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| -rw-r--r-- | guides/source/active_support_core_extensions.md | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/guides/source/active_support_core_extensions.md b/guides/source/active_support_core_extensions.md index 9fca3d585b..79ff945495 100644 --- a/guides/source/active_support_core_extensions.md +++ b/guides/source/active_support_core_extensions.md @@ -3721,23 +3721,21 @@ The auxiliary file is written in a standard directory for temporary files, but y NOTE: Defined in `active_support/core_ext/file/atomic.rb`. Extensions to `Marshal` --------------------- +----------------------- ### `load` -Unpatched Marshal#load doesn't call constant_missing so in order to support ActiveSupport constant autoloading load is patched using alias_method_chain. - -The method accepts the same arguments as unpatched Marshal#load and the result of calling it will be the same. +Active Support adds constant autoloading support to `load`. -For example, ActiveSupport uses this method to read from cache(in FileStore): +For example, the file cache store deserializes this way: ```ruby File.open(file_name) { |f| Marshal.load(f) } ``` -If Marshal#load didn't support constant autoloading then various caching stores wouldn't too. +If the cached data refers to a constant that is unknown at that point, the autoloading mechanism is triggered and if it succeeds the desarialization is retried transparently. -WARNING. If a IO (e.g. a file) is used as source it needs to respond to rewind (which a normal file does) because if an exception is raised calling the original Marshal#load the file will be exhausted. +WARNING. If the argument is an `IO` it needs to respond to `rewind` to be able to retry. Regular files respond to `rewind`. NOTE: Defined in `active_support/core_ext/marshal.rb`. |