Package com.puppycrawl.tools.checkstyle

Class PropertyCacheFile

  • final class PropertyCacheFile
extends java.lang.Object
    This class maintains a persistent(on file-system) store of the files that have checked ok(no validation events) and their associated timestamp. It is used to optimize Checkstyle between few launches. It is mostly useful for plugin and extensions of Checkstyle. It uses a property file for storage. A hashcode of the Configuration is stored in the cache file to ensure the cache is invalidated when the configuration has changed.

    • Field Detail

      • CONFIG_HASH_KEY

        public static final java.lang.String CONFIG_HASH_KEY
        The property key to use for storing the hashcode of the configuration. To avoid name clashes with the files that are checked the key is chosen in such a way that it cannot be a valid file name.
        See Also:
        Constant Field Values

      • EXTERNAL_RESOURCE_KEY_PREFIX

        public static final java.lang.String EXTERNAL_RESOURCE_KEY_PREFIX
        The property prefix to use for storing the hashcode of an external resource. To avoid name clashes with the files that are checked the prefix is chosen in such a way that it cannot be a valid file name and makes it clear it is a resource.
        See Also:
        Constant Field Values

      • details

        private final java.util.Properties details
        The details on files.

      • config

        private final Configuration config
        Configuration object.

      • fileName

        private final java.lang.String fileName
        File name of cache.

      • configHash

        private java.lang.String configHash
        Generated configuration hash.

    • Constructor Detail

      • PropertyCacheFile

        PropertyCacheFile​(Configuration config,
                  java.lang.String fileName)
        Creates a new PropertyCacheFile instance.
        Parameters:
        config - the current configuration, not null
        fileName - the cache file

    • Method Detail

      • load

        public void load()
          throws java.io.IOException
        Load cached values from file.
        Throws:
        java.io.IOException - when there is a problems with file read

      • persist

        public void persist()
             throws java.io.IOException
        Cleans up the object and updates the cache file.
        Throws:
        java.io.IOException - when there is a problems with file save

      • reset

        public void reset()
        Resets the cache to be empty except for the configuration hash.

      • flushAndCloseOutStream

        private static void flushAndCloseOutStream​(java.io.OutputStream stream)
                                    throws java.io.IOException
        Flushes and closes output stream.
        Parameters:
        stream - the output stream
        Throws:
        java.io.IOException - when there is a problems with file flush and close

      • isInCache

        public boolean isInCache​(java.lang.String uncheckedFileName,
                         long timestamp)
        Checks that file is in cache.
        Parameters:
        uncheckedFileName - the file to check
        timestamp - the timestamp of the file to check
        Returns:
        whether the specified file has already been checked ok

      • put

        public void put​(java.lang.String checkedFileName,
                long timestamp)
        Records that a file checked ok.
        Parameters:
        checkedFileName - name of the file that checked ok
        timestamp - the timestamp of the file

      • get

        public java.lang.String get​(java.lang.String name)
        Retrieves the hash of a specific file.
        Parameters:
        name - The name of the file to retrieve.
        Returns:
        The has of the file or null.

      • remove

        public void remove​(java.lang.String checkedFileName)
        Removed a specific file from the cache.
        Parameters:
        checkedFileName - The name of the file to remove.

      • getHashCodeBasedOnObjectContent

        private static java.lang.String getHashCodeBasedOnObjectContent​(java.io.Serializable object)
        Calculates the hashcode for the serializable object based on its content.
        Parameters:
        object - serializable object.
        Returns:
        the hashcode for serializable object.

      • putExternalResources

        public void putExternalResources​(java.util.Set<java.lang.String> locations)
        Puts external resources in cache. If at least one external resource changed, clears the cache.
        Parameters:
        locations - locations of external resources.

      • loadExternalResource

        private static byte[] loadExternalResource​(java.lang.String location)
                                    throws CheckstyleException
        Loads the content of external resource.
        Parameters:
        location - external resource location.
        Returns:
        array of bytes which represents the content of external resource in binary form.
        Throws:
        CheckstyleException - if error while loading occurs.

      • areExternalResourcesChanged

        private boolean areExternalResourcesChanged​(java.util.Set<PropertyCacheFile.ExternalResource> resources)
        Checks whether the contents of external configuration resources were changed.
        Parameters:
        resources - a set of PropertyCacheFile.ExternalResource.
        Returns:
        true if the contents of external configuration resources were changed.

      • isResourceLocationInCache

        private boolean isResourceLocationInCache​(java.lang.String location)
        Checks whether resource location is in cache.
        Parameters:
        location - resource location.
        Returns:
        true if resource location is in cache.