque data for Chrome. It need not be
unique compared to different manifests. We do not enforce uniqueness in the DB
as well.

+  optional Timestamp timestamp = 1;

[sclittle, 2016/08/11 22:52:36]

Why is this specifically a timestamp? Could this just be some opaque ID set by
the server?

[Raj, 2016/08/12 19:04:22]

I will try to change this manifest_id to a simple string or a number, so that
timestamp confusion is avoided.

+}
+
 // A manifest of cacheable resources to be precached for a specific host.
 message PrecacheManifest {
   // List of resources that we predict that the user will need if they are
   // likely to fetch the host.
   repeated PrecacheResource resource = 1;
 
   // Experiments running on this manifest.
   optional PrecacheExperiments experiments = 2;
+
+  optional PrecacheManifestId id = 3;

[bengr, 2016/08/11 18:49:15]

Add a comment.

[Raj, 2016/08/12 19:04:21]

Done.

 };
 
 message PrecacheExperiments {
   // A mapping between experiment groups and the resources that should be
   // considered for the experiment.
   map<fixed32, PrecacheResourceSelection> resources_by_experiment_group = 1;
 }
 
 message PrecacheResourceSelection {
   // Select the resources as a std::bitset over the resources listed in the
@@ skipping 32 matching lines @@
   // resources larger than this will be cancelled. This max applies only to new
   // downloads; cached resources are not capped.
   optional uint64 max_bytes_per_resource = 4 [default = 500000 /* 500 KB */];
 
   // The maximum number of bytes per precache run. While precaching, the total
   // number of bytes used for resources is tallied -- this includes new
   // downloads as well as cached resources. After this limit is reached, no
   // other resources will be downloaded.
   optional uint64 max_bytes_total = 5 [default = 10000000 /* 10 MB */];
 };