diff options
| -rw-r--r-- | activesupport/CHANGELOG.md | 13 | ||||
| -rw-r--r-- | activesupport/lib/active_support/cache/memory_store.rb | 17 | ||||
| -rw-r--r-- | activesupport/test/caching_test.rb | 28 |
3 files changed, 53 insertions, 5 deletions
diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md index c00cbaaa08..918a43bf36 100644 --- a/activesupport/CHANGELOG.md +++ b/activesupport/CHANGELOG.md @@ -143,4 +143,17 @@ *Daniel Schierbeck* +* Improve `ActiveSupport::Cache::MemoryStore` cache size calculation. + The memory used by a key/entry pair is calculated via `#cached_size`: + + def cached_size(key, entry) + key.to_s.bytesize + entry.size + PER_ENTRY_OVERHEAD + end + + The value of `PER_ENTRY_OVERHEAD` is 240 bytes based on an [empirical + estimation](https://gist.github.com/ssimeonov/6047200) for 64-bit MRI on + 1.9.3 and 2.0. GH#11512 + + *Simeon Simeonov* + Please check [4-0-stable](https://github.com/rails/rails/blob/4-0-stable/activesupport/CHANGELOG.md) for previous changes. diff --git a/activesupport/lib/active_support/cache/memory_store.rb b/activesupport/lib/active_support/cache/memory_store.rb index 4d26fb7e42..b0aae54aa4 100644 --- a/activesupport/lib/active_support/cache/memory_store.rb +++ b/activesupport/lib/active_support/cache/memory_store.rb @@ -122,6 +122,14 @@ module ActiveSupport end protected + + # See https://gist.github.com/ssimeonov/6047200 + PER_ENTRY_OVERHEAD = 240 + + def cached_size(key, entry) + key.to_s.bytesize + entry.size + PER_ENTRY_OVERHEAD + end + def read_entry(key, options) # :nodoc: entry = @data[key] synchronize do @@ -139,8 +147,11 @@ module ActiveSupport synchronize do old_entry = @data[key] return false if @data.key?(key) && options[:unless_exist] - @cache_size -= old_entry.size if old_entry - @cache_size += entry.size + if old_entry + @cache_size -= (old_entry.size - entry.size) + else + @cache_size += cached_size(key, entry) + end @key_access[key] = Time.now.to_f @data[key] = entry prune(@max_size * 0.75, @max_prune_time) if @cache_size > @max_size @@ -152,7 +163,7 @@ module ActiveSupport synchronize do @key_access.delete(key) entry = @data.delete(key) - @cache_size -= entry.size if entry + @cache_size -= cached_size(key, entry) if entry !!entry end end diff --git a/activesupport/test/caching_test.rb b/activesupport/test/caching_test.rb index d2382f0f5b..df570d485a 100644 --- a/activesupport/test/caching_test.rb +++ b/activesupport/test/caching_test.rb @@ -713,8 +713,8 @@ end class MemoryStoreTest < ActiveSupport::TestCase def setup - @record_size = ActiveSupport::Cache::Entry.new("aaaaaaaaaa").size - @cache = ActiveSupport::Cache.lookup_store(:memory_store, :expires_in => 60, :size => @record_size * 10) + @record_size = ActiveSupport::Cache.lookup_store(:memory_store).send(:cached_size, 1, ActiveSupport::Cache::Entry.new("aaaaaaaaaa")) + @cache = ActiveSupport::Cache.lookup_store(:memory_store, :expires_in => 60, :size => @record_size * 10 + 1) end include CacheStoreBehavior @@ -764,6 +764,30 @@ class MemoryStoreTest < ActiveSupport::TestCase assert !@cache.exist?(1), "no entry" end + def test_prune_size_on_write_based_on_key_length + @cache.write(1, "aaaaaaaaaa") && sleep(0.001) + @cache.write(2, "bbbbbbbbbb") && sleep(0.001) + @cache.write(3, "cccccccccc") && sleep(0.001) + @cache.write(4, "dddddddddd") && sleep(0.001) + @cache.write(5, "eeeeeeeeee") && sleep(0.001) + @cache.write(6, "ffffffffff") && sleep(0.001) + @cache.write(7, "gggggggggg") && sleep(0.001) + @cache.write(8, "hhhhhhhhhh") && sleep(0.001) + @cache.write(9, "iiiiiiiiii") && sleep(0.001) + long_key = '*' * 2 * @record_size + @cache.write(long_key, "llllllllll") + assert @cache.exist?(long_key) + assert @cache.exist?(9) + assert @cache.exist?(8) + assert @cache.exist?(7) + assert @cache.exist?(6) + assert !@cache.exist?(5), "no entry" + assert !@cache.exist?(4), "no entry" + assert !@cache.exist?(3), "no entry" + assert !@cache.exist?(2), "no entry" + assert !@cache.exist?(1), "no entry" + end + def test_pruning_is_capped_at_a_max_time def @cache.delete_entry (*args) sleep(0.01) |