Add daily quota for precache

components/precache/core/precache_fetcher.cc

Index: components/precache/core/precache_fetcher.cc
diff --git a/components/precache/core/precache_fetcher.cc b/components/precache/core/precache_fetcher.cc
index 90d05bb776b6eb6b841c69369f29a3acc5846c87..1f0d160f478081db344aaac955f8fe16c3243772 100644
--- a/components/precache/core/precache_fetcher.cc
+++ b/components/precache/core/precache_fetcher.cc
@@ -27,6 +27,7 @@
 #include "components/precache/core/precache_database.h"
 #include "components/precache/core/precache_switches.h"
 #include "components/precache/core/proto/precache.pb.h"
+#include "components/precache/core/proto/quota.pb.h"
 #include "components/precache/core/proto/unfinished_work.pb.h"
 #include "net/base/completion_callback.h"
 #include "net/base/escape.h"
@@ -204,6 +205,15 @@ std::deque<ManifestHostInfo> RetrieveManifestInfo(
   return hosts_info;
 }
 
+PrecacheQuota RetrieveQuotaInfo(
+    const base::WeakPtr<PrecacheDatabase>& precache_database) {
+  PrecacheQuota quota;
+  if (precache_database) {
+    quota = precache_database->GetQuota();
+  }
+  return quota;
+}
+
 }  // namespace
 
 PrecacheFetcher::Fetcher::Fetcher(
@@ -466,10 +476,11 @@ void PrecacheFetcher::StartNextResourceFetch() {
   DCHECK(unfinished_work_->has_config_settings());
   while (!resources_to_fetch_.empty() && pool_.IsAvailable()) {
     const auto& resource = resources_to_fetch_.front();
-    const size_t max_bytes =
+    const size_t max_bytes = std::min(
+        quota_.remaining(),
         std::min(unfinished_work_->config_settings().max_bytes_per_resource(),
                  unfinished_work_->config_settings().max_bytes_total() -
-                     unfinished_work_->total_bytes());
+                     unfinished_work_->total_bytes()));
     VLOG(3) << "Fetching " << resource.first << " " << resource.second;
     pool_.Add(base::MakeUnique<Fetcher>(
         request_context_.get(), resource.first, resource.second,
@@ -506,9 +517,13 @@ void PrecacheFetcher::NotifyDone(
 
 void PrecacheFetcher::StartNextFetch() {
   DCHECK(unfinished_work_->has_config_settings());
-  // If over the precache total size cap, then stop prefetching.
-  if (unfinished_work_->total_bytes() >
-      unfinished_work_->config_settings().max_bytes_total()) {
+  DCHECK(base::Time::FromInternalValue(quota_.expiry_time()) >
+         base::Time::Now());
+
+  // If over the precache total size cap or daily quota, then stop prefetching.
+  if ((unfinished_work_->total_bytes() >
+       unfinished_work_->config_settings().max_bytes_total()) ||
+      quota_.remaining() == 0) {
     size_t pending_manifests_in_pool = 0;
     size_t pending_resources_in_pool = 0;
     for (const auto& element_pair : pool_.elements()) {
@@ -622,6 +637,27 @@ void PrecacheFetcher::OnManifestInfoRetrieved(
     }
   }
   unfinished_work_->set_num_manifest_urls(top_hosts_to_fetch_.size());
+
+  PostTaskAndReplyWithResult(
+      db_task_runner_.get(), FROM_HERE,
+      base::Bind(&RetrieveQuotaInfo, precache_database_),
+      base::Bind(&PrecacheFetcher::OnQuotaInfoRetrieved, AsWeakPtr()));
+}
+
+void PrecacheFetcher::OnQuotaInfoRetrieved(const PrecacheQuota& quota) {
+  quota_ = std::move(quota);
+  if (base::Time::FromInternalValue(quota_.expiry_time()) <=
+      base::Time::Now()) {
+    // This is a new day. Update daily quota, that expires by end of today.
+    quota_.set_expiry_time(
+        (base::Time::Now().LocalMidnight() + base::TimeDelta::FromDays(1))
+            .ToInternalValue());
+    quota_.set_remaining(
+        unfinished_work_->config_settings().daily_quota_total());
+    db_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&PrecacheDatabase::SaveQuota, precache_database_, quota_));
+  }
   StartNextFetch();
 }
 
@@ -696,6 +732,17 @@ void PrecacheFetcher::UpdateStats(int64_t response_bytes,
       unfinished_work_->total_bytes() + response_bytes);
   unfinished_work_->set_network_bytes(
       unfinished_work_->network_bytes() + network_response_bytes);
+
+  if (base::Time::FromInternalValue(quota_.expiry_time()) > base::Time::Now()) {
+    int64_t remaining =
+        static_cast<int64_t>(quota_.remaining()) - network_response_bytes;
+    if (remaining < 0)
+      remaining = 0;
+    quota_.set_remaining(static_cast<size_t>(remaining));
+    db_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&PrecacheDatabase::SaveQuota, precache_database_, quota_));
+  }
 }
 
 }  // namespace precache