[net][disk_cache] Make Wasm code cache size limit 50% larger.

- Adds cache type parameter to disk_cache::PreferredSize.
- Changes implementation to make default cap size 50% larger in
  if cache type is net::GENERATED_NATIVE_CODE_CACHE.

Bug: chromium:917510, chromium:1019999
Change-Id: Ieb5dd21aa76e387774659131a3d3aa3e6eed2889
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1937852
Commit-Queue: Bill Budge <bbudge@chromium.org>
Reviewed-by: Maksim Orlovich <morlovich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#720678}

net/disk_cache/blockfile/backend_impl.cc

@@ -1456,7 +1456,7 @@ void BackendImpl::AdjustMaxCacheSize(int table_len) {
   if (table_len)
     available += data_->header.num_bytes;
 
-  max_size_ = PreferredCacheSize(available);
+  max_size_ = PreferredCacheSize(available, GetCacheType());
 
   if (!table_len)
     return;

net/disk_cache/cache_util.cc

@@ -153,7 +153,7 @@ bool DelayedCacheCleanup(const base::FilePath& full_path) {
 
 // Returns the preferred maximum number of bytes for the cache given the
 // number of available bytes.
-int PreferredCacheSize(int64_t available) {
+int PreferredCacheSize(int64_t available, net::CacheType type) {
   // Percent of cache size to use, relative to the default size. "100" means to
   // use 100% of the default size.
   int percent_relative_size;
@@ -173,6 +173,7 @@ int PreferredCacheSize(int64_t available) {
   int64_t scaled_default_disk_cache_size =
       static_cast<int64_t>(disk_cache::kDefaultCacheSize) *
       percent_relative_size / 100;
+
   if (available < 0)
     return static_cast<int32_t>(scaled_default_disk_cache_size);
 
@@ -186,6 +187,12 @@ int PreferredCacheSize(int64_t available) {
       preferred_cache_size = available / 5;
   }
 
+  // Native code entries can be large, so we would like a larger cache.
+  // Make the size limit 50% larger in that case.
+  if (type == net::GENERATED_NATIVE_CODE_CACHE) {
+    scaled_default_disk_cache_size = (scaled_default_disk_cache_size / 2) * 3;
+  }
+
   // Limit cache size to somewhat less than kint32max to avoid potential
   // integer overflows in cache backend implementations.
   DCHECK_LT(scaled_default_disk_cache_size * 4,

net/disk_cache/cache_util.h

@@ -40,8 +40,11 @@ NET_EXPORT_PRIVATE bool DeleteCacheFile(const base::FilePath& name);
 // task. Used by cache creator itself or by backends for self-restart on error.
 bool DelayedCacheCleanup(const base::FilePath& full_path);
 
-// Returns the preferred max cache size given the available disk space.
-NET_EXPORT_PRIVATE int PreferredCacheSize(int64_t available);
+// Returns the preferred max cache size given the available disk space and
+// cache type.
+NET_EXPORT_PRIVATE int PreferredCacheSize(
+    int64_t available,
+    net::CacheType type = net::DISK_CACHE);
 
 // The default cache size should not ideally be exposed, but the blockfile
 // backend uses it for reasons that include testing.

net/disk_cache/cache_util_unittest.cc

@@ -133,6 +133,11 @@ TEST_F(CacheUtilTest, PreferredCacheSize) {
               PreferredCacheSize(test_case.available));
   }
 
+  // Check that the cache size cap is 50% higher for native code caches.
+  EXPECT_EQ(((320 * 1024 * 1024) / 2) * 3,
+            PreferredCacheSize(50000 * 1024 * 1024LL,
+                               net::GENERATED_NATIVE_CODE_CACHE));
+
   // Check 100 "percent_relative_size" matches default behavior.
   {
     base::test::ScopedFeatureList scoped_feature_list;
@@ -144,6 +149,10 @@ TEST_F(CacheUtilTest, PreferredCacheSize) {
       EXPECT_EQ(test_case.expected_without_trial,
                 PreferredCacheSize(test_case.available));
     }
+    // Check that the cache size cap is 50% higher for native code caches.
+    EXPECT_EQ(((320 * 1024 * 1024) / 2) * 3,
+              PreferredCacheSize(50000 * 1024 * 1024LL,
+                                 net::GENERATED_NATIVE_CODE_CACHE));
   }
 
   // Check 200 "percent_relative_size".
@@ -157,6 +166,10 @@ TEST_F(CacheUtilTest, PreferredCacheSize) {
       EXPECT_EQ(test_case.expected_with_200_trial,
                 PreferredCacheSize(test_case.available));
     }
+    // Check that the cache size cap is 50% higher for native code caches.
+    EXPECT_EQ(((640 * 1024 * 1024) / 2) * 3,
+              PreferredCacheSize(50000 * 1024 * 1024LL,
+                                 net::GENERATED_NATIVE_CODE_CACHE));
   }
 }
 

net/disk_cache/simple/simple_backend_impl.cc

@@ -773,7 +773,7 @@ SimpleBackendImpl::DiskStatResult SimpleBackendImpl::InitCacheStructureOnDisk(
       result.net_error = net::ERR_FAILED;
     } else if (!result.max_size) {
       int64_t available = base::SysInfo::AmountOfFreeDiskSpace(path);
-      result.max_size = disk_cache::PreferredCacheSize(available);
+      result.max_size = disk_cache::PreferredCacheSize(available, cache_type);
       DCHECK(result.max_size);
     }
   }