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JVM Asset Pipeline library for serving static web assets, bundling, minifying, and extensibility for transpiling.
/*
* Copyright 2014 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package asset.pipeline
import java.util.concurrent.ConcurrentHashMap
/**
* A Cache Manager for the Asset-Pipeline runtime. This reduces repeat processing
* of files that have already been processed during the runtime of the asset-pipeline.
* It also is capable of persisting this cache as an ObjectStream to the '.asscache' file
* Private API Class
*
* @author David Estes
* @author Graeme Rocher
*/
public class CacheManager {
static final String CACHE_LOCATION = ".asscache"
static final Integer CACHE_DEBOUNCE_MS = 5000 // De-bounce 5 seconds
static Map> cache = [:]
static String configCacheBustDigest
static final Object LOCK_OBJECT = new Object()
static CachePersister cachePersister
/**
* Returns the cache string value of a file if it exists in the cache and is unmodified since last checked
* @param fileName The name of the file also known as the cache key
* @param md5 The current md5 digest of the file. This is compared against the original file
* @param originalFileName - Original file name of the file. This is for cache busting bundled assets
* @return A String value of the cache
*/
public static String findCache(String fileName, String md5, String originalFileName = null) {
loadPersistedCache()
checkCacheValidity()
def cacheRecord = cache[fileName]
if(cacheRecord && cacheRecord.md5 == md5 && cacheRecord.originalFileName == originalFileName) {
def cacheFiles = cacheRecord.dependencies.keySet()
def expiredCacheFound = cacheFiles.find { String cacheFileName ->
def cacheFile = AssetHelper.fileForUri(cacheFileName)
if(!cacheFile) {
return true
}
def depMd5 = AssetHelper.getByteDigest(cacheFile.inputStream.bytes)
if(cacheRecord.dependencies[cacheFileName] != depMd5) {
return true
}
return false
}
if(expiredCacheFound) {
cache.remove(fileName)
asyncCacheSave()
return null
}
return cacheRecord.processedFileText
} else if (cacheRecord) {
cache.remove(fileName)
asyncCacheSave()
return null
}
}
/**
* Creates a cache entry for a file. This includes a name, md5Hash and processed file text
* @param fileName The file name of the file to be cached (cache key)
* @param md5Hash The current md5 hash of the file
* @param processedFileText The processed text of the file being cached
* @param originalFileName The original file name of the base file being persisted
*/
public static void createCache(String fileName, String md5Hash, String processedFileText, String originalFileName = null) {
loadPersistedCache()
checkCacheValidity()
def thisCache = cache
def cacheRecord = thisCache[fileName]
if(cacheRecord) {
thisCache[fileName] = cacheRecord + [
md5: md5Hash,
originalFileName: originalFileName,
processedFileText: processedFileText
]
} else {
thisCache[fileName] = [
md5: md5Hash,
originalFileName: originalFileName,
processedFileText: processedFileText,
dependencies: [:]
]
}
asyncCacheSave()
}
/**
* Called during asset processing to add a dependent file to another file cache. This allows for cache busting on
* things like imported less files or sass files.
* @param fileName The name of the file we are adding a dependency to
* @param dependentFile the AssetFile object we are adding as a dependency
*/
public static void addCacheDependency(String fileName, AssetFile dependentFile) {
def cacheRecord = cache[fileName]
if(!cacheRecord) {
createCache(fileName, null, null)
cacheRecord = cache[fileName]
}
def newMd5 = dependentFile.getByteDigest()
cacheRecord.dependencies[dependentFile.path] = newMd5
asyncCacheSave()
}
/**
* Asynchronously starts a thread used to persist the cache to disk
* It also performs a debounce behavior so rapid calls to the save do not cause repeat saves
*/
public static void asyncCacheSave() {
synchronized(LOCK_OBJECT) {
if(!cachePersister) {
cachePersister = new CachePersister()
cachePersister.start()
}
}
cachePersister.debounceSave(CACHE_DEBOUNCE_MS);
}
/**
* Called by the async {@link CachePersister} class to save the cache map to disk
*/
public static void save() {
String cacheLocation = AssetPipelineConfigHolder.config?.cacheLocation ?: CACHE_LOCATION
FileOutputStream fos = new FileOutputStream(cacheLocation);
Map> cacheSaveData = [configCacheBustDigest: configCacheBustDigest, cache: cache]
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(cacheSaveData)
oos.close()
}
/**
* Loads an Asset Cache dependency graph for asset-pipeline.
* This is currently encoded in JSON
*
* If the asset cache file does not exist or a cache is already loaded, the cache store is not parsed.
*/
public static void loadPersistedCache() {
if(cache) {
return;
}
String cacheLocation = AssetPipelineConfigHolder.config?.cacheLocation ?: CACHE_LOCATION
File assetFile = new File(cacheLocation)
if(!assetFile.exists()) {
return;
}
try {
FileInputStream fis = new FileInputStream(cacheLocation);
ObjectInputStream ois = new ObjectInputStream(fis);
def fileCache = ois.readObject()
if(fileCache?.configCacheBustDigest) {
configCacheBustDigest = fileCache.configCacheBustDigest
}
if(fileCache?.cache) {
fileCache.cache.each{ entry ->
cache[entry.key] = entry.value
}
}
} catch(ex) {
// If there is a parser error from a previous bad cache flush ignore it and move on
}
}
/**
* Checks the config digest name to see if any configurations have changed.
* If they have the cache needs to be reset and marked as expired
*/
private static void checkCacheValidity() {
if(configCacheBustDigest != AssetPipelineConfigHolder.getDigestString()) {
cache.clear()
configCacheBustDigest = AssetPipelineConfigHolder.getDigestString()
}
}
}